Melatonin
If there is a “biological clock” that governs the decline in hormone production, then melatonin may be the loudest "tick". Melatonin is produced in the pineal gland at the center of the brain. This gland receives direct input from the eyes so that it knows when it is daytime and nighttime; therefore, it can regulate sleep and wake cycles. Melatonin is released in spurts at night to initiate sleep; because of this by taking it in a pill at bedtime it can be effective in resetting the clock of a person who changes time zones, thereby alleviating “jet lag.”
To test the theory that the pineal gland controls aging and the rhythms of our lives, Walter Pierpaoli, MD, PhD, in Italy transplanted the pineal glands of old mice into young mice and caused them to age much faster. When he did the reverse experiment, he caused rejuvenation of old mice. Finally, he has shown that by supplementing their diet with melatonin, mice can live up to 25 % longer. These studies have not been done in humans, for obvious reasons, but large doses of melatonin have been given to breast cancer patients without any significant side effects.
It is well documented that many humans produce less and less melatonin as they age. By age 60, many people produce less than 50 % of the melatonin they did at 20. Melatonin is also a strong anti-oxidant and cancer fighter (it has been shown that solid tumors partially regress with melatonin treatment). Because of these benefits and its safety in even very high doses, we often test for melatonin levels and usually recommend that patients take melatonin regularly at bedtime and increase dose as they get older to help with sleep.
Women who are trying to get pregnant or are breastfeeding should avoid melatonin: safety studies haven't been perfomed.
