US researchers have discovered that some people may drink more alcohol than others because of genetic differences that affect their taste buds. The scientists, based at the University of Conneticut, say their findings could help explain differences in people's drinking behaviour. The study focused on light to moderate drinkers, and so the results may not directly apply to people who abuse or are dependent on alcohol, says team leader Valerie Duffy. However, it could help research into early drinking behaviour, which is strongly linked to the development of alcoholism later in life.
The researchers studied 53 women and 31 men who drink alcohol in moderation, and tested their ability to taste a bitter substance called 6-n-propylthiouracil (PROP). This chemical tastes more bitter to some people than others, because of natural variations in taste bud 'receptor' protein. In 2003, scientists showed that variations in a taste receptor gene called TAS2R38 affect a person's sensitivity to PROP. For the latest study, Duffy's team wanted to see if these taste gene variations, PROP sensitivity and alcohol consumption were all linked.
The TAS2R38 gene comes in two main types, called PAV and AVI, which determine whether people are either 'super-tasters', medium tasters or 'non-tasters' of the bitter PROP chemical. The researchers found that the super-tasters in the study, who had two copies of the PAV form of the gene, drank around 130 alcoholic drinks per year, compared to those with one PAV and one AVI, who drank 180, and the non-tasters with two AVI genes, who downed 285. The team published their findings in the journal Alcoholism: Clinical and Experimental Research.
Duffy told New Scientist magazine that it 'makes sense' that people who taste the most bitterness aren't going to want to drink as much alcohol. However, she warned that people may override their tastebuds by drinking highly sweetened alcoholic drinks, or ignore them completely in some situations. US geneticist Dennis Drayna, who heads the team that discover the TAS2R38 gene, said that it is well known that there are genetic influences on alcoholism, but it is 'a very difficult tangle of facts'. That taste seems to be so clear a factor is 'very exciting', he added.