The results from the three-year analyses showed subjects with higher dietary GI and glycaemic load and higher consumption of added sugars, starch, and non-whole/refined grains were more likely to have insomnia.
Although starches are complex carbohydrates, sources such as refined white bread and boiled potatoes have high GIs, whereas other fibre-rich sources including legumes, nuts/seeds, and yams generally have low GIs.
The study also found that increased vegetable consumption was also associated with decreased insomnia prevalence and incidence.
A plausible mechanism by which a high-GI diet may increase the risk of insomnia is through acute spikes and troughs in blood glucose.
High blood sugar from carbohydrate consumption can initially make one drowsy, helping one to fall asleep, but the compensatory hyperinsulinaemia can awaken one from sleep.
Herbal medicines that can help reduce insomnia and promote a restful sleep include Zizyphus, Passionflower, Valerian, Chamomile. Lavender and Kava.