The other day, Jeff D. asked some great questions in the comments section of my post 10 Things I Wish I Knew Before I Went Vegan:
What are your thoughts concerning the inability to get B12 naturally on a vegan diet? It’s necessary for the body but a vegan diet only seems to get B12 through fortified foods and supplements.
Also, what about grains? It seems that a vegan diet relies on a lot of grains (bread, pasta, cereal, etc.). Recent research and acknowledgement of our anthropological history point to the idea that our bodies were not meant to process grains (especially gluten-based ones).
Grains are a topic for another post (check out The Paleo Diet Debunked?, by my friend Steve — a Paleo proponent but whose view on grains is almost identical to mine).
Right now, let’s stick to the B12 question; it’s a common one. Often, it takes a more argumentative and challenging tone, like this:
If we were really meant to be vegan, then why would we need to supplement with B12?
There’s little doubt about the presupposition: a vegan diet, without supplementation or fortification, is deficient in vitamin B12. Some will argue that you can get B12 from chlorella or “dirty produce,” and that before modern agricultural practices there was more B12 in the soil, but that’s not the discussion I want to have here.
My assumption in this post is that you can’t get B12, in the necessary amount, from a vegan diet unless you supplement or eat fortified foods. So …
How can one say we’re meant to be vegan?
My answer to this question often surprises the person asking me, and it might surprise you, too: I don’t think we’re “meant” to be vegan.
If there’s anything we’re meant to do, from an evolutionary perspective, it’s “reach reproductive age and have kids that do the same.” On whatever diet our environment affords us.
And, you must admit, our bodies are pretty remarkable in their ability to do this — to survive, and often thrive, on a huge range of diets.
Just look at how many people eat the Standard American Diet — it’s called “standard” for a reason. Anyone who thinks about their food agrees that the SAD is horrible, yet most people who eat that way don’t have any problem living long enough to have kids and to care for those kids until they’re old enough to care for themselves.
Less extreme: look at pro athletes, and what a vast range of diets they have. Whether in endurance sports, mainstream sports, Olympic sports, or combat sports, you can find someone on top of the world eating whichever diet you’re searching for. Paleo, vegan, fruitarian, fast food … you name it, someone (in a relatively small pool of elite athletes) is doing it.
The criteria for deciding which diet is best
So meant is a confusing term. Is the diet that maximizes longevity the one we’re “meant” to eat? Or is it the one, say, that makes us perform the best in sports, or the one that gives us six-pack abs?
Most of us aren’t pro athletes or even serious athletes. We do the sports we do in order to enrich our lives, but that’s it. And abs, well, we know you can have those for three easy payments of $19.99, and they’ll even throw in some Mighty Putty. So we’ll leave that be.
For me, and I suspect most other people, longevity is what we’re after.
Let’s look at the question from that perspective: What populations of people live the longest, and what do they eat?
Dr. Joel Fuhrman devotes a small section in his excellent book Super Immunity to this question. And his answer is:
The longest-lived societies in history — such as the Hunzas in central Asia, the Abkhazians in southern Russia, the Vilcambans in the Andes of South America, and the Okinawans in Japan — all ate very little animal products but were not completely vegan. As we drift considerably up from the occasional use of animal products, to include animal products in significant amounts, we see evidence that more heart disease and most cancers become more prevalent.
Of course, the source Fuhrman cites for this last assertion is T. Colin Campbell’s famous China study (not the book but the study itself), one that has drawn criticism, like many longevity studies, for mistaking correlation for causality. (Namely: people who choose plant-based diets tend already to make healthier choices, making it tougher to determine whether it’s the diet or their healthy lifestyle in general that is responsible for their longevity.)
But Fuhrman later describes the Adventist Health Studies, which were designed so as not to make this causation/correlation mistake. The population studied, the Seventh Day Adventists, is almost completely free of alcohol and tobacco use and lives a nearly uniformly healthy lifestyle, with one exception: half are vegetarian, and half eat small amounts of meat.
As it turns out, the study found that the vegetarians lived longer than those who ate small amounts of meat, but other factors like whether or not someone ate nuts and seeds actually had a larger effect on longevity than whether that person was vegetarian or near-vegetarian.
But back to B12 …
So if the healthiest populations in history have mainly eaten diets that include a small but (importantly!) nonzero amount of meat, what does that tell us?
To me, it says our bodies our great at thriving on plants, but there’s something in animal products that we need and can’t get elsewhere without supplementing. And that something is what we know as B12.
So the question remains:
If B12 is the only reason we used to need meat, and we can now supplement with B12 and avoid meat entirely, do we maximize health by doing so?
Studies like the Adventist Health Study, mentioned above, point to “yes,” but still with some hesitation over causality versus correlation. But the differences between a vegan diet and a near-vegan diet appear to be tiny, so tiny that I think they can be ignored (when it comes to health, not ethics, of course).
Even pro-vegan Dr. Fuhrman actually believes that a 100% vegan diet can result in “suboptimal levels” of other nutrients, like DHA, EPA, iodine, and zinc. But eating more animal products as a way to get these nutrients leads to increased heart disease and cancer rates, according to his research.
(This is why I like Dr. Furhman’s work, by the way. He avoids dogma and doesn’t let ethical leanings color his understanding and advice about health – I’m not even sure what his ethical stance on veganism is. When a scientist can’t admit a single fault of his or her diet of choice, that sounds an awful lot like religion to me.)
For me, the take home message, and (finally) my answer to Jeff’s question, is:
I believe that a diet with a very small amount of animal products, like what we see in the diets of the longest-lived societies, is extremely healthy. It’s clear that we need B12, and if there were no other way to get B12, then in general, I would consider a diet with a lot of plants and a very small amount of meat to be the healthiest possible type of diet.
Fortunately, for those of us with ethical reasons for wanting to avoid animal products, we can now do so healthily, by supplementing with B12. I haven’t seen any good evidence that a plant-based diet of mostly whole foods, along with a B12 supplement, is less healthy than any other diet — some studies show that a vegan diet might actually be healthier than a whole-food based diet that includes a tiny amount of meat, but to me it’s not clear that the difference is significant.
Whole foods, mostly plants
Eat whole foods, eat lots of plants, and whether you choose to eat a small amount of meat or not won’t make much difference in the healthfulness of your diet.
Ethically, it makes a dramatic difference, and that’s why I choose to be vegan. But arguing about whether a whole-foods based diet that includes a small amount of meat is healthier than a whole-foods, plant-based diet seems to me like a waste of time, when other factors make a bigger difference in health — like nuts and seeds in the Adventist Health Study, for example.
Worse, the argument unnecessarily widens the gap between whole-food vegans and whole-food omnivores. We’re both in the healthy minority, and I wish we’d embrace that instead of quibbling over whose diet is healthier. Again, that’s not to say there aren’t ethical grounds for disagreement, but if that’s what the argument really comes down to, don’t pretend it’s about health.
If you agree — and I’m well aware that many people don’t — a good place to start is with these two posts, one by me and one by Steve Kamb at Nerd Fitness. They’re written in much the same vein, just from opposite sides of the vegan/Paleo line.
2. The Paleo Diet Debunked? (Jeff and anyone else wondering what I think about grains, I agree with Steve’s take on them)
As always, I’m interested to hear your comments. I may not like arguing, but I learn something whenever I write a post like this and people chime in from different sides.