Vegetariërs hebben extra omega-3 en vitamine B12 nodig*
Uit een review van tientallen studies van de laatste dertig jaar over de biochemie van vegetarisme blijkt dat vegetariërs die nooit vlees of dierlijke producten eten een duidelijk verhoogde kans op
trombose en aderverkalking hebben.
Daardoor hebben deze vegetariërs hogere bloedwaarden homocysteïne en lagere
waarden van het goede cholesterol (HDL). Om hart- en vaatproblemen te voorkomen dienen zij volgens de onderzoekers dagelijks extra
omega-3 vetzuren en vitamine B12 te nemen.
Increased Heart Risk In Vegans' Requires Omega-3s And B12
People who follow a vegan lifestyle - strict vegetarians who try to eat no meat or animal products of any kind - 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. That's the conclusion of a review of dozens of articles published on the biochemistry of vegetarianism during the past 30 years. The article appears in ACS' bi-weekly Journal of Agricultural and Food
Chemistry.
Duo Li notes in the review that meat eaters are known for having a significantly higher combination of cardiovascular risk factors than vegetarians. Lower-risk vegans, however, may not be immune. Their diets tend to be lacking several key nutrients - including iron, zinc, vitamin B12, and omega-3 fatty acids. While a balanced vegetarian diet can provide enough protein, this isn't always the case when it comes to fat and fatty acids. As a result, vegans tend to have elevated blood levels of homocysteine and decreased levels of HDL, the "good" form of cholesterol. Both are risk factors for heart disease.
It concludes that there is a strong scientific basis for vegetarians and vegans to increase their dietary omega-3 fatty acids and vitamin B12 to help contend with those risks. Good sources of omega-3s include salmon and other 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.
ARTICLE:
Chemistry behind Vegetarianism
Duo Li*
Department of Food Science and Nutrition, Zhejiang University, 268 Kaixuan Road, Hangzhou, China 310029
J. Agric. Food Chem., 2011, 59 (3), pp 777–784
DOI: 10.1021/jf103846u
*Phone +86-571-86971024; fax +86-571-86971024; e-mail duoli@zju.edu.cn.
Abstract
This review summarizes the effect of a habitual vegetarian diet on clinical complications in relation to chemistry and biochemistry. Omnivores have a significantly higher cluster of cardiovascular risk factors compared with vegetarians, including increased body mass index, waist to hip ratio, blood pressure, plasma total cholesterol (TC), triacylglycerol and LDL-C levels, serum lipoprotein(a) concentration, plasma factor VII activity, ratios of TC/HDL-C, LDL-C/HDL-C and TAG/HDL-C, and serum ferritin levels. Compared with omnivores, vegetarians, especially vegans, have lower serum vitamin B12 concentration and n-3 polyunsaturated fatty acid (PUFA) levels in the tissue membrane phospholipids, which are associated with increased collagen and ADP stimulated ex vivo whole blood platelet aggregation, plasma 11-dehydrothromboxane B2, and homocysteine levels and decreased plasma HDL-C. This may be associated with an increased thrombotic and atherosclerotic risk. It is suggested that vegetarians, especially vegans, should increase their dietary n-3 PUFA and vitamin B12 intakes.
Source: American Chemical Society (Mei 2011)
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