STUDY: New insight into human sweet taste: a genome-wide association study of the perception and intake of sweet substances
AUTHOR: Liang-Dar Huang, et al (13)
QUESTION: Which genes are associated with the perception, liking, and consumption of sweet substances?
SUMMARY BY: Robyn Flipse, MS, MA, RDN
Verify previous reported associations within genes involved in the peripheral receptors systems and reveal novel loci.
Genome-wide association scans (GWAS) of the perceived intensity of 2 sugars (glucose and fructose) and 2 high-potency sweeteners (neohesperidin dihydrochalcone and aspartame) were performed in an Australian adolescent twin sample (n = 1757), in the perceived intensity, sweetness and the liking of sucrose in a US adult twin sample (n = 686), and in the intake of total sugars and sweets in a UK Biobank sample (n = ≤174,424). All participants were of European ancestry, there were more female than male participants, and the Australian sample was younger than the US and UK samples.
Strong association was found between the FTO gene located on chromosome 16 and total sugar intake, suggestive associations were seen in the phenotypes for the perception and intake of sweet substances, no support was found for the previously reported associations within TAS1R2, TAS1R3, GNAT3, and GLUT and sugar intake, and genetic evidence was seen for the involvement of the brain in both sweet taste perception and sugar intake.
Genes additional to those involved in the peripheral receptor system are also associated with sweet taste perception and intake of sweet-tasting foods. The functional potency of the genetic variants within TAS1R2, TAS1R3, and GNAT3 may be different between ethnic groups and warrants further investigation.
Dietary data may not accurately capture individual differences in taste perception since genetic profiles of intake of sweets can be different from those of sweet perception.
Molecules involved in stomach inflammation could modify or regulate human sweet taste receptors expressed along the gastrointestinal tract.
The single nucleotide polymorphism (SNP) associated with sugar intake is highly correlated with the BMI-associated SNP within the FTO gene, however, in this study it was associated with a lower intake of reported total sugars.
The same genetic variants might affect sweet perception and intake differently in different populations of the same genetic ancestry due to cultural differences, especially those populations with traditional compared to obesogenic foodways.
Robyn Flipse, MS, MA, RDN is a registered dietitian, cultural anthropologist and scientific advisor to the Calorie Control Council, whose 30+ year career includes maintaining a busy nutrition counseling practice, teaching food and nutrition courses at the university level, and authoring 2 popular diet books and numerous articles and blogs on health and fitness. Her ability to make sense out of confusing and sometimes controversial nutrition news has made her a frequent guest on major media outlets, including CNBC, FOX News and USA Today. Her passion is communicating practical nutrition information that empowers people to make the best food decisions they can in their everyday diets.Reach her on Twitter @EverydayRD and check out her blog The Everyday RD.