Archive | Sleep Duration and Health

More Sleep Does Not Improve Glucose Metabolism and Reduce Obesity Risk

Widely publicized claims have linked sleep loss to weight gain and diabetes risk due to impaired glucose metabolism. However, many studies have failed to replicate these findings, and massive epidemiologic evidence demonstrates a U-shaped relationship between sleep duration and obesity: long sleep and short sleep are equally associated with obesity. These studies, in conjunction with…

Some Animals, Like Humans, Need Very Little Sleep

Most scientists say sleep is so important that every animal needs it. Yet, according to a new study, some fruit flies (which are often used to study sleep and circadian rhythms) almost never sleep. This suggests that, in some animals, sleep may not be all that necessary or important. This may be because sleep is…

Long Sleep Associated Again With Greater Mortality Than Short Sleep

Two recent 2017 and 2018 meta-analyses found that both short and long sleep were significantly related to increased mortality and morbidity. However, using 65 years of age as a cut off, both studies found increased mortality among individuals with long sleep, but no significant association between short sleep and mortality. In a new study on…

Long Sleep Duration is Associated with Increased Cardiovascular Risk

New research published in the Journal of the American Heart Association from the United Kingdom has found that long sleep duration is associated with an increased risk of cardiovascular disease while short sleep duration was not. Led by researchers from Keele University, along with colleagues at the University of Manchester, the University of Leeds and…

Sleep Loss Does Not Lead to Overeating and Obesity

Widely publicized claims have linked sleep loss to weight gain and obesity. These claims are based primarily on two very small studies conducted by the same researchers on young male adults. They found that, compared to sleeping nine hours a night for one week, sleeping just under four hours a night for a week was…

Long Sleep Duration, But Not Short Sleep Duration, Predicts Mortality Risk

Recently, the largest meta-analysis to date on sleep duration and mortality risk, involving 35 published studies and over 1.5 million adults, found that the increased risk of death associated with sleeping more than 7 hours was significantly greater than the risk of sleeping less than 7 hours. Regarding short sleep and mortality risk, previous studies…

The Human Brain May Be Designed for Seven Hours of Sleep

New research suggests that seven hours of sleep is associated with: 1. the lowest mortality risk while longer sleep is associated with greater mortality risk than shorter sleep; and, 2. peak cognitive performance for individuals between the ages of 15-75. In a study published in a February, 2016 issue of Nature, the world’s most cited…

The Eight Hour Sleep Myth

The eight hour sleep myth has been perpetuated by some sleep scientists, pharmaceutical companies that fund those scientists, and organizations such as the National Sleep Foundation that are heavily funded by pharmaceutical companies. This myth was the focus of a historic symposium at the 2016 annual national sleep meetings (the Associated Professional Sleep Societies). The…