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The World Health Organization (WHO) estimates that depression affects about 5.7% of adults over the age of 60 and it is more common among women than men. New research suggests that following a Mediterranean diet is associated with a reduction of depression in older women. Depressive symptoms were more common in older women that live alone, are unmarried, take more medications and have overall poorer health outcomes.

“…women most closely adhering to a Mediterranean diet were around 60% less likely to experience depression.”

A new study published in the British Journal of Nutrition finds that women most closely adhering to a Mediterranean diet were around 60% less likely to experience depression. This effect was not observed in men. The study looked at an Italian cohort of older men (325) and women (473) aged 65-97 years old. Each participant was asked to fill out a 102-item questionnaire regarding their daily diet, which allowed researchers to calculate each person’s Mediterranean diet score (MDS). Based on the results, the participants were split up into three groups based on their adherence to the diet. All participants were also assessed for depression using the Center for Epidemiological Studies Depression Scale; depressive symptoms were found in 8% of the men and 27.9% of the women.

“…researchers found that consumption of fish and monounsaturated fatty acids compared with unsaturated fatty acids, both part of the Mediterranean diet, proved especially significant for the association.”

The study found that a close adherence to the Mediterranean diet was associated with a reduced risk of depressive symptoms, with a more significant beneficial association for women. More specifically, the researchers found that consumption of fish and monounsaturated fatty acids compared with unsaturated fatty acids, both part of the Mediterranean diet, proved especially significant for the association. High concentrations of monounsaturated fatty acids are found in olives, peanuts, canola oils, avocados, nuts (almonds, hazelnuts, and pecans) and seeds (pumpkin and sesame seeds). Unsaturated fatty acid content is high in fatty fish (fatty fish like tuna, salmon and sardines).

There was a 62% risk of depression reduction when three or more servings of fresh fish were consumed weekly (there was no association with canned tuna). While eating more fish was linked to a 44% overall reduction in depression risk for those in the top third of the groups, the reduction for women was 56%. For each gram of fish consumed per day, the risk fell by 2% for women. Researchers also found that nut and fruit consumption reduced the risk of depressive symptoms by 82% for men.

“…the high quantity of omega-3 fatty acids found in fish as well as the monounsaturated fatty acids found in the Mediterranean diet possess anti-inflammatory properties and support brain health.”

One reason for the sex-specific differences found in the study was that depressive symptoms were much more prevalent in women to begin with. A registered dietitian and nutritionist, Kristin Kirkpatrick, cited some research that there could be “differences in the brain, or perhaps it also relates to the data showing that women are more susceptible to mental illness than men and that women react differently to various stressors than men as well.” Kirkpatrick also shared that she was not surprised by the Mediterranean diet’s increased benefit to women given the results from existing research. She noted that “a 2021 study found that non-nutrient rich diets had a greater adverse impact on women’s mental health than men, and a 2018 study found that men and women had differences in dietary patterns and mental well-being.” Specifically regarding the health benefits of fish and monounsaturated fatty acids consumption, Routhenstein, another registered dietitian and nutritionist, added that the high quantity of omega-3 fatty acids found in fish as well as the monounsaturated fatty acids found in the Mediterranean diet possess anti-inflammatory properties and support brain health. Through neurotransmitter modulation and neuroprotection, these nutrients can potentially reduce the risk of depression. She also noted that the cardiovascular benefits of these nutrients may indirectly contribute to an overall improvement in mental health.

“…the Mediterranean diet can be beneficial for anyone looking to improve their mental health, mood and cognitive function.”

More broadly, the Mediterranean diet can be beneficial for anyone looking to improve their mental health, mood and cognitive function. The high quantity of polyphenols, flavonoids, and phytochemicals found in the wide range of fruits, vegetables, nuts, seeds, and olive oil that are staples of the Mediterranean diet contain antioxidant and anti-inflammatory properties which may help reduce oxidative stress and inflammation in the body. Kirkpatrick also noted that the restriction of sugar, refined grains and processed foods can also play a role in better mental health. All of these elements play a major role in supporting a healthy, diverse microbiome which has a significant impact on mental health outcomes and overall well-being.