A Mendelian trait for olfactory sensitivity affects odor experience and food selection

Area of Science:

• Genetics
• Olfactory Neuroscience
• Sensory Science

Background:

• Human odor acuity varies significantly, partly due to olfactory receptor (OR) gene variations.
• The impact of these genetic variations on odor experience and food selection is not fully understood.
• β-ionone, a key aroma compound in foods and beverages, exhibits extreme sensitivity differences among individuals.

Purpose of the Study:

• To investigate the genetic basis of β-ionone odor sensitivity.
• To determine how genetic variation in olfactory receptors affects the perception and experience of β-ionone.
• To explore the link between olfactory sensitivity, food choices, and emotional associations.

Main Methods:

• Genome-wide association studies and in vitro assays were employed.
• The causal variant rs6591536 in the OR5A1 gene was identified.
• Phenotypic variation in β-ionone sensitivity was quantified and correlated with genotype.

Main Results:

• The rs6591536 variant, causing an N183D substitution in OR5A1, explains over 96% of β-ionone sensitivity variation.
• Individuals with the sensitive genotype can better distinguish foods with and without β-ionone.
• Genotype influences the description of β-ionone (e.g., 'fragrant,' 'floral') and affects food/product choices and emotional responses.

Conclusions:

• A specific olfactory receptor gene variant (rs6591536 in OR5A1) is a major determinant of β-ionone sensitivity.
• Olfactory receptor variation directly impacts sensory perception, emotional associations, and consumer behavior related to food and products.
• This study highlights the significant role of genetic variation in olfactory receptors in shaping individual sensory experiences and preferences.