Contact: Joseph Firth, PhD
For Release: Immediately
There’s a surprising way to lift our mood during the dips of mild depression many of us have slogged through: Eat a diet loaded with healthy foods rather than “junk food”—sugar-and fat-laden products. That’s the hopeful message of a new report on 16 studies finding that programs to improve diet significantly reduce the symptoms of depression.
The researchers analyzed studies with a total of nearly 46,000 participants; all had randomly assigned people to either programs for improving diet or varied control groups that didn’t address unhealthy eating. The dietary programs covered a range from outright calorie or fat restrictions for weight loss to mostly vegetarian to even specialized diets such as vegan.
It’s the first study to take an overall look at what science has found so far on how diet-oriented programs affect mood, says lead author Joseph Firth, PhD, Senior Research Fellow at NICM Health Research Institute, Western Sydney University, and Honorary Research Fellow at the University of Manchester. The study is published online ahead of print and will appear in a forthcoming issue of Psychosomatic Medicine, journal of the American Psychosomatic Society.
Results showed that depressive symptoms improved significantly more for people who participated in healthy eating programs than for those in the control groups. However, women showed significantly greater benefits from the programs than men. Women also became significantly less anxious, but men did not. Since women have higher rates than men of mood disorders, their improvements may be more readily evident, Firth suggests. Compared to women, men also are known to rate diet as less important, and they have less nutritional knowledge. So, women may have been more likely to stick to their diet programs, Firth speculates. That also could account for women’s greater mood improvement. Lastly, there may be unknown sex differences in how food affects mood.
Junk food, packed with fat and sugar, raise the level of inflammation in our bodies. And depressed people also have higher levels of inflammation, Firth points out. So, by cutting down on unhealthy foods and lowering inflammation, depression may ease as well. This is the most likely reason for the food-mood link, he says.
Just one of the 16 studies in the review had participant with clinical depression, Firth cautions. So, the findings may not apply to people with a major mental disorder. They only apply to those of us with periodic bouts of garden-variety low mood. “But that affects most of us,” he notes, “and you don’t have to adopt extreme diets to get the positive effect.” Most programs overlapped in the specifics, typically featuring high-fiber, nutrient-dense foods with plenty of fruits and vegetables.
The findings suggest people should consider how nutrition is influencing their mental health, and clinicians should start thinking of diet as one possible way to lift mood, Firth concludes.
Study Link: : https://doi.org/10.1097/PSY.0000000000000673
The American Psychosomatic Society (APS) (http://www.psychosomatic.org), founded in 1943, is an international multidisciplinary academic society that organizes an annual scientific meeting and educational programs. Psychosomatic Medicine is its scientific journal. The membership of over 700 is composed of academic scientists and clinicians in medicine, psychiatry, epidemiology, health psychology and allied health services. The mission of the APS is “to advance and integrate the scientific study of biological, psychological, behavioral and social factors in health and disease.”