Short-Term Dietary Change Improves Depression Symptoms

Brain-healthy nutrients found in whole foods may be key to lowering severity of depression

Researchers found that study participants experienced a significant lessening of depression as their body absorbed their new, healthier food.BalanceFormCreative/Shutterstock

Proper brain function is dependent upon good nutrition. Omega-3 fatty acids, B vitamins, and zinc are all key nutrients for brain tissue. Vitamin B12, folate, and vitamin B6 are involved in the production of neurotransmitters, and zinc has antioxidant effects in the brain. The omega-3 fatty acids DHA and EPA are important for the structure of brain cell membranes. Inadequate levels of each of these nutrients have been linked to a greater risk of depression.

Protection against oxidative stress makes plant food-derived antioxidants beneficial for the brain. Also, many phytonutrients have anti-inflammatory and other non-antioxidant functions that may also enhance brain health.

By contrast, consumption of fast food has a dose-dependent association with the likelihood of depression, and greater consumption of commercial baked goods (muffins, donuts, and so forth) is also linked to a 38 percent increase in depression risk.

Diet as a Rapid Treatment for Depression

A new study investigated whether improving the diets of young adults with symptoms of depression could improve those symptoms. Men and women aged 17 to 35 were surveyed, and those with moderate to severe depression symptoms and high sugar and saturated fat intake were invited to participate.

Half the participants were asked to follow a diet that included five servings of vegetables daily, plus whole grains, legumes, fruits, nuts and seeds, turmeric, and cinnamon. They were also instructed to reduce sugars, other refined carbohydrates, processed meats, and sweetened beverages. Lean meats, eggs, unsweetened dairy products, fish, and olive oil were also permitted. The other group was given no dietary instructions. They were just asked to continue their regular diets and return again after three weeks for follow-up.

Importantly, the researchers were able to validate that the diet change group increased their intake of phytochemical-rich vegetables and fruit by using skin spectrophotometry. This light-based measurement responds to skin “yellowness” from the level of carotenoids in the skin, which is determined by carotenoid-rich vegetable and fruit intake.

Depression Scores Improve Alongside Skin Carotenoid Scores

Before and after the dietary intervention, the participants completed surveys rating their frequency and severity of depression symptoms. Participants were contacted again by phone three months later for another survey. Depression scores decreased in the diet intervention group between baseline and three weeks but stayed the same in the control group. The improvement in depression scores improved proportionally to increases in fruit and vegetable intake measured by skin carotenoid scores. There were also improvements in measures of stress and anxiety.

After three months, about 80 percent of the diet-change group said they had maintained at least some aspects of the diet. The group’s depression scores remained similar to their scores at the three-week follow-up, which were lower than their baseline scores. Three weeks of small improvements—eating more vegetables and fruits and reducing high-glycemic refined carbohydrates and processed meats—set the participants on a course to making longer-term dietary improvements and maintaining a lower level of depression symptoms.