Poor diet decisions? Blame your genetics

July 11, 2022
Why are some people inclined to select healthy food while others gravitate toward junk food? Dr. Scott Froum looks at how genetics (specifically taste-related genes) factor into food choices.

According to preliminary findings discussed at the 2022 American Society for Nutrition, genetic makeup may be a reason why a person selects certain foods over others.1 It is known that genetics influence taste. Recent advances in genome-wide association studies have found that taste-related genes may be one reason why some people are inclined to select healthy food options while others choose junk food and may be dependent upon a person’s polygenetic taste score.

What are genome-wide association studies?

A genome-wide association study uses two groups of participants, those with the disease being studied and those without the disease. DNA is obtained via a blood sample or cell harvesting via a cotton swab along the inside cheek of the mouth. The genome is then purified from the blood or cells and inserted onto tiny chips and scanned on automated laboratory machines.

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The machines survey each participant’s genome for strategically selected markers of genetic variation, which are called single nucleotide polymorphisms, or SNPs.2 If certain genetic variations are found to be coincident with the disease compared to people without disease, the variations are said to be “associated” with the disease. The associated genetic variations can serve as markers of the human genome where the disease-causing problem resides.

What is your polygenic taste score?

Polygenic taste scores show a gene’s influence on the perception of taste and categorize a person’s sensitivity to the five basic qualities of taste. Human taste perception is characterized by these five qualities: bitter, sweet, salty, sour, and savory (umami).3 If you score high for sour, you may be more sensitive to sour tastes than someone with a moderate or low score.

Polygenic taste score may determine food choices

In a new study of more than 6,200 adults, researcher Julie Gervis, PhD(c), of Tufts’ Jean Mayer USDA Human Nutrition Research Center on Aging, used polygenic taste scores combined with a detailed dietary questionnaire to ascertain if taste scores could predict a person’s preference for a particular food group. For example, study subjects with a high bitter score tended to eat fewer than two servings of whole grains a week. Whole grains have been shown to reduce both heart disease risk and the risk for colorectal cancers.4 Those scoring high for umami (savory) ate fewer vegetables such as carrots, peppers, and other vegetables linked to reductions in all forms of mortality.5

Future research

Diet is a complex topic determined not only by genetics but other factors including cultural, social, economic, and psychological motivators. This research is one step in the direction of the field of personalized nutrition and how genes influence food consumption, absorption, and system interaction. Many more randomized controlled clinical trials are needed to corroborate and validate these initial findings.

Editor’s note: This article originally appeared in Perio-Implant Advisory, a chairside resource for dentists and hygienists that focuses on periodontal- and implant-related issues. Read more articles and subscribe to the newsletter.

References

  1. Julie Gervis, MS, PhD candidate, Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston; Connie Diekman, RD, MEd, food and nutrition consultant, St. Louis, and former president Academy of Nutrition and Dietetics, Chicago; American Society for Nutrition Annual Meeting. Online, June 14-16, 2022.
  2. Genome-wide association studies fact sheet. National Human Genome Research Institute. Updated August 17, 2020. https://www.genome.gov/about-genomics/fact-sheets/Genome-Wide-Association-Studies-Fact-Sheet
  3. Gravina SA, Yep GL, Khan M. Human biology of taste. Ann Saudi Med. 2013;33(3):217-222. doi:10.5144/0256-4947.2013.217
  4. Zhang XF, Wang XK, Tang YJ. et al. Association of whole grains intake and the risk of digestive tract cancer: a systematic review and meta-analysis. Nutr J. 2020;19(1):52. doi:10.1186/s12937-020-00556-6
  5. Aune D, Giovannucci E, Boffetta P, et al. Fruit and vegetable intake and the risk of cardiovascular disease, total cancer and all-cause mortalit—a systematic review and dose-response meta-analysis of prospective studies. Int J Epidemiol. 2017;46(3):1029-1056. doi:10.1093/ije/dyw319
Scott Froum, DDS, a graduate of the State University of New York, Stony Brook School of Dental Medicine, is a periodontist in private practice at 1110 2nd Avenue, Suite 305, New York City, New York. He is the editorial director of Perio-Implant Advisory and serves on the editorial advisory board of Dental Economics. Dr. Froum, a diplomate of the American Board of Periodontology, is a volunteer professor in the postgraduate periodontal program at SUNY Stony Brook School of Dental Medicine. Contact him through his website at drscottfroum.com or (212) 751-8530.