A Common Genetic Influence on Human Intensity Ratings of Sugars and High-Potency Sweeteners

The perception of sweetness varies among individuals but the sources of this variation are not fully understood. Here, in a sample of 1,901 adolescent and young adults (53.8% female; 243 MZ and 452 DZ twin pairs, 511 unpaired individuals; mean age 16.2 ± 2.8, range 12-26 years), we studied the variation in the perception of sweetness intensity of two monosaccharides and two high-potency sweeteners: glucose, fructose, neohesperidine dihydrochalcone (NHDC), and aspartame. Perceived intensity for all sweeteners decreased with age (2-5% per year) and increased with the history of otitis media (6-9%). Males rated aspartame slightly stronger than females (7%). We found similar heritabilities for sugars (glucose: h ² = 0.31, fructose: h ² = 0.34) and high-potency sweeteners (NHDC: h ² = 0.31, aspartame: h ² = 0.30); all were in the modest range. Multivariate modeling showed that a common genetic factor accounted for >75% of the genetic variance in the four sweeteners, suggesting that individual differences in perceived sweet intensity, which are partly due to genetic factors, may be attributed to a single set of genes. This study provided evidence of the shared genetic pathways between the perception of sugars and high-potency sweeteners.