Greater food variety could cut risk of gastrointestinal cancers

Eating a wide variety of food may reduce the risk of gastrointestinal cancers, according to research funded by the World Cancer Research Fund network* and published in the European Journal of Cancer.
Little is known about how eating a wide variety of food species, also known as food biodiversity, may benefit our health or affect our cancer risk. Food species refer to a distinct type of plant or animal, such as wheat, chicken, or salmon. For example, salmon, mackerel, and tuna are all separate food species, even though they share some biological traits and belong to the same food group. Similarly, rocket, lettuce and spinach count as separate food species, even though they are all leafy green vegetables. However, chicken and a chicken’s egg belong to the same food species even though they are different types of food.
This study is the first to examine how the number of different food types consumed, measured as Dietary Species Richness (the number of species an individual consumes per year) affects the risk of the following gastrointestinal cancers:
- Oesophagus
- Throat
- Stomach
- Bowel
- Colon
- Rectum
- Gallbladder
- Pancreas
- Liver
The study followed 450,111 cancer-free adults in 9 European countries from the European Prospective Investigation into Cancer and Nutrition cohort for 14 years. The researchers, from the International Agency for Research on Cancer, found that individuals with the most diverse diets, by including more food species in their diet, had a 23% lower risk of developing gastrointestinal cancers compared with those with the least variety. The risk decreased by 6% for every 10 extra species per year added to their diet. People can do this by including more variety in the types of fruit and vegetables they eat, for example, choosing to eat local and seasonal fruit and vegetables of different colours.
Food biodiversity includes eating different types of food that provide the necessary nutrients for maintaining health. Investigating food biodiversity is important because it has the potential to benefit public health and sustainable food systems.
Dr Helen Croker, our Assistant Director of Research and Policy, said: “Diets have become more limited in the types of foods eaten and they are often high in fat, sugar and salt. However, for cancer prevention, it’s important to eat a healthy, balanced and varied diet with plenty of wholegrains, pulses, vegetables and fruit.”
Dr Helen Croker
This study is particularly interesting because it looks at the number of different foods people eat and the impact it can have on their cancer risk, in particular gastrointestinal cancers. More research is now needed to confirm these findings and further explore the link between dietary diversity and cancer prevention.
Dr Inge Huybrechts
This study shows how a more diverse diet, including a large variety of species, could lower the risk of gastrointestinal cancers, emphasising the importance of eating a wide variety of foods. The idea behind a diverse diet consisting of many types of plants and animals species may provide essential nutrients for the body while also strengthening ecosystems, making them more resilient, productive, and sustainable.
This study was funded by Wereld Kanker Onderzoek Fonds based in the Netherlands, as part of the World Cancer Research Fund International network.
