Scientists have found out why every hundredth person considers the smell of rotten fish pleasant

Irina Ziganshina

Genetics of Reykjavik biopharmaceutical company deCODE Genetics published in the journal Current Biology results of his research, according to which 2% of their compatriots and about 1% of all other people on Earth carry a mutation that allows them not to feel discomfort from odors that most people seem unbearable, informs The New York Times.

The 11,000 people who took part in the study were asked to sniff six sticks impregnated with synthetic scents reminiscent of cinnamon, mint, banana, licorice, lemon and fish. They were asked to identify each scent and rate its intensity and pleasantness.

The most recognizable was the smell of fish, it also received the lowest ratings on the pleasantness scale. However, a small group of people were enthusiastic about it. As it turned out, they all had a genetic mutation that knocked out a gene called TAAR5. TAAR5 is involved in making a protein that recognizes a chemical called trimethylamine, found in rotten and fermented fish, as well as in certain body fluids, including human sweat and urine.

Most people have an intact version of TAAR5 and therefore find the fishy aroma to be more or less repulsive: this ability probably once helped our ancestors to avoid spoiled food. But those with a defective gene do not feel it. Participants in the study, for example, mistook the smell of fish for the smell of dessert, ketchup, and some even dreamed of something floral in it.

The fact that this gene turned out to be defective in every fiftieth Icelander can probably be explained by the fact that fish occupies a prominent place in the national menu, and often it is a very stocky fish, for example, a fermented stingray or a haukarl - the Icelandic rotten shark. In other places: Sweden, Southern Europe and Africa - there were fewer such olfactory tolerant people - about 1%.