Summary: A new study reveals that vegetarians are twice as likely to suffer from depression as meat-eaters. While nutrition plays a role in depressive symptoms, the researchers say that social factors and discomfort from treating animals contribute to depressive symptoms.
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Vegetarians have about twice as many depressive episodes as meat eaters, according to a new study.
The study, based on survey data from Brazil, coincides with previous investigations which found higher rates of depression among those who give up meat. However, the new study suggests that this link exists regardless of nutritional intake.
It may seem easy to see a link between a diet and specific health problems and assume that the former is causing the latter through some form of nutritional deficiency.
However, the new analysis, published in the Journal of affective disorders, took into account a wide range of nutritional factors, including total calorie intake, protein intake, micronutrient intake, and the level of food processing. This suggests that the higher rates of depression among vegetarians are not due to the nutritional content of their diet.
So what might explain the link between vegetarianism and depression? Is there some non-nutritional mechanism that causes the former to cause the latter? Or is the relationship due to something else entirely?
First of all, it is possible that being depressed causes people to become vegetarian and not the other way around. the symptoms of depression it can include rumination about negative thoughts as well as feelings of guilt.
Assuming that depressed and non-depressed people are equally likely to encounter the unsettling truth of slaughterhouses and factory farms, it’s possible that depressed people are more likely to reflect on those thoughts and more likely to feel guilty about their part in doing so. creating demand. .
The depressed vegetarian, in this case, is not necessarily wrong to think this way. Although depression is sometimes characterized by unrealistic negative perceptions, there is evidence to suggest that people with mild to moderate depression have more realistic judgments about the outcome of uncertain events and more realistic perceptions of their own role and abilities.
In this case, there really cruel treatment of animals in meat production. And this really is caused by consumer demand for cheap meat.
Second, adhering to a vegetarian diet may cause depression for reasons other than nutrition. Even if no “happy nutrient” is missing from a vegetarian diet, it could be the case that giving up meat causes depression by other means.
For example, adopting a vegetarian diet can affect relationships with others and participation in social activities, and can sometimes be associated with teasing or other forms of social ostracism.
In particular, the new study is based on survey data collected in Brazil, a country famous for its diet rich in meat. Some survey data have pointed to a strong increase in vegetarianism in Brazil in recent yearsgoing from 8% in 2012 to 16% in 2018. However, the recent study surveyed more than 14,000 Brazilians and found only 82 vegetarians, just over half a percent.
One has to wonder if the same link between vegetarianism and depression would be seen in India or in other countries where vegetarianism is more of a social norm. More importantly, like the UK vegetarianism rises and other developed countries, will we see the relationship disappear over time?
Finally, neither vegetarianism nor depression may cause the other, but both are associated with some third factor. This could be any number of characteristics or experiences associated with both vegetarianism and depression.
For example, women are more likely than men to be vegetarian, and experience depression. However, the Brazilian study took gender into account and ruled out this third variable in particular.
not examined
One variable that was not examined, but is plausibly related to both vegetarianism and depression, is exposure to violent images from the meat industry. Preventing cruelty to animals is the most commonly cited reason vegetarians tend to avoid meat.
documentaries like Domain Y earthlings depicting cruelty in the meat industry cannot easily be described as feel-good movies. One can easily imagine that a person who consumes this type of media would become a vegetarian and, especially when most people choose to look the other way, become depressed.
There are several possible reasons for the link between vegetarianism and depression. This new study suggests that vegetarian nutrition is not the cause of depression.
Instead, vegetarian social experience may contribute to depression, depression may cause a higher likelihood of becoming a vegetarian, or both vegetarianism and depression may be caused by a third variable, such as exposure to violent industry images meat.
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About this research news on diet and depression
Author: Chris Bryant
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Contact: Chris Bryant – The Conversation
Image: The image is in the public domain.
original research: Closed access.
“Association between meatless diet and depressive episodes: a cross-sectional analysis of reference data from the Longitudinal Study of Adult Health (ELSA-Brazil)” by Ingrid Kohl et al. Journal of affective disorders
Summary
Association between meatless diet and depressive episodes: a cross-sectional analysis of reference data from the Longitudinal Study of Adult Health (ELSA-Brazil)
Background
The association between vegetarianism and depression is still unclear. Our aim was to investigate the association between a meat-free diet and the presence of depressive episodes among adults.
Methods
A cross-sectional analysis was performed with reference data from the ELSA-Brazil cohort, which included 14,216 Brazilians aged 35 to 74 years. A meat-free diet was defined from a validated food frequency questionnaire. The Clinical Interview Schedule-Revised (CIS-R) instrument was used to assess depressive episodes. The association between the meatless diet and the 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 consumption, physical activity , various clinical variables, self-control. – Assessed health status, body mass index, micronutrient intake, protein, level of food processing, daily energy intake, and dietary changes in the previous 6 months.
Results
We found a positive association between the prevalence of depressive episodes and a meat-free diet. Non-meat eaters experienced approximately twice the frequency of depressive episodes as meat eaters, with OR of 2.05 (95% CI: 1.00–4.18) in the crude model at 2.37 ( 95% CI: 1.24–4.51) in the fully adjusted model.
Limitations.
The cross-sectional design precluded investigation of causal relationships.
Conclusions
Depressive episodes are more prevalent in individuals who do not eat meat, regardless 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 the causal relationship.
