If broccoli makes you go 'blech!' the levels of mRNA expressed from your TAS2R38 bitter taste receptor gene may help explain why. Researchers from the Monell Chemical Senses Center and New York University report in the American Journal of Clinical Nutrition that the expression levels of the two alleles of the TAS2R38 taste receptor gene are associated with being able to taste bitterness and influences dietary habits.
As the Huffington Post notes, people with two copies of the PAV allele are sensitive to bitter taste while people with two copies of the AVI allele are not, though most people have one copy of each and fall in between.
In this study, the researchers asked 22 heterozygous people to sample broccoli and carrot juice, among others, and evaluate their bitterness. The researchers also collected data regarding the participants' diets and took taste bud samples to assess TAS2R38 expression levels.
From this, the Monell and NYU group found that relative expression varied and correlated with ratings of bitterness intensity for broccoli and 6-n-propylthiouracil.
"The amount of messenger RNA that taste cells choose to make may be the missing link in explaining why some people with 'moderate taster' genes still are extremely sensitive to bitterness in foods and drinks," study researcher Danielle Reed, a geneticist at Monell, tells the Huffington Post.