Alkaline water and it's benefits is one of the newer trends to have made its way into the already overcrowded wellness and healthy eating world. Drinking Alkaline water, it is said, offers more health benefits than one. It helps slow down the ageing process, regulate pH levels of the body and prevent various chronic diseases. Alkaline water refers to neutralising acid levels in the body, which normal water cannot do. This controversial health practice has been argued over its use by many health experts. Let's find out what alkaline water is all about and if it's worth the hype.
What is Alkaline Water?
Alkaline water is water that has been ionized, which means the pH level of water has been increased. The pH level is a number that measures how acidic or alkaline a substance is on a scale of 0 to 14. For instance, if the level is 1, it means the substance is very acidic and if it is 13, it is very alkaline.
Alkaline water has pH level of about 8 or 9 and pH level of normal tap water is 7, which is neutral. It is believed that alkaline water helps people with excess acidity as it helps neutralise the acid in the body; thanks to its alkaline nature.
This process of neutralising acids in the body helps prevent various ailments. There are ways to increase the alkaline properties of water by using special filters, faucet attachments and additives that raise the pH levels, making normal tap water go from neutral pH to Alkaline.
According to the Bangalore based Nutritionist, Dr. Anju Sood, "Your body secretes out a lot of juices. Now these juices are basically acidic in nature. So at that time alkaline water will neutralise the acid.
We always suggest having foods that are at least 70 percent alkaline and 30 percent acidic, so that once it is consumed; the pH of the body will be neutral. Alkaline water is suggested when you are not consuming food that is not balancing your pH levels in the body."
Benefits of alkaline water: Alkaline water is water that has been ionized
According to Mayo Clinic, regular water is best for most people, as there is no scientific evidence that fully verifies the claims made by supporters of alkaline water. According to a study published in the Annals of Otology, Rhinology & Laryngology, alkaline water with a pH level of 8.8 may help soothe acid reflux because the higher pH level kills pepsin, an enzyme involved in breaking down food proteins and a main cause of acid reflux. Another study published in the Journal of the International Society of Sports Nutrition has claimed that a significant difference in the whole blood viscosity after consuming high pH water as compared to regular water after a strenuous workout. According to a study published in the Shanghai Journal of Preventive Medicine, drinking alkaline water may be beneficial for people who suffer from high blood pressure, high cholesterol and diabetes.
Benefits of Alkaline water
While there is still a lack of proven scientific research, various proponents of alkaline water claim to believe in the following benefits of alkaline water:
Alkaline water has ultra-hydrating properties as compared to normal water. This can be a beneficial drink for people who work out on a daily basis and require more amount of water in their body. Scientifically speaking, the water molecules in alkaline water are smaller and more readily absorbed by your cells, which help your body re-hydrate quickly.
Alkaline water benefits also include boosting immunity. Your immune system may help neutralise the acidity in your body, which is caused by poor diet, stress and environmental toxins.
Alkaline water is said to have various minerals like magnesium and calcium, both of which are important for maintaining healthy bones.
Alkaline water has many potent antioxidants that help prevent the growth of cell damaging free radicals in the body, which can further rush up the ageing process.
One of the most important benefits of alkaline water is that it neutralises the acidity in our body by lowering excessive acidic content in the stomach and gastro-intestinal tract.
Benefits of alkaline water: Regular water is best for most people, as there is no scientific evidence
Water is really good for you. As a consumer, we have many varieties of bottled waters to choose from: “natural” spring water, water with vitamins or with minerals, flavored waters with natural fruit essence, added carbonation and alkaline. The bottled water industry has grown every year since 1977, topping out at $20 billion in annual revenue.
Health conscious people are looking for products to be more functional and provide more benefits. Alkaline water is said to make you healthier and more hydrated and provide numerous other health benefits. The most shared health claim among alkaline water manufacturers is the promise to detoxify the body and fight against the acidity of the Western diet. This is based on the belief that acidic properties in the body and blood are the cause of ill health and disease and needs to be neutralized.
What is alkaline water?
The pH scale ranges from 0 to 14, and is based around the hydrogen ion concentration of pure water, which is neutral—a pH of 7. A pH below 7 is considered acidic and above a 7 pH is referred to as basic. Alkaline water typically has a pH of 8 or 9. Water always contains some amount of dissolved solids (inorganic salts like calcium, magnesium, potassium) but the higher the total dissolved solids, the more alkaline the water tends to be. Some waters are naturally alkaline (hard water has more calcium and magnesium compared with soft water and therefore a higher pH level). A water ionizer creates alkaline water by running the water over positive and negative electrodes. Some water filters add alkalizing minerals and water that reverse osmosis. Adding baking soda to water can make it more alkaline.
Can you “optimize” the body’s alkalinity?
A wide range of pH values, from highly acidic to moderately alkaline can be found in different parts of the body. Gastric (stomach) fluids are highly acidic because they break down foods and limit the growth of unwanted microbes. Once the stomach contents enter the small intestine, they are made alkaline by digestive juices from the pancreas.
The pH of human blood is strictly maintained since the results of blood pH changes are life-threatening. The kidneys are primarily responsible for keeping your blood pH level between 7.35 and 7.45. Food or beverages you consume do not change blood pH. A change in blood pH can occur with severe infection or respiratory failure (both life-threatening conditions) and immediate hospitalization and treatment is vital to correct the blood pH with intravenous infusion of solutions and other medical treatments. Drinking alkaline water in this case is like fighting a forest fire with a garden hose.
Alkaline water and Cancer
With regard to cancer, a review of 252 literature papers to evaluate evidence for even a causal relationship between dietary acid/alkaline and alkaline water was conducted and reported in the British Medical Journal. There is almost no actual research to either support or disprove the idea that an alkaline diet and alkaline water plays any role in cancer prevention or treatment.
Take home message
When you hear many health and wellness claims it can be quite frustrating if you feel you need to spend more money to stay healthy. Good nutrition is not as complicated as many reports make you feel. Plain tap water works fine for hydration. We know that simple eating recommendations can make a difference in your health: Enjoy a wide variety of vegetables, fruits, whole grains and beans; Limit consumption of red and processed meats; Enjoy alcohol in moderation, if at all.
If you drink alkaline water because it makes you feel good or you like the taste of it, then you may drink more water and stay better hydrated. That is the only “magic” in alkaline water (but is also true of any form of water you choose).
Charis W. Spielman, MPH, RD, CSO, CNSC
Certified Specialist in Oncology Nutrition
What is alkaline water?
You may have heard various health claims about alkaline water. Some say it can help slow the aging process, regulate your body’s pH level, and prevent chronic diseases like cancer. But what exactly is alkaline water, and why all the hype?
The “alkaline” in alkaline water refers to its pH level. The pH level is a number that measures how acidic or alkaline a substance is on a scale of 0 to 14. For example, something with a pH of 1 would be very acidic and something with a pH of 13 would be very alkaline.
Alkaline water has a higher pH level than regular drinking water. Because of this, some advocates of alkaline water believe it can neutralize the acid in your body.
Normal drinking water generally has a neutral pH of 7. Alkaline water typically has a pH of 8 or 9. However, pH alone isn’t enough to impart substantial alkalinity to water.
Alkaline water must also contain alkaline minerals and negative oxidation reduction potential (ORP). ORP is the ability of water to act as a pro- or antioxidant. The more negative the ORP value, the more antioxidizing it is.
