A new study published in BMC Medicine found an intriguing statistical link between enjoying the smell and taste of onions and a lower risk of type 2 diabetes and high blood pressure. Researchers stressed that this does not prove onions themselves prevent disease, but it may offer new clues about how food preferences relate to long-term health.
The team, made up of researchers from Australia and other countries, analyzed genetic and dietary data from more than 160,000 people aged 37 to 73 in a large British health database. Their goal was to better understand how taste and smell preferences might influence the risk of chronic illness. They examined hundreds of genes tied to taste and smell, along with preferences for 140 different foods.
One of the strongest findings was a connection between liking onions and a specific variant of the OR2T6 gene, which is involved in smell recognition. The researchers then checked whether that same genetic variant was also linked to medical conditions. They found that people carrying the variant associated with onion preference had a lower risk of type 2 diabetes and hypertension.
Lead researcher Dr. Daniel Hwang of the University of Queensland said, “Genes related to taste and smell can be an important tool for understanding the links between diet and disease, and for helping us better examine cause-and-effect relationships in nutrition.” The researchers said genetic data has the advantage of being fixed at birth and not shaped by later lifestyle changes, unlike self-reported food habits. They described their approach as Mendelian randomization, which uses genetic variants as a marker for food preference. Still, they cautioned that the results need confirmation in larger and more diverse populations. They also noted that onion’s antioxidant and anti-inflammatory compounds could help explain the association, and said the method may eventually help identify other links between foods and diseases such as cancer, heart disease, and diabetes. They added that unhealthy diets cause about 11 million deaths worldwide each year.
