Recent studies at the Agricultural Research Service (ARS) have found that fruits and vegetables contain alkali-producing compounds that neutralize acids in the body. This appears to protect bones and muscles. A new ARS study now suggests that, in addition to the benefits of fruits and vegetables, it may also be important to reduce the amount of acid that is created through the breakdown of dietary protein.
Strong, dense bones depend on more than high calcium foods. Keeping bones strong also means protecting against bone loss by neutralizing acids in the bloodstream. Diets high in protein and low in fruits and vegetables produce a mildly acidic condition called “acidosis” with aging. The body is not able to adequately neutralize the acids, so calcium (with its alkaline pH) is pulled out of bones to do the job. While balance is regained in the blood, the bones suffer, and it appears that muscle loss is greater as well.
Researchers did a study of healthy people over the age of 50 on a controlled diet. Two randomly-selected groups were given either a placebo or potassium bicarbonate capsules designed to mimic the alkali-producing effect of 14 servings of fruits and vegetables. All participants were then given a 10 day low protein diet followed by a 10 day high protein diet, or vis versa, with a five-day wash out period in between. Blood, urine, and calcium absorption were analyzed after each diet phase, and muscle and bone metabolism were measured.
With the higher protein diet, the potassium bicarbonate (alkalinized) group showed less muscle wasting than the placebo group, indicating a protective effect against the acid-producing effect of the diet. On both diets, markers for muscle and bone conservation indicated that the alkalinized group also conserved more bone and muscle when compared with those taking the placebo.
The study suggests that the healthiest way to maximize the muscle-building effect of adequate protein intake is to eat plenty of fruits and vegetables. Their acid-neutalizing effect will minimize muscle wasting, causing a more positive net muscle balance. Eating lots of extra protein does not appear to be helpful for building muscle. The excess will just be eliminated and the additional acid load caused by its breakdown is linked to bone calcium losses and muscle wasting. If you needed another reason to eat more fruits and vegetables, now you have it!