Colorful fruits and vegetables are dietary superheroes—no doubt about that. But a growing number of experts are saying that forsaking all animal products could starve the brain of crucial nutrients.
Strictly vegan regimes lack nutrients such as complete proteins, certain healthy fats, zinc, and iron and may fail to adequately nourish the brain, potentially hampering mood, memory, and cognitive prowess.
Missing Nutrients
The deterioration in mental health over the past 75 years correlates with a decline in dietary quality, according to Dr. Georgia Ede, a Harvard-trained psychiatrist specializing in nutrition science and brain metabolism and author of “Change Your Diet, Change Your Mind.”
Both animal- and plant-based foods play a role in optimizing brain health, Shani La Grange, a registered dietitian, told The Epoch Times. Fiber intake is as important as protein intake to encourage the production of serotonin, which is important for several body functions, including mood stabilization, cognition, learning, and memory, she added. Fiber found in plant-derived foods stimulates the production of short-chain fatty acids, which, in turn, stimulates the production of serotonin.
A higher intake of plant-based foods could also promote a more anti-inflammatory effect, which could promote healthy brain aging and decrease the risk of certain conditions such as dementia.
However, Ms. La Grange said that strict plant-based diets pose a risk of vitamin B12 and iron deficiency (if not supplemented), which could be detrimental to neurological and cognitive health and might impair cognitive functioning.
Besides micronutrients, animal-derived fats and proteins are optimal for human physiology and structure, Dr. Natasha Campbell-McBride, a medical doctor with postgraduate degrees in neurology and human nutrition, wrote in her book “Vegetarianism Explained.” Her research suggests that fat and protein are the primary constituents of the human body after water, serving as vital building blocks for organs, bones, muscles, and the brain.
While a well-planned, adequately supplemented vegetarian diet with whole foods and eggs may support brain health, vegan diets pose nutritional deficiencies that are difficult to overcome even with careful supplementation, Dr. Ede said. The risks to mental health hinge on how plant-based diets are constructed.
For any diet to be “brain-healthy,” it must accomplish three objectives, according to Dr. Ede:
- Nourish the brain with all essential nutrients without relying on fortified processed foods or supplements, including some animal-source foods in the diet is recommended.
- Protect the brain by excluding ultra-processed ingredients such as refined carbs.
- Energize the brain by maintaining healthy blood sugar and insulin levels throughout life.
The Brain’s Need for Fat
The brain is two-thirds fat, with 20 percent being the essential omega-3 fatty acid docosahexaenoic acid (DHA), which plays a crucial role in cognitive function, according to Dr. Ede.
A 2019 review in the Asia Pacific Journal of Clinical Nutrition showed DHA’s essentiality for optimal neuronal function. The Framingham Heart Study, published in 2006 in the Journal of the American Medical Association’s Archives of Neurology, revealed a notable correlation: Higher plasma DHA levels corresponded with a reduced risk of all-cause dementia. People in the top quartile of plasma DHA experienced a 47 percent decreased risk of dementia.
According to Dr. Ede, the problem is that plant-based foods lack DHA, forcing reliance solely on animal-derived sources for this vital nutrient. While plants contain the omega-3 alpha-linolenic acid (ALA), converting it into the brain-critical DHA is exceedingly difficult, if not impossible.
A clinical trial involving young adult men published in the British Journal of Nutrition found that these men exhibit very low or absent capacity to convert ALA to DHA. Further insights came from another study on healthy young women, suggesting women have a slightly greater ALA-to-DHA conversion ability than men, potentially to meet the demands of fetal development and lactation.
The American Journal of Clinical Nutrition published a study comparing omega-3 levels. It showed that DHA levels were 31 percent lower in vegetarians and 59 percent lower in vegans compared to people who ate meat.
Inefficient Absorption
There are nutritional disparities between animal-based and plant-based foods, according to Dr. Ede. Only nondairy animal foods, including meat, seafood, and poultry, provide every essential nutrient in its most bioavailable form, she noted.
In contrast, not only do plant foods lack certain vital nutrients, but the forms of the nutrients they contain can also pose challenges for human use, Dr. Ede said.
Plant foods contain antinutrients that impede our ability to absorb nutrients from both plant and animal-derived foods.
“Just because a plant food contains a nutrient doesn’t mean we can access it,” Dr. Ede said.
For instance, grains, beans, nuts, and seeds are rich in phytate, an antinutrient known to inhibit the absorption of essential minerals such as iron, zinc, calcium, and magnesium, she noted. These minerals are crucial for various functions, including dopamine synthesis, neurotransmitter production, and energy metabolism, which are vital for optimal brain health and function.
Our eyes, brains, and immune systems rely on vitamin A for their function and structure. While plants contain carotenoids, which can be converted into retinol (the functional form of vitamin A) in a healthy body, Dr. Ede said this conversion process is challenging. Environmental toxins and nutritional deficiencies can hinder this conversion, leading to vitamin A deficiency despite one consuming carotenoid-rich plants such as carrots, sweet potatoes, and kale, she added.
Enhance Nutrient Absorption in Plant-Based Diets
Prudent cooking practices, ideal food combinations, and sprouting and fermentation processes can significantly improve the bioavailability of micronutrients from plant-based foods.
Specifically, sprouting and fermentation have been shown to enhance the bioavailability of iron and beta-carotene from plant foods, according to a 2016 review published in Critical Reviews in Food Science and Nutrition.
With careful meal planning and proper supplementation, it is theoretically possible for adults following a vegan or vegetarian diet—excluding pregnant or breastfeeding women—to meet their requirements for all essential nutrients, Dr. Ede said. However, achieving this can be challenging and requires diligent effort, she added.
Finding Balance
Plants primarily function as cleansers for the body, according to Dr. Campbell-McBride.
In their natural state, plants contain detoxifying compounds that aid in the removal of harmful chemicals and toxins accumulated in our bodies. However, it’s essential to reintroduce animal-based foods after a cleanse to prevent the body from deteriorating and experiencing starvation, she said.
This doesn’t mean one should overeat meat, as that also has its downsides. Some research has linked long-term, very high intake of animal proteins—especially red meat—to suboptimal brain health. In moderation, however, protein found in animal-based products is essential to overall nutrition, Ms. La Grange said.