Alkaline water is somewhat controversial. Many health professionals say there isn’t enough research to support the many health claims made by users and sellers. Differences in research findings may be related to the types of alkaline water studies.
According to the Mayo Clinic, regular water is best for most people. They state that there is no scientific evidence that fully verifies the claims made by supporters of alkaline water.
However, there are a few studies that suggest alkaline water might be helpful for certain conditions.
For example, a
Another study suggested that drinking alkaline ionized water may have benefits for people with high blood pressure, diabetes, and high cholesterol.
Those who consumed high-pH water reduced viscosity by 6.3 percent compared to 3.36 percent with standard purified drinking water. This means blood flowed more efficiently with alkaline water. This can increase oxygen delivery throughout out the body.
However, more research is needed beyond these small studies. In particular, research is needed to answer other claims made by alkaline water supporters.
Despite the lack of proven scientific research, proponents of alkaline water still believe in its proposed health benefits. These include:
- anti-aging properties (via liquid antioxidants that absorb more quickly into the human body)
- colon-cleansing properties
- immune system support
- hydration, skin health, and other detoxifying properties
- weight loss
- cancer resistance
They also argue that soft drinks, which are notoriously acidic, have very positive ORPs leading to many health problems, while properly ionized and alkalinized waters have highly negative ORPs. Green tea is rich in antioxidants and has a slightly negative ORP.
Although alkaline drinking water is considered safe, it may produce negative side effects.
Some examples of negative side effects include the lowering of natural stomach acidity, which helps kill bacteria and expel other undesirable pathogens from entering your bloodstream.
Additionally, an overall excess of alkalinity in the body may cause gastrointestinal issues and skin irritations. Too much alkalinity may also agitate the body’s normal pH, leading to metabolic alkalosis, a condition that may produce the following symptoms:
- hand tremors
- muscle twitching
- tingling in the extremities or face
Alkalosis can also cause a decrease in free calcium in the body, which can affect bone health. However, the most common cause of hypocalcemia isn’t from drinking alkaline water, but Loading ad
Water that’s naturally alkaline occurs when water passes over rocks — like springs — and picks up minerals, which increase its alkaline level.
However, many people who drink alkaline water buy alkaline water that’s been through a chemical process called electrolysis.
This technique uses a product called an ionizer to raise the pH of regular water. Makers of ionizers say that electricity is used to separate molecules in the water that are more acidic or more alkaline. The acidic water is then funneled out.
Still, some doctors and researchers say these claims aren’t backed by quality research. The water quality of the original source, before ionization, is crucial to ensuring contaminants aren’t present in the drinking water.
Some scientists advise using reverse-osmosis to adequately purify water before connecting an alkaline ionizer, which can raise pH and add minerals.
A study published by the
Alkaline water can be bought in many grocery or health food stores. It can also be found online.
Water ionizers are sold in many large chain stores as well.
You can also make your own at home. Even though lemon and lime juices are acidic, they contain minerals that can create alkaline byproducts once digested and metabolized. Adding a squeeze of lemon or lime to a glass of water can make your water more alkaline as your body digests it. Adding pH drops or baking soda is another way to make water more alkaline.
If water is properly filtered to remove contaminants, ionized and re-mineralized, or purchased from a quality source, there’s no evidence to suggest a limitation on how much alkaline water can be consumed daily.
The issue that many health professionals have with alkaline water isn’t its safety, but rather the health claims that are made about it.
There isn’t enough scientific evidence to support the use of alkaline water as a treatment for any health condition. Medical experts warn against believing all the marketing claims.
Drinking natural alkaline water is generally considered safe, since it contains natural minerals.
However, you should use caution with artificial alkaline water, which likely contains fewer good minerals than its high pH would have you believe, and may contain contaminants. Also keep in mind, drinking too much alkaline water may leave you deficient in minerals.
The alkaline diet is based on the idea that replacing acid-forming foods with alkaline foods can improve your health.
Proponents of this diet even claim that it can help fight serious diseases like cancer.
This article examines the science behind the alkaline diet.
DIET REVIEW SCORECARD
- Overall score: 2.13
- Weight loss: 2.5
- Healthy eating: 1.75
- Sustainability: 2.5
- Whole body health: 0.5
- Nutrition quality: 3.5
- Evidence based: 2
BOTTOM LINE: The Alkaline Diet is said to fight disease and cancer, but its claims aren’t backed by science. Although it may aid your health by restricting junk foods and promoting more plant foods, this has nothing to do with your body’s pH levels.
The alkaline diet is also known as the acid-alkaline diet or alkaline ash diet.
Its premise is that your diet can alter the pH value — the measurement of acidity or alkalinity — of your body.
Your metabolism — the conversion of food into energy — is sometimes compared to fire. Both involve a chemical reaction that breaks down a solid mass.
However, the chemical reactions in your body happen in a slow and controlled manner.
When things burn, an ash residue is left behind. Similarly, the foods you eat leave an “ash” residue known as metabolic waste.
This metabolic waste can be alkaline, neutral, or acidic. Proponents of this diet claim that metabolic waste can directly affect your body’s acidity.
In other words, if you eat foods that leave acidic ash, it makes your blood more acidic. If you eat foods that leave alkaline ash, it makes your blood more alkaline.
According to the acid-ash hypothesis, acidic ash is thought to make you vulnerable to illness and disease, whereas alkaline ash is considered protective.
By choosing more alkaline foods, you should be able to “alkalize” your body and improve your health.
Food components that leave an acidic ash include protein, phosphate, and sulfur, while alkaline components include calcium, magnesium, and potassium (
Certain food groups are considered acidic, alkaline, or neutral:
- Acidic: meat, poultry, fish, dairy, eggs, grains, alcohol
- Neutral: natural fats, starches, and sugars
- Alkaline: fruits, nuts, legumes, and vegetables
According to proponents of the alkaline diet, the metabolic waste — or ash — left from the burning of foods can directly affect the acidity or alkalinity of your body.
When discussing the alkaline diet, it’s important to understand pH.
Put simply, pH is a measurement of how acidic or alkaline something is.
The pH value ranges from 0–14:
- Acidic: 0.0–6.9
- Neutral: 7.0
- Alkaline (or basic): 7.1–14.0
Many proponents of this diet suggest that people monitor the pH of their urine to ensure that it is alkaline (over 7) and not acidic (below 7).
However, it’s important to note that pH varies greatly within your body. While some parts are acidic, others are alkaline — there is no set level.
Your stomach is loaded with hydrochloric acid, giving it a pH of 2–3.5, which is highly acidic. This acidity is necessary to break down food.
On the other hand, human blood is always slightly alkaline, with a pH of 7.36–7.44 .
When your blood pH falls out of rmal range, it can be fatal if left untreated .
However, this only happens during certain disease states, such as ketoacidosis caused by diabe.
The pH value measures a substance’s acidity or alkalinity. For example, stomach acid is highly acidic, while blood is slightly alkaline.
It’s critical for your health that the pH of your blood remains constant.
If it were to fall outside of the normal range, your cells would stop working and you would die very quickly if untreated.
For this reason, your body has many effective ways to closely regulate its pH balance. This is known as acid-base homeostasis.
In fact, it’s nearly impossible for food to change the pH value of blood in healthy people, although tiny fluctuations can occur within the normal range.
However, food can change the pH value of your urine — though the effect is somewhat variable .
Excreting acids in your urine is one of the main ways your body regulates its blood pH.
