Genes and Food Preference
In the new study, researchers wondered whether a simple smell test could predict who carries the single copy of the gene, and whether the gene influences the sniffer's perceptions of cooked meat.
It wasn't an entirely academic question. Europe is considering banning a practice that allows farmers to control the amount of androstenone in pork by castrating male pigs. Farmers are worried that consumers will turn their noses up at meat that contains higher levels of the hormone.
For the study, researchers recruited 23 healthy participants: 13 average eaters and 10 trained "sensory assessors," people with sensitive noses that can reliably pick out certain smells.
First, researchers added purified androstenone to two of three cups of water. People were asked to smell each cup and pick out the one that was different. If they were right, researchers classified them as sensitive. If they were wrong, they were considered insensitive.
Next, researchers had the study subjects eat cooked ground pork that had varying levels of androstenone added to it. They kept the levels within the range that might be naturally found in meat.
People were asked to rate the smell and the taste of the meat samples.
Next, researchers tested their genes. They found that all the people who could smell the androstenone had two copies of the gene needed to pick up the scent. These folks were also more likely to rate the taste of the pork with added androstenone as bad.
And everyone who had one copy of the gene could not smell the hormone. They were more likely to say the pork tasted good.
Still, "for those who cannot [initially] smell androstenone, if you try to smell this chemical every day for three weeks, about half of these non-smellers can acquire the ability to smell it," Matsunami says.
That suggests the ability to smell things isn't driven entirely by genes, but also by experience.
But, "it's a gene that's certainly influencing this preference, and I think people need to consider that fact," he says.