Adiposity in middle-aged women is associated with genetic taste blindness to 6-n-propylthiouracil.

OBJECTIVE

Taste blindness to the bitterness of 6-n-propylthiouracil (PROP) may be a genetic marker for food preferences and dietary choices that ultimately influence body weight. A previous study in middle-aged women showed that those who were taste blind to PROP (i.e., nontasters) had higher BMIs than those with the greatest sensitivity to PROP (i.e., supertasters). This study tested the hypothesis that the nontaster phenotype was associated with greater adiposity in middle-aged women.

RESEARCH METHODS AND PROCEDURES

Forty women with a mean BMI of 26.6+/-1.3 kg/m2 and a mean age of 41.8+/-1.8 years were recruited from the local community. They were classified as nontasters (n=8), medium tasters (n=18), or supertasters (n=14) of PROP using a filter paper screening procedure. Anthropometric measures included height, weight, body fatness, triceps skinfold thickness, and waist circumference. Dietary restraint and disinhibition were also measured to assess cognitions associated with body weight.

RESULTS

BMI was 6.2 units higher in nontaster women compared with supertaster women (29.7+/-0.9 vs. 23.5+/-0.9, respectively; p<0.05). Body fatness (p<0.01) and triceps skinfold thickness (p<0.05) were also higher in these women. Waist circumference showed a trend in the appropriate direction. Although disinhibition was associated with greater adiposity, the relation between PROP status and adiposity was not altered after controlling for disinhibition.

DISCUSSION

The PROP nontaster phenotype was strongly associated with several measures of adiposity in middle-aged women. These data confirm our previous findings and suggest that the PROP polymorphism may be a reliable indicator of weight gain susceptibility.