If you eat a large steak, your urine will be more acidic several hours later as your body removes the metabolic waste from your system.
Therefore, urine pH is a poor indicator of overall body pH and general health. It can also be influenced by factors other than your diet.
Your body tightly regulates blood pH levels. In healthy people, diet doesn’t significantly affect blood pH, but it can change urine pH.
Osteoporosis is a progressive bone disease characterized by a decrease in bone mineral content.
It’s particularly common among postmenopausal women and can drastically increase your risk of fractures.
Many alkaline-diet proponents believe that to maintain a constant blood pH, your body takes alkaline minerals, such as calcium from your bones, to buffer the acids from the acid-forming foods you eat.
According to this theory, acid-forming diets, such as the standard Western diet, will cause a loss in bone mineral density. This theory is known as the “acid-ash hypothesis of osteoporosis.”
However, this theory ignores the function of your kidneys, which are fundamental to removing acids and regulating body pH.
The kidneys produce bicarbonate ions that neutralize acids in your blood, enabling your body to closely manage blood pH.
Your respiratory system is also involved in controlling blood pH. When bicarbonate ions from your kidneys bind to acids in your blood, they form carbon dioxide, which you breathe out, and water, which you pee out.
The acid-ash hypothesis also ignores one of the main drivers of osteoporosis — a loss in the protein collagen from bone ).
Ironically, this loss of collagen is strongly linked to low levels of two acids — orthosilicic acid and ascorbic acid, or vitamin C — in your diet..
Keep in mind that scientific evidence linking dietary acid to bone density or fracture risk is mixed. While many observational studies have found no association, others have detected a significant link .
Clinical trials, which tend to be more accurate, have concluded that acid-forming diets have no impact on calcium levels in your body .
If anything, these diets improve bone health by increasing calcium retention and activating the IGF-1 hormone, which stimulates the repair of muscle and bone.
As such, a high-protein, acid-forming diet is likely linked to better bone health — not worse.
Although evidence is mixed, most research does not support the theory that acid-forming diets harm your bones. Protein, an acidic nutrient, even seems to be beneficial.
Many people argue that cancer only grows in an acidic environment and can be treated oreven cured with an alkaline diet.
However, comprehensive reviews on the relationship between diet-induced acidosis — or increased blood acidity caused by diet — and cancer concluded that there is no direct link .
First, food doesn’t significantly influence blood pH .
Second, even if you assume that food could dramatically alter the pH value of blood or other tissues, cancer cells are not restricted to acidic environments.
In fact, cancer grows in normal body tissue, which has a slightly alkaline pH of 7.4. Many experiments have successfully grown cancer cells in an alkaline enviro).
And while tumors grow faster in acidic environments, tumors create this acidity themselves. It is not the acidic environment that creates cancer cells, but cancer cells that create the acidic environment .
There is no link between an acid-forming diet and cancer. Cancer cells also grow in alkaline environments.
Examining the acid-alkaline theory from both an evolutionary and scientific perspective reveals discrepancies.
One study estimated that 87% of pre-agricultural humans ate alkaline diets and formed the central argument behind the modern alkaline diet .
More recent research approximates that half of pre-agricultural humans ate net alkaline-forming diets, while the other half ate net acid-forming diets .
Keep in mind that our remote ancestors lived in vastly different climates with access to diverse foods. In fact, acid-forming diets were more common as people moved further north of the equator, away from the tropics).
Although around half of hunter-gatherers were eating a net acid-forming diet, modern diseases are believed to have been much less common .
Current studies suggest that about half of ancestral diets were acid-forming, especially among people who lived far from the equator.
The alkaline diet is quite healthy, encouraging a high intake of fruits, vegetables, and healthy plant foods while restricting processed junk foods.
However, the notion that the diet boosts health because of its alkalizing effects is suspect. These claims haven’t been proven by any reliable human studies.
Some studies suggest positive effects in a very small subset of the population. Specifically, a low-protein alkalizing diet may benefit people with chronic kidney disease .
In general, the alkaline diet is healthy because it’s based on whole and unprocessed foods. No reliable evidence suggests it has anything to do with pH levels.
Last medically reviewed on September 25, 2019
Carbonated (Sparkling) Water: Good or Bad?
Carbonated water is a refreshing beverage and good alternative to sugary soft drinks.
However, some people are concerned that it may be bad for your health.
This article takes a detailed look at the health effects of carbonated water.
Carbonated water is water that has been infused with carbon dioxide gas under pressure.
This produces a bubbly drink that’s also known as sparkling water, club soda, soda water, seltzer water, and fizzy water.
Apart from seltzer water, carbonated waters usually have salt added to improve their taste. Sometimes small amounts of other minerals are included.
Natural sparkling mineral waters, such as Perrier and San Pellegrino, are different.
These waters are captured from a mineral spring and tend to contain minerals and sulfur compounds. They are often carbonated as well.
Tonic water is a form of carbonated water that contains a bitter compound called quinine, along with sugar or high-fructose corn syrup.
Carbonated water combines water and carbon dioxide under pressure. Sodium and other minerals are often added.
Carbon dioxide and water react chemically to produce carbonic acid, a weak acid that’s been shown to stimulate the same nerve receptors in your mouth as mustard.
This triggers a burning, prickly sensation that can be both irritating and enjoyable.
The pH of carbonated water is 3–4, which means it’s slightly acidic.
However, drinking an acidic beverage like carbonated water does not make your body more acidic.
Your kidneys and lungs remove excess carbon dioxide. This keeps your blood at a slightly alkaline pH of 7.35–7.45 regardless of what you eat or drink.
Carbonated water is acidic, but your body should maintain a stable, slightly alkaline pH no matter what you consume.
One of the biggest concerns about sparkling water is its effect on teeth, as your enamel is directly exposed to acid.
There is very little research on this topic, but one study found that sparkling mineral water damaged enamel only slightly more than still water. Furthermore, mineral water was 100 times less damaging than a sugary soft drink .
In one study, carbonated beverages showed strong potential to destroy enamel — but only if they contained sugar.
In fact, a non-carbonated sweet beverage (Gatorade) was more harmful than a carbonated sugar-free drink (Diet Coke) .
Another study placed samples of tooth enamel in various beverages for up to 24 hours. The sugar-sweetened carbonated and non-carbonated beverages resulted in significantly greater enamel loss than their diet counterparts
A review of several studies found that the combination of sugar and carbonation may lead to severe dental decay
However, plain sparkling water appears to pose little risk to dental health. Only the sugary types are harmful.
If you’re concerned about dental health, try drinking sparkling water with a meal or rinsing your mouth with plain water after drinking it.
Sugar-sweetened carbonated beverages can erode tooth enamel, but plain carbonated water appears relatively harmless.
Carbonated water may benefit your digestive health in several ways.
Can improve swallowing ability
Studies suggest that sparkling water may improve swallowing ability in both young and older adults .
In one study, 16 healthy people were asked to repeatedly swallow different liquids. Carbonated water showed the strongest ability to stimulate the nerves responsible for swallowing Another study showed that the combination of cold temperature and carbonation strengthened these beneficial effects.
In a study in 72 people who felt a persistent need to clear their throats, drinking ice-cold carbonated water led to improvements in 63% of participants. Those with the most frequent, severe symptoms experienced the greatest relief.
May increase feelings of fullness
Carbonated water may also extend feelings of fullness after meals to a greater extent than plain water.
