If Africans have a better sense of taste than Europeans and Asians, it can be attributed to their genes, said a team of American scientists.
The researchers say that studies have shown that Africans are better than Europeans and Asians at sensing bitter tastes, and surveys conducted in Kenya and Cameroon suggest that this may be due to a striking amount of diversity in a gene.
"If they have more genetic diversity, there's more variation in their ability to taste," New Scientist magazine quoted Sarah Tishkoff, a geneticist at the University of Pennsylvania in Philadelphia, as saying.
While presenting the findings at a recent conference, Sarah revealed that Europeans and Asians typically have only one of two forms of a gene called TAS2R38, which detects a bitter-tasting compound called PTC and similar chemicals in vegetables such as broccoli and Brussels sprouts.
With a view to finding out how Africans sense tastes, Sarah and her colleague Michael Campbell offered a wide range of dilutions of PTC to different populations of pastoralists and hunter-gatherers in Kenya and Cameroon.
"They keep tasting it until they make a yucky face and spit it out," she said.
The researchers observed that both Kenyan and Cameroonian populations could sense subtler gradients in the concentration than Europeans.
They also found that the Africans' TAS2R38 genes contained far more variation than is found in the rest of the world.
According to them, this could be because heterogeneity offered an evolutionary benefit to populations of Africans at some point in history.
"Maybe it was because there were certain plants that were beneficial to eat, but they were also bitter," Sarah said.
However, avoiding potentially toxic plants might not be the only reason for diversity in bitter taste genes, says Theodore Schurr, an anthropologist at the University of Pennsylvania, who was not involved in the study.
His team has found lots of variation in bitter taste genes in a Siberian population that has historically eaten few vegetables.
"We're surprised at the amount of diversity we see there. We're trying to figure out what this means," he says.