A 2009 survey by the Washington Post showed that vegans account for about a third of American vegetarians, or roughly 1% of the U.S. population. That’s not much, but compared to five years ago, on the whole the vegan movement is well on its way to the mainstream.
But how healthy can a vegan diet really be? A recent study that appeared in the Journal of Agricultural and Food Chemistry suggests that a fully plant-based diet has its risks: for one, vegans are more prone to blood clots and atherosclerosis, the buildup of fatty plaque in the arteries. These are diseases commonly associated with fatty diets and sedentary lifestyles, so what gives?
The lead author, Duo Li from China’s Zhejiang University, believes the risk may be due to the lack of vitamin B12 and omega-3 fatty acids, both of which are vital in the proper function and formation of red blood cells and reducing unhealthy fat. Both are also scarcely found in vegan foods.
Some components of omega-3 are found only in flax, hemp, and chia seeds, while others are present in some algae. Even with regular consumption of these foods, one may still need supplements to get to the required 1.4 to 1.6 grams per day.
Getting enough vitamin B12–the recommended dose is 2.4 mcg per day–is even harder. The only known whole food source is spirulina, a type of algae that’s popular among vegans because of its high protein content. Most vegans obtain it through reabsorption, a process in which previously released nutrients are reabsorbed by the body. As a result, vitamin B12 deficiency can take up to 20 years to manifest in people who switch from a regular to a vegan diet.
Omega-3 supplements abound in the market in oil, capsule, and gel forms. Some use fish oils, however, so strict vegans should read their choices carefully. As for vitamin B12 supplements, experts recommend oral types that can be dissolved under the tongue. They get absorbed faster and some say they give you a quick energy boost almost immediately.
Iron deficiency is also a common problem among vegans, although sources abound–they include beans, legumes, and dark green vegetables. This is because they contain a different type that’s less easily absorbed by the body. Doctors suggest combining these foods with a vitamin C source or supplements, taken during the same meal or shortly before, as they help break down the iron content for absorption.