Vegans and mental health

Veganism and Depression: What's the Link?

Major depressive disorders are the second largest worldwide contributor to the number of years a person lives in suboptimal health (1).

Many factors can influence why some people may experience depression, including what they eat.

Anecdotally, some people report improved mood and less anxiety when eating a vegan diet. However, others report worsened symptoms (1).

In this article, I’ll review what the latest studies have to say about veganism and depression, including if there’s a link between the two.

What you eat can influence how you feel, both physically and mentally.

When it comes to your mood, more than 50 studies conducted in various countries suggest that what a person eats may influence how likely they are to experience depression (1).

For instance, a large randomized control trial (RCT) — the gold standard in nutrition research — looked at the diets of people with major depressive symptoms.

It found that people with depression who followed a prescribed diet high in whole grains, lean protein, low fat dairy, and plant foods were four times more likely to experience remission than those who consumed a diet lower in those foods and higher in ultra-processed foods (2).

The drop in depressive symptoms was independent of changes in physical activity or body weight, and those who improved their diet the most reported the greatest reduction in depressive symptoms (2).

In another study, a Mediterranean-style diet coupled with fish oil supplements significantly improved self-reported symptoms of depression over three months (3).

A recent review further supports the notion that eating a high quality diet, regardless of whether it is plant-based, may reduce the risk of depression by up to 23% (4).

In these studies, the high quality diet was typically defined as one rich in fruits, vegetables, whole grains, nuts, seeds, olive oil, fish, and other seafood (1).

Keep in mind that these study results don’t mean that a diet low in those foods causes depression, though. Depression is caused or influenced by many various factors, with diet being only one of them.

That said, a well-rounded and nutritious diet does appear to help at least some people experience fewer symptoms of depression, so altering your diet may be a helpful strategy worth considering.

Finding support for depression symptoms

If you need to talk to someone right away, help is available:

Call the National Suicide Prevention Lifeline at 1-800-273-8255.
Text “HOME” to the Crisis Text Line at 741741.
If you’re living with a mental health or substance use disorder, call SAMHSA’s National Helpline at 800-662-4357.
If you’re a young person of color, text STEVE to 741741.
Call the Trans Lifeline Hotline at 877-565-8860 (US) or 877-330-6366 (Canada).
Not in the U.S.? Find a helpline in your country with Befrienders Worldwide.

If you’re not currently in crisis but you’re considering working with a mental health professional, these resources may be able to help you get started:

When to Consult a Psychologist
How Can I Get Help for Depression?
9 Tips for Finding the Right Therapist
Finding an LGBTQIA+ Affirming Therapist: Questions and Answers to Help
Therapy for Every Budget: How to Access It
The Best Affordable or Free Online Therapy Services of 2022

SUMMARY
A well-rounded, nutritious diet high in whole grains, fruits and vegetables, nuts and seeds, and lean proteins may help reduce your symptoms of depression or lower the likelihood that you’ll experience this mental illness.

A vegan diet tends to be naturally richer in fruits, vegetables, nuts, seeds, legumes, and whole grains — foods that are all predominant in the high quality diets that studies link to a lower risk of depression (1).

A higher intake of fruits and vegetables has also been independently linked to a lower risk of depression and overall better mental wellbeing (5).

Vegan diets tend to be rich in antioxidants and other beneficial nutrients shown to be protective against depression and depressive symptoms (6).

When it comes to the research, a handful of studies suggest that people who follow a vegan diet may experience a lower risk of depression (7, 8, 9).

Yet, other studies report either no difference or a higher risk of depression in vegans than people who eat meat, eggs, or fish (10, 11, 12, 13, 14).

Currently, a vegan diet is not typically recommended as a way to treat depression.

If you’d like to give it a try nonetheless, I encourage you to seek guidance from a registered dietitian (RD) to make sure that your diet fulfills all of your nutrient requirements.

That’s because a poorly-planned vegan diet might not provide you with enough of the nutrients essential for optimal brain health, such as vitamin B-12 and long-chain omega-3 fatty acids. That means making sure your diet is well-planned is a must (15, 16, 17).

If you’re worried that working with an RD is outside of your budget, remember that many RDs accept health insurance and Medicare or can adjust fees based on a sliding scale to help make their services more affordable.

