Health benefits of SLEEP

The importance of sleep

Researchers looked at how lack of sleep may affect the immune system. Chronic sleeplessness may harm the immune system, since lack of sleep is linked to an increase in cytokine molecules that control immune response.

The resulting inflammation and changes in blood chemistry may be behind a variety of diseases, such as heart disease, diabetes and neurological conditions.

"The foundations of good health are good diet, good exercise and good sleep, but two out of three doesn't get you there," said Dr. Anne Calhoun, a neurology professor at the University of North Carolina.

Sleep is important in maintaining your health, say experts. Without it, you become more susceptible to health problems, such as heart disease, stroke, diabetes, obesity and depression.


One study on more than 1,400 middle-aged adults over four years found those with sleep apnea, in which the airway becomes repeatedly blocked and sleep is interrupted, were twice as likely to develop depression.
Physicians treating people for depression should address poor sleep habits, Zee said.
A French study of nearly 600 people found a higher rate of sleep problems and daytime sleepiness among allergy sufferers, compared with a controlled group of people of the same age and sex who lived in the same area.
"The results show a significant impact of allergic rhinitis on all dimensions of sleep quality and, consequently, a lower quality of life as reflected by more somnolence [sleepiness], daytime fatigue and sleepiness, and impaired memory, mood and sexuality," Dr. Damien Léger of Assistance Publique Hôpitaux de Paris and colleagues wrote.

In the same issue of Archives of Internal Medicine, other studies concluded that men with diabetes and men with short or poor-quality sleep tended to have less control of their blood-sugar levels.

Skimping on sleep increases hunger


In 2004, researchers at the University of Chicago discovered that sleep loss could reduce the body's ability to regulate hormones that control hunger. This could lead to an increase in appetite and a preference for high-carbohydrate foods.


Research subjects who slept only four hours a night for two nights had an 18 per cent decrease in leptin, a hormone that tells the brain there is no need for more food, and a 28 per cent increase in ghrelin, a hormone that triggers hunger. "It provides biochemical evidence connecting the trend toward chronic sleep curtailment to obesity and its consequences, including metabolic syndrome and diabetes," said Eve Van Cauter, professor of medicine at the University of Chicago, in a press release.


As hunger increased in the research subjects, their food choices changed. After two nights of diminished sleep, the volunteers found foods such as candy, cookies and cake far more appealing than fruit, vegetables or dairy products.


"We don't yet know why food choice would shift," Van Cauter said. "Since the brain is fuelled by glucose, we suspect it seeks simple carbohydrates when distressed by lack of sleep."


Modern society seems to have forgotten the importance of sleep, according to Van Cauter.



"We are all under pressure to perform, in school, at work, in social and professional settings, and tempted by multiple diversions. There is a sense that you can pack in more of life by skimping on sleep. But we are finding that people tend to replace reduced sleep with added calories, and that's not a healthy trade."


Another study, presented at a conference sponsored by the American Academy of Sleep Medicine on June 11, 2007, suggested that people who don't get enough sleep are less likely to cook their own meals — and more likely to rely on restaurants and fast-food outlets for some of their meals. The study suggested that that could lead to weight gain or other nutrition-related problems. How much sleep is enough?


Experts say the amount of sleep varies from person to person. In general, most adults need about seven hours of sleep per night. Children and adolescents need even more — around nine or 10 hours each night.