Vitamin B12 & Folic Acid Supplementation Proved to Prevent
Professor Woo Kam Sang, Professor of Medicine and Therapeutics, The Chinese University of Hong Kong, in collaboration with scholars and researchers in Mainland China, discovered that long-term vegetarians in Hong Kong and rural Chinese in Shanxi are deficient in vitamin B12 and / or folic acid (micronutrients), and have worse atherosclerosis surrogate markers (endothelial function and intima-media thickness) compared with non-vegetarians or southern Chinese, despite a better blood cholesterol profile. Correction of such micronutrient deficiency significantly improves these atherosclerotic markers, reported by Professor Woo at a press conference on 6 May 2006 at the Prince of Wales Hospital.
¡§We have studied 125 vegetarians in Hong Kong, aged 25-60 years, and compared with 170 age and gender-matched non-vegetarians in 1998-2002. Vegetarians have endothelial function reduced by 26% and intima-media thickness increased by 18%,¡¨ Professor Woo elaborated. ¡§Subsequently in 2002-03, 50 vegetarians were given oral vitamin B12 (0.5mg/day) and image-identical placebo for 6 months in double-blind, randomized and crossover fashion, followed by open label vitamin B12 for 6 more months. Their endothelial function improved by 16% at 6 months and intima-media thickness improved by 6% at 1 year.¡¨
In 2001, they studied 320 farmers and coal-miners in Yu County of rural Shanxi, and discovered their diets were deficient in animal meats and fresh green vegetables and fruits. ¡§They have lower blood vitamin B12 and folic acid levels, and compared with southern Chinese, 24% lower endothelial function and 18% greater intima-media thickness,¡¨ Professor Woo continued.
Professor Woo¡¦s research collaborative team subsequently conducted a supplementation trial, under the Leungkitwah project, on 180 Yu County farmers / coal-miners in 2004-06, using oral vitamin B12 (0.5mg/day) and folic acid (5mg/day) or image identical placebo capsules, in double blind, randomized fashion for 1 year.
¡§Those volunteers receiving active vitamin B12 and folic acid have 12% better endothelial function at 6 months compared with those taking placebo, and sustained improvement of 13% at 1 year.¡¨
¡§Abnormal endothelial function and intima-media thickening are surrogate markers of early atherogenesis, predictive of occurrence of heart attacks and stroke in long-term. Improvement in such markers is likely to be translated into reduction in cardiovascular or stroke events in long-term.¡¨ Professor Woo explained. ¡§Vegetarians in Hong Kong and vitamin B12 / folic acid deficiency in rural northern China are 2 unique community models of atherogensis. Our trial results on micronutrient deficiency propose that long-term vitamin B12 or folic acid supplementation can prevent stroke and heart attacks in China. Further work is awaited with enthusiasm to confirm this health measure as a safe, affordable and very cost-effective strategy for primary atherosclerosis prevention in China.¡¨