Page 159 - The Memory Program How to Prevent Memory Loss and Enhance Memory Power

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sits in the lower middle part of the brain. Descartes called the pineal gland the seat of the soul, but
we now think of it merely as the source of melatonin, which regulates sleep and is involved in
immune processes.

Melatonin for Sleep

Melatonin release from the pineal gland has a predictable twenty-four-hour cycle: an increase in the
evening is associated with drowsiness and sleep, and a decrease in the morning leads to wakefulness.
Melatonin production from the pineal gland declines steadily with age, and this produces disruption
of internal clocks and rhythms, particularly the sleep-wake cycle. Melatonin is a good hypnotic,
particularly for jet lag. I know a couple of physicians who work for the pharmaceutical industry, and
they fly an average of once a week between Europe and the United States. They are quite happy with
melatonin's effects in giving them a good six hours of sleep on the flight, and feel that it is a good
antidote for jet lag. Melatonin doses of 0.5 to 3 mg are usually sufficient to induce sleep.

Melatonin for Memory Loss

Melatonin is an antioxidant, a superb scavenger of free radicals. Melatonin boosts its own
antioxidant effect by promoting the activity of glutathione peroxidase, an enzyme that is also an
antioxidant. Relatively high doses— 3 to 20 mg daily— are taken for its antioxidant, and possible
promemory, effects. Even in this higher dose range, it has few side effects. At doses above 100 mg
daily, melatonin can do a reverse flip and cause insomnia and depression.

There have been many tall claims about the use of melatonin for a wide range of maladies, based
primarily on results from animal studies. Clinical studies have focused on its sedative action, not its
effects on memory. Its antioxidant activity suggests potential promemory effects. The lack of well-
controlled studies using melatonin to treat mild memory loss or dementia, let alone to prevent
memory loss, makes it difficult for me to recommend melatonin as a promemory agent. Also, I
wonder if the anecdotal reports of melatonin's positive effects on memory are related to its property
of inducing restful sleep and thus indirectly boosting daytime cognitive performance, rather than a
direct memory-enhancing effect.