The anti-cancer benefits of vitamin C can be dramatically reduced by intake of dietary fats, according to a new study conducted at the University of Glasgow. The results of the study, which simulated what happens in the human stomach, were presented earlier this month at the annual meeting of the Society of Experimental Biology in Glasgow.
Researchers investigated how vitamin C affects the acidification of nitrite in the stomach. This acidification can lead to production of potentially carcinogenic N-nitroso compounds related to stomach cancer. According to the European School of Oncology, stomach cancer is the fourth most frequent cancer worldwide with 800,000 new cases diagnosed every year.
Carcinogenic compounds form when nitrite, found in saliva, and nitrate in some foods mix with stomach acids. Ascorbic acid (the active component of vitamin C) protects against the formation of these compounds. The study revealed vitamin C inhibited conversion to carcinogenic compounds by approximately 99.7 percent
Notably, the research team also found when dietary fats were added to the mix, the antioxidant properties of vitamin C were neutralized, and the carcinogenic N-nitrosamine was formed.
"These results indicate that the presence of lipid can markedly alter the protective effects of antioxidants with respect to potentially carcinogenic nitrosative chemistry occurring in the human stomach, and illustrate how a diet rich in lipids can directly influence gastric biochemistry," said lead author Emilie Combet.
Lipids are substances of the fat group and are insoluble in water. While some lipids are necessary for storing energy, others include a class of harmful trans-fatty acids found in hydrogenated oils and partially hydrogenated oils common not only in fast food but also in many products found on grocery store shelves -- including dairy products and meat. This year major cities in the U.S. are taking steps to ban trans-fats in food served in restaurants.
"This research helps explain why high-fat diets that focus on dairy products, meat products, and processed foods are so strongly correlated with cancer and heart disease," said Mike
Adams, author of Grocery Warning: How to Identify and Avoid Dangerous Food Ingredients. "Many superfoods perform best when consumed during a meal that has no fats," Adams said,
"But don't forget to consume healthy, plant-based fats later. Omega-3 fatty acids are essential for a healthy heart."