SUMMARY
A vegan diet seems to improve symptoms of depression for some people but worsen them for others. If you’re considering giving a vegan diet a try, make sure it’s well-planned so you don’t experience any nutrient deficiencies.

Some studies report that people eating a vegetarian or vegan diet may have an increased risk of depression and other mental illnesses.

For example, research has found an association between diets that eliminate entire food groups, including vegetarian and vegan diets, with eating disorders like orthorexia nervosa and anorexia nervosa (18, 19, 20).

Heads up

Trying to “do it right” when it comes to nutrition may feel tempting, but it can backfire.

If you are preoccupied with food or your weight, feel guilt surrounding your food choices, or routinely engage in restrictive diets, consider reaching out for support. These behaviors may indicate a disordered relationship with food or an eating disorder.

Disordered eating and eating disorders can affect anyone, regardless of gender identity, race, age, socioeconomic status, body size, or other identities.

They can be caused by any combination of biological, social, cultural, and environmental factors — not just by exposure to diet culture.

Feel empowered to talk with a qualified healthcare professional, such as a registered dietitian, if you’re struggling.

You can also chat, call, or text anonymously with trained volunteers at the National Eating Disorders Association helpline for free or explore the organization’s free and low cost resources.

However, others find either no change in risk or a lower risk of depression when eating a vegetarian or vegan diet (1).

Experts believe that the lack of consensus in the study findings can be explained by various factors. For instance, it’s possible that people with an already existing mental health issue may be more likely to try a vegan diet as a way to reduce their symptoms.

Another possibility is that people with depression have personality factors that may make them more likely to empathize with animals. As a result, they may stop eating meat and other animal products to live in accordance with their personal ethics (21).

The nutrient content of the diet may be yet another factor to consider.

For instance, omega-3s, choline, vitamins B-6 and B-12, and folate — as well as certain specific animo acids — are necessary to produce serotonin, dopamine, and norepinephrine. Those are three neurotransmitters (your body’s chemical messengers) that help regulate mood (1).

A well-planned vegan diet can provide enough of all of these nutrients. However, a poorly-planned one may lack sufficient amounts of the nutrients required for optimal brain functioning (22).

Most of the current studies don’t mention the participants’ nutrient status or the composition of the vegan diet they ate. Therefore, we need studies that are better designed before we can make strong conclusions.

Until more is known, people with depression who wish to try a vegan diet should consider reaching out to a RD specializing in plant-based diets to ensure that they meet all of their nutrient needs.

And remember, diet changes aren’t proven to cure mental health conditions, so feel empowered to reach out to a healthcare professional for additional support.

SUMMARY
It’s unclear whether a well-planned vegan diet contributes to depression. If you have depressive symptoms and wish to try a vegan diet, it’s especially important to speak with a dietitian to make sure it is well-planned to prevent nutrient deficiencies.

Experts suggest that choline, vitamins B-6 and B-12, and folate, as well as certain amino acids, are essential for your body to produce sufficient amounts of the neurotransmitters needed to regulate your mood (1).

Long-chain omega-3s also appear to help regulate dopamine and serotonin levels, which is why they are believed to help decrease symptoms of both depression and anxiety (1).

A vegan diet tends to be lower in some of these nutrients — particularly vitamin B-12 and long-chain omega-3s (1).

Therefore, vegans should take special attention to ensure a sufficient intake of these nutrients, either through fortified foods or supplements.

Foods typically fortified in vitamin B-12 include plant milks, breakfast cereals, nutritional yeast, and certain mock meats (23).

Vegan foods that are naturally rich in long-chain omega-3s are limited to algae and algae oil. However, you may help your body produce slightly more of these long-chain omega-3s by eating foods rich in alpha-linolenic acid (ALA), such as:

chia seeds
flaxseeds
walnuts
hemp seeds

That said, your body’s ability to convert ALA to long-chain omega-3s appears to be limited. Therefore, an algae oil supplement may also be beneficial (24).

It’s also worth remembering that high quality diets, regardless of the type, were the ones linked to a lower risk of depression (4).

Not all vegan diets are equally high in quality. To maximize your benefits, try favoring whole or minimally-processed plant foods over ultra-processed ones, such as meat and cheese substitutes, sweets, and pre-packaged vegan meals or snacks.

And always keep in mind that your diet isn’t the only factor playing a role in depression. Therefore, it’s important to explore all of the treatment avenues available to you together with a qualified mental health professional.

