Their conclusions were published in the Journal of the American Osteopathic Association. The paper doesn’t say anything that is particularly alarming, and, with a few exceptions, there isn’t much in it that I would take issue with.
But the Cleveland Clinic press-released the findings, giving the media a chance to scaremonger about vegan diets—and you know how much they like to do that.
As is often the case, headlines didn’t exactly reflect what is in the paper. For one thing, it wasn’t a “study.” It’s a very short review, which means that it is a discussion of already-published research and doesn’t provide any new information about vegan diets. Nor does the paper say, by any stretch of the imagination, that vegans are likely to be malnourished.
Here is what the authors actually said:
Vegans who don’t take vitamin B12 supplements or use fortified foods are likely to become deficient.
Yes, indeed. Have I mentioned one or two or a thousand times that vegans need to supplement with B12 via vitamin tablets or fortified foods? (And, by the way, so do many omnivores).
Vegans may consume more iron than omnivores.
The authors found this surprising, which suggests that they may not be all that knowledgeable about vegan nutrition. Plant foods are generally higher in iron than animal foods, and some animal foods—namely dairy—have barely any iron at all. It’s not at all surprising to see high iron intakes among vegans.
Young vegan women are at higher risk for iron deficiency anemia than older vegan women.
True and not particularly relevant. Women who have their period lose more iron than women who have stopped menstruating. So young women are generally at higher risk for iron deficiency than post-menopausal women.
Young vegan women are at higher risk for iron deficiency than omnivores.
The authors cited one study in Thailand to support this conclusion. But most research shows that, while vegans have lower iron stores than omnivores, our rates of iron deficiency anemia are pretty comparable. (Not that this is a good thing since iron deficiency is common among omnivores. Those eating any type of diet, especially young women, need to be aware of iron nutrition.)
Some vegans have low intakes of calcium and this could raise risk for bone disease.
They cited two studies (there are many more studies that have looked at calcium intake among vegans) and one of them was in children fed a restrictive macrobiotic diet in the 1980s. This is not the least bit relevant to modern vegans who eat a more liberal diet and who have access to a much greater variety of foods. The paper also didn’t acknowledge that even lower calcium intakes among vegans can (sometimes) translate to higher amounts of absorbed calcium if much of the calcium is coming from cruciferous vegetables. But definitely, vegans should make sure that their diets contain adequate calcium.
Vitamin D deficiency is not unique to the vegan diet.
This is an important point that anti-vegan critics often miss. Technically you can meet vitamin D needs from fish, but it’s not easy and it’s not sustainable. So most omnivores get their vitamin D the same way that vegans do—from fortified foods (cow’s milk is fortified) or sun exposure. (And many people, omnivores and vegans alike, don’t get enough.)
Concerns about DHA and EPA in vegan diets haven’t been substantiated, but vegans who are worried can take algae derived supplements.
That’s pretty much what I say.
No evidence has shown that vegans become deficient in specific amino acids
Again, this is true, because as long as vegans include legumes in their diets, total protein and amino acids needs are easily met.
In summary, while there are ways in which a vegan diet–like any diet– can fall short of nutrient recommendations, nothing in this paper suggests that a vegan diet is dangerous or ill-advised.
But, yes, being knowledgeable about food choices is important. Vegans need to pay attention to responsible sources of nutrition information; it’s not enough to “eat a variety of whole plant foods.” Humans did not evolve on a vegan diet, after all, and very few of us grew up within a vegan culture. Meeting nutrient needs is neither intuitive nor automatic.
It’s why I do what I do—which is to constantly harass vegans to make sure they are supplementing with vitamins B12 and D, eating legumes, and paying attention to calcium, iodine, and omega-3 fats. As long as vegans do so, we can meet nutrient needs easily. And it will get harder and harder for the media to pretend that our diet is dangerous.