How does a vegan diet affect intelligence and brain development?

The vegan diet contains low levels (and in some cases, no levels) of important brain nutrients. Does this affect vegans’ ability to think? The idea that avoiding meat is harmful to our brains is intuitive. Yes, anthropologists have argued for many years about how our distant ancestors ate, but many scientists believe that in order for an organ as unique as our brain to develop, it required a significant amount of bone marrow. Some are even convinced that it was meat that made us human.

One of the reasons for their arguments is that reason is costly to us: the brain consumes about 20% of all daily calories, although it weighs only 2% of our body weight. And where is it easiest to find the unimaginable variety of fats, amino acids, vitamins, and minerals that this finicky organ needs? Of course, in the meat of animals that have already assembled this set for us! And although it is hard to imagine our ancestors giving up meat in favor of turnips, the picture is very different today. According to the latest statistics, there are currently about 375 million vegetarians on the planet. In the West, veganism has shed its hippie stigma and become one of the fastest-growing trends of the new millennium (for example, the number of vegans in the United States increased by 600% between 2014 and 2017). Meanwhile, in India, vegetarianism has been a common practice since the 6th century BC.

Some even try to get their pets used to vegetarianism. Opponents accuse them of cruelty to animals. On the one hand, recent concerns about nutritional gaps in plant-based diets have led to articles with alarming headlines – for example, warning that a vegan diet can inhibit brain development and cause irreversible damage to the human nervous system. In 2016, experts from the German Society for Nutrition categorically stated: “A vegan diet is not recommended for children, pregnant or breastfeeding women, and adolescents. A repeated study in 2018 confirmed this statement. In Belgium, forcing children to follow a vegan diet can land you in jail. On the other hand, if abstaining from meat had a real effect on the human brain, we would probably have noticed it by now. So is veganism actually harmful to our intelligence, or are we just afraid of something we know little about? Ideally, to study the effects of a vegan diet on the brain, you would have to take a random group of people and ask half of them to stop eating animal products. And see what happens. But no such study has been done.

100% vegan food sounds proud. But is it all that good? We explain quickly, simply, and clearly what happened, why it matters, and what happens next. The number of episodes should remain the same. End of podcast advertising story. The only study that comes close to being ideal was conducted in Kenya, where 555 schoolchildren were given a diet like this: one-third meat soup, another third milk, and the remaining third soup with vegetable oil or no soup at all. This was done for seven school years. The subjects were tested before and after the experiment in order to compare the intelligence of the representatives of the three groups. It is worth noting that due to economic difficulties in the country, the majority of the children were de facto vegetarians before the experiment began. To the scientists’ surprise, tests showed that by the end of the study, the children who were given meat soup every day were significantly more intelligent than their peers. In addition, their arithmetic skills were the best of the three groups, but comparable to the children who were given soup with vegetable oil. Of course, more research is needed to be sure that this is the case. It is also unknown whether this will be the case for children from developed countries. Nevertheless, this raises the intriguing question, to say the least, of whether veganism may hinder children’s development.

In fact, there are several important nutrients for the brain that are simply not found in plants and fungi. Creatine, carnosine, taurine, omega-3, heme iron, and vitamins B12 and D3 are usually found only in foods prepared from animal sources (although they can be synthesized in the laboratory or extracted from non-animal sources such as algae, bacteria, or lichen and converted into dietary supplements). Some others can be found in vegan foods, but in tiny amounts: for example, to get the minimum daily requirement of vitamin B6 (1.3 mg) from one of the richest plant sources, potatoes, you would need to eat about 750 grams of it. This may be good for potato lovers, but it is still not very practical.

On a vegan diet, you need to consume about 750 grams of potatoes per day to get the minimum recommended dose of vitamin B6 – if you are not getting it from other sources. And while our bodies are able to produce some of these necessary substances from other ingredients in our food, they are not able to meet all of our needs. It turns out that vegetarians and vegans have reduced levels of all the above nutrients in their bodies. And in some cases, this deficiency is not the exception, but the rule. How this shortage affects the lives of vegans is currently a mystery. But some recent research gives us some clues. “I believe there are several direct consequences of the current popularity of plant-based diets,” says Taylor Wallis, registered dietitian and CEO of Think Healthy Group, a nutrition consulting firm. “It’s not that plant-based products are inherently harmful, that’s not true. But it seems to me that we don’t explain to people enough that certain essential nutrients are primarily found in animal products.