SUMMARY
To reduce your risk of depression on a vegan diet, it’s worth making sure your diet is made up mostly of whole and minimally-processed plant foods. It should also include fortified foods or supplements.

The relationship between veganism and depression is currently unclear. A vegan diet sometimes appears helpful at reducing symptoms of depression, but other times seems linked to a higher risk of depression.

If you’re experiencing depression and are curious about giving a vegan diet a try, consider one that prioritizes minimally-processed plant foods and provides sufficient amounts of all essential nutrients, including vitamin B12 and long-chain omega-3s.

You may need to take supplements or choose fortified foods to make sure you consume enough of the nutrients that support brain health and mood regulation, as vegan diets can lack them.

Reaching out to an RD to ensure that your vegan diet is well-planned and meets all of your nutrient needs can be helpful.

If you’ve made changes to your diet and are still not feeling better or if your symptoms are severe and affecting your day-to-day life, make sure to discuss other options, including medication, with a qualified mental healthcare provider.

Just one thing

Try this today: If you’re new to a vegan diet but cannot afford to book an appointment with a registered dietitian, I suggest you check out the Vegan Society. It’s a great tool to help you get started and includes free resources created by RDs specializing in a vegan diet.

Vegetarianism and veganism compared with mental health and cognitive outcomes: a systematic review and meta-analysis

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Meta-Analysis

. 2021 Mar 9;79(4):361-381.

doi: 10.1093/nutrit/nuaa030.

Isabel Iguacel^{1 2 3 4}, Inge Huybrechts⁵, Luis A Moreno^{6 7 8}, Nathalie Michels⁹

Affiliations

¹ GENUD (Growth, Exercise, NUtrition and Development) Research Group, Faculty of Health Sciences , University of Zaragoza, Zaragoza, Spain.
² Instituto Agroalimentario de Aragón, Zaragoza, Spain.
³ Instituto de Investigación Sanitaria Aragón, Zaragoza, Spain.
⁴ CIBERObn (Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición), Zaragoza, Spain.
⁵ Department of Public Health, Ghent University, Ghent, Belgium; and the International Agency for Research on Cancer, World Health Organization, Lyon, France.
⁶ GENUD (Growth, Exercise, NUtrition and Development) Research Group, Faculty of Health Sciences, University of Zaragoza, Zaragoza, Spain.
⁷ Instituto Agroalimentario de Aragón, Zaragoza, Spain; the Instituto de Investigación Sanitaria Aragón, Zaragoza, Spain.
⁸ CIBERObn (Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición) , Zaragoza, Spain.
⁹ Department of Public Health, Ghent University, Ghent, Belgium.

PMID: 32483598
DOI: 10.1093/nutrit/nuaa030

Meta-Analysis

Isabel Iguacel et al. Nutr Rev. 2021.

. 2021 Mar 9;79(4):361-381.

doi: 10.1093/nutrit/nuaa030.

Authors

Isabel Iguacel^{1 2 3 4}, Inge Huybrechts⁵, Luis A Moreno^{6 7 8}, Nathalie Michels⁹

Affiliations

¹ GENUD (Growth, Exercise, NUtrition and Development) Research Group, Faculty of Health Sciences , University of Zaragoza, Zaragoza, Spain.
² Instituto Agroalimentario de Aragón, Zaragoza, Spain.
³ Instituto de Investigación Sanitaria Aragón, Zaragoza, Spain.
⁴ CIBERObn (Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición), Zaragoza, Spain.
⁵ Department of Public Health, Ghent University, Ghent, Belgium; and the International Agency for Research on Cancer, World Health Organization, Lyon, France.
⁶ GENUD (Growth, Exercise, NUtrition and Development) Research Group, Faculty of Health Sciences, University of Zaragoza, Zaragoza, Spain.
⁷ Instituto Agroalimentario de Aragón, Zaragoza, Spain; the Instituto de Investigación Sanitaria Aragón, Zaragoza, Spain.
⁸ CIBERObn (Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición) , Zaragoza, Spain.
⁹ Department of Public Health, Ghent University, Ghent, Belgium.

PMID: 32483598
DOI: 10.1093/nutrit/nuaa030

Abstract

Context: Vegetarian and vegan diets are increasing in popularity. Although they provide beneficial health effects, they may also lead to nutritional deficiencies. Cognitive impairment and mental health disorders have a high economic burden.

