TAS2R38 bitter taste genetics, dietary vitamin C, and both natural and synthetic dietary folic acid predict folate status, a key micronutrient in the pathoaetiology of adenomatous polyps

Abstract

Taste perception may influence dietary preferences and nutrient intakes contributing to diet-related disease susceptibility. This study examined bitter taste genetics and whether variation in the TAS2R38 gene at three polymorphic loci (A49P, V262A and I296V) could alter dietary and systemic folate levels and dietary vitamin C intake, and whether a nutrigenetic circuit existed that might link bitter taste, folate/antioxidant status and risk for a colonic adenomatous polyp. TAS2R38 diplotype predicted bitter taste (PROP) phenotype (p value <0.00001) and red cell folate status (p=0.0179) consistent with the diplotype that has the broadest range of bitter perception (AVI/PAV) also possessing the highest average red cell folate value. However, TAS2R38 diplotype did not predict dietary intake of methylfolic acid, pteroylmonoglutamic acid or total folic acid. Neither did it predict dietary intake of vitamin C. Despite this, intake of dietary folate predicts red cell folate with analysis pointing to a key nutrient-nutrient interaction between vitamin C intake and systemic folate status. Analysis of 38 patients with an adenomatous polyp and 164 controls showed that individually, dietary nutrient intake, nutrient status and taste diplotype did not influence polyp risk. However, red cell folate status (in individuals below the population median value) did interact with bitter taste diplotype (AVI/PAV) to predict polyp risk (p=0.0145). Furthermore, synthetic folic acid (below median intake) was statistically associated with adenoma occurrence (p=0.0215); individuals with adenomatous polyps had a 1.77× higher intake than controls. Additionally, stepwise regression taking account of all dietary nutrients showed a tight relationship between methylfolic acid (but not pteroylmonoglutamic acid) intake and red cell folate level in those with a low folate status and occurrence of an adenomatous polyp (p=0.0039). These findings point to a role for folate in the pathoaetiology of adenomatous polyps, with the natural and synthetic vitamers not necessarily having the same biological effect.

Variations in the bitterness perception-related genes TAS2R38 and CA6 modify the risk for colorectal cancer in Koreans

“…Therefore, genetic variants in taste perception, especially bitterness sensing and its influence on dietary intake, are considered significant risk factors for CRC susceptibility. Because bitterness is a key determinant in the rejection/acceptance of food products, genetically modulated sensitivity to bitterness intensity may lead to an individual's differential intake of dietary and consumer goods, which may further be linked to the risk of diet-related diseases [3]. …”

“…The perception of the bitter thiocyanate (N-C=S) moiety as tested with 6-n-propylthiouracil (PROP) and phenylthiocarbamide (PTC) has been studied extensively as a human tasting trait with respect to dietary behavior and health outcomes [3]. The variability of PROP/PTC bitterness sensation among individuals is known to be associated with the taste receptor type 2 member 38 ( TAS2R38 , T2R38) gene, and its haplotype consists of three common missense variations (A49P, V262A and I296V).…”

Bitter Taste Perception and Dietary Intake Patterns in Irish Children

“…However, results examining how preference translates to intake in people of different taste perceptions are conflicting; some groups reported small differences in intake of certain vegetables such as of raw broccoli, cucumber and olives (when offered as a snack) [34], green salad vegetables [10], or in macronutrient consumptions [23], while others found none [35,36]. Such studies have varied in dietary intake assessment with some using traditional dietary intake methods [35,37] and others using biomarkers [36,38]. Further, many of these reports examined only PROP taster status, while others looked only at the TAS2R38 gene; in the present study, we examine both in the context of a dietary patterns analysis.…”

First objective evaluation of taste sensitivity to 6-n-propylthiouracil (PROP), a paradigm gustatory stimulus in humans

“…Within this nutritional context, PROP tasting, which is a common genetic trait present in all population groups across the globe5, has gained, in the last decades, considerable attention as a paradigm of general taste perception and as an oral marker for food preferences and eating habits that ultimately impacts on nutritional status and health3. This role is based on data showing that PROP sensitivity is associated with variation in perception and preference for various oral stimuli including fats and high-fat/high-energy foods6789, selection of fruits and vegetables101112, body composition1314, plasma antioxidant status15, and the colon cancer risk161718. Other studies, however, do not confirm these associations by reporting inconsistent results192021222324.…”