Are You a Super-taster?

For this year's science fair and showcase, I created a project in one of my interest areas: biology and the effect genetics have on the ability of the individual to taste certain substances and foods.

Firstly, I ordered four test strips from a laboratory: the control strip (plain paper), sodium benzoate, PTC, and thiourea. Then, I proceeded to survey sets of genetically related families, pairing each parent with each child, and recording the data. I also asked them if they enjoyed eating veggies, chocolate, soda, and if they had a history of thyroid disease in their family. Secondly, I conducted a survey of about 20 classmates and compared their results randomly, for a control group of non-genetically related subjects. I got some pretty strange results.

Out of the pairs I selected, approx. 90% of genetically related pairs had the ability to taste thiourea, and about 68% of non-genetically related pairs did. Thiourea is a substance that can either taste bitter, sweet, salty, or spicy, along with the other three substances I tested for. It is claimed that some individuals can taste thiourea, or PTC, but not both. PTC is an organosulfer thiourea, with a phenyl ring. According to a study conducted at Yale University, heavy thiourea tasters will be less likely to consume any bitter foods, including green-leafy vegetables, coffee or chocolate, and make up about 10 to 15% of the population. Non-tasters will be more likely to have a genetic risk in the family of thyroid disease, because thiourea is an anti-thyroid acting agent, and is seemingly used to treat patients with thyroid disease.

Out of the pairs I selected, exactly 75% of genetically related pairs had the ability to taste PTC, while about 43% of non-genetically related pairs did. Out of my knowledge, PTC is the only substance out of the three I tested that individuals can taste and be labeled what is called a “supertaster”! A “supertaster” is someone who is extremely sensitive to the taste of most substances—this influences their body type and the food they choose to eat. I found an even score of nearly 11% in each genetic/non-genetic category for “supertasters”. People who can taste PTC are less likely to smoke cigarettes and less likely to enjoy coffee/tea, while “supertasters” are also less likely to enjoy the taste of green vegetables. 70% of our population can taste PTC, even if they are not a “supertaster”, making PTC the second substance of the three, if given a popularity ranking.

Out of the pairs I selected, approx. 86% of the genetically related pairs had the ability to taste sodium benzoate, along with 100% of non-genetically related pairs. Sodium benzoate is in fact the substance discovered in soft drinks (Coca-Cola, Sprite, etc), which could hint at how widespread the ability to taste may be. None of my non-genetically related test subjects said that they disliked the taste of soda, nor couldn’t taste it, which could be the answer to this 100% even data. Approximately 75% of our population can taste sodium benzoate, giving it the ranking of #1 in popularity.

Throughout my findings I did discover that genetic factors do influence the ability to taste, however, due to the non-genetic percentage of findings in the sodium benzoate test, I have to reject a portion of my hypothesis. Due to the reliability of my test subjects, I am well aware this test is far from “professional” status, and enjoyed the experience I had with the individuals I interviewed. I collected the data, but did not analyze the data as far as to group what exactly these individuals tasted, exactly how much they tasted, etc. These results are merely based upon the individuals that tasted something, sometime, somewhere, of all different ages, racial backgrounds, weights, and lineage.

My favorite part of this experiment was being able to find out how similar my adoptive parents were to me, and what traits my boyfriend held, to compare the differences we had—it certainly settled the debate regarding why we dislike the opposite foods! I think everybody could learn and have fun with this experiment or one similar. Taste strips are easy to get your hands on, affordable, and can be ordered directly from a high-quality lab. I would recommend this experiment to any individual looking to discover themselves, and/or what possible genetic factors them and their partner could be contributing to their future offspring.