If you’ve spent any amount of time online reading about diet, you’ve encountered the Mediterranean diet, rich in vegetables, whole grains, and heart-healthy fats like fish. Its myriad benefits include improvements to heart healthTrusted Source, blood sugarTrusted Source, and cognitive functioningTrusted Source.
Now, researchers in the field of nutritional neuroscience, which examines nutrition through the lens of neurochemistry, have found that the Mediterranean diet also appears to play a role in improving mood and dealing with stress. On the other hand, the Western dietTrusted Source, known for highly processed foods, red meat, and high-glycemic index foods, appears to exacerbate negative feelings associated with stress.
The findings were published in the journal Nutrition and Health.
Lina Begdache, PhD, RDN, an Associate Professor of Nutritional Neuroscientist, Registered Dietitian, and Senior Author of the research, told Healthline, “We closed a gap in the literature by looking at the impact of diet quality on [the] perception of stress.”
“Our results showed that the Mediterranean diet reduced feelings of distress as well as increased feelings of eustress [positive stress]. Whereas the Western diet lowered the perception of the positive stress and promoted distress,” she said.
Kristin Kirkpatrick, MS, RD, a nutritionist at the Cleveland Clinic, and co-author of Regenerative Health, who wasn’t affiliated with the study, told Healthline, “This research is aligned with others looking at a Mediterranean dietary pattern and its association with depression and anxiety.”
She pointed out that trials including the AMMENDTrusted Source, SMILESTrusted Source, and HELFIMEDTrusted Source have all found similar results. They focused specifically on the effects of the diet on depression.
How the study was conducted
The study involved 1591 participants who answered a series of surveys and questionnaires about diet and mood. More than 70% of the participants (1,117) were female. Nearly all participants (1,412) were between the ages of 18-29, while a few were 30 years or older.
Researchers used a validated tool, the food-mood questionnaire (FMQ), which Begdache developed, to explore how food makes someone feel.
They also used a standard measurement for feelings of distress known as the Kessler Scale, which asks respondents to give a numerical rating to indicate the frequency of certain feelings, like “nervous,” “hopeless,” and “worthless.” The Perceived Stress Scale (PSS), which has been used since 1983, asks respondents how frequently they feel various feelings like being able to “control irritations” or whether things were “going your way.”
Begdache and her team then linked how specific components of the Mediterranean and Western diets affected these feelings.
Dark leafy greens, a staple of the Mediterranean diet, were inversely correlated with nearly all of the negative feelings of the Kessler Scale. Meanwhile, components of the Western diet, like fast food and sugary (high-glycemic index) foods, were positively correlated with these negative feelings.
Not only that but many of the same components that were inversely associated with negative feelings were also positively associated with positive feelings. For example, leafy vegetables, whole grains, exercise, nuts, and oats all correlated with feelings like “confident to handle problems” and “able to control irritations.”
“This suggests that these foods not only promoted the positive outlook regarding stress but reduced the negative perception of stress,” said Begdache.
The Western diet wasn’t all bad either.
White meat, eggs, and even red meat, for the most part, showed negative associations with feelings of stress and mental distress and positive associations with positive feelings like confidence.
