Q: I would like to request you to please discuss in your column the health benefits of alkaline ionized bottled water compared to usual purified water cause recently I switched to alkaline as I’ve heard it’s better than purified. How true is this?

--”mean fran”

A: Ads and promotional materials on alkaline drinking water claim that alkaline water helps neutralize acids and remove toxins from the body. Some even go to the extent of asserting that it retards the aging process and prevents cancer. Unfortunately, there is not a single iota of scientific evidence to support any of these claims.

The alkalinity or acidity of any solution or fluid is determined by its pH level. A substance with a pH that is higher than 7.0 is alkaline or basic while a substance with a pH that is lower than 7.0 is acidic.

Normal alkalinity or acidity (i.e., pH level) differs in the various body fluids. This is so because the numerous metabolic activities the body undertakes occur at different pH levels. Thus, the pH level of the different body fluids has to be maintained within a narrow normal range. Changing the pH in any body fluid would make a person very sick or even kill him/her. Accordingly, there are cells, tissues and organs in the body that ensure that the pH levels of the various body fluids are kept within normal range.

For example, the pH of blood, which is slightly alkaline or basic (normal pH = 7.4.), is kept constant primarily by the kidneys and the lungs. Any excess acid generated by the cells of the body is removed by the kidneys and excreted with urine. The lungs do their part by expelling carbon dioxide, which is also acidic. Another example, gastric juice, which has to be highly acidic for proper digestion, is maintained at a very low pH (about 1.4) by the continuous production of hydrochloric acid by certain cells of the stomach.

While excess acidity in any part of the body is bad, so is excess alkalinity. Why should you then try to alkalinize your body by drinking alkaline water?

Fortunately, drinking alkaline water will not endanger your health because the mechanisms that maintain the normal acid-base balance within the body are very efficient; so efficient that the pH level of practically all body fluids cannot be significantly altered by the intake of food, beverage or any kind of drinking water. Ingested food and fluid, no matter how alkaline, will become highly acidic in the stomach. When the highly acidic stomach content reaches the small intestines, on the other hand, it is rendered alkaline by intestinal juice.

The only body fluid whose pH can be altered by ingested food or beverage is urine and that is because the kidneys dump excess base or acid into urine for disposal.

Thus, alkaline drinking water cannot change the pH in any part of the body; much less can it have any beneficial health effects.

The claims of alkaline water advocates are clearly outrageous. Yet, they have been successful in convincing many people including you to replace their drinking water with it. But if it is any consolation for those who drink it, alkaline water apparently has no adverse effects, except on one’s wallet.

But why do some people swear they feel better when they drink alkaline instead of tap water? The answer is placebo effect, a very remarkable phenomenon where an otherwise ineffective treatment alleviates the symptoms and improves the feeling of wellbeing of someone who believes the treatment works.

(E-mail inquiries on health matters to: medical_notes@yahoo.com or wellbeing@mb.com.ph.)