Higher TNF-α, IGF-1, and Leptin Levels are Found in Tasters than Non-Tasters

Area of Science:

• Endocrinology
• Human Physiology
• Metabolic Regulation

Background:

• Taste perception is mediated by taste cells in the tongue, which also secrete metabolic hormones.
• Taste receptors in the tongue, gut, and pancreas are implicated in local hormone secretion.

Purpose of the Study:

• To investigate the relationship between taste sensitivity and circulating metabolic hormone levels in humans.
• To determine if taste sensitivity is associated with peripheral metabolic regulation.

Main Methods:

• Thirty-one subjects were classified as tasters or non-tasters using the phenol thiocarbamide (PTC) bitter taste test.
• Fasting plasma and saliva samples were collected for hormone and cytokine assays.
• Correlations between hormone levels, body mass index (BMI), and glucose were analyzed.

Main Results:

• Tasters exhibited significantly higher plasma levels of leptin, tumor necrosis factor-α (TNF-α), and insulin-like growth factor 1 (IGF-1) compared to non-tasters.
• Positive correlations between BMI and glucose were observed only in non-tasters.
• Tasters showed a positive correlation between plasma C-peptide and BMI, and a negative correlation between saliva TNF-α and BMI.

Conclusions:

• Distinct differences in circulating metabolic hormones exist between individuals with varying taste sensitivities.
• Taste perception is closely associated with metabolic hormone levels, extending beyond appetite regulation.
• These findings suggest that taste sensitivity may influence responses to nutrient intake and could inform novel therapeutic strategies for metabolic disorders like obesity and Type 2 diabetes.