Texas University-Prof Russell Reiter, who led the research, said: 'Once you go to bed you should not even switch the light on for a minute. Your brain immediately recognises the light as day and lower melatonin levels.' Scientists have found the body needs darkness to produce a chemical that fights cancer.
Someone who sleep with the light on could risk leukaemia. Leukaemia is a cancer of the blood-forming cells, which are made in the bone marrow. Leukaemia causes large numbers of white blood cells to be produced. This can crowd the bone marrow and may affect the production of normal cells. A person with leukaemia may be more likely to pick up infections and have trouble getting rid of them.
Lower levels of melatonin may be associated with breast cancer risk, prostate cancer. Melatonin may help elderly people with insomnia and help with sleep problems associated with menopause.
Melatonin is a hormone secreted by the pineal gland in the brain. It helps regulate other hormones and maintains the body's circadian rhythm. The circadian rhythm is an internal 24-hour “clock” that plays a critical role in when we fall asleep and when we wake up. When it is dark, your body produces more melatonin. When it is light, the production of melatonin drops. Being exposed to bright lights in the evening or too little light during the day can disrupt the body' s normal melatonin cycles. For example, jet lag, shift work, and poor vision can disrupt melatonin cycles. Even switching the light on for the toilet, staying up late, travelling across time zones, or the light from street lamps can stop enough melatonin being made. Production of melatonin which normally happens between 9pm and 8am.
Melatonin also helps control the timing and release of female reproductive hormones. It helps determine when a woman starts to menstruate, the frequency and duration of menstrual cycles, and when a woman stops menstruating (menopause).
Some researchers also believe that melatonin levels may be related to aging. For example, young children have the highest levels of nighttime melatonin. Researchers believe these levels drop as we age. Some people think lower levels of melatonin may explain why some older adults have sleep problems and tend to go to bed and wake up earlier than when they were younger. However, newer research calls this theory into question.
Melatonin has strong antioxidant effects. Preliminary evidence suggests that it may help strengthen the immune system.
by Steven D. Ehrlich