Mediterranean Diet May Prevent and Treat Symptoms of Depression

October is Depression and Mental Health Awareness and Screening Month. This observance works to raise awareness for mental screenings and treatment.

Olive oil has shown promise with regard to the prevention and treatment of depression and anxiety. The human brain is 60% fat by weight. Nutritional psychiatrists are studying the role that consuming healthy fats have in developing healthy brain function. Here is a summary of studies showing the link between olive oil consumption and a reduction in symptoms of depression. 

• At Macquarie University in Australia, researchers found that young adults with depression who followed a Mediterranean-style diet (containing vegetables, fruit, whole grains, fish, lean meats, tofu, beans, and about 2 tablespoons of extra virgin olive oil per day) reduced depression symptoms to a “normal” range after just 3 weeks, along with stress and anxiety. [1]
• Another Australian study, the SMILES Trial from 2017, showed that a 12-week Mediterranean diet intervention resulted in around 30% of participants going into remission for their depression.[2]
•  “The SUN Project” assessed the association between the Mediterranean diet and clinical depression in Spain. Adherents to the Mediterranean diet experienced more than a 30% reduction in depression risk. [3]
• The 2022 AMMEND study was a 12-week randomized control trial where the Mediterranean diet was studied as a treatment for depressive symptoms in young men (aged 18-25).  The intervention was found to "significantly" improve symptoms.[4]
  “It suggests that medical doctors and psychologists should consider referring depressed young men to a nutritionist or dietitian as an important component of treating clinical depression,”  - Lead researcher Jessica Bayes, a Ph.D. candidate in the UTS Faculty of Health at the University of Technology Sydney
• Data from the PREDIMED study showed that eating a Mediterranean diet not only protected participants’ cardiovascular health but also reduced the prevalence of depressive symptoms. Research from this study also highlighted an unintended benefit in improving participants’ sleep[5]

The reasons why the Mediterranean Diet is associated with positive mental health outcomes are still being studied. But researchers think that one factor could be the impact that the MD has on gut microbiota.  It is well established that the foods that are commonly eaten in the Mediterranean Diet such as fruit, vegetables, legumes, olive oil, and whole grains lead to gut microbe diversity in the colon which in turn, results in improved cognitive function and mental health. [6]

Last but not least, the nutrients in olive oil, particularly extra virgin olive oil, may have a significant impact on mental health. More than 30 phenolic compounds, which are strong antioxidants and free radical scavengers, are found in olive oil. It is a large source of vitamins E and K, which have been shown to have positive effects on brain health. Brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF), two important brain chemicals, have been reported to increase in concentration when olive oil is consumed[7,8]. Additionally, acetylcholine, a neurotransmitter involved in memory and learning, is increased by monounsaturated fats, such as those present in olive oil.

This content is provided for informational purposes only and is not intended to be a substitute for professional advice, diagnosis, or treatment. Always seek the advice of a qualified health provider.

If you are in crisis or you think you may have an emergency, call your doctor or 911 immediately. If you're having suicidal thoughts, call 1-800-273-TALK (8255) to talk to a skilled, trained counselor at a crisis center in your area at any time (National Suicide Prevention Lifeline). If you are located outside the United States, call your local emergency line immediately.

[1] A brief diet intervention can reduce symptoms of depression in young adults – A randomised controlled trial

[2] A randomised controlled trial of dietary improvement for adults with major depression (the ‘SMILES’ trial)

[3] Association of the Mediterranean Dietary Pattern With the Incidence of Depression

[4] The effect of a Mediterranean diet on the symptoms of depression in young males (the “AMMEND: A Mediterranean Diet in MEN with Depression” study): a randomized controlled trial

[5] Mediterranean dietary pattern and depression: the PREDIMED randomized trial

[6] Gut microbiome-Mediterranean diet interactions in improving host health

[7] The effect of the Mediterranean diet on plasma brain-derived neurotrophic factor (BDNF) levels: the PREDIMED-NAVARRA randomized trial

[8] Effects of olive polyphenols administration on nerve growth factor and brain-derived neurotrophic factor in the mouse brain