Genes, age, and dietary habits can all affect how food tastes to us.
Foods like kale and broccoli may taste more bitter to some people. Photo: ShutterstockDo you wonder why some people do not like bitter foods like broccoli, black coffee or dark chocolate, while others enjoy them? This difference in taste is mainly because of a gene called TAS2R38.
What is the TAS2R38 gene?
The TAS2R38 gene is an important part of our DNA that helps us taste bitterness. It creates a protein that helps the tongue to taste things.
This gene makes people sensitive to some bitter chemicals, such as phenylthiocarbamide (PTC) and propylthiouracil (PROP). These chemicals are not naturally found in foods, but how we taste them is similar to how we taste other bitter things – and some of these can be toxic.
The TAS2R38 gene comes in different forms known as alleles. There are two main types: the “taster” allele (T) and the “non-taster” allele (t). Individuals who have at least one T allele are called “tasters”, and they are more sensitive to bitter tastes.
On the other hand, individuals with the tt genotype (two non-taster alleles) are known as “non-tasters” (see graphic). These individuals would not be able to notice the bitterness from PTC and PROP.
But if PTC and PROP are not naturally found in foods, why do vegetables such as kale and broccoli taste bitter to some people? These foods have chemicals called glucosinolates, which are similar in structure to PTC and PROP. Because of this, tasters may find that these vegetables have a strong, unpleasant taste.
Other things that change our ability to taste bitterness
Our genes are an important part of how we taste things, but there are also other factors that affect how we experience bitter flavours.
One important factor is age. Research shows that most children are more sensitive to bitter flavours compared to adults, even when they share the same genetic traits.
Two other key influences are hormones.
At different times of their lives, women go through changes in their hormones, for example during pregnancy. This makes them more sensitive to bitter flavours. This ability can help pregnant mothers detect flavours that could harm their baby.
Also, dietary habits and overall health can affect how we taste things. For example, those who often eat bitter foods may develop a higher tolerance to bitterness. This means they become less sensitive to bitterness as they taste it more often.
Certain medications or health problems can also change how we experience tastes.
For example, people with diabetes are more likely to have taste disorders that can lower their ability to identify sweet, sour, bitter or salty flavours. Difficulty in tasting is also often one of the first signs of a Covid-19 infection.
All of these factors help explain why people can eat the same thing but have different reactions to it.
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