The Mediterranean Way of Life, Part 2: What Siesta, Rhythm and Cortisol Actually Have to Do With Each Other

That people around the Mediterranean seem more relaxed is a cliché – but part of it can be studied surprisingly concretely: from whether the classic siesta genuinely helps the heart, to what the Mediterranean diet itself does to the stress hormone cortisol.

This is Part 2 of our four-part series on the Mediterranean way of life. Part 1 covered diet as the foundation; Part 3 will look at social connection and community, and Part 4 at sunlight and vitamin D. Today: stress, rhythm, and what the research actually shows about the "relaxed south".

What "Mediterranean lifestyle" actually means beyond the menu

Scientifically, the Mediterranean lifestyle is mostly operationalised through diet, since it can be captured fairly reliably via questionnaires. Culturally, though, other elements belong to it too, and these are increasingly studied in their own right: a pronounced daily rhythm with a rest period after lunch (siesta), shared and often slower meals, and an overall slower pace of daily life. How much these factors contribute independently of diet itself to the observed health outcomes is an active area of research – and not always easy to disentangle.

What the research shows about the Mediterranean diet and psychological strain

In the PREDIMED study, a randomised controlled trial (RCT) involving over 7,000 people at high cardiovascular risk, the Mediterranean diet supplemented with nuts was associated with a lower depression risk trend (hazard ratio 0.78), though the result did not reach statistical significance. Several observational studies have found an inverse relationship between adherence to the Mediterranean diet and depressive symptoms; a review of polyphenols and depressive symptoms, along with a smaller randomised controlled trial from Iran (60 participants), also reported more favourable stress, anxiety and depression scores after 12 weeks of Mediterranean-style dietary counselling. On a physiological level, the DIRECT-PLUS trial, an 18-month RCT with 294 participants, examined morning cortisol levels under a polyphenol-rich "green Mediterranean" diet; the authors report more favourable cortisol patterns compared with a standard dietary recommendation. Overall, the evidence on mental health is less consistent and robust than the cardiovascular data from Part 1 – but the direction of findings is remarkably consistent across different study designs.

What the research on siesta actually shows – and where it disagrees with itself

The siesta is often seen as the symbol of Mediterranean relaxation, but the evidence is mixed. A large Greek cohort study (observational, over 23,000 participants, published 2007) found that regular midday napping was associated with roughly 37 percent lower mortality from heart disease. Other cohort studies and more recent meta-analyses, however, arrive at opposite findings: they observe an increased risk of cardiovascular disease, atrial fibrillation and stroke with long or irregular midday naps (roughly 30 to 60 minutes or more). A Spanish cohort study of over 20,000 university graduates found the highest risk of atrial fibrillation in the combination of a long nap and insufficient nighttime sleep. The most cautious interpretation: short, regular naps of around 10 to 30 minutes appear unproblematic to potentially beneficial, while long or irregular naps may be more a sign of an underlying sleep problem or health burden than a cause of benefit in themselves. All studies cited here are observational; they can show associations but cannot establish causality.

What magnesium and calming herbs show for stress regulation

Beyond sleep and daily rhythm, research also looks at the role of individual micronutrients in stress. A systematic review of magnesium and subjective anxiety found positive effects across several, mostly smaller, randomised controlled trials in people with elevated anxiety tendencies (including mild anxiety symptoms and premenstrual syndrome); the authors explicitly note that the overall evidence quality remains weak and call for larger, better-controlled trials. A separate meta-analysis of randomised controlled trials in people with diagnosed depressive disorder found a significant improvement in depression scores under magnesium supplementation, though based on a still-limited set of seven included studies. Within the EU, it's authorised to state that magnesium contributes to normal functioning of the nervous system, and that magnesium and vitamin B6 contribute to the reduction of tiredness and fatigue. Plants traditionally used in European herbal knowledge for inner tension, such as lemon balm, lavender and passionflower, are also being examined in clinical studies; the evidence for each individual plant is covered in detail in our respective topic articles.

Safety, limitations and who should take particular care

A balanced daily rhythm with short rest periods is generally considered safe. Anyone experiencing strong daytime fatigue, long involuntary midday naps or poor nighttime sleep should treat this as a reason to investigate sleep quality or underlying conditions, rather than as simply "Mediterranean lifestyle". Magnesium supplements should only be taken after consulting a doctor in cases of significantly impaired kidney function, since excretion may be affected. High single doses can have a laxative effect. Lemon balm, lavender and passionflower are considered well tolerated at typical intake amounts; prior consultation with a healthcare professional is advisable during pregnancy, breastfeeding, or concurrent use of sedative medication.

Conclusion: what's well established – and what remains open

The link between the Mediterranean diet and psychological strain is plausible and points in a consistent direction across several study designs, but it's less robustly established than the cardiovascular data from Part 1 – the key RCT (PREDIMED) did not reach statistical significance for depression. The picture on siesta is split: short, regular naps appear unproblematic, while long and irregular ones look more like a warning sign than a health prescription. For magnesium and stress or anxiety: the direction of effects in early studies is positive, but by the authors' own assessment the strength of evidence remains limited. Anyone wanting to draw a lifestyle lesson from this should focus less on any single element and more on the interplay of rhythm, recovery and diet.

This article is for general informational purposes only and does not replace individual medical or psychological advice. Dietary supplements are not a substitute for a balanced and varied diet and a healthy lifestyle.