Can the Mediterranean diet increase stress and depression?
Key Takeaways
A cross-sectional analysis published in Nutrients suggests that there’s an association between the Mediterranean diet (MedDiet) and symptoms of anxiety and stress.
The MedDiet is widely considered a go-to for healthy eating, with many clinical sources citing its benefits. This study is in direct opposition with previous findings.
Findings were based on 294 participants over the age of 60. Certain foods were associated with increased anxiety and stress symptoms, but experts think the analysis has many flaws.
A new cross-sectional analysis published in Nutrients explores the association between the uber-popular Mediterranean diet (MedDiet) and increased symptoms of depression, anxiety, and stress in adults 60 years or older—findings that go against previous research.[]
The MedDiet generally includes a focus on eating fruit and vegetables, whole grains, nuts, fish, legumes, lean white meats, and olive oil. The diet was reportedly first described by Ancel Keys, who took inspiration from food culture in Greece and Southern Italy in the 1960s.[]
Today, the MedDiet is widely accepted as a gold standard for healthy eating, according to 2024 research published in Endocrine, Metabolic & Immune Disorders. The authors say it’s more a lifestyle than a diet, with its emphasis on a sense of balance in both the kitchen and life. Beyond specific foods, the authors note, the MedDiet also encourages eco-friendliness; moderation in food consumption; the use of local, seasonal, and traditional products; engagement in preparing your own food and eating with others; and good hydration, rest, and exercise.[]
In terms of the MedDiet’s physical health benefits, research in The British Journal of Pharmacology points to both observational and experimental evidence suggesting that the MedDiet could “lower risk of mortality, cardiovascular disease, metabolic disease, and cancer.”[]
It’s thought that the diet’s polyphenols, monounsaturated and polyunsaturated fatty acids, or fiber have a positive effect on “reduction of blood lipids, inflammatory and oxidative stress markers, improvement of insulin sensitivity, enhancement of endothelial function, and antithrombotic function,” the journal states.
With all of these obvious positives, what’s the drawback?
The Nutrients analysis included 294 participants and found that the MedDiet was inversely associated with the severity of anxiety and stress symptoms, regardless of age, gender, BMI, physical activity, sleep, and other variables. When it came to depression, however, there were no associations with the MedDiet—which is more in line with previous findings.
A closer look at the specifics showed that vegetable intake was inversely associated with depressive symptoms and that increased intake of nuts and legumes was inversely associated with the severity of anxiety-related symptoms, although significance was lost after adjusting for cognitive risk.
Fruit intake was also inversely associated with symptoms of stress, while low consumption of sugar-sweetened beverages was associated with anxiety, independent of other variables.
On the flip side, other studies have found that patients sticking to the MedDiet experienced reduced depression symptoms and improved mental health.
Michelle Routhenstein, MS, RD, CDCES, CDN, a preventive cardiology dietitian, echoes this sentiment, saying that previous research has highlighted the positive impact of the MedDiet on mental health, “such as the nutrient-rich content of fruits, nuts, and legumes, which contain vitamins, minerals, antioxidants, and phytochemicals associated with improved mental well-being.”
How might the MedDiet be associated with anxiety and stress symptoms?
As the authors of the analysis say, “[d]iet quality may be an important modifiable risk factor for mental health disorders. However, these findings have been inconsistent, particularly in older adults.”
The authors offer up some ideas about why these inconsistencies exist, saying that “differences in the modalities used to identify depression or depressive symptoms” could be to blame.
The authors also say that there are limited studies in this context that have been done on older adults, with many failing to adjust for variables like cognitive status, which, they say, coexists with depression in older adults. “Moreover, it is possible that any observed association between MedDiet adherence and severity of symptoms related to anxiety were secondary to a reduction in disease risk, improved health-related quality of life or improvements in the management of clinical perturbations, rather than a direction association with mental health and psychological well-being,” the authors also suggest.
What do experts think about this analysis?
Cheryl Mussatto MS, RD, LD, a clinical dietitian at Cotton O'Neil Diabetes and Endocrinology Clinic in Topeka, KS, says that it’s important to point out one major limitation in the analysis: the fact that participants self-reported their eating. “While this method is standard in dietary research, it is prone to recall bias. Participants may struggle to remember their food consumption accurately over a given period, potentially leading to underestimating their consumed foods,” she says.
Routhenstein also says that the participant pool could have skewed the results: “It is also worth noting that the analysis findings may not be accurate due to the relatively good health status of the analysis sample, which consisted mostly of a few reportings of significant mental health issues, as only 13.5% reported depression and 1.7% reported anxiety,” she says.
But that’s not all: Sarah Hormachea, MS, RD, a registered dietitian at Nourish, says that the analysis didn’t control for income or socioeconomic status—variables that could play into a person’s well-being. “The Mediterranean diet, high in fresh fruits and vegetables, fatty fish, whole grains, and heart-healthy oils, can be more expensive, and assumes that one has easy access to a supermarket. There is ample research to support that higher-income individuals tend to have less stress and perhaps less anxiety,” Hormachea offers.
On top of that, she wonders if sticking to a particular diet could actually drive anxiety for some people.
What this means for you
The Mediterranean diet is widely considered the gold standard for eating, with numerous studies pointing to its many physical and mental health benefits. While this particular analysis points to an inverse association between the diet and anxiety and stress, experts are quick to point out its limitations. You should discuss this information clearly with patients who may be wondering whether the diet is right for them.