T. Colin Campbell is the author of The China Study, the book that vegans most often cite to prove the superiority of the vegan diet for health. So why is Campbell, who has been “99% vegan since about 1990,” not looking so hot?

Campbell recently appeared on Larry King Live for an episode about E. Coli-tainted hamburgers. Campbell’s role was to be the vegetable guy, to agitate for a “plant-based diet,” and presumably to tie this into the recent New York Times story about the woman who was paralyzed from a bad burger. Campbell succeeded on the first two counts, but apparently didn’t see the need to talk about tainted ground beef in particular, since he considers all animal products to be equally indefensible.

Campbell was up against two meat lovers and one flexitarian. On the pro-meat side were Anthony Bourdain, celebrity chef, weird food lover and notorious vegan hater (who claimed the bottom left corner of the screen), and Dr. Nancy Rodriguez, a not very articulate meat and dairy advocate who is apparently in the pocket of the meat and dairy industries, according to vegan bloggers. Twice she excused herself from an argument because it was outside of her realm of expertise. She also was called out for noting the E. coli contamination in certain vegetables but not mentioning that the original source was feces from cows. She was in the upper-right corner of the screen.

The guy who called her out was Jonathan Safran Foer, resident of the bottom-right corner and author of the upcoming “Eating Animals.” He seemed to be an advocate of eating animal protein in minimal amounts (ideally from pasture-raised animals), and said he was basically on Bourdain’s side, but bashed Bourdain for not mentioning that most meat comes from factory farms.

Larry King, a meat eater, seemed most impressed by Bourdain, and wasn’t particularly enamored with Campbell’s views, which meant the veggie proselytizer was on his own.

Even more discouraging for vegans tuning in from around the world, Campbell was easily the most sickly looking of the group.

Do you see what I mean about vegan sickliness? Compared to the other three, Campbell looks downright green. Maybe anti-vegan bias prompted them to light Campbell with a sickly-colored gel. It is the “meaty-a,” after all.

Still. Lighting can only be blamed for so much. T. Colin Campbell may speak truth to power and Rodriguez may be a brainwashed propagandist, but at least her skin looks flush and alive.

As for Bourdain, according to Campbell’s research, all those unusual animal parts he eats should have given him cancer and a fatal heart attack by now. Campbell should be debating an empty square, but look at this vibrant, confident graveyard of animal corpses he’s up against. Bourdain doesn’t even need to say anything. The side-by-side comparison is enough to suggest flaws in Campbell’s research methods.

Campbell was at least able to present a soundbite version of his views:

“A plant-based diet — a whole foods plant-based diet, really has all the nutrients that we actually need at optimum levels of intake. And what we learned early in my career, that instead of protein, especially animal protein, being a good nutrient, so to speak, and creating good health, what we learned is that we could actually turn on cancer development by simply increasing the level of animal protein intake above the amount of protein that we really needed. We could turn it off by simply taking it away.”

But as bad as he looked, Campbell might have done the vegan cause a better service if he claimed to follow a strict Eskimo-style blubber-only diet.

I haven’t read The China Study, nor have I really read critiques of it, but I did just now skim an anti-Campbell article on a pro-cholesterol site. One of its main arguments seems to be that Campbell only studied the milk protein casein, and then generalized those results to apply to all animal proteins. Whey, it seems, can help prevent colon cancer, which suggests that the deleterious effects of casein can’t be used to condemn all dairy proteins, much less all animal proteins.

No doubt that pro-cholesterol site is biased, but based on what Campbell says in his interview with Vegetarians in Paradise, it does seem like he mostly studied casein: “In experimental animals (rats and mice) we could turn on and off experimental cancer development by feeding and withdrawing casein at levels above minimum protein requirements.”

This turning off and turning on cancer rhetoric does sound like what he said in the above quote on Larry King Live, except that he substituted “animal protein” for “casein.” Smart move. It made his case sound stronger, and probably made for marginally better television. “What the hell is casein?” most of America would have asked if Campbell been more specific.

It gives me an idea for a nutrition book, though. It would be called “The Cancer Switch.” The cover image would be of a light switch, illuminating a mobile of various-sized tumors hanging from the ceiling; a finger would be on the switch, about to turn it off.

Anyway, I’m not really qualified to poke holes into Campbell’s conclusions from studies he has done over decades, because I haven’t even read them. The only studies I do are comparing the complexions of meat eaters to long-term vegans. So all I can honestly say about Campbell’s assertions is: “This is what a human on the optimal diet looks like? Really?”

Is he just doing veganism wrong? You’ll have to tell me, since I (like all ex-vegans) apparently did veganism wrong. In the Vegetarians in Paradise interview, he elaborates that he’s on a diet that is “almost entirely plant-based with no added oil or sugar, and very little or no added salt. About 60-70% of it is raw. I also exercise every day, jogging, mostly 3-6 miles, and work out on the weights.”

Sounds like what a lot of vegans would consider to be the healthiest diet ever.

But alright, T. Colin Campbell is old. He was born in 1934, making him either 74 or 75 now. That’s three quarters of a life. Don’t all old people look sickly? Maybe it isn’t fair to compare Campbell to these feisty young meat-lovers.

So here he is next to Larry King, born in 1933, making him a year older than Campbell.

Remarkably, around the time Campbell voluntarily adopted the diet of an impoverished Chinese rural laborer for its health benefits, Larry King was recovering from a heart attack caused by a three-pack-a-day smoking habit.

Sure, Larry King is a TV man and has to look as good as he can, lest he be replaced by some young upstart intern. He also probably has a better on-hand make-up team than Campbell does there in Cornell. But Campbell is a full-time advocate for what he says is the world’s healthiest diet, and which one looks to be barely clinging onto life?

Forget The China Study — Campbell should do a T. Colin Campbell study.