High dietary GI ups risk of insomnia in postmenopausal women

A diet with high glycaemic index (GI) may lead to insomnia among postmenopausal women, suggests a recent study.

Cross-sectional and longitudinal analyses revealed an association between higher dietary GI and an increased risk for prevalent (fifth vs first quintile odds ratio [OR], 1.11, 95 percent confidence interval [CI], 1.05–1.16; p_trend=0.0014) and incident (fifth vs first quintile OR, 1.16, 95 percent CI, 1.08–1.25; p_trend<0.0001) insomnia in fully adjusted models.

Moreover, increased consumption of dietary added sugars, starch and nonwhole/refined grains independently correlated with a higher risk of incident insomnia. On the other hand, higher intake of nonjuice fruit and vegetables significantly correlated with a reduced risk of incident insomnia.

Higher intakes of dietary fibre, whole grains, nonjuice fruit and vegetables also resulted in a significant reduction in prevalent insomnia risk.

“Substitution of high-GI foods with minimally processed, whole, fibre-rich carbohydrates should be evaluated as potential treatments of, and primary preventive measures for, insomnia in postmenopausal women,” the authors said.

This prospective cohort study involved postmenopausal women who participated in the Women’s Health Initiative Observation Study. The authors examined the associations of GI, glycaemic load, other carbohydrate measures (ie, added sugars, starch, total carbohydrate), dietary fibre, and specific carbohydrate-containing foods (ie, whole grains, nonwhole/refined grains, nonjuice fruits, vegetables, dairy products) with the risk of insomnia at baseline and after 3 years of follow-up.

“Previous studies have shown mixed results on the association between carbohydrate intake and insomnia,” the authors said. “However, any influence that refined carbohydrates have on risk of insomnia is likely commensurate with their relative contribution to the overall diet, so studies are needed that measure overall dietary GI, glycaemic load and intakes of specific types of carbohydrates.”