It is already known that genetic variations of bitter taste receptor genes can help account for how people differ with regard to taste perception and food choice.
However, the team from the Monell Chemical Senses Center, USA, noted that one baffling piece of the puzzle remained: that two people with exactly the same genetic makeup can still differ markedly regarding how bitter certain foods and liquids taste to them.
Led by senior author Dr Danielle Reed, the Monell team therefore examined differences in the expression of messenger RNA (mRNA) RNA – the gene's instruction guide that tells a taste cell to build a specific receptor – in people with the same genetic variations, but who had different perceptions of bitter taste.
Writing in theAmerican Journal of Clinical Nutrition, the researchers reveal that a person's sensitivity to bitter taste is shaped not only by which taste genes that person has, but also by how much messenger their cells make.
"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," said Reed.
The Monell team suggested that their findings add a new level of complexity to our understanding of the cellular mechanisms of taste perception, adding that such information could ultimately lend insight into individual differences in food preferences and dietary choices.