My husband has always hated raw broccoli, Brussel sprouts, and coffee. Turns out he is not just being picky, he can actually taste a bitter flavor that I can’t detect. It really is all in the genes!
It was discovered in the 1930’s that some people can taste a bitter compound known as phenylthiocarbamide (PTC) while to others it has no bitter taste. You may remember this as a classic biology class activity about inheritance involving PTC taste paper. PTC is a similar compound to one found in foods such as broccoli, cabbage, Brussel sprouts, coffee, and dark beer, which can taste bitter to some people. The snp rs713598 on the gene TAS2R38 is a mostly accurate predictor of whether a person is a taster of PTC or not.
Another bitter compound is known as PROP or 6-n-propylthiouracil. A group of three snps on the TAS2R38 gene will give the range of whether a person is a ‘taster’ or not.
From a study on nutrition and taste:
For example, the TAS2R38 gene is characterized by three non synonymous coding SNPs (rs713598 – G145C, Ala49Pro; rs1726866 – T785C, Val262Ala; rs10246939 – A886G, Ile296Val) which give rise to several haplotypes… Subjects possessing at least one copy of the PAV haplotype (i.e. the alleles coding for proline at rs713598, alanine at rs1726866 and valine at rs10246939) are significantly more responsive to the bitter tastants PROP, PTC, and chemically similar compounds… Such individuals display the so-called taster phenotype, and are distinct from those who are homozygous for the AVI haplotype and display the so-called non-taster phenotype. Tasters show a reduction in their intake of several vegetables such as cabbage, spinach, lettuce… Given the importance of diet in longevity, genetic variation in taste receptor could directly affect a healthy aging by modulating food preference during life.
To figure out your taster genes, check your 23andMe results for the following snps:
|Check your 23andMe results for rs713598:
Check your 23andMe results for rs1726866:
Check your 23andMe results for rs10246939:
Everyone is different, and the SNPs above are accurate for about 80% of people.
Note on SNPedia orientation information on rs713598:
Each rs# in SNPedia has a field along the right side called ‘Orientation.
If the value is ‘minus’ you need to change: