New research suggests that vegetarians are more prone to be depressed than meat eaters

A new study based on survey data from Brazil has found that vegetarians have twice as many depressive episodes as those who eat meat.

Although the study adjusts with previous research, which found that the rates of depression are higher among people who exclude meat from their diets, it differs from them by suggesting that this link is independent of nutritional intake.

A wide range of nutritional parameters was taken into consideration in the current investigation, such as total calorie consumption, protein intake, micronutrient intake, and the degree of food processing.

A third factor

According to the study, the nutritional intake of vegetarians' diets is not the reason for higher rates of depression. On the contrary, depression could be one of the reasons that lead to becoming vegetarian since its symptoms can include being more prone to negative thoughts such as feelings of guilt.

Although depression is commonly associated with overly pessimistic thoughts, research suggests that people with mild to moderate depression make more realistic predictions about the outcomes of uncertain situations and more accurately evaluate their role and potential.

In this case, vegetarians are more likely to figure out that the cruel treatment of animals in meat production is caused by consumer demand for cheap meat.

Even though pursuing a vegetarian diet can make individuals feel light-hearted, it is possible that giving up meat leads to unhappiness due to other factors. For instance, being a vegetarian may impact a person's relationship with their environment and the social activities they can participate in. It may also lead to teasing or other types of social exclusion in some cases.

Finally, depression and vegetarianism may be both results of a third factor rather than one of them directly causing the other. This might be any number of characteristics or experiences that are linked to both depression and vegetarianism. For example, women are more likely than men to become vegetarians and experience depression. However, the Brazilian study took sex into account, ruling out this particular third variable.

Regardless of financial status and lifestyle choices, people who don't consume meat have depressive episodes more frequently. This connection, however, cannot be explained by nutrient deficiencies. Longitudinal data are required to shed light on this relationship.

The study was published in the Journal of Affective Disorders.

Abstract:

Background: The association between vegetarianism and depression is still unclear. We aimed to investigate the association between a meatless diet and the presence of depressive episodes among adults.

Methods: A cross-sectional analysis was performed with baseline data from the ELSA-Brasil cohort, which included 14,216 Brazilians aged 35 to 74 years. A meatless diet was defined from in a validated food frequency questionnaire. The Clinical Interview Schedule-Revised (CIS-R) instrument was used to assess depressive episodes. The association between meatless diet and presence of depressive episodes was expressed as a prevalence ratio (PR), determined by Poisson regression adjusted for potentially confounding and/or mediating variables: sociodemographic parameters, smoking, alcohol intake, physical activity, several clinical variables, self-assessed health status, body mass index, micronutrient intake, protein, food processing level, daily energy intake, and changes in diet in the preceding 6 months.

Results: We found a positive association between the prevalence of depressive episodes and a meatless diet. Meat non-consumers experienced approximately twice the frequency of depressive episodes of meat consumers, PRs ranging from 2.05 (95%CI 1.00–4.18) in the crude model to 2.37 (95%CI 1.24–4.51) in the fully adjusted model.

Limitations: The cross-sectional design precluded the investigation of causal relationships.

Conclusions: Depressive episodes are more prevalent in individuals who do not eat meat, independently of socioeconomic and lifestyle factors. Nutrient deficiencies do not explain this association. The nature of the association remains unclear, and longitudinal data are needed to clarify causal relationship.