Dr. Valerie B. Duffy

One area of research is to understand variation in chemosensory perception in humans and how this variation influences food flavor, food preference, and food intake. My ultimate goal is to understand how chemosensory variation influences our ability to follow a healthy diet for the prevention of chronic disease and obesity.

Perception of the taste, touch, and irritation from eating shows genetic variation. One marker for genetic variation in taste is the perceived bitterness of 6-n-propylthiouracil (PROP). Some individuals find PROP tasteless (nontasters) and others find PROP intensely bitter (supertasters). In comparison with PROP nontasters, supertasters taste sweeteners (e.g., sucrose) as more sweet, bitters (e.g., calcium chloride) as more bitter, and perceive more pain from oral irritants (e.g., capsaicin, alcohol). We were first to report that supertasters may be more aware of the oral textural cues of fat in food. These sensory differences have an anatomical basis. Supertasters of PROP can have the highest density of fungiform papillae and taste buds on the anterior tongue. Genetic variation influences food preferences (eg, for sweet and high fat foods) as well as intake of alcohol, fat, and use of salt at the table. For example, supertasters report greater creaminess from dairy products, less frequent consumption of high-fat foods, and more favorable serum lipids than do nontasters. Nontasters, however, report less bitterness from high-bitter beverages and more frequent intake of green vegetables than do supertasters. Collaborations with Dr. Linda Bartoshuk are working to refine the phenotypic characterization of supertasting while those with Dr. Kenneth Kidd are working to identify the genotypic characterization of supertasting. This research has been funded or is currently funded by the USDA and the NIH.

Another area of research involves improving dietary quality of individuals of economic disadvantage. Funding from the USDA-Food Stamps and The American Diabetes Association Foundation has enhanced collaborations between the Connecticut Department of Public Health and the Dietetics Program in the School of Allied Health. These collaborations aim to improve the food habits of preschool children and their families. Through involvement of undergraduate and graduate student research, we are investigating the effectiveness of interventions in the Head Start Program to improve vegetable intake and level of physical activity of preschool children. Please see www.captain5aday.org for more information.

- Chair, American Dietetic Association Expert Work Group, Evidence-based Analysis, Non-nutritive sweeteners (http://www.adaevidencelibrary.com/topic.cfm?cat=2797) 2005-2006
- Member, American Dietetic Association Scholarship Committee, 2000-2002
- Chair, American Dietetic Association Positions Committee, 1997-1999
- Member, American Dietetic Association Positions Committee, 1995-1997
- Postdoctoral Fellowship, Yale University, Taste Psychophysics, 1992-1994
- Delegate, American Dietetic Association, 1993-2000
- Member, National Alpha Eta Honor Society, 1995
- Member, Phi Kappa Phi Academic Honorary Society, 1988
- Registered Dietitian, Commission on Dietetic Registration, 1984