¹Departments of Food Science, RMIT University, Melbourne 3001, Australia

²Medical Laboratory Science, RMIT University, Melbourne 3001, Australia

³School of Nutrition and Public Health, Deakin University, Malvern, VIC 3144, Australia

Correspondence to: Dr A Sinclair, Department of Food Science, RMIT University, GPO Box 2476V, Melbourne, VIC 3001, Australia.

^aGuarantor: A Sinclair Contributors: D Li, A Sinclair, N Mann, A Turner and M Ball initiated the study. D Li prepared the drafts of paper, did laboratory assays, collected data, and did the statistical analysis. A Sinclair selected the study site, supervised the project, and secured the funding. N Mann, F Kelly, L Abedin and A Wilson helped data collection and provided technical assistance. All investigators contributed to the drafts of paper.

Objective: The aim of this study was to assess thrombosis tendency in subjects who were habitual meat-eaters compared with those who were habitual vegetarians.

Design: Cross-sectional comparision of habitual meat-eaters and habitual vegetarians.

Setting: Free living subjects.

Subjects: One hundred and thirty-nine healthy male subjects (vegans n=18, ovolacto vegetarians n=43, moderate-meat-eaters n=60 and high-meat-eaters n=18) aged 20-55 y who were recruited in Melbourne.

Outcome measures: Dietary intake was assessed using a semi-quantitative Food Frequency Questionnaire. The parameters of thrombosis were measured by standard methods.

Results: Saturated fat and cholesterol intakes were significantly higher and polyunsaturated fat (PUFA) was significantly lower in the meat-eaters compared with vegetarians. In the meat-eaters, the platelet phospholipids AA levels were significantly higher than in the vegetarians, but there was no increase in ex vivo platelet aggregation and plasma 11-dehydro thromboxane B₂ levels. Vegetarians, especially the vegans, had a significantly increased mean collagen and ADP stimulated ex vivo whole blood platelet aggregation compared with meat-eaters. The vegan group had a significantly higher mean platelet volume than the other three dietary groups. However, meat-eaters had a significantly higher cluster of cardiovascular risk factors compared with vegetarians, including increased body mass index, waist to hip ratio, plasma total cholesterol (TC), triacylglycerol and LDL-C levels, ratio of TC/HDL-C and LDL-C/HDL-C and plasma factor VII activity.

Conclusions: Consumption of meat is not associated with an increased platelet aggregation compared with vegetarian subjects.

Sponsorship: Meat Research Corporation, Australia.

vegetarians; meat; hemostatic factors; platelet aggregation; lipoprotein lipids; fatty acids