Isn’t this a fantastic scenario: you’re sitting at your desk and a mysterious white powder floats through the air and lands on your face. Some of it lands on your lips and, being the risk-taking individual that you are who is apparently not averse to putting unidentified powders in your mouth, you taste it and immediately complain to your colleagues about how disgustingly bitter it is. The powder has landed on their faces too and they taste it too and… no, it doesn’t taste of anything, actually. It’s not bitter in the least, they say to you with suspicious eyes and 50% of their eyebrows raised. Well then, aren’t you quite the weirdo? Please take your imaginary bitter taste and go sit in the corner.
This is how they discovered that people can experience tastes quite differently from each other. It was only 1930 when A.L. Fox accidentally released some phenylthiocarbamide into the air in his lab while trying to create an artificial sweetener and it landed on the faces of his colleagues (good work!), and while some of them complained of its bitterness (you’d think that would be the least of their problems if they’re working in a lab where chemicals routinely drift onto their faces and into their lungs), Fox himself couldn’t taste the bitterness. It turned out that about 30% of people find phenylthiocarbamide tasteless, whereas the rest find it moderately to intensely bitter.
It’s not exactly uncommon knowledge now that the ability to taste bitterness varies from person to person and that this is down to genetics. A whole heap of studies over the years have looked at how genetic variants within the TAS2R family of genes mean that some people taste bitterness of particular substances more easily than others. For TAS2R38, the gene that codes for the protein that allows phenylthiocarbamide to be tasted, you can have one of three possible combinations of variants, allowing you to be either a non-taster, a medium taster, or… a supertaster, in which case you can taste that phenylthiocarbamide better than about 75% of the population! Well done, you.
So, like I was saying, we know bitterness perception varies from person to person due to genetics, but it’s kind of boring if you just look at that within the scope of “Oh, Person X can taste this very specific chemical really easily whereas Person Y can’t taste it at all”. Pretty limited relevance. The interesting part is how it affects behaviour — how well you can taste bitterness can affect how much you like particular foods, and that can have a reasonably big impact on eating behaviours.
Studies have been a bit inconclusive when it comes to bitterness gene variants and liking for somewhat bitter vegetables (such as broccoli, spinach, Brussels sprouts, kale and cucumber), with high-tasters of bitterness sometimes liking these vegetables more than low-tasters, and sometimes less. However, sensitivity to bitterness changes with age, so maybe you need to look at these things in particular age groups to get a clearer picture. Certainly, some studies have found that in children, non-tasters who aren’t so sensitive to bitterness find these vegetables more pleasant to eat than the tasters who are sensitive to bitterness, and non-tasters generally eat more vegetables than tasters. Some studies have found the same in adults.
Consumption of bitter fruits can also be affected by genes, with female adult supertasters finding a drink containing naringin (a compound from grapefruit peel) less pleasant, and the same went for just plain grapefruit juice. It looks like the intensity of the bitterness matters too, since taster children were no different from non-taster children when drinking a mixture of 25% grapefruit juice and 75% orange juice, but then the tasters disliked a more bitter mixture of 50% grapefruit juice and 50% orange juice compared to non-tasters.
So it all sort of makes sense — people who are more sensitive to bitterness kind of dislike things that are a bit bitter. However, the intrigue continues with research that has found that genetic variants for bitterness are also associated with different perception of sweetness and saltiness and sourness, the detection of the pungency or flavour of food, and also the ability to discriminate fat content in food and drinks.
But I will go into detail for those in future posts, and for now, you can make some Pimm’s Cup cupcakes. Complete with whipped lemonade and simulated cucumber! It’s a bitter orange and cucumber gel, cut into sticks, to which I attached real cucumber skin. Don’t you want to do something so convoluted and arduous too?
Read on for the recipe for Pimm’s Cup cupcakes.