So-called “alkaline” water products are being promoted by their manufacturers and some health gurus as the answer to health problems ranging from indigestion to cancer. They claim that those with high body acidity are at an increased risk of osteoporosis and kidney stones, among other medical problems, and an alkaline diet can help you to lose weight, slow aging, cure arthritis and treat diabetes. But does this recent fad hold up to scientific scrutiny?  

The pH level in our blood controls the speed of our body’s critical biochemical reactions. A low pH is considered acidic, whereas a high pH is considered alkaline. Our pH varies throughout the body, but it’s the blood that must maintain a relatively stable pH level. The body works hard to ensure that the blood remains at an average pH level of about 7.4, which is on the alkaline side. If our blood becomes too acidic, calcium is removed from our bones and other tissues in order to ensure a healthy pH balance.

However, although studies have shown that eating acid-promoting foods such as meat and processed foods will raise the level of acid in our urine, there is no scientific evidence that eating or drinking alkaline products has any effect on altering our blood acidity. If our blood becomes too acidic, the excess acid is excreted via the kidneys (thus the acidic urine), and more acid in the urine just means that your kidneys are doing their job.

Tanis Fenton, an adjunct assistant professor at the University of Calgary in Alberta, has found that alkaline products have no effect on either bone health or cancer. In a study on alkalinity and bone health, published in Nutrition Journal, Fenton and a team of researchers reviewed 238 studies looking for a link between an alkaline diet and bone health, and found none. She also was involved in another study that found an alkaline diet was not effective for either the prevention or treatment of cancer.

Scientists agree that the pH of water has no effect on the acidity of the blood or of the body’s cells, so there is no need to spend money on alkaline water products. The emphasis that the alkaline diet places on eating more fruits and vegetables is a good one. However, experts warn that cutting out meat and dairy may lead to other health problems, as they are among the easiest ways of getting necessary nutrients such as protein, calcium, vitamin B12 and vitamin D. In addition, physicians warn that those who have kidney disease be wary of an alkaline diet because levels of potassium, sodium and phosphorus can build up to dangerous levels.

Ultimately, your body’s acidity or alkalinity is not what determines good health. Simply eating a wide variety of whole foods and avoiding processed foods and sugar will ensure you get the optimal health from your diet.