Researchers at Deakin University found that switching from an unhealthy diet, high in sugar and processed foods, to a healthy diet, rich in veggies and protein, significantly reduced depression symptoms. What’s more, the switch to a healthier diet helped more than simply attending social support sessions. The findings suggest that, in some cases at least, improving diet is the low-hanging fruit that people with depression should try first.
“You are what you eat”
The researchers enlisted 67 subjects, men and women who were all taking antidepressants and attending psychotherapy. All subjects had an unhealthy diet at the beginning of the study, high in sugar, processed meat, and salty snacks, and low in fruits, vegetables, and dietary fiber. Half of the subjects were placed on a healthy diet, which included extra-virgin olive oil, nuts, seeds, eggs, fruits, veggies, fatty fish and grass-fed beef. The other half kept their unhealthy diets and were additionally required to join social support sessions.
Three months later, the intervention group on a healthy diet saw marked improvements in their depression symptoms, as rated by a common depression scale. The average improvement was by 11 points, and 32% of the participants had scores so low they no longer met the criteria for depression. Meanwhile, the social support group saw only 4 points of improvement, on average. Only 8% of participants achieved remission in this latter group, the scientists reported in the journal BMC Medicine.
These findings underscore the potentially life-changing impact something as relatively simple as eating more healthily can have on the human psyche. The relationship between food and mood has been receiving a lot of attention lately, and for good reason, but we’ve only scratched the surface so far
It makes a lot of sense, too. Take a moment to realize that about 95% of your serotonin — the neurotransmitter that regulates sleep and appetite, but also mediates mood and inhibits pain — is produced in the gastrointestinal tract, which, by the way, is lined with over a hundred million nerve cells.
Important nutrients affect brain chemistry, impacting mood, memory and cognitive function. What’s more, simply eating at regular intervals, regardless of the food you intake, can have a significant impact. Research carried out by the University of Illinois Extension found that eating regular meals and snacks at the same times every day helps keep your blood sugar levels steady, which also helps keep the mood steady.
Refined carbohydrates, such as sugar, are mood-boosting foods — the bad kind — and it’s wise to keep them off your grocery list. Junk food satisfies our taste buds and makes us feel better short-term, but it will probably ruin your mood in the long-run, according to researchers at the Cleveland Clinic. It’s worth mentioning that alcohol is a depressant that can also disturb sleep, so everyone should also be mindful of how much alcohol they intake.
Previously, scientists who compared “traditional” diets, such as the Mediterranean diet and the traditional Japanese diet, to a typical “Western” diet found that the risk of depression is 25% to 35% lower in those who eat a traditional diet. Such diets are rich in vegetables, fruits, unprocessed grains, and fish and seafood, with very modest amounts of lean meats and dairy. Traditional diets also completely lack processed or refined foods and sugars, present in ample amounts in the typical Western diet.
Concerning the mechanisms by which diet impacts mood, research suggests that there may be a link between inflammation and depression. A poor diet can lead to chronic low-grade inflammation, which is linked to Type 2 diabetes and Alzheimer’s disease. Healthy foods provide micronutrients like magnesium or vitamins that help the brain cope with daily stress: this may explain why simply cutting down on junk food can have such a pronounced effect on depression symptoms.
Tibi is a science journalist and co-founder of ZME Science. He writes mainly about emerging tech, physics, climate, and space. In his spare time, Tibi likes to make weird music on his computer and groom felines.