Objective: A meta-analysis was conducted to examine the relationship between vegan or vegetarian diets and cognitive and mental health.

Data sources: PubMed, Scopus, ScienceDirect, and Proquest databases were examined from inception to July 2018.

Study selection: Original observational or interventional human studies of vegan/vegetarian diets were selected independently by 2 authors.

Data extraction: Raw means and standard deviations were used as continuous outcomes, while numbers of events were used as categorical outcomes.

Results: Of 1249 publications identified, 13 were included, with 17 809 individuals in total. No significant association was found between diet and the continuous depression score, stress, well-being, or cognitive impairment. Vegans/vegetarians were at increased risk for depression (odds ratio = 2.142; 95%CI, 1.105-4.148) and had lower anxiety scores (mean difference = -0.847; 95%CI, -1.677 to -0.018). Heterogeneity was large, and thus subgroup analyses showed numerous differences.

Conclusions: Vegan or vegetarian diets were related to a higher risk of depression and lower anxiety scores, but no differences for other outcomes were found. Subgroup analyses of anxiety showed a higher risk of anxiety, mainly in participants under 26 years of age and in studies with a higher quality. More studies with better overall quality are needed to make clear positive or negative associations.

Systematic review registration: PROSPERO registration no. CRD42018097204.

Keywords: anxiety; cognition; dementia; depression; memory; mental health; stress; vegan; vegetarian diet; well-being.

Cited by

The Association between Vegan, Vegetarian, and Omnivore Diet Quality and Depressive Symptoms in Adults: A Cross-Sectional Study.
Walsh H, Lee M, Best T. Walsh H, et al. Int J Environ Res Public Health. 2023 Feb 13;20(4):3258. doi: 10.3390/ijerph30043258. Int J Environ Res Public Health. 2023. PMID: 36833953 Free PMC article.
Mediterranean-Style Diet and Other Determinants of Well-Being in Omnivorous, Vegetarian, and Vegan Women.
Kaluza J, Lozynska K, Rudzinska J, Granda D, Sicinska E, Szmidt MK. Kaluza J, et al. Nutrients. 2023 Feb 1;15(3):725. doi: 10.3390/nu15030725. Nutrients. 2023. PMID: 36771431 Free PMC article.
Effect of a Vegan Diet on Alzheimer's Disease.
Katonova A, Sheardova K, Amlerova J, Angelucci F, Hort J. Katonova A, et al. Int J Mol Sci. 2022 Nov 29;23(23):14924. doi: 10.3390/ijms232314924. Int J Mol Sci. 2022. PMID: 36499257 Free PMC article. Review.
The importance of vitamin B₁₂ for individuals choosing plant-based diets.
Niklewicz A, Smith AD, Smith A, Holzer A, Klein A, McCaddon A, Molloy AM, Wolffenbuttel BHR, Nexo E, McNulty H, Refsum H, Gueant JL, Dib MJ, Ward M, Murphy M, Green R, Ahmadi KR, Hannibal L, Warren MJ, Owen PJ; CluB-12. Niklewicz A, et al. Eur J Nutr. 2023 Apr;62(3):1551-1559. doi: 10.1007/s00394-022-03025-4. Epub 2022 Dec 5. Eur J Nutr. 2023. PMID: 36469110
Why context matters when changing the diet: A narrative review of placebo, nocebo, and psychosocial context effects and implications for outcome research and nutrition counselling.
Neumann M, Wirtz MA, Lutz G, Ernesti A, Edelhäuser F. Neumann M, et al. Front Nutr. 2022 Oct 28;9:937065. doi: 10.3389/fnut.2022.937065. eCollection 2022. Front Nutr. 2022. PMID: 36386910 Free PMC article. Review.

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Meat improves mental health | Psychological help

Image by RitaE from Pixabay

11/15/2021

According to a new meta-analysis published in the journal Critical Reviews in Food Science and Nutrition, meat consumption is associated with reduced levels of depression and anxiety.

In 2017, mental illness was recognized as the leading cause of disability worldwide. The World Health Organization estimates that about 300 million people suffer from depression and 260 million experience anxiety, reflecting a significant increase in these disorders over the past two decades.