Sparkling water may help food remain in your stomach longer, which can trigger a greater sensation of fullness .
In a controlled study in 19 healthy young women, fullness scores were higher after the participants drank 8 ounces (250 ml) of soda water, compared with after drinking still water .
However, larger studies are needed to confirm these results.
May help relieve constipation
People who experience constipation may find that drinking sparkling water helps relieve their symptoms.
In a 2-week study in 40 older individuals who had experienced a stroke, average bowel movement frequency nearly doubled in the group that drank carbonated water, compared with the group that drank tap water.
What’s more, participants reported a 58% decrease in constipation symptoms .
There’s also evidence that sparkling water may improve other symptoms of indigestion, including stomach pain.
One controlled study examined 21 people with chronic digestive issues. After 15 days, those who drank carbonated water experienced significant improvements in digestive symptoms, constipation, and gallbladder emptying .
Carbonated water has benefits for digestion. It may improve swallowing, increase feelings of fullness, and reduce constipation.
Many people believe that carbonated beverages are bad for bones because of their high acid content. However, research suggests the carbonation isn’t to blame.
A large observational study in over 2,500 people found that cola was the only beverage associated with significantly lower bone mineral density. Carbonated water appeared to have no effect on bone health.
Unlike carbonated water and clear soda, cola drinks contain a lot of phosphorus.
The researchers proposed that the cola drinkers may have been consuming too much phosphorus and insufficient calcium, providing a potential risk factor for bone loss.
In another study, teen girls who consumed carbonated drinks were found to have lower bone mineral density. This was attributed to beverages that replaced milk in their diet, resulting in inadequate calcium intake .
In a controlled study in 18 postmenopausal women, drinking 34 ounces (1 liter) of sodium-rich sparkling water daily for 8 weeks led to better calcium retention than drinking plain mineral water .
Additionally, no negative effects on bone health were observed in the sparkling water group.
Animal research suggests carbonated water may even improve bone health.
Supplementing hens’ diets with carbonated water for 6 weeks led to increased leg bone strength compared with tap water.
Drinking carbonated cola drinks may harm bone health, but plain sparkling water appears to have a neutral or positive effect.
Research suggests carbonated water may improve heart health, although the evidence is very limited.
One study in 18 postmenopausal women showed that drinking sodium-rich carbonated water decreased LDL (bad) cholesterol, inflammatory markers, and blood sugar.
What’s more, they also experienced an increase in HDL (good) cholesterol .
Additionally, the estimated risk of developing heart disease within 10 years was 35% lower among those drinking carbonated water than those drinking the control water.
However, since this was only one small study, significantly more research is needed before any conclusions can be reached.
Carbonated water may have beneficial effects on your cholesterol, inflammation, and blood sugar levels, potentially reducing your risk of heart disease. However, more studies are necessary.
No evidence suggests that carbonated or sparkling water is bad for you.
It’s not that harmful to dental health, and it seems to have no effect on bone health.
Interestingly, a carbonated drink may even enhance digestion by improving swallowing ability and reducing constipation.
It’s also a calorie-free beverage that causes a pleasurable bubbly sensation. Many people prefer it over still water.
There’s no reason to give up this beverage if you enjoy it. In fact, it may even improve your overall health.
What to Drink for Acid Reflux
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If you have acid reflux or gastroesophageal reflux disease (GERD), you may spend mealtimes avoiding certain foods and drinks. These conditions cause stomach acid to leak back into the esophagus.
GERD symptoms are affected by what you eat. The symptoms can include coughing, nausea, and hoarseness. Burping, sore throat, and regurgitation are also commonly associated with GERD. What you decide to incorporate or avoid in your diet can help relieve some of your symptoms.
Beverages such as coffee, colas, and acidic juices often top the list of “don’ts.” These beverages may increase the risk of GERD symptoms. Instead, here’s what you should drink to help reduce symptom1
Herbal teas help improve digestion and soothe many stomach problems, such as gas and nausea. Try caffeine-free herbal tea for acid reflux, but avoid spearmint or peppermint teas. Mint triggers acid reflux for many.
Chamomile, licorice, slippery elm, and marshmallow may make better herbal remedies to soothe GERD symptoms.
Licorice helps increase the mucus coating of the esophageal lining, which helps calm the effects of stomach acid. However, there’s insufficient evidence to confirm the effectiveness of fennel, marshmallow root, or papaya tea.
When using dried herbs as extracts in tea, you should use one teaspoon of herb per one cup of hot water. Steep leaves or flowers, covered, for 5 to 10 minutes. If you’re using roots, steep for 10 to 20 minutes. For best results, drink two to four cups per day.
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Be aware that some herbs can interfere with certain prescription medications, so talk to your doctor before trying an herbal remedy.
Cow’s milk is hard for some people to digest and can contain a significant amount of fat. Like all high-fat foods, full-fat cow’s milk may relax the lower esophageal sphincter, which can cause or worsen reflux symptoms.
If you have to go with cow’s milk products, choose the ones that are lowest in fat.
For people who are lactose intolerant or just experience an increase of acid reflux symptoms from dairy, plant-based milks are a good solution. Today, there are a variety of these products available, including:
- soy milk
- almond milk
- flax milk
- cashew milk
- coconut milk
Almond milk, for example, has an alkaline composition, which can help neutralize stomach acidity and relieve acid reflux symptoms. Soy milk contains less fat than most dairy products, making it a safer choice for people with GERD.
Carrageenan is a common additive in nondairy beverages and may contribute to digestive symptoms. Check your labels and avoid this additive if you have GERD.
Citrus drinks and other drinks such as pineapple juice and apple juice are very acidic and may cause acid reflux. Other types of juices are less acidic and thus are less likely to trigger GERD symptoms in most people. Good options include:
- carrot juice
- aloe vera juice
- cabbage juice
- freshly juiced drinks made with less acidic foods, such as beet, watermelon, spinach, cucumber, or pear
Because tomato-based foods can trigger reflux symptoms, avoiding tomato juice may also reduce GERD symptoms.
Smoothies are a great way for nearly everyone to incorporate more vitamins and minerals into their diets. They’re an exceptionally good (and tasty!) option for people with GERD.
When making a smoothie, look for the same low-acid fruits as you would for juices, such as pear or watermelon. Also, try adding green vegetables such as spinach or kale.
Try this simple, low-carb smoothie that incorporates spinach and avocado. Another option is this vegan green tea smoothie with green grapes.
Sometimes the simplest solutions make the most sense. The pH of most water is neutral, or 7.0, which can help raise the pH of an acidic meal.
Although this is very uncommon, keep in mind that too much water can disrupt the mineral balance in your body, which would increase the likelihood of acid reflux.
Unsweetened coconut water can be another great option for people with acid reflux. This beverage is a good source of helpful electrolytes such as potassium. These electrolytes promote pH balance in the body, which is crucial for controlling acid reflux.
Get a whole case online to quench your thirst!
Some drinks can aggravate reflux symptoms and should be avoided. Examples include fruit juices, caffeinated beverages, and carbonated beverages.
Citrus juices are naturally highly acidic and thus can aggravate acid reflux. Examples of citrus juices include:
- lemon juice
- orange juice
- tangerine juice
- lime juice
- grapefruit juice
The citric acid that’s naturally present in citrus fruit can irritate the esophagus. While the stomach is made to withstand more acidic foods, the esophagus is not.
