Hormones and Aging

Another hormone that greatly influences human behavior and development
is human growth hormone (HGH). This hormone is produced by the
anterior pituitary (adenohypophysis) gland under the control of the hypothalamus.
HGH production peaks during adolescence, corresponding to
the growth spurt. While it is produced throughout life, it declines with age
in all species studied to date. In humans, HGH production tends to drop
quickly beginning in the thirties so that by age sixty,HGHproduction is only
about 25 percent of what it was earlier in life, and it continues to decline until
death. The decrease in HGH production with age has been tied to thinning
of skin and wrinkle formation, muscle wasting, sleep problems, cognitive
and mood changes, decreased cardiac and kidney function, lessening of
sexual performance, and weakening of bones, contributing to osteoporosis.
Nutritional supplements including the amino acids arginine, lysine, and
glutamine are being investigated as growth hormone releasers, thought to
decrease signs of aging. Their use remains controversial.