In parallel with the observed increase in mental disorders, vegetarianism and veganism are on the rise.

These dietary choices are motivated by ethical, environmental and animal rights considerations and attempts to improve mental health through diet.

Urska Dobersek and colleagues used data from 20 existing studies with cross-sectional and longitudinal designs, as well as randomized control trials. In these studies, depression and anxiety were assessed using self-assessment, prescription medication, medical diagnosis, or diagnostic interview.

This meta-analysis included a total of 171,802 participants aged 11 to 105, of whom 157,778 ate meat and 13,259 abstained from meat. The geography of participants included Europe, Asia, North America and Oceania.

Researchers found that people who ate meat experienced lower levels of depression and anxiety compared to those who abstained from meat.

Vegans have been found to experience more depression than meat eaters. The gender of the participants did not explain these associations.

In addition, the analysis showed that the more rigorously the studies were conducted (i.e., based on physician-diagnosed mental illness rather than self-report questionnaires), the greater the benefits of eating meat.

This work has several strengths, including a large sample size and criteria to include only those studies that provided a clear dichotomy between meat eaters and abstainers.

However, researchers note several limitations. This meta-analysis included studies published only in English, which may have biased the results towards Western norms.

By ignoring articles in other languages (eg Hindi), one could miss studies that were conducted in regions with a predominantly vegetarian or plant-based diet.

In addition, despite the observed relationship between meat consumption and mental health, these results do not allow inferences about the temporal order of these variables and causal relationships.

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How a Vegan Diet Affects Intelligence and Brain Development

Zaria Gorvette
BBC Future

February 1, 2020

Image copyright Getty Images

Vegan diets are low in (and in some cases completely devoid of) important brain nutrients. Does this affect the ability of vegans to think?

The idea that avoiding meat is bad for our brains is intuitive. Yes, anthropologists have been arguing over the years about exactly how our distant ancestors ate, but many scientists believe that it took a lot of bones to suck on the development of such a unique organ as our brain.

Some even believe that it was meat that made us human.

One of the reasons they base their argument is that the mind costs us dearly: the brain consumes about 20% of all daily calories, although its weight is only 2% of our body weight.

Where is the easiest place to find that unimaginable variety of fats, amino acids, vitamins and minerals that this fastidious organ needs? Of course, in the meat of animals that have already collected this whole set for us!

Although it is hard to imagine that our ancestors abandoned meat in favor of turnips, today the picture is quite different.

Vegans and vegetarians are at greater risk of stroke than meat eaters
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According to the latest statistics, there are now about 375 million vegetarians on the planet. In the West, veganism has shed the hippie stigma and become one of the fastest growing trends of the new millennium (for example, in the US, the number of vegans grew by 600% between 2014 and 2017).

Meanwhile, in India, food without meat has been a completely common thing since the 6th century BC.

Image copyright, Getty Images

Image caption,

Some people even try to make their pets vegetarian. Opponents accuse them of cruelty to animals

On the one hand, recent concern about nutritional deficiencies in plant-based diets has led to articles with scary headlines, such as warnings that a vegan diet can stunt brain development. and cause irreparable damage to the human nervous system.

In 2016, experts from the German Nutrition Society categorically stated that a vegan diet is not recommended for children, pregnant or lactating women and adolescents. A follow-up study in 2018 confirmed this claim.

In Belgium, forcing children to eat vegan can put you in jail.

But, on the other hand, if abstaining from eating meat really affected the human brain, we would probably already notice this?

So is veganism really damaging to our intellect, or are we just afraid of something we don't know much about?

Ideally, to test the effects of a vegan diet on the brain, one would take a randomly selected group of people and ask half of them to stop eating animal products. And see what happens. But no such study has yet been carried out.

Image copyright Getty Images

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The only study even remotely close to ideal was in Kenya, where 555 schoolchildren were fed the following pattern: one-third meat soup, one-third milk soup, and one-third soup with vegetable oil or no soup at all. And so for seven school years.

Subjects were tested before and after the experiment to compare the intelligence of the three groups. It is worth noting that due to economic difficulties in the country, most of the children before the start of the experiment were de facto vegetarians.

To the researchers' surprise, tests showed that children who were given meat soup every day were significantly more intelligent than their peers by the end of the study. In addition, their arithmetic ability was the best among the three groups, but comparable to children who were given vegetable oil soup.

