Large Study Shows Vegans and Lacto-Ovo-Vegetarians are More Likely to Have Poorer Mental Health
Go vegan, go mental
Those who’ve observed the antics of militant vegans could be forgiven for concluding a meatless diet makes people insane. Whether it’s sleazy internet bully Harley “Durianrider” Johnstone raucously belittling a domestic violence victim, a bunch of PETA nutters rolling around in fake blood, or celebrity vegan chef and serial flasher Dan Hoyt tugging on his tofu in a New York subway, it’s clear the vegan crowd has a penchant for extreme behavior.
If you’re among the many who’ve concluded a vegan diet and lifestyle renders one more susceptible to mental health issues, guess what?
The science indicates you’re probably right.
In 2021, Critical Reviews in Food Science and Nutrition published a sweeping analysis by a group of researchers led by Urska Dobersek (Department of Psychology, University of Southern Indiana, USA). Their systematic analysis examined psychological health in meat-consumers and meat-abstainers.
The study is noteworthy because of its size, and because one of the inclusion criteria for the studies under review was provision of a clear distinction between meat-consumers and meat-abstainers. Some research groups categorize subjects by the amount of red/white meat, and seafood, they consume, but this alleged consumption relies on notoriously unreliable self-reports. Other research groups frequently slot ‘vegetarians’ into several subdivisions based on the types of foods they claim to exclude. This method of categorization routinely tags people who do in fact eat animal flesh as ‘vegetarian’ (e.g. flexitarian, pescatarian).
In this analysis, the researchers kept it simple: To be included in the review, a study must have had a group that reported abstinence from meat, and a group that reported eating meat.
Their literature search yielded eighteen papers that met the inclusion criteria. These included 16 cross-sectional, 1 mixed cross-sectional and longitudinal study, and 1 RCT. The total sample included 160,257 participants (85,843 females and 73,232 males) with 149,559 meat-consumers and 8,584 meat-abstainers from geographic regions including Europe, Asia, North America, and Oceania. The sample sizes ranged from 38 to 90,380 participants with an age-range from 11 to 96 years. The articles were published from 1997 to January 2019.
The studies were placed in five categories based on their score for methodological rigor. Two of the 18 selected studies had a low risk of bias; 5 had moderate risk; 4 had moderate-to-high risk; 4 had a high risk, and 3 studies had a severe risk of bias. The quality of the study appeared to affect the outcome of the study.
Fourteen of the 18 studies examined depression, anxiety, and/or related symptoms. Independent of methodological rigor, 7 of the 14 studies found a higher prevalence or risk in participants who avoided meat consumption.
Three studies found no group differences, 2 studies demonstrated mixed results (e.g., higher rates in females only), and 2 of the 14 studies found a higher prevalence or risk in meat-consumers.
The four most rigorous studies demonstrated that the prevalence or risk of depression and/or anxiety (or related symptoms) was significantly greater in participants who avoided meat consumption.
The results of the five least rigorous studies were less clear; two studies demonstrated that meat-consumers had a higher risk or prevalence of depression and anxiety, one study found no group differences, and two found that meat-consumers had a lower risk or prevalence.
The most rigorous study reviewed (Michalak, Zhang, and Jacobi, 2012), found a clear relation between avoidance of meat and depression and anxiety in both a representative sample of German adults (including 3,872 non-vegetarians and 54 “complete vegetarians”) and a socio-demographically matched subsample of non-vegetarians (n = 242).
“Complete vegetarians” had 1-month, 12-month, and lifetime prevalence of unipolar depressive disorders of 7.4%, 24.1%, and 35.2%, respectively. The prevalence was substantially lower in meat-consumers: 6.3%, 11.9%, and 19.1% in the full sample, and 5.0%, 10.3%, and 20.7% in the matched sample.
The 1-month, 12-month, and lifetime prevalence of anxiety disorders for meat-abstainers was 20.4%, 31.5%, and 31.5%, respectively. As with their results for depression, the prevalence in meat-consumers was significantly lower: 10.7%, 17.0%, and 18.4% in the full sample and 8.7%, 13.2%, and 15.3% in the matched sample.
Similarly, the results from the largest and second most rigorous study in the review (Matta et al 2018) found that in a very large, nationally representative sample of French adults (n = 90,380), 28.4% of meat-abstainers had symptoms of depression, whereas only 16.2% of meat-consumers did. The odds of having depressive symptoms increased when meat was excluded from the diet.
