Researchers and addiction specialists are well aware that a large component of each person’s risk for alcohol use disorder (alcohol abuse and/or alcoholism) comes from genetic influences passed down through family bloodlines. However, specialists in the field have not previously known if genetics play a role in any given individual’s chances of liking the taste of alcohol. In a study published in September 2014 in the journal Alcoholism: Clinical & Experimental Research, researchers from four U.S. institutions examined the impact that inherited variations in three taste-related genes have on the favorable reactions that the average person has to alcohol intake.
Alcohol and Genetics
Genetic influences have such a tremendous impact on human health because many of the genes encoded in DNA come in specific versions or variations that get passed down from parents to children. People who inherit one variation of even a single gene can have dramatically different health outcomes than people who inherit another variation of the same gene.
All humans carry dozens of genetic variations that can collectively increase or decrease their susceptibility to hazardous alcohol consumption and the subsequent onset of alcohol use disorder. Some of these gene versions exert their influence more or less directly, while others exert their influence in combination with at least one additional variation. A well-known example is an alcohol-processing gene that decreases or increases the risks for alcohol use disorder by making an individual more or less susceptible to the unpleasant side effects of drinking. (People who feel these effects more strongly will typically drink less than people with a less intense negative reaction.) Genetic influences on alcohol-related risks interact in complicated ways with environmental influences that appear during a person’s lifetime.
Alcohol and Taste
Many adult drinkers know that, generally speaking, the taste of alcohol does not particularly appeal to children, especially at first introduction. This fact is largely related to the relative bitterness of the substances used to make certain forms of alcohol, as well as the bitterness of many manufactured alcoholic beverages (particularly beer, malt liquor and distilled liquor). There are a number of genes in the body that help us distinguish bitter tastes from sweet tastes and other flavor profiles. Two genes that affect the perception of bitterness are known as TAS2R13 and TAS2R38. Variations in these genes can essentially make a person more or less sensitive to the bitterness level of the foods and beverages he or she consumes.
In the study published in Alcoholism: Clinical & Experimental Research, researchers from Penn State University, Brown University, Rhode Island Hospital and the Veterans Administration used an assessment of 93 adult alcohol consumers to compare the impact that variations in the TAS2R13 gene and the TAS2R38 gene have on the appeal of the taste of alcohol. The researchers also looked at the impact of variations in a third gene that helps the tongue perceive burning sensations. This project was conducted, in part, because a favorable outlook on the taste of alcohol can significantly increase the odds that any given person will begin a pattern of excessive alcohol intake that ultimately leads to diagnosable alcohol-related problems. All of the study participants were European Americans between the ages of 18 and 45. The researchers used saliva samples to develop genetic profiles for each individual. Each person submitted his or her subjective reactions to the taste of an alcohol/water combination in four separate drinking sessions.
The researchers concluded that the study participants had three total versions of the TAS2R38 gene, a single version of the TAS2R13 gene and 16 versions of the gene that helps the tongue perceive burning sensations. They also concluded that some participants had gene variations that made them less sensitive to the bitterness of alcohol; in addition, some participants had gene variations that made them less sensitive to the burning sensations of alcohol. The researchers additionally concluded that some of the study participants had a combination of bitterness genes and burning-related genes that made them less susceptible to the unpleasant tastes that many people associated with alcohol intake.
The study’s authors believe that genetically reduced sensitivity to the unpleasant taste of alcohol may increase the likelihood that some people will start drinking alcohol or drink alcohol in dangerous ways. However, they don’t believe that genetic sensitivity has the same impact in people who are already physically dependent on alcohol intake.