Healthy telomerized old skin cells become young skin in laboratory cell-culture experiments. Impaired gene expression caused by gradual loss of telomers with age is now thought to be more important than total loss of telomers. Increased anti-oxidant protection is therefore needed with aging to protect cell constituents. Many research studies show that victims of coronary artery and cardiovascular disease produce less melatonin. Testosterone improves mood and psychological symptoms more than estrogen.
Progesterone helps slow-wave sleep.
Cortisone increases with age. The age-related changes in both of those hormones add to undesirable symptoms of aging. In a lifetime, we eat 50 million calories and 36,000 pounds of food. But on the average, we gain only 50 pounds. It's a very fine balance.