Monell Chemical Senses Center

Genetic Variant Linked to Onion Preference Associated with Lower Blood Pressure and Reduced Type 2 Diabetes Risk

- A Mendelian randomization study found that a genetic variant in the OR2T6 olfactory receptor gene linked to onion liking is associated with lower systolic blood pressure (≈1.3 mmHg) and diastolic blood pressure (≈0.7 mmHg). - Individuals with the onion-preference genetic variant had a roughly 14% reduced risk of developing type 2 diabetes, with no effect on BMI, blood fats, or blood sugar levels. - Researchers screened over 1,200 genetic variants across 325 taste and smell receptor genes in UK Biobank data from nearly 500,000 adults, identifying 25 robust genetic instruments for 20 different foods. - The study introduces a novel method using chemosensory biology-grounded genetic instruments to address confounding and reverse causation that have long challenged nutritional epidemiology.