Insomnia can have a serious impact on a person’s health and well-being. Now, a study of females aged 50 and over has found that some parts of the diet most likely contribute to this sleep disorder.

Insomnia affects many people all over the world. According to the National Sleep Foundation, up to 40% of people in the United States experience some insomnia symptoms each year.

Researchers have taken due note of this, as numerous studies have suggested that insomnia is not just a mild annoyance: It may actually be linked with many other negative health outcomes.

According to the Centers for Disease Control and Prevention (CDC), short sleep duration and sleep disruptions are associated withTrusted Source cardiovascular problems, diabetes, and depression, to name a few.

For this reason, specialists have been looking for ways of preventing or treating insomnia and other sleep disorders — starting by looking for all the possible causes.

Existing research has already called attention to the fact that diet may influence a person’s sleep qualityTrusted Source. Now, a study from Columbia University Vagelos College of Physicians and Surgeons in New York City, NY, suggests that a diet high in refined carbohydrates — particularly added sugars — is linked to a higher risk of insomnia. This, at least, appears to be the case among females aged 50 and over.

The research team reports these findings in a study paper that now appears in The American Journal of Clinical NutritionTrusted Source.

“Insomnia is often treated with cognitive behavioral therapy or medications, but these can be expensive or carry side effects,” explains senior study author James Gangwisch, Ph.D.

But, he adds, “[b]y identifying other factors that lead to insomnia, we may find straightforward and low cost interventions with fewer potential side effects.”

The possible underlying mechanism

The researchers worked with the data of 53,069 female participants aged 50–79, all of whom had enrolled in the Women’s Health Initiative Observational Study between September 1994 and December 1998.

To understand whether or not there really is a link between dietary choices and the risk of insomnia, the investigators looked for any associations between different diets and sleep disruptions.

Gangwisch and colleagues found a link between a higher risk of insomnia and a diet rich in refined carbohydrates. This includes foods with added sugars, soda, white rice, and white bread.

The researchers caution that it was unclear from their analysis whether the consumption of refined carbohydrates led to insomnia, or that people who experienced insomnia were more likely to consume refined carbs, especially sugary foods.

However, they do note that there is a possible underlying mechanism that might explain added sugars causing sleep disruptions.

“When blood sugar is raised quickly, your body reacts by releasing insulin, and the resulting drop in blood sugar can lead to the release of hormones such as adrenaline and cortisol, which can interfere with sleep,” Gangwisch explains.

Why fruit will not impact sleep

The study authors also explain why not all foods that contain sugar will lead to the same effect. Fruits and vegetables — which naturally contain sugar — are unlikely to raise blood sugar levels nearly as quickly as foods containing added sugars.

This is because these natural foods are also high in fiber, which means that the body absorbs the sugar more slowly, preventing a spike in blood sugar levels.

Indeed, the female participants who had diets rich in vegetables and whole fruits — but not fruit juices — did not have an increased risk of insomnia.

“Whole fruits contain sugar, but the fiber in them slow the rate of absorption to help prevent spikes in blood sugar,” says Gangwisch.

“This suggests that the dietary culprit triggering the women’s insomnia was the highly processed foods that contain larger amounts of refined sugars that aren’t found naturally in food.”

James Gangwisch, Ph.D.

The researchers only worked with females aged 50 and over, but they believe that the findings could also apply to males and people of other ages. Going forward, they argue that this idea is worth exploring in more detailed studies.

“Based on our findings, we would need randomized clinical trials to determine if a dietary intervention, focused on increasing the consumption of whole foods and complex carbohydrates, could be used to prevent and treat insomnia,” concludes Gangwisch.