When buying juice drinks, check for and avoid citric acid. It’s sometimes used as a flavoring.
Morning coffee is a daily habit for many, but people with acid reflux should avoid it when possible. Coffee can stimulate excess gastric acid secretions that may rise up to your esophagus, particularly when you drink a lot of it. This results in heightened acid reflux symptoms.
Other caffeinated beverages, such as sodas or teas, can have similar effects and should be avoided as much as possible.
Alcohol can negatively affect acid reflux, regardless of whether you’re drinking a glass of wine or downing a margarita. Hard liquor is more likely to aggravate reflux conditions quickly, though a glass of wine with a large or acidic meal can cause discomfort, too.
Heavy consumption of alcohol may be a risk factor for developing GERD, and it could cause mucosal damage in the stomach and esophagus.
Some women who have never had acid reflux before develop acid reflux or heartburn symptoms for the duration of their pregnancy. This is normal, and many women have decreased or no symptoms after the pregnancy is over.
In addition to following the guidelines discussed above, try sipping liquids instead of drinking them quickly to help prevent acid reflux symptoms. Keeping a food diary to help track what aggravates your symptoms can help you prevent symptoms throughout your pregnancy.
If your GERD or acid reflux hasn’t responded to purely dietary changes, other remedies and medications may offer relief.
Over-the-counter (OTC) treatments include:
- temporary use of OTC antacids, such as calcium-carbonate (Tums)
- proton pump inhibitors, such as omeprazole (Prilosec) or lansoprazole (Prevacid)
- H2 receptor blockers, such as famotidine (Pepcid AC)
- deglycyrrhizinated licorice
Prescription medications include:
- prescription-strength proton pump inhibitors
- prescription-strength H2 receptor blockers
In extreme cases, surgery may be in an option. Surgery can reinforce or strengthen the lower esophageal sphincter.
As with eating, when and how you drink beverages can make a difference in GERD symptoms. The following tips can help keep symptoms at bay:
- Avoid skipping breakfast or lunch, which can lead to overeating — and overdrinking — late in the day.
- Give up late-night snacks, including beverages that may cause heartburn. This includes carbonated and caffeinated drinks.
- Maintain an upright position during and after eating and drinking. Don’t eat for at least three hours before bedtime.
- Moderate your alcohol consumption. Drinking too much alcohol can cause reflux symptoms in some people.
- Reduce or eliminate spicy foods and fried foods.
- Elevate the head of your bed so gravity can help keep acid from creeping into your esophagus.
By practicing healthy drinking habits and taking note of how your symptoms respond to specific foods and drinks, you can reduce your reflux symptoms and improve your quality of life.
End constipation and bloating, and experience perfect daily bowel movements. Clinically proven ingredients to get your gut going and support overall digestive health.
Last medically reviewed on June 14, 2019
Lemon Juice: Acidic or Alkaline, and Does It Matter?
Lemon juice is said to be a healthy drink with potential disease-fighting properties.
It’s particularly popular in the alternative health community because of its supposed alkalizing effects. However, lemon juice has an unarguably low pH and should therefore be seen as acidic, not alkaline.
This article examines why some people consider lemon juice to be alkalizing, despite its acidic pH, and what that does to your body.
When discussing acidic versus alkalizing foods, it’s important to understand the concept of pH.
Put simply, pH is a rating of how acidic or alkaline a solution is on a scale from 0–14. A pH of 7 is considered neutral. Any pH value below 7 is considered acidic, and any pH value over 7 is considered alkaline (1, 2).
On the pH scale, the difference between adjacent numbers represents a tenfold difference in acidity. For instance, a pH of 5 is 10 times more acidic than a pH of 6 and 100 times more acidic than a pH of 7.
Because they contain a high amount of citric acid, lemons have an acidic pH.
Lemon juice has a pH between 2 and 3, which means it’s 10,000–100,000 times more acidic than water (1, 2, 3).
A food’s pH is a measure of its acidity. The pH of lemon juice falls between 2 and 3, meaning it is acidic.
The Alkaline Diet has gained popularity in recent years.
It’s based on the principle that the foods you eat may alter your body’s pH.
To set the record straight, there is no evidence to support the Alkaline Diet. According to research, the foods you eat have very little effect on the pH of your blood.
Nevertheless, the Alkaline Diet categorizes foods into three groups:
- Acidifying foods: meat, poultry, fish, dairy, eggs, and alcohol
- Neutral foods: natural fats, starches, and sugars
- Alkalizing foods: fruits, nuts, legumes, and vegetables
Proponents of the diet believe that eating large amounts of acidifying foods can cause your body’s pH to become more acidic, increasing your vulnerability to illness and disease.
For instance, many believe that your body steals alkaline calcium from your bones to buffer the acidifying effects of the foods you eat.
Some also believe that cancer grows only in acidic environments and that you can prevent or even cure it if you eat an alkaline diet.
Therefore, followers of this diet attempt to improve their health and reduce their risk of disease by limiting acidifying foods and favoring alkalizing ones instead.
Certain people believe that alkalizing foods lower their body’s pH, thereby promoting health and preventing disease.
Whether a food has an acidic or alkaline effect on the body has little to do with that food’s pH before it is digested.
Instead, it depends on whether acidic or alkaline byproducts are created once it is digested and processed by your body.
One method of estimating which type of byproduct a food will produce is the “ash analysis” technique.
In this method, foods are burned in a laboratory to simulate digestion. The pH of their ash is used to classify the foods as either acid or alkaline. Ash analysis is the reason foods are sometimes said to produce acid or alkaline “ash” (
However, ash analysis is an imprecise estimation, so scientists now prefer to use a different formula that grades foods based on their potential renal acid load (PRAL).
The PRAL of a particular food is the amount of acid that is expected to reach the kidneys after the body metabolizes that food (
Typically, the kidneys keep the blood’s pH constant by getting rid of excess acid or alkali through the urine.
Acidic nutrients such as protein, phosphorus, and sulfur increase the amount of acid the kidneys must filter out. Meats and grains, which tend to contain these nutrients, are therefore given a positive PRAL score (
On the other hand, fruits and vegetables are high in alkaline nutrients such as potassium, calcium, and magnesium. These ultimately reduce the amount of acid that the kidneys will need to filter out and are thus given a negative PRAL score (
Like other fruits, lemon juice produces alkaline byproducts once it has been metabolized. Therefore, it has a negative PRAL score.
This is why some people consider lemon juice to be alkaline even though it has an acidic pH before it is digested.
Once digested and metabolized, lemon juice produces alkaline byproducts, which make the urine more alkaline. This is why some people think of it as alkalizing, despite its acidic pH before it is digested.
Many proponents of the Alkaline Diet use pH test strips to check the alkalinity of their urine. They believe this helps them determine how alkaline their body truly is.
What they do not realize is that while lemon juice may make the pH of your urine more alkaline, it does not have the same effect on the pH of your blood.
