Refined
carbs may trigger insomnia, finds study
Columbia University Irving Medical
Center
An estimated 30% of adults
experience insomnia, and a new study by researchers at Columbia University
Vagelos College of Physicians and Surgeons suggests that diet may be partly to
blame.
The study found that postmenopausal
women who consumed a diet high in refined carbohydrates -- particularly added
sugars -- were more likely to develop insomnia.
Women whose diet included higher
amounts of vegetables, fiber, and whole fruit (not juice) were less likely to
develop problems with insomnia.
"Insomnia is often treated with
cognitive behavioral therapy or medications, but these can be expensive or
carry side effects," says the study's senior author James Gangwisch, PhD,
assistant professor at Columbia University Vagelos College of Physicians and
Surgeons.
"By identifying other factors
that lead to insomnia, we may find straightforward and low-cost interventions
with fewer potential side effects."
Link Between Diet and Sleep Is an
Emerging Research Area
Previous studies have explored a
possible link between refined carbohydrates and insomnia, but results have been
inconsistent. And because the studies didn't follow individuals over time, it's
not clear if a diet that's high in refined carbs triggered the onset of
insomnia, or if insomnia caused individuals to eat more sweets.
One way to determine if carb intake
is causing sleep problems is to look for the emergence of insomnia in people
with different diets.
In the current study, Gangwisch and
his team gathered data from more than 50,000 participants in the Women's Health
Initiative who had completed food diaries. The researchers looked at whether
women with higher dietary glycemic index were more likely to develop insomnia.
All Carbs Aren't Created Equally
Different kinds and amounts of
carbohydrates increase blood sugar levels to varying degrees. Highly refined
carbohydrates -- such as added sugars, white bread, white rice, and soda --
have a higher glycemic index, and cause a more rapid increase in blood sugar.
"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 says.
The researchers hypothesized that
the rapid spikes and troughs in blood sugar after eating refined carbs may
trigger insomnia.
Refined Carbs Triggered Insomnia
They found that the higher the
dietary glycemic index -- particularly when fueled by the consumption of added
sugars and processed grains -- the greater the risk of developing insomnia.
They also discovered that women who consumed more vegetables and whole fruits
(not juices) were less likely to develop 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."
Since most people, not just postmenopausal
women, experience a rapid rise in blood sugar after eating refined
carbohydrates, the authors suspect that these findings may also hold true in a
broader population.
"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," says Gangwisch.