Of course, more research is needed to make sure this is how it all works. In addition, it is not known whether this will be the case for children from developed countries.

However, this raises intriguing questions, to say the least, about whether veganism can hold children back.

In fact, there are several important brain nutrients that are simply not found in plants and mushrooms.

Creatine, carnosine, taurine, omega-3s, heme iron, and vitamins B12 and D3 are usually only found in foods made from animal products (although they may be synthesized in the laboratory or extracted from such non-animal products, like algae, bacteria or lichen, and made into food additives).

Some others can be found in vegan foods, but in minuscule amounts: for example, to get the minimum daily requirement of vitamin B6 (1. 3 mg) from one of the richest plant sources, potatoes, you need to eat about 750 grams of it .

For potato lovers this might be nice, but still not very practical.

Image copyright, Getty Images

Image caption,

On a vegan diet, you need to eat 750 grams of potatoes a day to reach the minimum recommended vitamin B6 intake - unless you are also getting it from other sources

Although our body is able to create some of these essential substances from other ingredients in our food, it is not capable of fully meeting all needs.

It turned out that in the body of vegetarians and vegans - a reduced level of all the nutrients listed above. And in some cases, such a deficit is not an exception, but the norm.

It is currently a mystery to us how this deficiency affects the lives of vegans. But some recent research offers us some clues.

"I believe there are a number of direct implications of the current popularity of plant-based diets," says Taylor Wallis, dietitian and CEO of nutrition consultancy Think Healthy Group.

"It's not that plant foods are inherently bad, they're not. But I don't think we're educating people enough that some nutrients are found primarily in animal foods."

One of the most well-known problems for vegans is getting enough vitamin B12, which is found only in animal products such as eggs and meat.

Other species get it from bacteria that live in their digestive system or in their excrement - they either ingest it directly or eat their own feces, which is unfortunately (or fortunately - depending on the point of view) impossible for humans.

Image copyright, Getty Images

Image caption,

At first glance, vegans seem to have a varied diet. But the brain doesn't get everything it needs from it.

To understand how important vitamin B12 is for the brain, look at what happens when we don't get enough of it. For children, B12 deficiency can have serious consequences.

"There have been some tragic cases where a child's brain didn't develop properly because the parents were ill-informed vegans," says Benton.

In one case, the child could not sit, could not smile. In another case, the children simply fell into a coma.

At an older age, the amount of B12 in a person's blood is directly related to his IQ, intelligence quotient.

In old age, one study found that the brains of people with low levels of B12 are six times more likely to shrink than those without it.

And yet low B12 levels are common among vegans. One British study found that half of the vegans surveyed were deficient.

This problem is endemic in parts of India, possibly due to the prevalence of vegetarianism there.

Iron is another ingredient rare in typical vegan diets. Among other things, it plays an important role in mental development and is necessary for maintaining brain health throughout life.

For example, one 2007 study found that women taking iron supplements led to a significant (five to sevenfold) increase in their intellectual abilities.

Image copyright, Getty Images

Image caption,

It's important for vegans to take supplements to compensate for their lack of nutrients from animal products, experts say

It's surprisingly easy to slip into an iron deficiency. Up to 2 billion people are thought to experience it, making it the most common nutrient deficiency worldwide.

Vegans are particularly susceptible, as heme iron, which is most easily absorbed by the body, can only be found in animal proteins.

A German study found that 40% of vegans surveyed by scientists consumed less than the recommended daily allowance for iron.

Vegans are also often deficient in vitamin D3, omega-3 fatty acids, selenium, iodine and folic acid.

Although our bodies produce vitamin D3 when exposed to direct sunlight, it does not compensate vegans for the amount they lack.

During the winter months, omnivores in the UK have almost 40% more vitamin D3 than vegans.

Of course, some of these substances can be obtained in the form of dietary supplements. However, others are so obscure that vegans are unlikely to have even heard of them, let alone understand what exactly their body lacks.

For example, taurine. This enigmatic amino acid is one of the most abundant in our brains, where it is thought to underlie several important processes, such as regulating the number of neurons.

It is often added to coffee energy drinks because of the (probably false) belief that it gives the brain an immediate cognitive boost.

While some dairy products contain small amounts of taurine, the main source of taurine is meat and seafood.

