Supertaster, regular taster or non-taster ? (Genes to blame)

For ages, we have believed, and it has been repeatedly been proven that all our lifestyles, physical and many more features are linked to our genetic make-up. People eat different foods for a variety of reasons such as cultural, seasonal, and economic among many others. However, recent literature studies show that genes might be just one more reason to add to this list. So, if you have been dodging that coriander (cilantro) for years, or the broccoli (well, really scared of people who like it), it might not be you to blame, it is just your genes doing the work.

Most of you being food scientists or even in elementary school have seen a diagram showing tongue with different colored portions. The image shows five basic tastes perceived by humans – sweet, sour, bitter, salty, and umami (more recently). However, this may not be true to some extent. You can place salty water in different places of your tongue and still perceive the saltiness. The genes in our body do not affect our taste buds but change the sensitivity and intensity of our taste buds.

Food in our mouth is perceived by specialized receptors. These receptors are also present in our nose. The receptors combinedly send signals to the brain, when we eat to form a flavor. 35 receptors are present in the human mouth to detect the five basic tastes. The aroma can be detected by 400 varied receptors. The proteins in these receptors are encoded by genes, and well, we all know how DNA varies by only 0.1% in all humans (sarcasm intended).

In the 1930s, a chemist named Arthur Fox blew phenylthiocarbamide (PTC) in the air accidentally. He observed that some of his colleagues complained about the compound tasting bitter, however, others did not taste anything, including himself. This was studied many years later and concluded that a particular gene, TAS2R38 encoded for a taste receptor that sensed PTC. Nonetheless, not only taste but also eating patterns like calorie intake and meal size can be linked to genes. The linkage of genes to our diet can be studied under the field of Nutrigenetics.

Genes could classify people as supertasters and regular tasters (You already know which one you are!). In 2006, a study conducted in Philadelphia at Monell Chemical Center linked the perception of glucosinolates to a gene receptor hTAS2R38. Glucosinolates are bitter compounds commonly found in broccoli, turnips, and kale. The study was conducted on 35 people expressing three genotypes; PAV/PAV, PAV/AVI, and AVI/AVI. Supertasters were people with PAV/PAV who were very sensitive to bitter taste in all other foods as well. Regular tasters were people with PAV/AVI were people who sense bitter foods, but with lesser intensity. Non-tasters were people with AVI/AVI who were completely insensitive to the bitter taste. These taste perceptions would undeniably affect the way people eat, and their food choices. Across the world, the variation of these tasters and non-tasters changes in different populations for reasons yet unknown. In populations such as Japan and China, non-tasters are as less as 3%, whereas in North America 30%, and India around 40% were studied to be taste blind.

In a 2004 American study, it was found that the olfactory receptors are present in mutational hotspots, meaning that they are more prone to genetic variation. This variation will affect the intensity and sensitivity of the aroma perceived. Another American study concluded that the differences that exist in humans in terms of genetic, can account for up to 30-40%difference in aroma receptors.

Just understanding this influence of genes on sensory preferences can go a long way in the future. It can affect the way a product is marketed to a specific target population. It can be used to personalize diets for weight loss. Another important research could be marked by understanding our possibility on could we alter these genes to make people not only eat healthier forcefully but also to like eating it.

Saying all of this, I believe that we all are in our own perfect and unique sensory worlds, and no one can take that away from us.

References

1. Genetics of Taste, Susha Cheriyedath, www.news-medical.net

2. Blame it on mum and dad: how genes influence what we eat, Nicholas Archer, www.theconversation.com

3. Do Your Genetics Affect How You Taste? www.sciencemeetsfood.org