VEGETARIAN EATING AND ADOLESCENT COGNITIVE FUNCTION: PRELIMINARY RESULTS FROM A STUDY IN SELECTED NSW INDEPENDENT SCHOOLS
ROBYN PEARCE1, ROSS GRANT2, CEDRIC GREIVE1, BEVAN HOKIN3, PETER MOREY1
1Avondale College, Cooranbong, NSW 2265 Australia
2Australasian Research Institute, Wahroonga, NSW 2076 Australia
3Sydney Adventist Hospital, Wahroonga, NSW 2076 Australia
Vegetarian adolescents may have compromised vitamin B12 status and signs of impaired cognition with poor performance on Raven's Progressive Matrices (Louwen et al Am J Clin Nutr 2000; 72:762-9). We hypothesised that there would be significant differences in performance on Raven's Standard Progressive Matrices between groups defined by vegetarian and vitamin B12 status. 177 students from years 9 and 10 attending a set of five NSW independent schools participated in the study. Raven's test scores, age and serum B12 were obtained for 177 participants and diet-related data for 176. Participants were categorized by vegetarian and vitamin B12 status and age-corrected Raven's grades. Vegetarians were defined as eating red meat, chicken and fish less than once a week. Deficient vitamin B12 status was defined by serum B12 < 221pmol/L (<300pg/mL) (Yao et al J Fam Pract 1992; 35:524-528). Raven's scores were converted to five age-corrected grades using Australian norms. The bottom two grades were collapsed for χ2 tests. 20.4% of vegetarians scored Grade 1 (at or above the 95th percentile for their age) compared to 7.1% of non-vegetarians. Differences in distributions of age-corrected grades for vegetarians (n = 49) and non-vegetarians (n = 127) were just outside significance (P = 0.051). Distributions of age-corrected grades for vitamin B12 adequate (n = 137) and deficient (n = 40) students were not significantly different (P = 0.689). The hypothesis was not supported. The higher proportion of vegetarians than non-vegetarians reaching the highest grade was unexpected. The relationship of vegetarianism to cognitive function requires further study.
Funding source: Avondale College Foundation