Mediterranean diet vs. Western diet: How what you eat could affect your stress levels

Could what you eat change how stressed you feel? A new study from Binghamton University, State University of New York, suggests that it might. Researchers found that following a Mediterranean diet—rich in vegetables, fruits, whole grains, and healthy fats—may help lower your perceived stress levels, while consuming a traditional Western diet, high in processed foods and sugars, may have the opposite effect. This finding adds to the growing body of evidence that what we eat affects not just our physical health, but our mental well-being too.

The research has been published in Nutrition and Health.

The study, led by Lina Begdache, an associate professor of health and wellness studies, aimed to explore the connection between diet and perceived stress. Perceived stress refers to how much stress an individual feels they are under, regardless of the actual stressors in their life. Begdache and her team wanted to know whether different dietary patterns, particularly the Mediterranean and Western diets, influence this perception of stress.

Previous research has established links between the Mediterranean diet and improvements in mental and physical health. However, little is known about how this diet might influence perceived stress—how much stress someone feels they can handle. On the other hand, most studies on diet and stress have focused on how stress affects dietary choices, leaving a gap in understanding the reverse relationship: how diet might affect stress.

To investigate this, Begdache and her colleagues conducted a large-scale survey involving 1,591 participants. The participants, mainly college students from various universities, were asked about their dietary habits and their levels of perceived stress. The survey included questions about the frequency of consuming specific food groups that are characteristic of either the Mediterranean or Western diets. Additionally, participants answered questions from the Perceived Stress Scale, which measures how much stress they feel in their lives, and the Kessler Psychological Distress Scale, which assesses mental distress.

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The research team used a machine learning model to analyze the data, looking for correlations between the types of foods participants ate and their reported levels of stress and mental distress. This approach allowed them to identify patterns in how different dietary habits were associated with stress perceptions.

Participants who followed a Mediterranean diet reported lower levels of perceived stress and mental distress. Specifically, the study found that consuming foods like leafy green vegetables, fruits, nuts, whole grains, and fish — all staples of the Mediterranean diet — was associated with lower stress levels. These foods are rich in nutrients that support brain health, including vitamins, minerals, and antioxidants that help regulate neurotransmitters, the chemicals in the brain that influence mood and stress responses.

Conversely, the study found that participants who consumed a Western diet, characterized by high intake of processed foods, sugars, and high-glycemic index foods like white bread and sweets, reported higher levels of perceived stress and mental distress. Foods like fast food, sugary snacks, and caffeinated beverages were particularly associated with higher stress levels. These findings suggest that the Western diet may exacerbate stress by promoting inflammation and disrupting the balance of hormones that regulate stress.

“Stress is recognized to be a precursor to mental distress, and research, including our own, has demonstrated that the Mediterranean diet lowers mental distress,” Begdache said. “Thus, one element of the puzzle may be explained by the fact that the Mediterranean diet may be associated with a decrease in the negative components of perceived stress and an improvement in its positive attributes.”

Interestingly, the study also found that some components of the Western diet, such as meat and dairy products, were not as strongly associated with increased stress levels as other Western dietary components like fast food and sugary snacks. In fact, certain animal proteins showed a slight negative association with stress, which the researchers suggest could be due to their content of nutrients like tyrosine, a precursor to the mood-regulating neurotransmitter dopamine.

While the findings are compelling, the study has some limitations. One of the main limitations is its cross-sectional design, which means the researchers only observed participants’ dietary habits and stress levels at a single point in time. This design makes it difficult to determine causality—whether the Mediterranean diet actually causes lower stress levels or whether people who are less stressed are more likely to eat a Mediterranean diet. Longitudinal studies, which follow participants over time, would be needed to establish a clearer cause-and-effect relationship.

Another limitation is the reliance on self-reported data. Participants may not have accurately recalled or reported their dietary habits, which could introduce bias into the results. Additionally, while the sample size was large, it was primarily composed of college students, a group that may not represent the general population. Future research should aim to include a more diverse sample to see if the findings hold true across different age groups and backgrounds.

Finally, the study opens up new questions for future research. For example, what specific components of the Mediterranean diet are most effective at reducing stress? Are there particular nutrients or combinations of foods that have the greatest impact? Additionally, research could explore the biological mechanisms underlying the relationship between diet and stress, such as the role of inflammation and gut health in influencing mental well-being.

“Most foods comprising the Mediterranean diet are rich in antioxidants and anti-inflammatory agents,” the researchers concluded. “They also consist of nutrients that are building blocks for neurotransmitters that regulate mood and stress. On the other hand, the Western diet lacks these nutrients and includes a higher ratio of Omega-6 to Omega-3 fats, which fuel inflammation. Consuming processed, high-sugar food and caffeine has also been associated with higher levels of cortisol, which adds to the stress response. Overall, the results of the study pave the way for future research on the effects of dietary patterns and their association with different components of stress response and mental distress.”

The study, “Effects of Mediterranean and Western dietary patterns on perceived stress and mental distress,” was authored by Ushima Chowdhury, Sabrina Bubis, Katerina Nagorny, Megan Welch, Lexis Rosenberg, and Lina Begdache.