Most people think they choose foods simply because of habit or culture. However, scientists are increasingly discovering that our genes may also play an important role in shaping what we enjoy eating.
Some people love spicy foods, while others prefer sweet flavours. Some enjoy strong-smelling vegetables like onions, and others dislike them.
Researchers at The University of Queensland have now found evidence that these genetically influenced food preferences may also provide clues about our risk of chronic diseases.
Their study, published in BMC Medicine, found that people who are genetically more likely to enjoy the taste and smell of onions tend to have lower blood pressure and a reduced risk of type 2 diabetes.
The findings are part of a larger effort to solve a long-standing problem in nutrition science. It is surprisingly difficult to prove whether a specific food actually causes health benefits. Nutrition studies often show that people who eat certain foods are healthier, but this does not necessarily mean that the foods themselves are responsible.
For example, someone who regularly eats fruits and vegetables may also be physically active, avoid smoking, and receive better medical care. All of these factors can influence health. This makes it challenging to separate cause from coincidence.
Dr. Daniel Hwang and his colleagues at The University of Queensland’s Institute for Molecular Bioscience wanted to approach the problem differently. They reasoned that because taste and smell strongly influence food choices, genes affecting these senses might provide valuable clues about how diet and disease are connected.
The research team analysed data from the UK Biobank, an enormous health database containing information from hundreds of thousands of people in the United Kingdom. They focused on more than 160,000 adults aged between 37 and 73 years.
The scientists examined 325 genes involved in taste and smell and explored how these genes were linked to preferences for 140 different foods. To ensure that their findings were reliable, they also studied another group of participants from the Avon Longitudinal Study of Parents and Children, which involved younger adults around 25 years old.
The results revealed an interesting pattern. People whose genes made them more likely to enjoy onions were also more likely to have lower blood pressure and a lower risk of type 2 diabetes.
Onions are rich in plant compounds and nutrients that have been studied for their possible health benefits. Previous research has suggested that compounds found in onions may help reduce inflammation, improve blood vessel function, and support healthy blood sugar control. However, the new study was not designed to test onions themselves. Instead, it focused on how genetically influenced food preferences may help scientists better understand disease risk.
The researchers also used an advanced analytical method known as Mendelian randomization. This approach uses naturally occurring genetic differences to investigate whether a relationship between two factors is likely to be causal rather than simply an association.
The technique has become increasingly popular because it can sometimes answer questions that would be difficult or expensive to study through long-term clinical trials.
According to the researchers, the new framework could help nutrition science move beyond simple observations and provide stronger evidence about which foods and dietary patterns truly influence disease.
This work is particularly important because unhealthy diets have become a major global health problem. Scientists estimate that poor eating habits contribute to millions of deaths every year, largely due to heart disease and cancer. Rates of obesity and type 2 diabetes are also rising rapidly in many countries.
The study does have limitations. Food choices are influenced by many factors besides genes, including culture, income, family traditions, and food availability.
In addition, genetic studies cannot capture every aspect of human eating behaviour. Therefore, more research will be needed before scientists fully understand why a preference for onions appears to be linked with better health.
Nevertheless, the study provides a fresh and innovative way of thinking about nutrition. Instead of focusing only on what people report eating, researchers can now explore how genetically driven food preferences may help uncover the true links between diet and disease.
In the future, this approach may contribute to more personalized nutrition advice and better strategies for preventing chronic illnesses such as diabetes and heart disease.
If you care about nutrition, please read studies about berry that can prevent cancer, diabetes, and obesity, and the harm of vitamin D deficiency you need to know.
For more health information, please see recent studies about the connection between potatoes and high blood pressure, and results showing why turmeric is a health game-changer.
Source: The University of Queensland.
