According to a new meta-analysis published in the journal Critical Reviews in Food Science and Nutrition, compared to meat abstention, meat consumption is associated with lower levels of depression and anxiety.
In 2017, mental illness was considered to be the leading cause of disability globally. The World Health Organization estimated that approximately 300 million people suffered from depression, and 260 million were living with anxiety, reflecting a considerable increase in these disorders over the past two decades. In parallel with the observed increases in mental disorders, vegetarianism and veganism are becoming more prevalent. Motivators for this dietary choice include ethical, environmental, and animal rights-based concerns, as well as attempts to improve mental health via diet.
Urska Dobersek and colleagues extracted data from 20 existing studies, including cross-sectional and longitudinal studies, as well as randomized control trials. In these studies, depression and anxiety were assessed through self-report ratings, the use of prescription medication, a medical diagnosis, or diagnostic interview. A total of 171,802 participants between ages 11 to 105 were included in this meta-analysis, of which, 157,778 identified as meat consumers while 13,259 identified as meat abstainers. Participants’ geographic locations included Europe, Asia, North America, and Oceania.
The researchers found that individuals who consumed meat experienced lower levels of depression and anxiety compared to individuals who abstained from meat. Vegans were found to experience greater levels of depression compared to meat consumers. Participants’ sex did not explain these associations. Further, the analyses revealed that the more rigorous studies were (i.e., relying on physician-diagnosed mental illness as opposed to self-report questionnaires), the stronger the observed benefits of meat consumption.
This work has several strengths, including its large sample size, and criteria to include only studies that provided a clear dichotomy between meat consumers and meat abstainers.
However, the researchers note a few limitations. This meta-analysis only included studies that were published in English, which could bias the results toward Western norms. Excluding papers in other languages (such as Hindi), could have omitted studies that were conducted in regions that follow predominantly vegetarian or plant-based diets. As well, despite the observed link between meat consumption and mental health, these results prevent inferences about the temporal order of these variables and causal conclusions.
The meta-analysis, “Meat and mental health: A meta-analysis of meat consumption, depression, and anxiety”, was authored by Urska Dobersek, Kelsey Teel, Sydney Altmeyer, Joshua Adkins, Gabrielle Wy, and Jackson Peak.