According to research reviews published in 2013 and 2012, the foods you eat have a very limited effect on your blood pH (
Some much older studies estimated that you’d need to eat the equivalent of 18 pounds (8 kg) of oranges — which have an alkalizing potential similar to that of lemons — all in one sitting to increase your blood pH by just 0.2 (8,
Foods have such limited effects on the pH of your blood because your body needs to maintain pH levels from 7.35–7.45 for your cells to function properly (
If your blood pH values fall outside this range, you’re in a state called metabolic acidosis or metabolic alkalosis, which can be dangerous or even fatal if left untreated (
However, this rarely occurs, because your body is very good at preventing your blood pH values from falling outside the normal range. One of the ways it keeps the levels constant is by using your kidneys to filter out excess acids through your urine (
This is why your urine can become more acidic a couple of hours after you eat a large steak or less acidic after you follow a diet high in alkalizing foods (
Yet while the acidity of your urine can vary as a result of the foods you eat, the pH of your blood remains constant. So even if drinking lemon juice results in more alkaline urine, it’s unlikely to have any effect on the pH of your blood.
Lemon juice may have an alkalizing effect on your urine. However, contrary to the premise of the Alkaline Diet, it has very little influence on the pH of your blood.
Proponents of the Alkaline Diet seem to believe that the foods you eat can affect your health by influencing the pH of your blood. They generally claim that alkalizing foods prevent bone loss and can prevent or treat cancer.
However, as discussed above, this theory completely ignores the role your kidneys play in regulating the pH of your blood, among other methods your body uses to maintain pH (
In addition, contrary to popular belief, many large reviews have concluded that acidifying diets have no impact on calcium levels in the body (
In fact, several studies actually link high protein diets, which are thought to be acid-forming, with healthier bones (
As for the effects some people think acidifying foods have on cancer, studies show there is no direct link between the amount of acidifying foods you eat and your risk of developing the disease (
Nevertheless, an alkaline diet may offer some health benefits to certain individuals.
For instance, people with kidney disease usually need to restrict their protein intake. Consuming an alkaline diet may slightly decrease the need for this (
It may also reduce the risk of kidney stones in those prone to developing them (
However, more research on these purported benefits is needed before strong conclusions can be made.
Your body is designed to keep the pH of your blood within a narrow, healthy range. The foods you eat have very little effect on this pH.
Despite having very little alkalizing effect on the blood, regularly drinking lemon juice may promote several other health benefits.
For instance, lemon juice is high in vitamin C, a strong antioxidant that helps keep the immune system strong and prevents and fights disease (
One fluid ounce (30 ml) of lemon juice actually provides around 13% of your daily vitamin C requirement (
What’s more, drinking a vitamin C-rich beverage, such as lemon water, with meals may help increase your absorption of some minerals, including iron (
Lemon juice also contains small amounts of antioxidants that may help reduce the risk of heart disease by strengthening blood vessels, reducing inflammation, and preventing the accumulation of plaque (
In addition, some research suggests that regularly consuming lemon juice may help prevent the formation of certain types of kidney stones (
Regularly consuming lemon juice may strengthen the immune system, increase mineral absorption, reduce risk factors of heart disease, and prevent certain types of kidney stones.
Lemon juice has an acidic pH before it is digested. However, once metabolized by the body, it produces alkaline byproducts.
These alkaline byproducts can make your urine more alkaline but have very little effect on the pH of your blood.
Therefore, any health benefits lemon juice may offer are unlikely to come from its purported alkalizing effect.
Last medically reviewed on September 7, 2021
Detox Water Health Benefits and Myths
There’s a lot of hype about the supposed health benefits of “detox water.”
Yes, staying hydrated is important for health.
Therefore, it’s often recommended that you drink eight glasses of water per day.
But some people think adding extra ingredients to water boosts its health benefits.
The result, called detox water, is said to help your body get rid of toxins, improve your energy levels, and help you lose weight.
Here’s a detailed look at detox water. It separates the true health benefits from the myths.
Detox water is water that has been infused with the flavors of fresh fruits, vegetables, or herbs. It’s sometimes referred to as fruit-infused water or fruit-flavored water.
You can make detox water at home in lots of different ways. You can use any combination of fruits, vegetables, and herbs that you like.
Because it’s made by infusing flavor, rather than juicing or blending, detox water contains very few calories. That makes it a popular drink for detox regimens like the “lemon detox” or “master cleanse.”
Detox water is also often recommended in weight loss plans, especially in place of high sugar drinks like soda and fruit juice.
Detox water is made by infusing water with fruits, vegetables, or herbs. You can make your own at home using a variety of flavors.
Making detox water at home is very simple. All you need is water and a selection of fruits, vegetables, and herbs.
Simply chop your ingredients and add them to hot or cold water, depending on your preference. The more of an ingredient you use, the stronger the flavor will become.
If you’re making a cold drink, you can leave the detox water in the fridge for 1–12 hours to allow the flavors to infuse more deeply. Be sure to remove the ingredients after this time, though, so they don’t begin to decompose.
If you’re in a hurry, crushing or bruising your fruit and herbs before using them can help release the flavors more quickly.
Here are some popular detox water recipe combinations:
- cucumber and mint
- lemon and ginger
- blackberry and orange
- lemon and cayenne pepper
- watermelon and mint
- grapefruit and rosemary
- orange and lemon
- lemon and lime
- strawberry and basil
- apple and cinnamon
To make detox water, add fruits, vegetables, and herbs to water and then let it stand. Crushing or bruising fruits and herbs can help release more of their flavors.
Detox water is said to have many health benefits, including:
- weight loss
- toxin removal or detox
- balancing body pH
- better digestive health
- boosting immune function
- improving mood
- increasing energy levels
- improving complexion
The exact properties of detox water will vary depending on the ingredients you use and the strength of the infusion.
But many of the health claims for detox water can be attributed to the water itself, rather than the ingredients it’s flavored with.
That’s because you don’t get that many nutrients from the ingredients in detox water, especially not compared to eating them in their whole form.
Detox water has been claimed to help remove toxins, help with weight loss, balance your pH, and boost your immune system.
Below is a detailed look at the science behind detox water’s health claims. A few are valid, though exaggerated in some instances.
Helps with weight loss
Drinking water may help you lose weight, and this applies to detox water too. Water has been shown to temporarily raise your metabolic rate, so you burn more calories.
Studies have shown that drinking 17 ounces (half a liter) of water can increase your metabolic rate by up to 30% for about an hour (
In fact, people who drink the recommended amount of water as part of a weight loss program tend to lose more weight than those who don’t (
One study found that overweight adults who drank 17 ounces (half a liter) of water before their meals lost 40% more weight than those who didn’t (
This can be partially explained by a rise in metabolism, but may also be due to the effect water has on your appetite. Drinking water has been linked to reduced hunger, so if you drink water before a meal, you may eat less (
Improves digestive health
Hydration is important for digestive health and maintaining regular bowel movements. Chronic dehydration can cause constipation, which can make you feel bloated and sluggish (
Drinking plenty of water may help food pass smoothly through your gut and prevent you from becoming constipated.
Improves mood and energy levels
Even mild dehydration can affect mood, concentration, and energy levels.
Studies have shown that dehydration levels of around 1% can significantly decrease mood, reduce concentration span, and cause headaches (
One study looked at adults who consumed less than 41 ounces (1.2 liters) of water per day. When they increased their water intake to 85 ounces (2.5 liters) per day, they were happier, had more energy, and felt calmer (
If you’re not drinking enough, increasing your water intake could improve your mood and give you more energy.
Boosts immune function
This is one claim about detox water that may be a little exaggerated.
It’s true that eating fruits and vegetables, and even fruit juices, can help support your immune system (
In particular, vitamin C has been shown to benefit your immune system when consumed on a regular basis (
However, the amount of these nutrients that you’d get from an infusion like detox water is likely to be minimal and highly variable.
