This past weekend, my dad came to State College to visit for Parent’s Weekend. The number one thing I was most excited for was a gourmet and expensive (since I wasn’t paying) meal. My dad and I share similar food preferences, so with a doubt, I knew we would be up for a quality steak or some late night pizza. With our other similarities that could possibly be due to genetics, I wondered are our food likes were due to genetics. With that I asked the question do genetics or environmental factors affect our taste/food preferences or do we learn them?
To explain the scientific reasoning behind genetics’ affect in taste, a study reported by Medical Daily explains that genetics affects food preferences based on different taste receptors and the certain genes that are found in them. Another source agrees by saying preferences or reluctances are found through bitter, sweet, unami (savory), and even fatty tastes. Although, Medical Daily’s studies focuses on the personal nutritional engineering to cope with several disorders, making the study irrelevant to my question. I still need to see how environment does or doesn’t play a role in taste preferences.
In a British Study , a large-scale longitudinal observation was conducted by researchers in the United Kingdom to behold the possible genetic and environmental influence first recorded in pre-school aged twins, and followed them into adolescence. There were 2686 identical and fraternal twins ages 18-19. (The American Journal of Clinical Nutrition 1). The process began when the twins were at an average age of 3.5 years old. This is when the twins’ parents all recorded their food preferences at this age. These preferances were then divided into 6 food groups of fruits, vegetables, meat/fish, dairy, starch, and snack-like foods. (The American Journal of Clinical Nutrition p1). With this separation of food, another question can be asked- Are certain preferences for food groups determined more by genetics or environment?
The take away I made from this study is that through high and low correlations of preference between food groups, we can see the possible genetic influence. In addition, it is noted that family life is the main contribution to environmental influences, which is unique to age since the younger twins will typically spend more time in family life. With this take away, I came up with the null hypothesis that neither genetics nor environment will have long term effect on the twins, and the possible alternative hypotheses being combinations of these two factors having some and none effect in long term, or both having effect in long term.
It is then noted that the controlled variables were age, type of twin, the division of gender (slightly more females than males), there was an average BMI, some indicated certain diets and food allergies.(The American Journal of Clinical Nutrition 4).
The results of the first trial conducted in the twins when they were 3.5 years-old say that between fruits and vegetables, there was the strong correlation of liking/disliking the food. This is identified by a difference of percentage being lower than the p-value exhibited. (The American Journal of Clinical Nutrition 5). Although, there was a low correlation between snacks, starches, and dairy. This half of the study then shows that based on the stronger correlated preferences, genetics influences these tastes more than the lower correlations. Although, environmental factors influence the lower correlations more since children are born with a natural liking for sweet and salty snack-like foods, but they are only strengthened by a continuous exposure to it more so than fruits, vegetables, and meats, according to Dr. Alison Fildes, a researcher in the study . This natural preference for these tastes, as Fildes explains, is because in the past during food scarce periods, people sought out sweet and energy rich foods, which we adapted to these cravings over time.
Although, when research was re-conducted on the 18-19 year-olds, since environmental factors were not as present anymore, they began to develop independent preferences for starch, dairy, and snacks and their previously strong genetically influenced food of fruits, vegetables, and meat was only moderate now.
According to these results, environmental factors are unique and change as we grow, therefore having more effect when we are younger and little to no effect when we are older. Although genetically speaking, there is a moderate affect that follows us into adolescence and beyond. This would conclude with the alternative hypothesis among research, with support from the p-value data.
This study is very large and states that similar observations have been conducted in younger children with the same results, although there has not been much research that follows these children in long term effect. Therefore making these results not as reliable no matter the size and longevity of this observation. Leaving real life to accept the null, making the overall conclusion false-positive.
In my opinion, the take-away from these results is something I personally agree with based on experience. This is because, as I grew older and became more independent, my taste preferences grew but some stayed the same in accordance with the results of the specific food categories affected by genetics. In addition to my inference, one of the articles I utilized then made a very useful and important take-away statement. A child’s like and dislikes of good and bad food isn’t entirely dependent on genetics and can actually be changed through restrictions and re-introducing foods to them, hence the environmental factors of family life.