Melatonin is a naturally occurring hormone produced by the pineal gland deep within the hypothalamus of the brain. This gland controls the release of melatonin through circadian response. In other words, it controls our biological clocks based on a 24-hour period. Melatonin secretion is stimulated by lower levels of light exposure, like sundown. Melatonin levels increase at night and begin to subside between 2 a.m. to 4 a.m. What seems to be responsible for triggering the release of melatonin is a set of photoreceptors within the eyes. There are inconclusive reports that children appear to produce higher levels of melatonin than older adults, which may explain why young people have less sleep problems than the elderly. Maybe this is why melatonin is presumed to be such a wonderful sleep aid. But how can melatonin deter the aging process? Could those assertions also be based on the same reports?
Consider the claims of melatonin as an immune system enhancer and antioxidant. These effects are being studied since it has been promoted as a multifaceted free radical scavenger. According to Dr. J.R. Reiter, et al. [1], not only is it thought to be an antioxidant itself, it also catalyzes other detoxifying enzymes within the body while inhibiting the prooxidative enzyme, nitric oxide synthase. These actions overall enhance the antioxidant effect. In a nutshell, melatonin turns on the good stuff and tuns off the bad stuff.
In regards to cancer studies, melatonin appears to subdue cancer growth by inhibiting the cancer's uptake of lineolic acid. Lineolic acid happens to be an essential polyunsaturated fatty acid that our bodies require, but seems to promote the cancer growth process [2]. Manufacturers of melatonin make many medical claims on the basis of these isolated studies but research is far from the extensive understanding that's required. Before the medical world can embrace this hormone as an approved drug, risks and side effects must be elucidated. Lack of information includes bioavailability, melatonin receptors and their sites, amongst other various aspects.
