An old Irish proverb says, “A good laugh and a long sleep are the best cures in the doctor’s book.” But research suggests it would be wiser to think of good sleep as an ingredient of well-being — a starting point for health, not a fixer upper. Sleep is an essential building block of good health, along with quality nutrition, moderate exercise, socioeconomic connectivity, mindfulness, and ample good luck. Guidelines recommend “Seven to nine hours of good-quality sleep for adults aged 18 to 64 on a regular basis, with consistent sleep and wake times for health benefits.” For adults aged 65 and older, a slightly modified “seven to eight hours of sleep” is advised. But sleep is too often neglected — insufficient in both quantity and quality. According to a global sleep survey, 62 per cent of adults worldwide feel they don’t sleep well when they go to bed. Surveys show that North Americans, on average, sleep just under seven hours a night. Some are getting more — and good for them. Some are getting less — with serious consequences.

Poor quality sleep has harmful implications for insomniacs. The U.S. National Heart, Lung, and Blood Institute reports, “Sleep deficiency is linked to many chronic health problems, including heart disease, kidney disease, high blood pressure, diabetes, stroke, obesity, and depression.” But drowsy people have negative implications for other people too. Lack of sleep is a major factor in deadly car accidents and other transportation tragedies. Both the Chernobyl nuclear plant disaster and the Exxon Valdez oil spill involved workers affected by sleep deprivation. Although people commonly try to “catch up” on sleep during the weekend, studies have found this to be a losing strategy. For one thing, less weekday sleep equates to later nights, awake and snacking, which leads to weight gain and involves challenges in managing diabetes, for example.

It may be disappointing to learn more bad news. Research now shows that even long periods of sufficient sleep don’t make up for sleep deficits. Not getting good sleep? The damage is done. Scientists are starting to unpack exactly what kind of problems develop from lack of good sleep. One study found that consistently losing an hour and a half of sleep a night can increase the risk of inflammatory disorders and cardiovascular disease. The study, published in the Journal of Experimental Medicine, showed that sleep disruptions in both humans and mice led to the same loss in the protective effects of their immune systems “actually making infections worse.” In effect, poor sleep causes trouble in blood cell production, leading to overproduction of white blood cells that normally fight infections, but the overabundance instead results in inflammation. Another study involving more than7,000 men and women at the ages of 50, 60 and 70, found that people at age 50 getting five hours of sleep or less were “20 per cent more likely to have been diagnosed with a chronic disease and 40 per cent more likely to be diagnosed with two or more chronic diseases over 25 years, compared to people who slept for up to seven hours.” Those are big differences! Those two more hours of sleep gives the body enough time to complete one full sleep cycle, allowing brain and body to recuperate and immune systems to function effectively.

What are some tips for healthy sleep? Get natural daylight exposure. Limit alcohol before bed. Eliminate noise and light disruptions. And at bedtime, allow into the mind those things that sooth the soul. These days, that means turning off the evening news and turning instead to a good book.

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-W. Gifford-Jones, MD