By Dr. Laura Pawlak
Based on the fact that about two-thirds of the body is composed of water, it seems obvious that consuming water is important for health. Water requirements have been studied for decades. Recommendations are narrowed to two alternatives: Consume a minimum of eight cups of liquid per day or drink to quench thirst.
Research now reveals that drinking water when feeling thirsty boosts the brain’s performance in mental tests. Dr. Caroline Edmonds, the author of a lead study, found that reaction times were faster after people drank water, particularly if they were thirsty before drinking.
Drinking more water than normally consumed is associated with a reduced intake of calories and sodium. The study, led by Prof. Ruopeng An, showed that people who increased their consumption of plain water by one to three cups daily lowered total energy intake by 68-205 calories each day and their sodium intake by 78-235 grams per day.
A popular trend these days, alkaline water is promoted as a healthier choice than plain water. Several brands of alkaline water are available or machines can be purchased that make alkaline water.
Proponents claim that alkaline water kills cancer cells, banishes belly fat, lubricates joints, protects bone density, reduces acid reflux, and improves hydration. What scientific evidence lies behind these claims? Despite the promotion of alkaline water by the manufacturers of the product and by the media, there is very little research either to support or disprove the claims.
The pH of water is neutral, a pH of 7. Chemicals and gases can alter the pH of water. For example, rainwater’s pH is slightly below 7, as carbon dioxide in the air dissolves in the water and increases acidity.
Water that is too alkaline (pH above 7) has a bitter taste. It can cause deposits that encrust pipes and appliances. Highly acidic water tastes sour and may corrode metals or even dissolve them. Fortunately, as the kidneys filter blood, the pH of blood and all cells are rebalanced close to neutral, avoiding any unhealthy effect of liquids or foods that raise or lower pH.
Citrus fruits are named for their citric acid content, but don’t be fooled by that fact. Citrons, lemons, limes, oranges, and grapefruits — all citrus fruits — produce alkaline byproducts once digested. So, you can squeeze juice from a lemon or other citrus into plain water and make your own alkaline water. Enjoy!
Dr. Laura Pawlak (Ph.D., R.D. emerita) is a world-renowned biochemist and dietitian emerita. She is the author of many scientific publications and has written such best-selling books as “The Hungry Brain,” “Life Without Diets,” and “Stop Gaining Weight.” On the subjects of nutrition and brain science, she gives talks internationally.