Your junk food cravings are written in your DNA – dictated by the ‘salt gene’
IT'S divisive, tearing the snackers among us in two - crisps or chocolate, sweet or savoury?
And while the majority of us no doubt have a preference, new research suggests it is more than just a preference, it is a craving that's written in our DNA.
Scientists believe they have identified the gene that is responsible for making some people crave salt.
According to preliminary research presented at the American Heart Associations Scientific Sessions yesterday, inherited differences in taste perception may explain why some people eat more salt than others.
The research found that people with an increased bitter taste perception - meaning they taste bitter foods more intensely - may also taste salt more intensely and therefore enjoy eating it more.
Researchers looked at the food diaries of 407 people who had two or more heart disease risk factors and were participating in a cardiovascular risk-reduction study in Kentucky.
The average age of participants was 51-years-old and 73 per cent were female.
Comparing participants with one or two of the genes, called TAS2R48, that enhance bitter taste perception, researchers found they were almost twice as likely to eat more than the minimum recommended daily limit of salt.
The American Heart Association recommends a minimum sodium intake of no more than 2,300mg a day and an ideal limit of no more than 1,500 mg per day.
Too much sodium, found mostly in dietary salt from processed, prepacked, and restaurant foods, can increase the risk of developing high blood pressure, which can lead to heart attacks and strokes.
But the study also found that participants with the bitter-enhancing genes were not likely to eat more than the recommended daily amounts of sugar, saturated fats or alcohol.
The genetics only increased their taste for salt.
Lead author and Ph.D student at the University of Kentucky College of Nursing, Jennifer Smith, said: "Genetic factors that influence taste aren’t necessarily obvious to people, but they can impact heart health by influencing the foods they select.
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"There is some research suggesting that individuals who taste bitter more intensely may also taste salt more intensely and enjoy it more, leading to increased sodium intake.
"Another theory is that they use salt to mask the bitter taste of foods and thus consume more sodium.
"By identifying which gene variant a person has, we may be able to help them make better food choices through education that is personally tailored to them."
However, more research is needed to fully understand how people's genes impact how much sodium they eat, the researchers noted.
Previous research, according to the study's authors, showed that people who have one of the two most common gene variants that enhances bitter perception were likely to avoid heart-healthy foods with bitter tastes, such as broccoli and dark leafy greens.
This prompted researchers to determine where bitter-enhancing genes would also influence other food choices.
Individuals who taste bitter more intensely may also taste salt more intensely and enjoy it more, leading to increased sodium intake
Jennifer Smith, University of Kentucky College of Nursing
They hope that information about genetic influences on taste perception may some day help people select heart-healthy foods they can enjoy rather than trying to fight against their hereditary preferences.
Other factors that might affect taste perception, such as age, weight, smoking status and the use of blood pressure medication, were also taken into account for the study.
The authors also noted that, although the study participants were mostly white, the results are likely to be similar in other ethnic groups because more than 90 percent of the U.S. population has one of the two gene variants they studied.
They now plan to conduct an ethnically diverse study.