Although it’s theoretically possible, it’s unlikely detox water has any meaningful effect on immune function.
Drinking detox water could help you lose weight, have better digestive health, and make you happier. However, you’ll get all these benefits from drinking regular water too.
Many myths surround detox water.
Some are not supported by science, and others have been shown to be downright false.
Myth 1: It detoxifies your body
Detoxification is a popular claim for many diets, cleanses, and nutrition products like detox water.
Detox products often claim to facilitate health and well-being by eliminating toxins from the body and aiding weight loss.
However, both “toxins” and “detox” are vague terms. They don’t really define what is eliminated or how it happens.
Your body has well-designed detox pathways that eliminate toxins from the body. There’s currently no evidence that any product or diet speeds them up or makes them more efficient (
More details in this article: Detox Diets 101: Do These “Cleanses” Really Work?
Myth 2: It balances your pH
“Alkalizing” foods and drinks are a popular dietary trend at the moment.
They’re said to promote a more alkaline environment in the body. According to the acid-alkaline theory of disease, this will promote better health.
However, this theory isn’t supported by science. It’s impossible to alter the pH of your blood or cells through the foods you eat (
Myth 3: It improves your complexion
As with many other detox products, some people claim that detox water flushes toxins from your skin and improves its appearance.
However, there’s little evidence to back up these claims. Drinking water will improve your skin’s hydration if you’re dehydrated. However, it won’t change the appearance of your skin unless the dehydration is severe (
There’s no evidence that detox water is more effective than plain water for this.
Detox water won’t help you flush toxins from your body or make it more alkaline. There’s also no evidence that it improves complexion.
The idea that you can speed up and improve your body’s detox pathways by drinking detox water is unlikely.
That said, it’s still a healthy drink with a few health benefits. Nevertheless, you could probably get most of these benefits from drinking regular water.
However, people often find plain water boring.
If infusing your water with fruits and vegetables means that you drink the recommended amount of water each day and fewer sugary drinks, then it can only be a good thing.
Last medically reviewed on August 25, 2021
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Alkaline water side effects
Although alkaline water is considered safe for consumption, it may have negative side effects too. One of the side effects is that while it may be alkalizing your body, there is a chance that excessive consumption may ruin the natural acids of your stomach killing the good bacteria. Furthermore, excessive alkalinity in your body may cause problem in the gastrointestinal tract and skin.
Alkaline Water and Longevity: A Murine Study
The biological effect of alkaline water consumption is object of controversy. The present paper presents a 3-year survival study on a population of 150 mice, and the data were analyzed with accelerated failure time (AFT) model. Starting from the second year of life, nonparametric survival plots suggest that mice watered with alkaline water showed a better survival than control mice. Interestingly, statistical analysis revealed that alkaline water provides higher longevity in terms of “deceleration aging factor” as it increases the survival functions when compared with control group; namely, animals belonging to the population treated with alkaline water resulted in a longer lifespan. Histological examination of mice kidneys, intestine, heart, liver, and brain revealed that no significant differences emerged among the three groups indicating that no specific pathology resulted correlated with the consumption of alkaline water. These results provide an informative and quantitative summary of survival data as a function of watering with alkaline water of long-lived mouse models.
Alkaline water, often referred to as alkaline ionized water (AKW), is commercially available and is mainly proposed for electrolyte supplementation during intensive perspiration. Early studies on animal models reported that alkaline water supplementation may exert positive effects on body weight improvement and development in offspring [1, 2]. Even biochemical markers were analyzed, suggesting that alkaline ionized water intake can cause elevation of metabolic activity. In particular, hyperkaliemia was observed in 15-week-old rats and pathological changes of necrosis in myocardial muscle were found .
More recently, studies were carried out on alkaline reduced water (ARW), referring to electrolyzed water produced from minerals, such as magnesium and calcium, which is characterized by supersaturated hydrogen, high pH, and a negative redox potential. This hydrogen-rich functional water has been introduced as a therapeutic strategy for health promotion and disease prevention .
Alkaline and electrolyzed water have been shown to exert a suppressive effect on free radical levels in living organisms, thereby resulting in disease prevention . Various biological effects, such as antidiabetic and antioxidant actions , DNA protecting effects , and growth-stimulation activities , were documented.
Although a variety of bioactive functions have been reported, the effect of alkaline water on lifespan and longevity in vivo is still unknown. Animal alkalization has been shown to be well tolerated and to increase tumor response to metronomic chemotherapy as well the quality of life in pets with advanced cancer . Therefore, we performed a study based on survival rate experiments, which play central role in aging research and are generally performed to evaluate whether specific interventions may alter the aging process and lifespan in animal models.
2. Materials and Methods
Biological effects of alkaline water were evaluated on a selected population of 150 mice (CD1, by Charles River, Oxford, UK). Pathogen-free mice were purchased and placed in a specific breeding facility. No other animal was present in the room. Contact with animal caretakers was minimized to feeding and watering. The population was divided into 3 groups, each consisting of 50 individuals, as follows:
Group A: 50 mice conventionally fed and watered with alkaline water produced by the Water Ionizer (mod. NT010) by Asiagem (Italy). The Water Ionizer is a home treatment device for producing alkaline drinking water.
Group B: 50 mice conventionally fed and watered with alkalized water obtained by dilution of a concentrated alkaline solution (AlkaWater by Asiagem, Italy). AlkaWater is a concentrated alkaline solution for preparing alkaline drinking water.
Group C: 50 mice conventionally fed and watered as conventional (control group) with tap water. The local water supply was evaluated weekly for assuring the absence of toxins and pathogens. The pH values were in the 6.0–6.5 range.
All procedures involving animals were conducted in accordance with the Italian law on experimental animals and were approved by the Ethical Committee for Animal Experiments of the University of Padua and the Italian health Ministry (Aut. no. 39ter/2011). Efforts were made to minimize animal suffering.
2.1. Histological Examination
Treated aged mice were sampled postmortem and subjected to histological examination. Animals belonging to the populations treated with alkaline water, A and B, were sacrificed after 24 months and compared to mice treated with tap water. Samples from kidneys, intestine, heart, liver, and brain were fixed in 10% neutral buffered formalin, and 4 μm sections were analyzed by optical microscopy.
2.2. Statistical Analysis
In order to investigate the biological influence of alkaline water on mouse longevity, we employed the accelerated failure time model (AFT) , which allows formally exploring the possible effect on survival curves of the applied three-level treatment, that is, examining the role of group membership as a covariate of lifespan. As a more robust alternative to the commonly used proportional hazards models, such as the Cox model, the use of AFT models is advised in the field of survival analysis when the goal is to investigate if a covariate may affect the lifespan in a way that the life cycle may pass more or less rapidly. In fact, whereas a proportional hazard model assumes that the effect of a covariate is constant over time, an AFT model assumes that the effect of a covariate is to accelerate or decelerate the life course.
The relevance of AFT model for biomedical studies has been already recognized in the literature . With more specific reference to the issue of aging, Swindell  observed that some genetic manipulations were found to have a multiplicative effect on survivorship which were well characterized by the AFT model “deceleration factor.” Moreover, Swindell  argued also that the AFT model should be utilized more widely in aging research since it provides useful tools to maximize the insight obtained from experimental studies of mouse survivorship.