"Some species have the ability to produce enough taurine in the body," says Yang Yen Wu, a biomedical scientist at Florida Atlantic University (USA). "But humans are almost unable to do this."

Vegans tend to have less taurine for this reason. So far, no one has yet studied how this affects their cognitive abilities.

Image copyright, Getty Images

Image caption,

A vegan diet is a kind of self-experimentation

But based on what we know about taurine's role in brain function, Wu recommends that vegans take taurine tablets - after all vegetables simply do not have this substance.

In fact, our lack of knowledge about exactly what our brain needs for health can be a big problem for vegans. After all, it is difficult to add to your diet something that scientists have not yet discovered.

"There are so many unknowns," says Nathan Kofnas, a biologist at the University of Oxford. You are risking yourself."

Let's take choline: it is used in the brain to produce acetylcholine, which is needed for many tasks, including the transmission of information between nerve cells. It is the most important substance for our ability to think (even insects have it in their tiny brains), and the body cannot produce enough of it on its own.

But it's a very poorly researched nutrient, Wallis says. "We only began to consider it important (a food-derived element) only in the late 1990s."

Some vegan foods contain some choline, but the main sources are eggs, beef and seafood.

In fact, even with a normal diet, 90% of Americans don't get enough of it. According to an unpublished study by Wallis, vegetarians consume it in the least amount of any demographic group, and this should be a concern, the scientist said.

Image copyright, Getty Images

Image caption,

Vegans can get their protein from alternative sources like soy, but soy doesn't have choline or creatine

Otherwise, we know even less. For example, creatine is a white loose substance that can often be found in fitness shakes. Its natural function in the body is to supply our cells with energy, which is why it is respected by the regulars of fitness clubs.

But it is also important for the brain. Studies show that increasing its intake has a number of benefits - such as reduced mental fatigue and improved memory recognition. Not so long ago, creatine began to be used as a "pills for the mind."

Neither vegetables nor mushrooms contain creatine - so this is a problem for vegans and vegetarians: they are known to lack creatine in their bodies.

Scientists wondered if creatine deficiency would lead to slower development in humans. In one study, they tested how the intellectual abilities of vegetarians and those who eat everything changed five days after they started taking supplements.

"We found that vegetarians especially benefited," says David Benton of Swansea University, who led the study.

As for the omnivores, little has changed. And this may indicate that they had enough creatine in their brains before.

However, Caroline Rey, who led the other study, says there is not yet enough evidence to support the need for creatine supplementation. This can lead to unforeseen consequences - for example, to reduce the ability of the brain to produce this substance itself.

"I've been suggesting for a long time that taking creatine might be useful for preparing for exams, but it would be interesting to find out what happens to people after they stop taking it - whether their intellectual abilities are inhibited."

Finally, the brain basically creates its own supply of creatine, so it's unclear if vegans really need extra creatine.

Food-based creatine may only be used by the brain in extreme cases, such as stress.

However, Kofnas is concerned about the potential for creatine deficiency in vegans.

"It can make a big difference in your life," he says, referring to the intellectual advances of vegans taking creatine supplements.

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Image caption,

Creatine, carnosine, taurine, omega-3s, heme iron, and vitamins B12 and D3 are normally only found in animal products

What's the verdict?

"I think more research is needed on the health and nutrition of vegans," says Heather Russell, a nutritionist at the Vegan Society, a British charity. who are well suited to a vegan diet."

Brain and cardiovascular health are inextricably linked, and vegans tend to have healthier hearts.

"I tell people all the time, if you want to go vegan or vegetarian, that's fine," says Wallis. to understand what their brain needs."

Moreover, some of the nutrients that vegans lack (choline, creatine, taurine and carnosine) need to be taken in fairly large amounts - one tablet is not enough.

Benton agrees. “I am sure that if you are knowledgeable, careful and committed to healthy eating, if your personality fits this hobby, then it is quite possible to be a vegan without harm to health,” he says. “But it is also clear that you may encounter nutritionally deficient."

Cofnas has a tougher take on this. While vegans can take supplements, it's unrealistic to expect all of them to do so, he says.

On this basis, he finds the current trend towards a plant-based diet disturbing, although he is sympathetic to the arguments in favor of such a diet.

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Vegetarianism and veganism compared with mental health and cognitive outcomes: a systematic review and meta-analysis

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Meat improves mental health | Psychological help

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