One of the most common 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 living in their digestive systems or in their feces – they either ingest it directly or eat their own feces, which is unfortunately (or fortunately, depending on your point of view) not possible for humans.

At first glance, it seems that vegans have a wide variety of foods to choose from. However, their brains are not getting all the nutrients they need. To understand how important vitamin B12 is for the brain, let’s look at what happens when we don’t get enough of it. B12 deficiency can have very serious consequences for children. “There have been several tragic cases where a child’s brain did not develop properly because their parents were ill-informed vegans,” says Benton. In one case, the child could not sit, could not smile. In another case, the children simply went into a coma. As people age, the amount of B12 in their blood is directly related to their IQ, or intelligence quotient. As people age, one study found that the brains of people with low levels of B12 are six times more likely to deteriorate than those who are not deficient. And yet, low B12 levels are a common problem among vegans. A British study found that half of the vegans surveyed were deficient. In some regions of India, this problem is endemic, possibly due to the prevalence of vegetarianism.

Iron is another ingredient that is rare in typical vegan diets. Among other things, it plays an important role in mental development and is necessary to maintain brain health throughout life. For example, a 2007 study found that women who took iron supplements experienced a significant (five to seven times) increase in their intellectual abilities.

Experts believe that it is very important for vegans to take biodegradable supplements to compensate for the lack of nutrients from animal products in their bodies. It is surprisingly easy to develop an iron deficiency in the body. It is believed that up to 2 billion people suffer from iron deficiency, making it the most common nutritional deficiency in the world. Vegans are particularly at risk because heme iron, which is most easily absorbed by the body, is found only in animal protein. One of the German studies found that 40% of vegans surveyed consumed less than the recommended daily intake of iron. Vegans are also often deficient in vitamin D3, omega-3 unsaturated fatty acids, selenium, iodine, and folic acid. Although our bodies produce vitamin D3 when we are exposed to direct sunlight, it does not compensate for the amount vegans lack. During the winter months, the blood of omnivores in the UK contains almost 40% more vitamin D3 than that of vegans. Of course, some of these substances can be obtained in the form of biodegradable additives. Others, however, are so little known that vegans are unlikely to have even heard of them, let alone understand what their bodies are missing. Take taurine, for example. This mysterious amino acid is one of the most abundant in our brain, where it is believed to be the basis of several important processes, such as regulating the number of neurons. It is often added to coffee energy drinks in the (probably false) belief that it gives the brain an instant cognitive boost. And although a small amount of taurine is found in some dairy products, its main source is meat and seafood. “Some biological species have the ability to produce a sufficient amount of taurine in their organisms,” says Yan En Wu, a biomedical scientist at Florida Atlantic University (USA). “But humans are almost incapable of doing so.” For this reason, vegans tend to have less taurine in their bodies. No one has studied how this affects their cognitive abilities.

The vegan diet is, in a sense, an experiment on oneself. However, based on what we know about taurine’s role in brain function, Wu recommends that vegans take taurine in pill form – because vegetables simply do not contain it. In fact, the lack of knowledge about what exactly our brains need for health can become a big problem for vegans. After all, it’s hard to add to your diet what scientists haven’t yet discovered. “There is so much that is unknown,” says Nathan Kofnas, a biologist at the University of Oxford. “If you deviate from the typical diet for your biological species and switch to a diet that has not been tested for brain health criteria, you are experimenting on yourself and taking risks.” Take choline: it helps the brain produce acetylcholine, which is necessary for a variety of tasks, including the transmission of information between nerve cells. This 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 this is a very poorly understood nutrient,” Wallis says. “We only started to consider it important (as a dietary element) in the late 1990s.” Some vegan products contain small amounts of choline, but the main sources are eggs, beef, and seafood. In fact, even with a normal diet, 90% of Americans do not get enough of it. According to Wallace’s unpublished research, vegetarians consume the least of any demographic group, and that should be concerning, the scientist believes.

