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Every athlete knows that sleep is a key aspect of recovery, but how many people actually get a perfect night's sleep? According to the National Institutes of Health, about 30 percent of Americans complain of insomnia, and 10 percent have symptoms associated with insomnia. There are many possible causes, but a new study published in the American Journal of Clinical Nutrition found that there may be an unexpected culprit for some insomnia cases: a person's diet. In particular, a diet high in refined carbohydrates and added sugars could be to blame.
Researchers at Columbia University's Vagelos College of Physicians and Surgeons looked at data from more than 50,000 postmenopausal women from the Women's Health Initiative and found that those who followed a diet high in refined carbohydrates, especially added sugars, ingested, more likely to suffer from insomnia. Those who ate more vegetables, fiber, and whole fruits had fewer problems with insomnia.
It is important to note that it is not the carbohydrates in general, but the refined carbohydrates that affect sleep. Foods with a higher glycemic index – think of added sugar, white rice, or soda – cause an increase in blood sugar, and it's the rapid increase in blood sugar that researchers think is contributing to insomnia. Although fruits contain natural sugar, Gangwisch points out that the fiber they contain helps to prevent blood sugar levels from rising.
"When blood sugar levels rise rapidly, your body responds by releasing insulin," said James Gangwisch, Ph.D. and senior study author, said in a press release. "The resulting drop in blood sugar can lead to the release of hormones like adrenaline and cortisol, which can disrupt sleep," he said. Highly processed foods contain more refined sugar, which is not found in nature, and this sugar triggers blood sugar spikes.
Although the study was conducted on post-menopausal women, the authors believe that the results may apply to the general population, since most people, regardless of age or gender, notice an increase in blood sugar after consuming refined carbohydrates. That said, more research is needed to find out for sure.
"Based on our knowledge, we need randomized clinical trials to determine whether a dietary intervention aimed at increasing the consumption of whole foods and complex carbohydrates can be used to prevent and treat insomnia," said Gangwisch.