Effects of a long-term vegetarian diet on biomarkers of antioxidant status and cardiovascular disease risk.
OBJECTIVE
We compared plasma biomarkers of antioxidant status, oxidative stress, inflammation, and risk for coronary heart disease in long-term vegetarians and age- and sex-matched omnivores.


METHODS
Thirty vegetarians (mean age +/- standard deviation: 44.2 +/- 9.0 y) were recruited. The subjects had been vegetarian for 5 to 55 y (21.8 +/- 12.2 y). The control group comprised 30 adults selected by age-stratified sampling from a community health project (mean age: 44.0 +/- 9.2 y). Fasting plasma total antioxidant status (ferric-reducing antioxidant power), ascorbic acid (AA), alpha-tocopherol (total and lipid standardized), malondialdehyde, total cholesterol, triacylglycerol, uric acid (UA), and high-sensitivity C-reactive protein (hsCRP) were measured.


RESULTS
Plasma AA was significantly higher in the vegetarians than in the omnivores (90.5 +/- 21.0 and 61.8 +/- 17.0 microM; P < 0.001). The vegetarians had lower concentrations of triacylglycerol, UA, and hsCRP. Plasma total and lipid-standardized alpha-tocopherol concentrations were also lower in the vegetarians: 22.0 +/- 5.9 and 27.0 +/- 7.9 microM versus 3.76 +/- 0.57 and 4.23 +/- 0.58 microM per millimoles per liter of total cholesterol plus triacylglycerol, respectively. There was a significant inverse correlation between AA and UA (r = -0.343, P < 0.01; n = 60) and between AA and hsCRP (r = -0.306, P < 0.05; n = 55). Plasma ferric-reducing antioxidant power and malondialdehyde did not differ significantly between groups; however, the contribution of AA to the total antioxidant capacity of plasma was approximately 50% greater in the vegetarians.


CONCLUSIONS
A long-term vegetarian diet is associated with markedly higher fasting plasma AA concentrations and lower concentrations of TAG, UA, and hsCRP. Long-term vegetarians have a better antioxidant status and coronary heart disease risk profile than do apparently healthy omnivores. Plasma AA may act a useful marker of overall health status.
Szeto
Y T
YT
Antioxidant Research Team, School of Nursing, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China.
Kwok
Timothy C Y
TC
Benzie
Iris F F
IF
D000328:Adult; D000975:Antioxidants / Q000032:analysis / Q000378:metabolism*; D001205:Ascorbic Acid / Q000097:blood*; D015415:Biomarkers / Q000097:blood*; D002097:C-Reactive Protein / Q000032:analysis; D002318:Cardiovascular Diseases / Q000097:blood*; D016022:Case-Control Studies; D003327:Coronary Disease / Q000097:blood* / Q000453:epidemiology; D014676:Diet, Vegetarian; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D018384:Oxidative Stress; D012307:Risk Factors; D014280:Triglycerides / Q000097:blood; D014527:Uric Acid / Q000097:blood
D000975:Antioxidants; D015415:Biomarkers; D014280:Triglycerides; D014527:Uric Acid; D002097:C-Reactive Protein; D001205:Ascorbic Acid