Similarly, the largest study of women exclusively (Baines, Powers, and Brown, 2007) found greater risk of depression and anxiety in meat-abstainers; the largest study of men exclusively (Hibbeln et al, 2018) found a greater risk/prevalence of depression in meat-abstainers.
Three studies examined self-harm behaviors. Baines et al found that in a large, representative sample of Australian women (n = 9,113), the prevalence of deliberate self-harm was over three times greater in meat-abstainers than meat-consumers (10.0% vs. 3.1%).
Baines et al also found use of prescription medications for depression in women who abstained from meat was nearly twice that of women who ate meat (8.0% vs. 4.2%).
Interestingly, Baines et al also found meat-abstaining women were more likely to have a university degree than semi-vegetarian and non-vegetarian women. Despite this, they were more likely to report lower income than their semi-vegetarians and meat-eater counterparts.
In a large sample of US adolescents (n = 4,746), Perry et al (2001) found suicide attempts were more than twice as prevalent in meat-abstainers compared to meat-consumers (18.3% vs. 8.6%), and the prevalence of suicidal ideation (i.e., thinking about killing oneself) was 34.7% in meat-abstainers versus 24.9% in meat-consumers.
Similarly, in a matched sub-sample of adolescents (n = 321), Neumark-Sztainer et al (1997) found that suicide attempts were more prevalent in meat-abstainers (25%) compared to meat-consumers (17%).
The sole RCT in the analysis was conducted by Beezhold and Johnston (2012).
They claimed “Restricting meat, fish, and poultry improved some domains of short-term mood state in modern omnivores.”
In that study, 39 participants were randomized to consuming either 1) meat, fish, and poultry daily; 2) fish 3-4 times weekly but avoiding meat and poultry; 3) a vegetarian diet avoiding meat, fish, and poultry.
The participants spent a mere two weeks on their assigned diets.
In addition to telling us nothing about the affects of these diets beyond a mere fortnight, nine of the 11 psychological measures showed no significant differences between groups. The only 2 scores showing a statistically significant difference between groups were “DASS-S stress” and “POMS-C confusion”.
It does not comfort me to know giving people a novel diet for a mere 2 weeks improved only 2 of 11 psychological questionnaire ratings, when out in the real world meatless diets are associated with higher levels of depression, anxiety and suicidal behavior.
Which Came First: The Mental Illness or the Diet?
One of the questions arising from such research is whether the higher prevalence of mental illness among vegans is a result of the diet, or simply an artifact of the type of people who are attracted to veganism.
Some researchers, for example, have proffered that some people turn to vegan diets in an attempt to treat chronic health issues, and that the chronic health issues may in fact be the real reason for the mental health issues.
I don’t buy it.
Both my own observations and the published literature indicate that dogma about animal welfare, environmental concerns, and optimal health (as opposed to correcting a preexisting health disorder) are the primary motivations for following vegan diets.
I suspect the explanation is two-fold:
Extreme diets lack key nutrients that are essential for proper cognitive and neural function;
People with extreme personality traits (such as high levels of neuroticism, orthorexia, etc) may be attracted to extreme diets.
In the study by Matta et al 2018, removal of individuals with chronic diseases from the analysis, and further adjustment for self-rated health and “eating to stay healthy”, did not diminish the statistically significant association between lacto-ovo-vegetarian diets and depressive symptoms (the results for vegans became non-significant, probably due to the very small number of vegan participants).
Further supporting a causal link between meat avoidance and mental health disorders is the fact that meatless diets dramatically reduce the intake of nutrients such as vitamin B12, creatine and long-chain fatty acids - all of which are crucial for proper cognitive and neural function.
Let He Who Has Not Sinned Cast the First Lentil
The Dobersek et al study was funded in part via an unrestricted research grant from the Beef Checkoff, through the National Cattlemen's Beef Association.
Wow, look at all the vegans screaming “CONFLICT OF INTEREST!!!”
To which I respond with a question:
How come you vegans and vegetarians never scream “CONFLICT OF INTEREST!!!” at the multitude of blatantly biased pro-vegan/vegetarian studies?
The overwhelming majority of pro-vegan/vegetarian propaganda research comes from three highly-biased sources:
Oxford University. More specifically, the Oxford Vegetarians and The Vegan Society. A grouping of activists that could hardly be described as impartial.
