Friday, March 30, 2012

Are Strict Vegan Diets Healthy?

I've recently started reading Jack Norris' blog. Mr. Norris is a Registered Dietitian and a vegan. He addressed this question (Are strict vegan diets healthy?) in his latest post:
Try it Again, Dr. Kim!

Dr. Kim is a chiropractor who runs a fasting clinic in Ontario, Canada. This was the post by Dr. Kim that Mr. Norris was discussing in his blog:
More Thoughts on Earthlings Documentary, Including Potential Problems with a Strict Vegan Diet

Dr. Kim was a strict vegan for 4 years, but he says:
"I only felt like I was optimally supporting my health for the first two of those years. The last two years were marked by low energy, constant cravings for some animal foods, skin breakouts, and emotional lows that I had never previously experienced."
This is what he ate for 4 years:
"My strict vegan diet consisted of plenty of fresh leafy greens, tomatoes, bell peppers, cucumbers, celery, sprouts, many varieties of steamed greens, steamed root vegetables like potatoes, sweet potatoes, hard squashes, carrots, and red beets, whole grains like brown rice and quinoa, a wide variety of fruits (including avocados), legumes like chickpeas and red beans, and small amounts of raw nuts and seeds. I also drank fresh lettuce-based vegetable juices a few times a week."
Mr. Norris says that Dr. Kim probably wasn't getting enough vitamin B12:
"Obviously, if a vegan is not taking B12 supplements or eating fortified foods, for more than two years, chances are excellent they are going to get fatigued and have mental issues."
He also says he probably lacked adequate protein:
"If you read Dr. Kim’s description of his diet you have to get well into his list before you come across a plentiful source of protein (quinoa), and the most reliable sources that most vegans rely on, even raw foodists, are listed second to last and last!"
So, both Jack Norris and Dr. Kim state that vegan diets fail to provide adequate vitamin B12. Mr. Norris says that vegans need to be attentive to consuming higher protein plant foods. Dr. Kim says vegans risk deficiencies in the longer-chain omega-3 fatty acids DHA and EPA, in vitamin A (not the plant-based carotenoid precursors), cholesterol and saturated fats (although our body makes these from plant food, he says not enough are made), and several minerals including zinc, iron, and calcium.

I think B12 and minerals are a problem. I still don't know about protein, longer-chain omega-3s, saturated fat, and vitamin A. Although, it's true that animal foods are good sources for these.

What do you think?


Dr. Mel said...

They should eat lots of purslane, to get fatty acids. Highest plant source for such.

mammafelice said...

No problem for minerals, vitamin A (Beta-carotene is better, because it is also anti-oxidant e no risk of extra vit.A than needed) and protein as long as you eat enough calories.
Problemas came with B12, but personally I think it is because of different factors (spoilation of soil micro organism, extra clean vegetables, inner intestinal problems, absense from the diet of the small insects that all frugivores and erbivores do eat with their greens etc.). Sorry for my awful English, but I'm a healthy (blood test perfect!) vegan mum of two (vegan from 5 yaers), vegetarian since I was 14 and thats my opinion :-)

Laurie Endicott Thomas said...

It's silly for vegans to worry about protein or omega 3s. Both are easily supplied by ordinary vegetable foods. Nutrition scientists have known for about 100 years that if you eat enough unrefined plant foods to get enough calories, you will automatically get enough protein. The EPIC study showed that female vegans had higher serum levels of DHA than the women who ate fish. The only essential nutrients that can't be obtained from ordinary plant sources are vitamin D (the sunshine vitamin) and vitamin B12 (which comes from bacteria). Vitamin B12 is the only supplement that is routinely recommended for otherwise healthy vegans.

Ben P. DaSalt said...

As a vegan for about 5 years now and a vegetarian for about 13 years before, I’m obviously biased. Well, technically pescatarian during those 13 years, but that sounds like I ate fish all the time when it really was every once and a while. Also I had a couple fish free years leading up to becoming vegan.

I don’t claim super human health or anything, but I’m active enough--running, gym classes, other stuff, with average abilities--and generally feel fine as far as I can tell. I don’t try to eat a clean diet, I don’t follow any particular plan aside from eschewing animal products. As for supplements, I take a vegan children’s daily multiple vitamin.

Is a vegan diet “optimal?” No one really knows for sure and it depends on a lot of other factors. There’s enough mainstream evidence to suggest that a “well-planned” vegan diet is fine and offers some reduced risk factors over some other diets. Chuck in other considerations other than health, it becomes far more compelling, at least to me.

