Observational studies have tied eating a Mediterranean diet – plentiful in vegetables and fruits, whole grains, fish, pulses, nuts and olive oil – to a lower risk of developing depression in adults, adolescents and children.
This eating pattern has also been found to be helpful in treating depression in middle-aged adults.
Now, a study published online this month in the American Journal of Clinical Nutrition has shown that improving diet quality significantly eased depressive symptoms in young men. What’s more, mood improvements occurred within a short time frame.
About the study
The latest randomized controlled trial (called “AMMEND”) investigated whether following a Mediterranean diet would improve mood and quality of life in males, ages 18 to 25, with moderate to severe depression.
According to the Centre for Addiction and Mental Health, young people aged 15 to 24 are more likely to experience a mental health illness than any other age group.
For the 12-week trial, researchers assigned 72 participants to either a Mediterranean diet or befriending therapy (the control group). Befriending involves the researcher talking to the participant about neutral topics of interest such as hobbies, sports and movies.
Participants in the Mediterranean diet group received three 60-minute dietitian counselling sessions throughout the study. These offered personalized diet advice, goal-setting and mindful eating strategies to support adherence to the Mediterranean diet.
Diet quality, depressive symptoms and quality of life were assessed in both groups at the start of the study, halfway through and at 12 weeks. Participants were not asked to stop their depression medications or psychotherapy appointments for ethical reasons.
Mediterranean diet guidance
For the Mediterranean diet, participants were advised to eat daily servings of whole grains (5 to 8), vegetables (5+) and fruits (2+). A serving of pulses (e.g., beans, lentils) and nuts were to be included once a day, fish twice a week and extra virgin olive oil daily.
Dairy foods, eggs and chicken were also included in the diet; red meat was to be eaten no more than once a week. Consumption of sweets, fried foods, processed meats and sugary drinks were limited to three servings per week.
Participants were given an online daily food diary as well information on serving sizes, sample meal plans, recipes, dining-out options and eating-on-a-budget tips.
The latest findings
Compared to those in the befriending group, participants following the Mediterranean diet had significant improvements in both diet quality and depression, with 35 per cent reporting low to minimal depressive symptoms after 12 weeks.
Increased concentration, sleep and energy were also reported in the Mediterranean diet group.
The low dropout rate in the Mediterranean diet group suggests that, with nutrition counselling, making dietary change is very feasible for young males with clinical depression.
A limitation of this study is its short duration. It’s not known how well participants maintained their Mediterranean diets after the study ended or the effect this may have had on depressive symptoms.
Still, these findings add to growing evidence that improving diet by eating more whole fresh foods while reducing the intake of fast foods, added sugars and processed meat plays a role in the treatment of depression.
How a heathy diet may ease depression
Whole foods such as vegetables, fruits, whole grains and pulses offer nutrients and phytochemicals that reduce inflammation in the body. It’s thought that inflammatory immune cells communicate with the brain, affecting mood and energy levels.
Prebiotic fibres, found in certain whole grains, vegetables, fruits, pulses and fermented dairy products, nourish “good” gut bacteria, helping to maintain a healthy gut microbiome. Most of our brain’s serotonin, a brain chemical that regulates mood, is made by our gut microbes.
As well, omega-3 fatty acids found in oily fish are important for maintaining healthy brain cell membranes. Consuming too few of these fats may alter how brain cells respond to brain chemicals that influence mood.
According to a 2020 survey of Australian males (ages 18 to 25) with diagnosed depression, one-third perceived their diet as having a major effect on their mental health.
Most participants (84 per cent) believed it’s important or very important to eat a healthy diet. And 77 per cent said they’d be willing to change their diet if it would improve their depression symptoms.
Together with findings from the AMMEND trial, this suggests that psychologists, psychiatrists and general practitioners should consider referring young male patients with depression to a dietitian for nutrition counselling as a part of their treatment plan.
Leslie Beck, a Toronto-based private practice dietitian, is director of food and nutrition at Medcan. Follow her on Twitter @LeslieBeckRD
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