The associations between bitter and fat taste sensitivity, and dietary fat intake: Are they impacted by genetic predisposition?

A relationship between bitter and fat taste sensitivity, CD36 rs1761667 and TAS2R38 has been demonstrated. However, research is scarce and does not take diet into account. This study aimed to explore associations between genetics, fat and bitter taste sensitivity and dietary fat intake in healthy UK adults. A cross-sectional study was carried out on 88 Caucasian participants (49 females and 39 males aged 35 ± 1 years; body mass index 24.9 ± 0.5 kg/m2 ). Bitter taste sensitivity was assessed using phenylthiocarbamide (PTC) impregnated strips and the general Labelled Magnitude Scale. Fat taste sensitivity was assessed by the Ascending Forced Choice Triangle Procedure and dietary intake with a semi-quantitative food frequency questionnaire. Genotyping for rs713598, rs1726866, rs10246939 and rs1761667 was performed. Participants with TAS2R38 PAV/PAV diplotype perceived PTC strips as more bitter than groups carrying AVI haplotypes (AVI/AVI, p = 1x10-6 ; AVI/AAV, p = 0.029). CD36 rs1761667 was associated with fat taste sensitivity (p = 0.008). A negative correlation between bitter taste sensitivity and saturated fat intake was observed (rs = -0.256, p = 0.016). When combining the CD36 genotypes and TAS2R38 diplotypes into one variable, participants carrying both TAS2R38 AVI haplotype and CD36 A allele had a higher intake of saturated fat compared to carriers of CD36 GG genotype or TAS2R38 PAV/PAV and PAV/AAV diplotypes (13.8 ± 0.3 vs 12.6 ± 0.5 %TEI, p = 0.047) warranting further exploration in a larger cohort.