Less acid, more bone.

Eating a diet that makes you excrete less acid may help preserve bone.

Researchers randomly assigned 171 men and women over age 50 to take potassium bicarbonate (6,750 mg a day), sodium bicarbonate (5,670 mg a day), potassium chloride (5,030 mg a day), or a placebo. Each participant also took 600 mg of calcium (as calcium phosphate), 50 mg of magnesium, 125 IU of vitamin D, and a multivitamin with another 400 IU of vitamin D.

After three months, the potassium or sodium bicarbonate takers excreted less acid and less calcium in their urine and had lower levels of a marker of bone loss.

What to do: Eat more fruits and vegetables, which make your urine less acidic. (Grains and proteins, on the other hand, make your body produce acid.) Taking a calcium carbonate or calcium citrate supplement could also neutralize acid excretion.

J. Clin. Endocrinol. Metab. 94: 96, 2009.