Can vitamin C prevent cancer? Here’s what new research found

For decades, citrus fruits have been go-to remedies when illness strikes. Having oranges during a cold is believed to improve overall health. It turns out an orange a day might do more than just keep the sniffles away. A new study from the University of Waterloo examined how vitamin C influences digestion-related cancer risk. The findings are published in the Journal of Theoretical Biology.Vitamin C is a water-soluble vitamin essential for the body’s overall health and functioning. This micronutrient helps boost the immune system, fight infections, and maintain healthy skin, blood vessels, bones and cartilage. The body cannot produce or store it; you get it from foods such as citrus fruits, berries, tomatoes and leafy greens, or from supplements.The new study from the University of Waterloo used mathematical modelling to examine how vitamin C affects chemical reactions in the digestive system that are linked to cancer development.North American diets have seen a steady increase in exposure to nitrates and nitrites over the past decades. These compounds are found in cured meats as well as in fruits and vegetables grown using polluted soil and water. Although nitrates and nitrites play important roles in neurological and heart health, in the stomach they undergo nitrosation, a chemical reaction that forms compounds which many scientists suspect increase cancer risk.“Since at least the 90s, researchers have been studying the link between cancer and these compounds, with conflicting results. Our work suggests that the presence of dietary vitamin C may help explain these inconsistencies,” Dr Gordon McNicol, a postdoctoral researcher in applied mathematics and the first author of the study, said in a statement.To understand the link, the researchers built a mathematical model of the salivary glands, stomach, small intestine and plasma. They then simulated how nitrites and nitrates move through the body and change over time. During the study, the model demonstrated that vitamin C present in foods such as leafy greens like spinach, which contain both vitamin C and nitrate, could decrease cancer risk.The research also showed that vitamin C supplementation after each meal could have a moderate positive effect in reducing the formation of nitrosation products associated with cancer risk from dietary nitrites and nitrates, such as those found in foods like bacon and salami.“This work provides a mechanistic roadmap for future clinical and laboratory studies by identifying the key interacting drivers of these potentially harmful chemical reactions, including nitrite exposure, antioxidant intake, meal timing, gastric conditions and oral microbiome activity. This model can help researchers design more targeted experiments and interventions, focusing on when and in whom nitrosation is most likely to occur,” Dr Anita Layton, Professor of Applied Mathematics and Canada 150 Research Chair, said.The researchers hope these findings will contribute to future nutrition research.