Vegans can get the protein they need from alternative sources such as soy, but soy does not contain choline or creatine. In other cases, we know even less. Creatine, for example, is a white powdery substance often found in fitness cocktails. Its natural function in the body is to provide energy to our cells, which is why it is revered by health club regulars. But it is also important for the brain. Research shows that increasing creatine intake has a number of benefits, including reducing mental fatigue and improving recognition memory. Recently, creatine has been used as a “smart pill”. Neither vegetables nor mushrooms contain creatine, so this is a problem for vegans and vegetarians: their bodies are known to lack creatine. Scientists wondered if a creatine deficit could lead to a slowdown in human development. In a study, they tested how the intellectual abilities of vegetarians and those who ate everything changed after five days of taking bio-supplements. “We found that vegetarians in particular benefited,” says David Benton of Swansea University, who led the study. And here not much has changed for omnivores. And this may indicate that they already had enough creatine in their brain before. However, Caroline Ray, who led another study, says there is currently not enough evidence to support the need for creatine supplementation. Doing so could have unintended consequences, such as reducing the brain’s ability to produce the substance itself. “I have long hypothesized that creatine supplementation may be beneficial for test preparation, but it would be interesting to find out what happens to people after they stop taking it – whether their intellectual abilities slow down. Finally, the brain makes most of its own creatine reserves, so it is unclear whether vegans really need extra. Food-based creatine can only be used by the brain in extreme cases, such as during times of stress. However, Kofnas is concerned about the potential creatine deficit in the vegan body. “It can have a significant impact on your life,” he says, referring to the intellectual advances of vegans who have taken creatine supplements.

Creatine, carnosine, taurine, omega-3, heme iron, and vitamins B12 and D3 are typically found only in animal products. “I think new research is needed into the health and nutrition of vegans,” says Heather Russell, a nutritionist with the Vegan Society, a British charity.

As far as we can judge at the moment, it is possible to be vegan and have a healthy lifestyle – there are undoubtedly people for whom a vegan diet is very appropriate. Brain health and cardiovascular health are closely linked, and vegans tend to have healthier hearts.

“I always tell people, if you want to be vegan or vegetarian, that’s fine,” Wallace says. “I certainly have nothing against that. But there are about 40 essential nutrients. So vegans should study this very carefully to understand what their brains need. Also, some of the nutrients that vegans are deficient in (such as choline, creatine, taurine, and carnosine) need to be consumed in fairly large amounts – you can’t get by with just one tablet.

Benton agrees. “I am confident that if you are knowledgeable, careful, and committed to a healthy diet, if the characteristics of your personality match that passion, then it is quite possible to be a vegan without compromising your health,” he says. “But it is also clear that you may face nutrient deficiencies.”

Kofnas takes a more rigid view. Although vegans can take bioiddavki, he believes it is unrealistic to expect everyone to do so. As a result, he finds the modern trend of switching to a plant-based diet alarming, although he sympathizes with the arguments in favor of such a diet. “Without a doubt, veganism can cause iron and vitamin B12 deficiency, and without a doubt, this deficiency affects your intellectual abilities,” he points out.

Mahatma Gandhi, a lifelong vegetarian, tried meat only once in his life – and he did not like it. It is said that Mahatma Gandhi, India’s national hero and a hereditary vegetarian, decided to try meat as a teenager under the influence of friends. He found it tough and tasteless and never touched it again. But his dietary experiments did not stop there. He gave up salt, then went back to it, then tried veganism. After suffering from dysentery, which turned him into a walking skeleton, he decided that consuming dairy products was necessary for his health after all…

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Vegan Jordi Casamitjana has taken this case to the Employment Tribunal of the English city of Norwich, claiming that he was sacked from the animal welfare charity League Against Cruel Sports because of his vegan beliefs.