Bitter‑taste gene matters
- Commentators noted the TAS2R38 'bitter taste' gene influences food preferences and vegetable acceptance (x.com). - People with certain TAS2R38 variants taste bitterness more strongly, making some healthy foods less appealing (x.com). - Taste‑gene differences are suggested as one reason dietary advice succeeds for some individuals and fails for others (x.com).
Taste is partly built into the tongue. The human gene TAS2R38 helps detect bitter compounds in Brassica vegetables, and common versions of the gene change how strongly people taste them. (ncbi.nlm.nih.gov) TAS2R38 encodes a receptor — a molecular sensor on taste cells — for glucosinolates, the bitter chemicals found in broccoli, Brussels sprouts, cabbage, and related plants. The same receptor is also tested in labs with phenylthiocarbamide, or PTC, and 6-n-propylthiouracil, or PROP. (ncbi.nlm.nih.gov) The best-known forms are called PAV and AVI. The National Center for Biotechnology Information says PAV is the common “taster” form, AVI is the common “non-taster” form, and the two differ at three coding positions in the receptor protein. (ncbi.nlm.nih.gov) In a 2013 American Journal of Clinical Nutrition study, researchers found that people with the PAV form detected PROP and broccoli bitterness at lower concentrations. Among 22 heterozygotes, higher PAV messenger RNA expression in taste cells tracked with stronger bitterness ratings for PROP and broccoli juice. (ncbi.nlm.nih.gov) That helps explain why the same plate of vegetables can taste sharply bitter to one person and mild to another. The receptor is sensing plant defense chemicals, and the signal is louder in some genotypes than in others. (ncbi.nlm.nih.gov) The food effect shows up early. In a 2019 Genes & Nutrition study of 131 infants, 31% of bitter-insensitive infants finished a 150 milliliter first complementary meal on the first try, compared with 13% of bitter-sensitive infants. (ncbi.nlm.nih.gov) The gap also appears in adult diet programs. A 2018 University of North Carolina-led study of 497 participants found no genotype difference at baseline, but after six months of counseling, bitter non-tasters and intermediate tasters increased vegetable intake more than stronger bitter tasters. (pubmed.ncbi.nlm.nih.gov) More recent population work points in the same direction, with caveats. A 2024 Appetite study of 41,839 people in the Korean Genome and Epidemiology Study found TAS2R38 diplotypes were associated with diet-quality scores, with the pattern differing by obesity status. (pubmed.ncbi.nlm.nih.gov) Researchers do not treat TAS2R38 as destiny. The 2018 intervention study found counseling still changed intake, and the 2019 infant study said feeding behavior was shaped by both environmental and genetic factors. (pubmed.ncbi.nlm.nih.gov; ncbi.nlm.nih.gov) The practical point is narrower than “eat for your genes.” If broccoli tastes harsher to one person because of TAS2R38, a diet plan that swaps preparation methods, repeats exposure, or uses less bitter vegetables may fit better than one that assumes everyone tastes the same food the same way. (pubmed.ncbi.nlm.nih.gov; ncbi.nlm.nih.gov)
