MEDITERRANEAN DIET IMPROVES DEPRESSION

Diet matters when it comes to mental health.  Two recent trials have found that when people with severe depression follow the Mediterranean diet, they experience significant improvement in mental health.  The effects were shown to last up to 6 months.  

In the most recent randomized controlled trial to examine the effect of the Mediterranean diet on individuals with severe depression, researchers recruited 152 adults aged 18-65.  Participants were randomly assigned to the Mediterranean diet or control group. The Mediterranean diet intervention included an initial nutritional consultation, biweekly group cooking workshops, easy, inexpensive recipes, and take-home food hampers for making the recipes.  Some of the intervention group was also given fish oil but that was found not to significantly improve outcomes.  The control group attended biweekly meetings that included social activities such as board games, book clubs, and photo sharing.  Participants’ dietary intake as well as their levels of depression, anxiety, and stress were assessed at the beginning of the study and then at 3 and 6 months.

Both the intervention and control groups experienced mental health improvements, but the Mediterranean diet brought improvement to 45% of participants while 27% of the control experienced mood improvement.  The investigators also found that the Mediterranean diet was significantly associated with lower anxiety and negative affect, and better coping and overall quality of life. Earlier in the year a smaller trial found similar results.  33% of depressive individuals in the Mediterranean diet intervention were able to put their depression in remission while only 8% of the controls achieved remission.

The Mediterranean diet is based on the dietary traditions of the island of Crete in Greece circa 1950.   It is rich in fruits, vegetables, nuts, beans, whole grains, fish, and olive oil while minimizing meat, sugar, and refined flour.  In these two studies those on the Mediterranean diet consumed per day 6 servings of vegetables (serving = ½ cup cooked, 1 cup raw), 5 servings of whole grains (serving = 1/3 cup or 1 oz), 3 servings of fruit (serving = ½ cup cooked, 1 cup raw), 2 servings of unsweetened dairy (serving = 1 cup milk/ yogurt or  1 oz cheese), 1 serving of raw nuts (serving = 1 oz or ~1/3 cup), and 3 tablespoons of olive oil.  Each week they consumed 2 or more servings of fish (serving = 2oz) while limiting themselves to no more than 3 servings of lean red meat (serving = 2oz), 2 servings of chicken (serving = 2oz), and 6 eggs (serving = 1 egg).  They also were permitted no more than 3 servings per week of sweets or refined flour products. 

What to do:  The role of diet in mental health has been underappreciated in the past but it is increasingly an area interest.  Emerging research continues to elucidate how the health of the gut and its microbiome are intricately linked to our mental well being.  Besides benefiting mood, incorporating a Mediterranean eating pattern has also been found to improve cardiovascular and immune health, and lower rates of cancer, diabetes, dementia and many other chronic diseases.   Even if you are not ready to commit to all aspects of the Mediterranean diet, try more modest changes such as limiting sugary foods to a few times a week or eating 2+ cups of veggies daily.

Sources

Jacka FN, O’Neil A, Opie R et al.  A randomised controlled trial of dietary improvement for adults with major depression (the ‘SMILES’ trial).  BMC Medicine 2017 15:23. Available online at:  https://doi.org/10.1186/s12916-017-0791-y

Sarris J, Logan AC,  Akbaraly TN et al.  Nutritional medicine as mainstream in psychiatry. The Lancet Psychiatry, 2015; 2 (3): 271. Available online at: http://dx.doi.org/ 10.1016/S2215-0366(14)00051-0

Parletta N, Zarnowiecki D, Cho J, et al.  A Mediterranean dietary intervention supplemented with fish oil improves diet quality and mental health in people with depression: A randomized controlled trial (HELFIMED).  Nutritional Neuroscience 2017; 0:0. Available online at:  https://doi.org/10.1080/1028415X.2017.1411320

Adapted from articles available at:

https://www.sbs.com.au/news/mediterranean-diet-can-beat-depression-research-suggests

https://www.medscape.com/viewarticle/890506