Researchers from Columbia University Medical Center in New York have determined that a diet high in refined carbohydrates increases the risk of depression in postmenopausal women by 22 percent—and 23 percent if you factor in added sugars.
They examined the health data for roughly 70,000 women between the ages of 50 and 79, compiled as part of the National Institutes of Health Women’s Health Initiative Observational Study. By focusing on glycemic index scores and comparing them to diet as well as rates of depression, researchers discovered that eating a lot of highly refined carbs and added sugars (like those found in white bread, white rice, snack foods and sugary drinks) increases the risk for depression later in life.
Glycemic index, or GI, measures the amount of sugar in the bloodstream after eating. Study authors explain that in addition to triggering a sharp rise in blood sugar (and, as a result, elevated GI scores) highly refined carbohydrates cause a hormonal response in the body that results in mood changes, fatigue and other symptoms of depression. In previous studies, a diet high in refined carbs and sugars has been linked to increased inflammation, which is also a risk factor for depression.
On a positive note, researchers observed that women who ate more dietary fiber—especially in the form of vegetables, fruits, and whole grains—and who avoided sugary beverages were less likely to develop depression after menopause, suggesting that dietary changes may play an important role in the prevention and treatment of depressive disorders.