Something smells fishy? The answer is all in your genes

THOSE who complain about the taste and smell of fish are often dismissed as being fussy or overly sensitive.

But scientists have discovered that liking fish is actually in your genes, and that some people have a specific mutation that makes that distinctive whiff quite pleasant.

Olfactory receptor genes dictate how each person reacts to different smells.

They can even influence whether a person likes the taste of certain foods based on their smell.

A study by Icelandic researchers, published in the journal Current Biology, found that just one mutation of a single specific receptor made certain odours less intense. For that group – up to 2.2 per cent of the population – the smell of fish is so inoffensive it is indistinguishable from sweet scents such as roses.

Some 9,000 people were asked to “name that smell” in a series of sniff tests involving liquorice, cinnamon, fish, lemon, peppermint and banana.

Dr Rosa Gisladottir, a researcher at DECODE Genetics in Reykjavik, said: “Carriers of the variant find the fish odour less intense, less unpleasant, and are less likely to name it accurately.

“We discovered sequence variants that influence how we perceive and describe fish, liquorice, and cinnamon odours. Since our sense of smell is very important for the perception of flavour, these variants likely influence whether we like food containing these odours.”

Participants were asked to smell odours from pen-like devices that released a particular scent when uncapped. After sniffing each odour pen, they were asked to name the smell and rate its intensity and pleasantness.

The results revealed variants in three genes of interest, one of which was a noncanonical olfactory receptor gene called trace amine-associated receptor 5 ( TAAR5). In the smell tests, people with a particular variant of this gene were unlikely to smell anything when presented with the fish odour, or they likened it to other things.

The frequency of the variants also differed between populations. TAAR5 appeared in 2.2 per cent of Icelanders and 1.7 per cent of Swedes, but only in 0.8 and 0.2 per cent, respectively, of southern Europeans and Africans.