ARS | Publication request: 6-n-Propylthiouracil sensitivity and obesity status among ethnically diverse children

Submitted to: Public Health Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 11, 2009
Publication Date: October 1, 2010
Citation: Baranowski, J., Baranowski, T., Beltran, A., Watson, K., Jago, R., Missaghian, M., Tepper, B. 2010. 6-n-Propylthiouracil sensitivity and obesity status among ethnically diverse children. Public Health Nutrition. 13(10):1587-1592.

Interpretive Summary: Whether a person can taste a chemical (6-n-propylthiouricil, abbreviated as PROP) found in brassica vegetables (broccoli) has been related to obesity among adults and children. There have, however, been conflicting findings, and primarily small samples with mostly white-middle class have been used. This study tested the PROP – adiposity relationship in two age groups of children (9-10 year olds and 17-18 year olds), since taste preferences change from childhood through adolescence. A significant relationship between PROP sensitivity and adiposity was detected only among the top socioeconomic status group, but it was very weak. This finding is consistent with the literature in that most published studies were with white middle class sample. By itself PROP would not account for the recent large increases in adiposity among children, but is consistent with the genetic findings that although 70% of adiposity is heritable, any one gene accounts for only small percentage of that effect.

Technical Abstract: Objective was to examine the relationship of 6-n-propylthiouracil (PROP) sensitivity to BMI while statistically controlling for demographic characteristics in two age groups of children: 9-10 years and 17-18 years (n 1551). Cross-sectional design with a multi-ethnic (White, African-American, Hispanic, Other) sample of 813 children aged 9-10 years and 738 children aged 17-18 years. Children were recruited from local elementary and high schools with at least 30 % minority ethnic enrollment. Children's height, weight and waist circumference were measured along with their PROP taster status. PROP was measured using two paper discs, one impregnated with NaCl (1.0 mol/l) and the other with PROP solution (0.50 mmol/l). Results showed a significant PROP sensitivity by socio-economic status (SES) interaction term (P = 0.010) was detected wherein supertasters had the largest BMI percentile and Z-score, but only among the group with highest SES. The results suggest that other factors overwhelmed the influence of PROP sensitivity on adiposity in lower-SES groups. The percentage of variance accounted for by the interaction term was about 1 %. Thus, PROP supertasters had the largest BMI percentile and Z-score, but only among the highest-SES group.