It’s well-established that most people should eat more plants, and generally speaking, less meat. But what about abstaining from meat completely? And what about abstaining from all animal products?

For a more general overview (rather than specifically brain health), check out: Do We Need Animal Products To Be Healthy?

Now, about brains…

Before Homo sapiens was a thing, our precursors such as Homo habilis developed language (thus: greatly enhanced collaborative teamwork) and cooking, resulting in Homo ergaster (who came approximately next in line, give or take taxonomical quibbles) having twice the cranial capacity, generally attributed to being able to acquire and—where appropriate—cook calorie-dense food, which included meat, and also tubers that can’t be safely eaten raw. It’s estimated (based on forensic examination of tooth wear, mineralization, microdeposits of various kinds, etc) that our consumption of animal products in that era was around 10% of our diet (fluctuating by region, of course), but it likely was an important one.

By the time we got to Homo erectus, our skulls (including our cranial cavities, and thus it is presumed, our brains) were actually larger than in Homo sapiens. You may be wondering about Homo neanderthalensis; our cousins (or in some cases, ancestors—but that is beyond the scope of today’s article) also had larger cranial cavities than us, and certainly enjoyed comparatively advanced culture, arts, religion, etc.

Fast-forward to the present day. Nothing is going to meaningfully change our skull size, as individuals. Brain size? Well, keep hydrated or it’ll shrink. Don’t overhydrate or it’ll swell. Neuroplasticity means we can increase (or lose) volume in specific areas of the brain, according to what we do most of. For example, if you were to scan this writer’s brain, you’d probably find overdevelopment in the various areas pertaining to language and memory, as that’s been “my thing” for as long as I can remember (which is a long way). See also: An Underrated Tool Against Alzheimer’s

The impact of diet in the modern day

Unlike our distant ancestors, if we want a high-calorie snack we can buy some nuts from the supermarket, and if anything, this can be a problem (as many people’s go-to high-calorie snack may be a lot less healthy than that), and in turn cause problems for the brain, because too many pizzas, cheeseburgers, tater tots, and so forth cause chronic inflammation, and thus, neuroinflammation.

See also: 6 Worst Foods That Cause Dementia

So much for “calories for the brain”. Yes, the brain definitely needs calories (it expends a very large portion of our daily calorie intake), but you can have too much of a good thing.

In any case, the brain needs more than just calories!

For example, you may remember the “6 Pillars Of Nutritional Psychiatry”, which are:

1. Be whole; eat whole
2. Eat the rainbow
3. The greener, the better
4. Tap into your body intelligence
5. Consistency & balance are key
6. Avoid anxiety-triggering foods

For more on all of those, see Dr. Uma Naidoo’s 6 Pillars Of Nutritional Psychiatry ← She’s a Harvard-trained psychiatrist, professional chef graduating with her culinary school’s most coveted award, and a trained nutritionist. Between those three qualifications, she knows her stuff when it comes to the niche that is nutritional psychiatry.

When it comes to any potential nutritional deficiencies of a vegetarian or vegan diet, it’s a matter of planning.

Properly planned vegetarian diets are rich in essential nutrients like carbohydrates, fiber, magnesium, potassium, folate, vitamins C and E, and an abundance of phytochemicals, which support brain health (and overall health too, but today is about brain health).

However, if not well-planned, they can indeed lack certain nutrients such as vitamin B12, iron, and omega-3 fatty acids, which are critical for brain function.

In essence, there’s a difference between a “whole foods plant-based diet” and junk food that just happens to be vegetarian or vegan.

Vitamin B12 is usually supplemented by vegans, but it can also be enjoyed from nutritional yeast used in cooking (it adds a cheesy flavor to dishes for which that’d be appropriate).

Iron is a fascinating beast, because while everyone thinks of red meat (which is indeed rich in iron), not only are there good plant-based sources of iron, but there are important considerations when it comes to bioavailability differences between heme and non-heme iron. In few words, heme iron (from blood etc) is more bioavailable by 1.8x, but all iron, including non-heme iron (from beans, greens, etc) can have its bioavailability multiplied by 5x just by having it with vitamin C:

Avoiding Anemia (More Than Just “Get More Iron”)

Omega-3 fatty acids, for vegetarians that mostly means eggs. See: Eggs: All Things In Moderation?

For vegans, we must look to nuts and seeds, for the most part. Or supplement—many omega 3 supplements are vegan, made from algae, or seaweed (that in turn is composed partially or entirely of algae):

A Deeper Dive Into Seaweed

So really, it comes down to “make sure you still get these things”, and once you’re used to it, it’s easy.

For those who prefer to keep some meat in their diet

Our summary in our top-linked article (Do We Need Animal Products To Be Healthy?) concluded:

• Most of us can live healthily and happily on just plants if we so choose.
• Some people cannot, and will require varying kinds (and quantities) of animal products.
• As for red and/or processed meats, we’re not the boss of you, but from a health perspective, the science is clear: unless you have a circumstance that really necessitates it, just don’t.
  • Same goes for pork, which isn’t red and may not be processed, but metabolically it’s associated with the same problems.
• The jury is out on poultry, but it strongly appears to be optional, healthwise, without making much of a difference either way
• Fish is roundly considered healthful in moderation. Enjoy it if you want, don’t if you don’t.

And the paper from which we’ve largely been working from today included such comments as:

❝ Evidence suggests that vegan and vegetarian diets, when well planned, can be rich in phytonutrients and antioxidants, which have been associated with lower levels of inflammatory markers, such as C-reactive protein (CRP) and interleukin-6 (IL-6). These findings indicate a potential role in reducing systemic inflammation and oxidative stress, both of which are linked to neurodegenerative diseases.

However, deficiencies in critical nutrients such as vitamin B12, DHA, EPA, and iron have been consistently associated with an increased risk of cognitive decline, mood disturbances, and neurodegenerative disorders.

While plant-based diets provide anti-inflammatory and antioxidant benefits, their neurological implications depend on nutrient adequacy. Proper planning, supplementation, and food preparation techniques are essential to mitigate risks and enhance cognitive health.❞

Source: Impact of Vegan and Vegetarian Diets on Neurological Health: A Critical Review ← you can see that they also cover the same nutrients that we do

One final note, not discussed above

We often say “what’s good for your heart is good for your brain”, because the former feeds the latter (with oxygen and nutrients) and assists in cleanup (of detritus that otherwise brings about cognitive decline).

So with that in mind…

What Matters Most For Your Heart? ← hint: it’s fiber. So whether you eat animal products or not, please do eat plenty of plants!

Take care!