Broccoli and genetics
Yes, even how we perceive flavours can have a genetic origin. Have you ever wondered why there are foods you find harder to eat or that even taste terrible to you? Is it impossible for you to eat broccoli or cabbage? Do you wonder how it is possible that someone can drink black coffee or eat high-percentage dark chocolate? The intensity with which we perceive bitterness in foods may have a genetic explanation due to the presence of variants in the TAS2R38 gene, located on chromosome 7, which can influence our perception, preferences and food consumption.
How do genetic variants influence our ability to eat broccoli?
This gene encodes a subunit of the bitter taste receptor TAS2R38 and has two alleles: a dominant allele that confers the ability to strongly detect bitter taste, known as “taster”, and a recessive allele known as “non-taster”, which allows bitterness to be perceived with lower intensity. Around 25% of the population are “non-tasters”, capable of perceiving bitter flavours less intensely. Therefore, this implies that around 75% of people perceive this taste as overly intense at first, and possibly even unpleasant.
Does my diet influence my genes, or do my genes influence my diet?
Recently, the scientific journal Nature published a study carried out by the RIKEN Center for Integrative Medical Sciences and Osaka University, in which genetic data and dietary preferences of more than 160,000 people in Japan were analysed to identify genetic links to food preferences. “We know that what we eat defines who we are, but we found that who we are also defines what we eat,” said Professor Yukinori Okada from Osaka University.
Regarding variants responsible for detecting bitterness, it was concluded that “non-taster” individuals consumed more foods such as tofu and drank more alcohol and coffee than “tasters”, i.e. those who perceive bitterness more intensely.
How does broccoli affect us according to our genetics?
The TAS2R38 gene encodes a receptor associated with the bitter taste of broccoli, Brussels sprouts, cabbage, watercress, chard and ethanol (the alcohol found in alcoholic beverages).
In addition, this receptor can influence our food preferences and therefore our food consumption. For example, whisky may taste less bitter and sweeter to “non-tasters”, making it easier for them to consume alcoholic drinks or other high-calorie foods, which could increase the potential risk of obesity, diabetes or other associated conditions.
The same would apply to the plant foods mentioned above: although they are rich in nutrients and phytochemicals, “non-tasters” may consume them easily from a taste perspective, which is positive for this group, but represents a significant disadvantage for “tasters”.
How can understanding our genetics help with our diet?
Gaining an in-depth understanding of our genetic code can be extremely important when designing a rich and varied nutritional plan , one that also fits our tastes and preferences. Imagine following a generic nutrition plan that insists on prolonged consumption of foods such as rocket, broccoli or endive, which you already find unbearable – failure would almost certainly be guaranteed.
Ultimately, taste is an individual preference influenced by the genes we carry and which determines our energy intake. The average human has more than 9,000 taste buds, so it comes as no surprise that we love eating and greatly enjoy certain foods. However, understanding the genes we carry helps us choose foods more intelligently and achieve a healthy life without dietary frustration.
In conclusion, once we interpret our genetics, we can design a nutritional plan knowing that we may have a predisposition to reject foods with a strong bitter intensity. This also allows us to anticipate how to prepare them: for example, if broccoli always puts you off, you can roast it or add pumpkin to slightly sweeten it, or choose specific spices when seasoning your food. Thanks to genetic knowledge, our diet can become both healthy and enjoyable.
References
1. Hwang LD, Gharahkhani P, Breslin PAS, et al. Bivariate genome-wide association analysis strengthens the role of bitter receptor clusters on chromosomes 7 and 12 in human bitter taste. BMC Genomics. 2018;19(1):678. doi:10.1186/s12864-018-5058-2
2. Risso DS, Mezzavilla M, Pagani L, et al. Global diversity in the TAS2R38 bitter taste receptor: revisiting a classic evolutionary proposal. Sci Rep. 2016;6:25506. doi:10.1038/srep25506
3. Rahim HM, Majeed RK, Rostam NA. Prevalence, biochemical and genetic analysis of the mutated gene related to bitter taste perception of phenylthiocarbamide in Sulaymaniyah province, Iraq. Babylon Med J. 2018;15:201.
4. Yamamoto K, Sakaue S, Matsuda K, et al. Genetic and phenotypic landscape of the mitochondrial genome in the Japanese population. Commun Biol. 2020;3:104. doi:10.1038/s42003-020-0812-9
5. Kohlmeier M. Nutrigenetics: Applying the Science of Personal Nutrition. Academic Press; 2012.