To perform all calculations, we applied a parametric survival analysis approach using a class of 3-parameter AFT distribution models implemented within the statistical software Minitab, version 17.2.1 . More specifically, we employed three types of random distributions, namely, log-logistic, log-normal, and generalized Weibull.
The experiment consisted in an initial 15-day acclimatization period. After acclimatization, animals (50, group A) were watered with alkaline water (pH 8.5), obtained by the Water Ionizer (Asiagem, Italy), whereas group B animals (50) were watered with water alkalized at pH 8.5 by a concentrated alkaline solution (AlkaWater by Asiagem, Italy) for 15 days. Group C animals (50), control group, were watered with the local water supply. This period has been identified to gradually accustom the animals treated with alkaline water. At the end of the second period of acclimatization, group A and B animals were watered with alkaline water at pH 9.5 (by the Water Ionizer and by AlkaWater by Asiagem, Italy), while animals of group C were watered with local tap water.
After the first year, the most aggressive individuals were moved to other cages within the same group and an environmental enrichment protocol was employed in order to decrease the hyperactivity. This phenomenon was observed especially in animals of groups A and B.
Table 1 reported basic statistics on mice survival of treated and control animals.
|Treatment level||Mortality rate |
|Lifespan mean (std. dev.) |
|Group A||88||679 (209)|
|Group B||92||671 (180)|
|Group C||96||667 (185)|
Regarding group A, animals (50) were watered with alkaline water (pH 8.5), obtained by the Water Ionizer (Asiagem, Italy). As for group B, animals (50) were watered with water alkalized at pH 8.5 by a concentrated alkaline solution (AlkaWater by Asiagem, Italy) for 15 days. Regarding group C, animals (50), control group, were watered with the local water supply.
A first look on experimental data is provided in Figure 1, where nonparametric hazard and survival plots seem to suggest that even if no macroscopic difference emerges, starting from the second year of life mice watered with alkaline Water Ionizer and those treated with AlkaWater overwhelmed control mice.
In order to explore the possible effect of different treatments, that is, to examine the role of group membership on longevity, we applied a parametric survival analysis approach using a class of 3-parameter survival distributions that represent flexible accelerated failure time, AFT models. First of all, using the Anderson-Darling goodness-of-fit statistic, we compared three specific survival distributions, that is, log-logistic (AD = 6.397), log-normal (AD = 6.519), and generalized Weibull (AD = 6.447). Since the best fitting was shown by log-logistic model, we adopted this one as final survival distribution model. The straight lines in the log-logistic distribution QQ plots (Figures 2(a) and 2(b)) indicate that this distribution provides a suitable fit to our survival data.
Finally, by including our treatment as covariate, we performed a parametric distribution analysis whose results are graphically represented in Figure 3.
Starting with the second year of life, it is worth noting that both alkaline water treated groups denote a decreasing hazard curve over time, while the corresponding curve for control group is monotonically increasing. To more formally compare the treatment levels, the proposed analysis provided also suitable p values. Since the p values related on the null hypotheses of equality of location, scale and threshold parameters were, respectively, less than 0.001 (for both locations and scales) and 0.634 (for thresholds) at a 5% significance level; we can state that there is enough experimental evidence to conclude that the treatment significantly affects the mice longevity; in particular the alkaline water provides a benefit to longevity in terms of “deceleration aging factor” as it decreases the hazard functions when compared with the control group. Note that the treatment effect cannot be directly related to no one of the three distribution parameters. Anyway, using the estimated parameters, it should be possible to provide an estimate for the effect of each treatment on survivorship: setting the reference survival time to 1000, 1200, and 1400 days, Table 2 summarizes the estimated point and 95% interval survival probabilities by each treatment level.
|Treatment level||Time (days)||Estimated probability||Lower 95% CI limit||Upper 95% CI limit|
As final remark, it should be noted that even if our parametric AFT survival analysis was performed using the log-logistic distribution, our conclusions are consistent with results obtained using the generalized Weibull distribution, while via log-normal distribution no significant effect was found.
3.1. Histological Examination
No significant differences emerged from the histological examination among the three groups. In all examined samples, renal tissue was characterized by a mild-to-moderate lymphoplasmacytic interstitial infiltrate and few occasional glomerular changes as glomerular size reduction and increasing of Bowman's space (Figure 4).
Final diagnosis was mild chronic progressive nephropathy for the three analyzed mouse groups.
The microscopic examination of the liver revealed a multifocal nodular pattern of the parenchyma and diffuse mild-to-moderate hepatocellular cytoplasmic hydropic degeneration with multifocal binucleation in all explored animals (Figure 5).
Mild-to-moderate anisokaryosis was the most relevant alteration, with few pleomorphic nuclei and frequent intranuclear pseudoinclusions and karyomegaly. A specific mild perivascular infiltrate was occasionally present. Final diagnosis was mild-to-moderate diffuse hepatopathy with multifocal hyperplastic hyperplasia.
The pulmonary parenchyma showed mild multifocal areas of interstitial thickening of the interalveolar septa due to moderate congestion and mild cellular mixed infiltrate (Figure 6). Mild areas of emphysema were detected at the periphery of the parenchyma. Final diagnosis was multifocal very mild atelectasis and mild vicarious emphysema.
At the same time, no relevant histopathologic histological changes have been noticed in intestine (Figure 7), brain, and heart.
The present work presents a 3-year survival study on a population of 150 mice and the data were analyzed with accelerated failure time (AFT) model. Kaplan-Meier statistical analysis of the survival data indicates the possibility of a positive effect of alkaline water on mouse lifespan and AFT model allowed evaluating differences starting from the second year of the survival curves. These results provide an informative and quantitative summary of survival data as a function of watering with alkaline water on long-lived mouse models. It should be pointed out that, from the standpoint of aging research, this statistical approach presents appealing properties and provides valuable tools for the analysis of survival. The observation of tissues of deceased animals was performed for the assessment of the state of internal organs to be compared with similar analyses of untreated animals. The renal lesions observed at histology were specific and common for the three animal groups. Chronic progressive nephropathy has been well described as normal aging change in mice [11, 12]. In our cases animals did not show any clinical sign of nephropathy or any other histological evidence of specific kidney disease and we ascribed the lesions to the aging process [11, 12].
The examined livers were also affected by typical lesions of mature subjects, such as hyperplastic nodules. Furthermore, well known aging changes were individuated in the hepatocytes, such as karyomegaly, nuclear pleomorphism, and pseudoinclusions cysts [11, 12].
A 3-year survival study on a population of 150 mice was carried out in order to investigate the biological effect of alkaline water consumption. Firstly, nonparametric hazard and survival plots suggest that mice watered with alkaline water overwhelmed control mice. Secondly, data were analyzed with accelerated failure time (AFT) model inferring that a benefit on longevity, in terms of “deceleration aging factor,” was correlated with the consumption of alkaline water. Finally, histological examination of mice kidneys, intestines, hearts, livers, and brains was performed in order to verify the risk of diseases correlated to alkaline watering. No significant damage, but aging changes, emerged; organs of alkaline watered animals resulted to be quite superimposable to controls, shedding a further light in the debate on alkaline water consumption in humans.
This paper is dedicated to the memory of Tommaso Nicoletti. The authors are grateful to Rocco Palmisano for original ideas and support. The authors would like to thank Asiagem (Italy) for partial support and Ludovico Scenna, Carlo Zatti, and Silvano Voltan for their scientific and professional contribution.
The authors declare that there are no competing financial interests.