Even on our plates, our genes seem to have a say.
Some people eat fruits and vegetables every day, while others eat far fewer. Price, family habits, and personal tastes explain some of these differences. But does our DNA also play a role? To find out, researchers studied thousands of twins.
The study included 5,789 people aged 45 to 90 from four countries: the United States, Australia, Denmark, and Sweden. The researchers compared their eating habits. The advantage of studying twins is straightforward: identical twins share almost all their genes, whereas fraternal twins share only about half, like ordinary siblings.
Both identical and fraternal twins naturally shared the same family environment, with the same foods offered at the same ages.
If identical twins eat the same foods more often than fraternal twins do, this may reveal a genetic influence. Using this comparison, the researchers estimated that genes explained about 25% of the differences in fruit consumption and 17% of those concerning vegetables.
Although measurable, genetics alone therefore does not determine what is on our plates.
Why might our genes have an influence? They can, in particular, alter our sensitivity to certain flavors, such as the bitterness of several vegetables. However, this study did not look for specific genes and does not directly show why one person prefers one food over another. The next step is to understand which genes are actually involved.