According to the results of a 2008 study, an alkaline diet rich in potassium - such as fruits and vegetables - along with a reduced acid load helps to increase muscle mass in men and women as they age.

There has been a significant change from pre-agricultural human civilization to the present when it comes to net acid load in our diet. A typical modern diet is likely to induce so-called ‘metabolic acidosis’, especially with aging.

Health experts believe metabolic acidosis leads to muscle wasting. Diets rich in net acid-producing protein and cereal grains relative to their content of net alkali-producing fruit and vegetables are likely to contribute to a reduction in lean tissue mass in older adults with age.

In fact, health conditions such as chronic renal failure that result in chronic metabolic acidosis have been shown to lead to an accelerated breakdown of skeletal muscle in patients.

The authors of the 2008 study looked at whether there was an association between levels of urinary potassium and the fruit and vegetable content of the diet with the percentage lean body mass (LBM) or change in percentage LBM in older subjects.

A total of 384 men and women 65 years or older participated in the 3-year trial. Along with urinary levels of potassium, percentage LBM was measured before the start of the study and then 3 years later - as was physical activity and the height and weight of every participant.

At the end of the study, percentage LBM was higher in the overall study population. Levels of urinary potassium were positively associated with percentage LBM before the start of the study, but not with the change in percentage LBM after 3 years.

In other words, increased intake of fruit and vegetables - known to be alkalizing foods - can help to preserve, even increase muscle mass in men and women as they age.

Health experts believe that correction of acidosis may also help to preserve muscle mass in conditions in which muscle wasting is common, such as diabetic ketosis, trauma, sepsis, chronic obstructive lung disease and renal failure.