Monell is in the vanguard of exploring how the taste, smell, and flavor of food and drink affects the choice of what we eat, and in turn our health. We also study taste and smell across the lifespan. Early childhood is a time of great benefit to intervene with healthy choices, but the latter part of life is equally important. For example, understanding how responses to macronutrients are sensed holds great promise for preventing and treating certain chronic diseases. Current work on a molecular level includes the role of sweet-taste receptors and bitter-sensing cells.
Genetic variation shapes an individual’s perception of fatty foods. Liking of fatty foods depends on inborn genetic traits related to fat perception, rather than simply the fat content of the food. Participants in a recent study sampled six types of high- and low-fat potato chips and reported on how fatty they tasted and how much they liked them. Genetically identical twins were more similar in their pattern of liking for the high- and low-fat potato chips compared to fraternal twins. They also identified two specific gene variants that correlated with the twins’ ratings of liking, tying these genes for the first time to the perception of fattiness.
Stress affects all aspects of life – taste included, as well as food intake, gut health, and metabolism. Inflammation caused by chronic stress shortens the lifespan of taste cells, and acute stress response changes the expression of certain taste receptors. Reduced taste sensitivity can increase an individual’s preference for sugar and salt and may contribute to overeating and obesity. Practical applications from these studies include designing foods and dietary strategies to prevent or balance the negative effects of stress on taste and health.
While there is variation in the rates of growth among infants, growing “too fast” during the first months is increasingly considered a risk factor for later obesity. Faster weight gain during the first months accelerated the timing of infants’ first tooth and the number of primary teeth that erupted by their first birthday. Infants who gained weight rapidly were also at greater odds for obesity at one year, but this relationship was lower for infants who breastfed compared to those who were formula fed. The timing and patterning of teething may be a biomarker for increased risks for oral and systemic conditions such as obesity and dental caries.
The relationship between sweet taste preference (concentration of sucrose most preferred) and sensitivity (lowest concentration of sucrose detected) in taste studies with children is helping to answer this. While children require higher sucrose concentrations to detect sweetness and most kids preferred higher concentrations of sucrose, sweet taste sensitivity did not predict preference. The fact that both aspects of sweet-taste perception (sensitivity and preference) change during development, but do not go hand in hand, suggests these aspects of taste undergo distinct developmental trajectories from childhood to adulthood.