A ‘research’ group led by Hana Kahleova, who belongs to the Physicians Committee for Responsible Medicine, which was exposed years ago as a sham medical outfit. By its own admission, less than 1.7% of its members are “physicians”. Neal Barnard, founder and president of the pro-vegan PCRM, is also president of the Foundation to Support Animal Protection (also known as “The PETA Foundation”). His former partner is Ingrid Newkirk, head of the rabidly pro-vegan PETA, an organization claiming to care about animals, but is in fact ideologically opposed to pet ownership and runs a kill shelter from which it enacts its sickening fetish for unnecessarily euthanizing perfectly healthy and rehomeable animals.
Loma Linda University, which is owned by Seventh-day Adventists, whose prophetess, Ellen G. White, claimed that meat (along with tea, coffee and spices) caused every ailment under the sun, including an uncontrollable urge to masturbate.
Seriously.
For conclusive refutation of this hare-brained theory, I again refer readers to celebrity vegan restauranteur, serial subway flasher, and public peepee spanker, Dan Hoyt.
Furthermore, inspection of the key studies cited by Dobersek et al shows no conflict of interest.
Michalak, Zhang, and Jacobi, 2012 was supported by a grant from the German Federal Ministry of Research, Education and Science.
Matta et al 2018 was funded by French Institute for Public Health Research and a number of pharma companies (MSD, AstraZeneca and Lundbeck), but no food or agricultural groups.
Baines, Powers, and Brown, 2007 was funded by the Australian Commonwealth Department of Health and Ageing.
Hibbeln et al, 2018 was funded/supported by UK Medical Research Council and the Wellcome Trust , the University of Bristol, the Intramural Research Program of the National Institute on Alcohol Abuse and Alcoholism, the Waterloo Foundation and a personal gift from John M. Davis, M.D.
Perry et al 2001 was supported by a grant from the Maternal and Child Health Bureau, Health Resources and Service Administration, U.S. Department of Health and Human Services
Neumark-Sztainer et al 1997 does not mention funding but was conducted by the same research group as Perry et al 2001.
Beezhold and Johnston (2012), which dubiously claimed improved mood on a vegetarian diet during a brief RCT, does not list funding source/s.
If you value your sanity, you’d be best served giving meatless diets a wide berth.
A great book on this is “The Vegetarian Myth” by Lierre Keith, a vegan for twenty years who cares intensely about nature and animals, loses her health, can barely walk, and tries to recover by growing her own food. She tells a poetic and heart-wrenching tale of how even vegetables aren’t vegan!! How she tries to avoid all animal products to grow vegetables but things fail to grow unless she adds compost including animal products, manure, and blood and bone. Plants eat animals. She breaks down the moral, environmental and nutritional arguments.
Possibly some vegans/vegetarians are ok if the are part of the 5-10% of people who can easily convert beta carotene to vitamin A and ALA etc to EPA but the process for conversion is wildly inefficient for 90% of people, says former raw vegan Denise Minger (auto of Raw Food SOS blog), so most people don’t do too well on vegetarian diets and need those things from animal sources. But a few do fine.
I suspect environment plays a role too? Eg in Amazon jungle I could eat way more fruit and veg, in colder areas I ate more meat etc be and have no desire for fruit lol.
That's great, I had a few laughs. Speaking of which - how do you know someone is vegan... wait, they'll tell you.
You mentioned care for animals or managing a chronic illness as reasons for veganism. Another is identity, I was a sanctimonious vegetarian for this reason, as well as a desire to live with a more philosophical mind. I became very depleted and when approaching 60 had strong signs of dementia with yes, a hardened attitude. I've been eating a meat based diet for about 15 years and at 72 I'm as well as I've ever been with a brain that's well recovered.
I believe the key nutrient is the fat of which the premium is tallow - the fat of a ruminant, an animal with four stomachs that eats grass. I now eat a lot of it and the health food shops are stocking it, everyone's waking up.
As Mark Purdey mentioned in his remarkable book Animal Pharm, the plant based agenda is handing local food production to agribusiness. The meat based diet is truly paddock to plate, it's the most nutrient dense food, and regenerative pasturing is carbon negative.
I'm a naturopath and I spend an inordinate amount of time trying to convince vegetarians to eat meat. Half of them think I'm a sacrilegious heathen and avoid me, the other half make the shift and are most grateful.
I think diets with labels are dumb and vegans are loonies.