Early animal studies demonstrate reduced stress levels with a Mediterranean diet.
According to the American Physiological Association, some of the highest perceived stress in the world was reported by Americans. Stress can contribute to negative effects in both personal and work lives and can increase risk of chronic health conditions, such as heart disease. The psychological nature of stress, however, makes it difficult to reduce as many stressors are often unavoidable. Environmental stressors, such as an unhealthy diet, can also add to an individual’s overall stress level. The opposite might also be true, according to a recent study looking at the link between Mediterranean diet and stress.
Diet is a modifiable factor that individuals have control over. Previous studies have observed a higher level of stress associated with diets rich in saturated fats and simple sugars whereas a lower level of stress was observed with diets rich in fruits, vegetables, and plant source protein. Long-term effects of a sustained diet pattern on stress response have not been extensively studied.
A team of scientists in the United States conducted an animal study with macaque monkeys to evaluate how physiological stress responses differ between a Western diet (e.g. high sodium and saturated fats and protein derived from animal sources) versus the a Mediterranean diet (e.g. high monounsaturated fatty acid content and fats and protein derived from plant sources). The results were published in Neurobiology of Stress.
The study looked at thirty-eight middle-age monkeys that were fed with either a Western diet or a Mediterranean diet over a course of 31 months, which is approximately nine human years. The effects of chronic stress as a result of low social status and acute stress as a result of social isolation were studied, particularly on the sympathetic nervous system (responsible for the “fight or flight” panic response) and the parasympathetic nervous system (responsible for keeping the body in a calm state). Factors such as heart rate, blood pressure, and stress hormone levels (e.g. cortisol) were evaluated.
The researchers found that animals fed a Mediterranean diet had lower sympathetic activity and were more robust against stress compared to those fed a Western diet. The animals fed a Mediterranean diet had quicker recovery from stress and lower cortisol levels in response to stress. Although there was an increase in sympathetic activity over the course of the 31 months in the animals, the aging of the sympathetic nervous system was slowed with a Mediterranean diet compared to a Western diet.
The results of this study provide evidence that diet can modify the body’s response to stress, which in turn can have effects on health. A Mediterranean diet, as studied here, could be a possible strategy that is relatively easy and cost-effective to adopt that can help reduce stress and improve overall health.
Written by Maggie Leung, PharmD
Shively, C. A., Appt, S. E., Chen, H., Day, S. M., Frye, B. M., Shaltout, H. A., . . . Register, T. C. (2020). Mediterranean diet, stress resilience, and aging in nonhuman primates. Neurobiology of Stress, 13, 100254. doi:10.1016/j.ynstr.2020.100254
Mediterranean diet helps reduce effects of stress in animal model, study shows. (2020, November 16). Retrieved from https://www.eurekalert.org/pub_releases/2020-11/wfbm-mdh111620.php
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