I put well-planned in quotes because I don’t really plan my eating habits all that well. Sure, I probably eat “healthier” than most Americans, I refrain from eating junk food most of the time, but I don’t pay all that much attention to meal-planning in the formal sense. I don’t drink vegetable juice or eat wheat grass or spirulina or anything like that on a daily basis, though I do shop at health food stores and hit up the farmers market when I can.

Oh, and I eat as much nuts and seeds (and peanuts) as I feel like. Long ago as a vegetarian I decided that since I don’t eat meat I wouldn’t care about limiting nuts. These days as notions of very low-fat diets have relaxed, and while there’s still advice to limit nuts, there’s enough evidence to suggest that nut consumers aren’t risking their health.

I’ve gotten blood work done a couple times and according to the standard interpretations (if you accept their numbers that is) I’m in not at risk for heart disease and my nutrient levels were all within normal, it not ideal parameters.

Here’s my tip-offs as for why I’m not all the phased by Dr. Kim feeling that a plant-based diet didn’t work for him.

• He refered to his diet as strict. I never refer to how I eat in this way.
• He’s a chiropractor. Sorry, but the woo is strong in many chiropractors.
• Fasting clinic? Chet Day? “14-day water fast?” “detoxing?” “beneficial cleansing reactions?” “malnourishment?” (This word means hungry African children to me.)
• He sounds like the archetypal ex-vegan. There are a few ex-vegan stories that get publicized on the Internet and they really do share a similar pattern. “I thought I had the perfect health diet once (based on more than a few tenuous ideas). Now I found a new perfect health diet (based on more than a few tenuous ideas).”
• Dr Kim thinks pasteurized milk is unhealthy and recommends reading Sally Fallon’s Nourishing Traditions. He mentions Weston A. Price, both the man and the organization often.

Is it possible that someone couldn’t thrive on a vegan diet. I’m quite open to the possibility. There’s no strong mainstream evidence as to why, or what particularly would be a problem that can’t be adequately addressed, but I can appreciate the idea that someone with food allergies or whatever would have tighter limits on plant-food diversity.

However, the usual vegan failure testimonials don’t convince me though for the patterns I already described especially since they always claimed that they followed the perfect vegan health diet.

I don’t put much effort into eating “a perfect diet.” Sure, I gravitate towards whole plant foods, but there’s room for junk food and eating out, etc. I’m consistent with not eating animal products and I don’t find it particularly difficult, nor am I all that special.

Ben P. DaSalt said...

Regarding B12

“Supplementing with B12 is unnatural so therefore veganism is bad,” just isn’t an argument that holds any merit to me. Okay, I admit, at first it somewhat bothered me when I was starting veganism. Now I don’t care, not when the merits of veganism are so worthwhile, and I don’t mean health.

Also, in practice, supplementing with B12 is always made to sound like some herculean event. It’s not like you’re diabetic and have to measure blood sugar and give yourself shoots. It’s a stupid pill that you can get for pennies per pill. If you forget to take it for a day, a week, a month, it’s unlikely that anything will happen, there’s plenty of buffer since your body stores it.

Don’t want pills, even though most everyone takes a bunch of vitamins anyway? Do B12 patches, chew B12 gum, drink B12 vitamin water, or just work other B12 fortified foods into your diet, plant milks, nutritional yeast, Marmite. Sure B12 is important, but the effort perception for vegans obtaining it is just way overblown.

Look, if people could take a pill with absolutely no side effects whatsoever to prevent say, heart disease, or cancer, they would do it. B12 supplements work that way. It prevents a disease risk for vegans and non-vegans alike, making the risk factor essentially zero, and there are no known side effects. It parallels iodine, made a ubiquitous supplement by having it added to table salt. Goiters are eliminated and no one these days notices or cares how. The only difference being that you can overdose on iodine, where B12 has no know overdose symptoms.

The best summary of my own feelings on the subject of B12 can be found here:

I don’t endorse everything on the rest of the blog, but I feel like I could have written most of that particular post. Don Matesz recently moved away from a paleo diet and while I don’t know if he’s entirely plant-based now, he certainly leans that way as far as I can tell and is pursing the more important ethical implications. More important than what he eats, his thinking has really shifted. While some of that B12 post is speculative, he grasps the very basic logical conclusions that a lot of people just seem to insist on not understanding.

Bix said...

"As a vegan for about 5 years now..."

Well, how about that. I wouldn't have guessed!