title: Plasma homocysteine levels in Taiwanese vegetarians are higher than those of omnivores.
abstract: Mild hyperhomocysteinemia is an independent risk factor for cardiovascular disease and may result from a deficiency of folate, vitamin B-6 or vitamin B-12. Because vitamin B-12 deficiency is often associated with vegetarianism, this study was designed to examine the effect of Taiwanese vegetarian diets on B-vitamin status and plasma homocysteine levels. Female Buddhist lacto-vegetarians (n = 45; 31-45 y) and matched omnivores (n = 45) recruited in Hualien, Taiwan, were investigated. Taiwanese vegetarians consumed normal amount of folate, but only 21% of Taiwan Recommended Daily Nutrient Allowances (RDNA) values of vitamin B-12. Compared with the omnivores, the vegetarians had significantly higher levels of plasma folate (14.79 +/- 7.70 vs. 11.98 +/- 8.29 nmol/L), but lower levels of vitamin B-12 (207.7 +/- 127.1 vs. 403.5 +/- 138.9 pmol/L). Fasting plasma homocysteine levels were significantly higher in vegetarians than in omnivores (mean: 11.20 +/- 4.27 vs. 8.64 +/- 2.06 micromol/L; median: 10.5 vs. 8.5 micromol/L). Fasting plasma homocysteine was inversely correlated with plasma folate and vitamin B-12 in the vegetarian group. Multiple regression analysis revealed that plasma folate, vitamin B-12 and creatinine were independent determinants of homocysteine variation and contributed to 38.6% of homocysteine variation in the vegetarians. Compared with the omnivores, vegetarians also had significantly lower serum levels of valine, isoleucine, leucine, lysine, alanine and arginine, but higher levels of glycine. In the vegetarian group, fasting plasma homocysteine correlated negatively with serum threonine, lysine, histidine, arginine and cystine, and these amino acids contributed to 38.7% of homocysteine variation. In conclusion, the Buddhist nuns who consumed a lacto-vegetarian diet had mildly elevated fasting plasma homocysteine levels presumably due to lower levels of plasma vitamin B-12.
authors.affiliation: Department of Biochemistry, College of Medicine, Tzu-Chi University, Hualien, Taiwan.
authors.forename: Chien-Jung
authors.initials: CJ
authors.lastname: Hung
authors.forename: Po-Chao
authors.initials: PC
authors.lastname: Huang
authors.forename: Shao-Chun
authors.initials: SC
authors.lastname: Lu
authors.forename: Yi-Hwei
authors.initials: YH
authors.lastname: Li
authors.forename: Hsien-Bin
authors.initials: HB
authors.lastname: Huang
authors.forename: Bi-Fong
authors.initials: BF
authors.lastname: Lin
authors.forename: Sue-Joan
authors.initials: SJ
authors.lastname: Chang
authors.forename: Hsu-Fang
authors.initials: HF
authors.lastname: Chou
mesh_terms: D000328:Adult; D000596:Amino Acids / Q000378:metabolism; D002318:Cardiovascular Diseases / Q000097:blood / Q000209:etiology*; D014676:Diet, Vegetarian / Q000009:adverse effects*; D005215:Fasting; D005260:Female; D005492:Folic Acid / Q000008:administration & dosage / Q000097:blood*; D005494:Folic Acid Deficiency / Q000150:complications; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D020138:Hyperhomocysteinemia / Q000150:complications / Q000209:etiology; D008875:Middle Aged; D009752:Nutritional Status; D012044:Regression Analysis; D012307:Risk Factors; D013624:Taiwan; D014805:Vitamin B 12 / Q000008:administration & dosage / Q000097:blood*; D014806:Vitamin B 12 Deficiency / Q000097:blood / Q000150:complications*; D025101:Vitamin B 6 / Q000008:administration & dosage / Q000097:blood*; D026681:Vitamin B 6 Deficiency / Q000150:complications
chemical_list: D000596:Amino Acids; D006710:Homocysteine; D025101:Vitamin B 6; D005492:Folic Acid; D014805:Vitamin B 12