Inherited taste differences may explain why some people consume too much salt, research suggests.
People with taste buds especially sensitive to bitter flavours are nearly twice as likely to have excessive salt intakes, a US study has shown.
Previous research had revealed that people carrying a common variant of the gene TAS2R38 tend to avoid heart-healthy foods with bitter properties, such as broccoli and dark leafy greens. The gene enhances bitter taste perception.
The new study found that individuals with the same gene variant were 1.9 times more likely to consume higher than recommended levels of sodium than those without it.
Too much sodium, largely obtained from salt-laden processed, pre-packed and restaurant foods, is a known risk factor for high blood pressure which in turn contributes to heart attacks and strokes.
Currently, the American Heart Association recommends a sodium intake of no more than 2.3g per day, and ideally less than 1.5g.
The UK has similar guidelines. Adults are advised to consume no more than 2.4g of sodium per day, equivalent to about a teaspoon-full of salt.
Lead researcher Jennifer Smith, a PhD student at the University of Kentucky college of Nursing, said: "Genetic factors that influence taste aren't necessarily obvious to people, but they can impact heart health by influencing the foods they select.
"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."
The findings were presented at the American Heart Association's Scientific Sessions meeting in New Orleans.
As part of the study the researchers analysed the dietary habits of 407 people with an average age of 51 who had two or more heart disease risk factors.
The scientists took account of factors that might affect taste and diet, such as age, weight, smoking status, and use of blood pressure medicines.