
NUMEROUS STUDIES HAVE SHOWN that the incidence of depression is
higher in the elderly. It has been suggested that this pattern is
associated with serotonin, a brain chemical that influences mood and
behavior. Normal aging is associated with a decline in serotonin
levels. At the same time, there have been many documented studies showing
that people who exercise experience less depression. These studies
suggest that exercise provides a protective effect against the development of
depression in older individuals.
A recent study published
in Medicine and Science in Sports and Exercise may help
explain the beneficial impact of exercise on depression. The researchers
measured the effect of exercise on the level of tryptophan in men aged
57-70. The amino acid tryptophan is an important precursor for the
manufacture of serotonin. The researchers surmised that serotonin levels
would be higher in elderly individuals who exercise regularly, and that is
exactly what they found based on changes in tryptophan metabolism.. There
was a corresponding increase in serotonin synthesis during exercise and
serotonin remained elevated during post-exercise recovery. This study elucidates an important reason for the positive mental benefits
derived from exercise.