Source: BBC
Brain - Some people 'genetically wired' to avoid some vegetables
Key Highlights

It encodes for a protein in the taste receptors on the tongue which allows us to taste bitterness

People who inherit two copies of a variant of the gene TAS2R38 are not sensitive to bitter tastes from certain chemicals

Those with one copy of AVI and another called PAV perceive bitter tastes of these chemicals, but not to such an extreme degree as individuals with two copies of PAV, often called " super-tasters "

The scientists studied 175 people and found those with two copies of the bitter taste PAV version of the gene ate only small amounts of leafy green vegetables

BBC News