People who follow a vegan lifestyle — strict vegetarians who eat no meat or animal products of any kind — are thought to be at lower risk of cardiovascular diseases. However, their diets may increase their risk of developing blood clots and atherosclerosis or “hardening of the arteries,” which are conditions that can lead to heart attacks and stroke. This is the conclusion of Duo LI of the Department of Food Science and Nutrition, Zhejiang University, China in a review of research papers on the biochemistry of vegetarianism published during the last 30 years. The review appears in the Journal of Agricultural and Food Chemistry http://pubs.acs.org/stoken/presspac/presspac/full/10.1021/jf103846u
In general, compared with an omnivorous diet, vegetarian diets are rich in fiber, magnesium, Fe3+, folic acid, vitamins C and E, n-6 polyunsaturated fatty acid (PUFA), phytochemicals, and antioxidants but low in total fat, saturated fatty acid (SFA), cholesterol, sodium, zinc, Fe2+, vitamins A, B12, and D, and especially n-3 PUFA
Low intake of total fat, SFA, and sodium and increased intake of fiber, phytochemicals, and antioxidants in vegetarians is associated with decreased blood pressure and body mass index (BMI). These factors are known to reduce the risk of cardiovascular disease (CVD). However, there is concern over whether vegetarians, and particularly vegans, have an adequate intake of several important nutrients including iron, zinc, vitamin B12, and omega-3 fatty acids.
There is therefore a strong scientific basis for vegetarians and vegans to increase their intake of these missing nutrients. Good sources of omega-3s include oily fish, walnuts and certain other nuts. Good sources of vitamin B12 include seafood, eggs, and fortified milk. Dietary supplements also can supply these nutrients.