Fat Perception in Humans (09-0873)

Completed

Brief Summary: There are many substances naturally present in the mouth that may help us taste fat in food. Two of these substances (lipases and CD36) will be examined in this study.

The presence of fat in food increases food tastiness, therefore people often over-eat high-fat foods and gain weight. The purpose of this study is to determine if blocking lipases and some genetic variations in the CD36 gene will make fatty food less tasty so that people eat less. Our hypothesis is that Orlistat and a particular gene will increase one's ability to detect fat.

Detailed Description: 1. Determine the effect of lipolysis inhibition in oral cavity on orosensory detection of fat in humans.

Hypothesis: Orally applied Orlistat will increase detection thresholds of TAGs but not FFA in humans.

To test this hypothesis we will measure triolein (a TAG) and oleic acid (a FFA) taste detection thresholds with a three-alternative forced-choice (3-AFC) ascending concentration method under two conditions (Orlistat day vs. Control day). To control for olfactory input, subjects will be assessed wearing noseclips.

2. Determine the effect of CD36 variants on fat taste perception in humans. Hypothesis: SNPs that associate with reduced CD36 expression will be associated with higher FFA and TAG detection thresholds

To test this hypothesis we will measure triolein and oleic acid taste detection thresholds in subjects who carry of the common CD36 e-SNP rs1761667 (i.e. a SNP that significantly reduces CD36 level and has a minor allele frequency of 38-48%). We expect subjects who are at least heterozygous for the expression reducing allele to have higher triolein and oleic acid taste detection thresholds compared to non-carrier subjects.

Recruitment & Eligibility

Inclusion Criteria

Exclusion Criteria

Primary Outcome Measures

Name	Time	Method
Oleic Acid Detection Level	Ranges from 5 days after screening to several weeks, pending availablity of participant.	We will measure oleic acid detection levels as a marker of subjects' ability to detect free fatty acids. Oleic acid taste detection thresholds were separately assessed using a three-alternative forced-choice (i.e. 3-AFC) ascending concentration.
Triolein Detection	Ranges from 5 days after screening to several weeks, pending availablity of participant.	We will measure triolein detection levels as a marker of subjects' ability to detect triglyceride. Triolein taste detection thresholds were separately assessed using a three-alternative forced-choice (i.e. 3-AFC) ascending concentration.

Secondary Outcome Measures