Many ex-vegans and ex-vegetarians quit for health reasons, but animal agriculture abolitionist James McWilliams doubts their credibility in his post “The Evidence for a Vegan Diet,” saying:

Perhaps inspired by Lierre Kieth’s The Vegetarian Myth, a book that chronicles the author’s losing battle with a plant-based diet, bloggers have clogged foodie networks with angst-ridden accounts of fatigue, sickness, hair loss, anxiety, diminished sex drive, and mental breakdown after quitting animal products. The problem with these accounts, as far as I can tell, is that those who made the vegan leap (and I praise them for doing it) did so without doing due diligence on the details of intelligent veganism. Someone can live on potato chips, pot, and cherry soda and call himself a vegan. Many recidivists have evidently tried to do just that.

McWilliams then goes on to imply that if only all vegans ate at restaurants like the vegan macrobiotic spot Casa de Luz in Austin, the above issues would never happen:

For me, the most persuasive evidence supporting a healthy vegan diet is anecdotal. The vegans who frequent Casa de Luz, my breakfast (and often lunch) destination, are paragons of good health. Many of them are significantly older than I am — in their 50s, 60s, and 70s — but they rock on with glowing intensity, looking much younger (in some cases by 20 years) than they are. Every now and then a local vegan hero will drop in — John Mackey (founder of Whole Foods), Rip Esselstyn (pioneer of the Engine 2 diet), a noted musician who will remain unnamed — and we’ll gawk in admiration. The everyday reality, though, is that a dozen or so ordinary people with whom I eat have done extraordinary things as a direct result of intelligent veganism. They’ve conquered obesity, chronic disease, depression, and a host of food-related disorders by exclusively eating an exciting diversity of plants. If there’s one lesson I’ve learned by eating with seasoned vegans it is this: the diet empowers.

Dude, I used to work at Casa de Luz. I volunteered there off and on for a couple of years before I finally got a job there, which I kept for about a year; I quit to leave Austin for New York, where I quickly got a job at the quasi-macrobiotic vegan restaurant Angelica Kitchen. It’s all about who you know: one of the managers at Angelica was the daughter of a manager at Casa de Luz. I worked there for about a year too, and it was only six months after my Angelica run that I quit veganism because of angst-riddenness, fatigue, sickness and brain fog. I still had some Angelica Kitchen hijiki in my freezer when I started loading up on salmon and eggs. And look at the blog I write now! Are you sure that telling vegans to eat at Casa de Luz is a good idea, McWilliams?

McWilliams makes scientific claims for veganism to bolster his anecdotes, but fails to cite sources for his claims that:

a low-fat vegan diet can substantially mitigate the impacts of type 2 diabetes, rheumatoid arthritis, and Parkinson’s disease. Veganism reduces the risk of colon cancer. … Veganism is more effective at combating obesity than other prescribed diets, such as that promoted by the National Cholesterol Education Program.

He also quotes vegan activist Dr. Michael Greger saying, “A plant-based diet is like a one-stop shop against chronic diseases.” But what about these vegans, Dr. Greger?!

Admittedly, when I reference vegan health issues, I fail to cite studies about brain fog in long-term vegans, but I don’t try to make grand health claims about veganism on this blog (…anymore). The the only direct claims I’d make about health and veganism now are that: some nutrients are harder or impossible to get on a vegan diet without supplementation (I’m including “non-essential” nutrients because some bodies are better at manufacturing them than others), a more varied diet has good potential to be healthier than a less varied diet and veganism is a less varied diet (but of course it depends on what constitutes the added variety in the diet and on the person), and many people quit veganism after feeling horrible and then feel better once they start eating animal products again.

Anyway, after referencing a little science, McWilliams then re-emphasizes, “I could continue in this scientific vein, but again, it’s the stories of personal transformation that make the biggest impression.”

Though there are vegan success stories, as McWilliams says, there are plenty of vegan failure stories too, and not all of these ex-vegans subsisted on potato chips and pot. In fact, vegan RDs Jack Norris and Ginny Messina have suggested that it’s ironically the most health-obsessed vegans who often end up failing the most, because they restrict too much — such as raw foodists and the clientele at Casa de Luz, many of whom are terrified of nightshade vegetables and refined soy products.

Here’s an anecdote for you, McWilliams: Michio Kushi, founder of the macrobiotic Kushi Institute, got colon cancer at 81. He fortunately survived, but his wife died of cervical cancer at 78. And unless it’s changed since I left, they sell Kushi’s books at Casa de Luz, including The Cancer Prevention Diet and The Macrobiotic Approach to Cancer.

McWilliams is right that many new vegans experience health improvements. This isn’t surprising, since veganism inspires many people to switch from a junky mainstream diet to a fruit- and vegetable-heavy one, which cuts out a lot of harmful foods. The problem, many ex-vegans theorize, is that veganism often swings the pendulum too far in the other direction — from excess to deficiency. Which means that early improvements are no proof that everyone benefits from being vegan for life. 

So if you want to go after the ex-vegans, McWilliams, you’ll need to do better than suggesting that all failed vegans were non-supplementing, chip-addicted potheads who skipped too many Casa de Luz Guatemalan nights.

(Thanks for the tip, Stella)