Plant Foods for Preserving Muscle Mass
By Rosalie Marion Bliss
May 23, 2008
Fruits and vegetables contain essential vitamins, minerals and fiber
that are key to good health. Now, a newly released study by
Agricultural Research Service (ARS)-funded scientists suggests plant foods also may help preserve muscle mass in older men and women.
The study was led by physician and nutrition specialist Bess Dawson-Hughes at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University in Boston, Mass.
The typical American diet is rich in protein, cereal grains and
other acid-producing foods. In general, such diets generate tiny
amounts of acid each day. With aging, a mild but slowly increasing
metabolic "acidosis" develops, according to the researchers.
Acidosis appears to trigger a muscle-wasting response. So the
researchers looked at links between measures of lean body mass and
diets relatively high in potassium-rich, alkaline-residue producing
fruits and vegetables. Such diets could help neutralize acidosis. Foods
can be considered alkaline or acidic based on the residues they produce
in the body, rather than whether they are alkaline or acidic
themselves. For example, acidic grapefruits are metabolized to alkaline
residues.
The researchers conducted a cross-sectional analysis on a subset of
nearly 400 male and female volunteers aged 65 or older who had
completed a three-year osteoporosis intervention trial. The volunteers'
physical activity, height and weight, and percentage of lean body mass
were measured at the start of the study and at three years. Their
urinary potassium was measured at the start of the study, and their
dietary data was collected at 18 months.
Based on regression models, volunteers whose diets were rich in
potassium could expect to have 3.6 more pounds of lean tissue mass than
volunteers with half the higher potassium intake. That almost offsets
the 4.4 pounds of lean tissue that is typically lost in a decade in
healthy men and women aged 65 and above, according to authors. The
study was published in the March issue of the American Journal of Clinical Nutrition.
Sarcopenia, or loss of muscle mass, can lead to falls due to
weakened leg muscles. The authors encourage future studies that look
into the effects of increasing overall intake of foods that metabolize
to alkaline residues on muscle mass and functionality.
Source: U.S. Department of Agriculture, Agricultural Research Service
Article abstract: Dawson-Hughes,
B., Harris, S S, and Ceglia, L. 2008.
Alkaline diets favor lean tissue mass in older adults.
American Journal of Clinical Nutrition,
87: 662 - 665.
|
