Maintaining an Acid-Alkaline Balance

When I first heard, years ago, that acidic foods could somehow contribute to disease, I thought the idea was pretty far fetched. It struck me as a particularly odd prohibition against eating certain foods.

Recently, I became a believer. It turns out that acid and alkaline foods do have a bearing on health, but that the science has often been misunderstood or misrepresented. (See the article that follows.) The body functions best at a neutral or slightly alkaline pH. The problem has nothing to do with whether foods are acidic or alkaline per se. Rather, it’s about whether foods have an acid or alkaline effect after digestion and when they reach the kidneys.

Because the body strives to maintain a neutral pH, acid-yielding foods trigger the release of calcium and magnesium from bone and ammonia from the protein in muscles. The calcium, magnesium, and ammonia neutralize the acid, but they do so at a serious price: both bones and muscles weaken, over the long term setting the stage of osteoporosis and age-related loss of muscle mass and strength.

The principal acid-generating foods are animal proteins, grains, dairy products, and any food with a lot of added salt. The salt yields both sodium and chloride, which shift the body toward an acidic pH. Large amounts of animal protein release sulfuric acid through the metabolism of sulfur-containing amino acids, also contributing to an acidic pH.

Potassium bicarbonate, which is sold by prescription, can reduce acidity. Some other mineral supplements, such as those in citrate and carbonate forms, can also reduce acidity.

But the biggest alkaline effect comes from eating lots of fruits and vegetables. Even citrus fruits and tomatoes, which are acidic, have a net alkaline yield. That's because fruits and vegetables are rich in potassium and bicarbonate, both of which produce an alkaline pH. Eating 35 percent of your calories as fruits and vegetables is enough to maintain alkalinity – and help preserve your bones and muscle.

And Speaking of Acid-Alkaline Balance…

A lack of magnesium and calcium can contribute to many serious health problems including arrhythmias, osteoporosis, migraine, and fatal heart attack. The body’s levels of these essential minerals are strongly influenced by dietary levels – and by whether the overall diet produces an acid or alkaline load.

Ragnar Rylander, PhD, Thomas Remer, PhD, and their colleagues at the University of Goteborg, Sweden, studied 85 men and women, most in their sixties. The researchers measured the subject’s urine levels of magnesium, calcium, potassium, and acidity over 24 hours.

Rylander and Remer found that both magnesium and calcium losses in the urine were highest when urine was the most acidic. The loss of magnesium was not influenced by magnesium intake.

“Magnesium deficiency could thus, apart from insufficient intake, partly be caused by the acid load in the body,” wrote the researchers.

They also noted that “the Western diet induces a chronic low-grade metabolic acidosis.” Reference: Rylander R, Remer T, Berkemeyer S, et al. Acid-base status affects renal magnesium losses in healthy, elderly persons. Journal of Nutrition, 2006;136:2374-2377.