Nutrition and Stomach Cancer: Prevention
Nutrition and lifestyle factors play a major role in the prevention and management of cancer, including stomach cancer. Stomach cancer is the third most common cause of cancer-related death1 and, unfortunately, diagnosis often comes too late, when the cancer has already progressed. This article will discuss which lifestyle factors may help prevent stomach cancer and which might contribute to its development. I will focus on practical, evidence-based strategies that you can use in your everyday life to help reduce the risk of stomach cancer. If you are interested in a more individualized approach, please speak to a registered dietitian to create a detailed nutrition plan that specifically fits your needs.
Nutrition Prevention Strategies
Food and nutrition are notoriously difficult to study because there are so many confounding factors, and while a lot of associations have been made, it’s hard to know exactly what might help or harm an individual in the prevention and development of cancer. That being said, a few key themes continue to repeat themselves, such as the protective effects of eating plenty of vegetables and fruits, and the probable harmful effects of eating too much red and processed meat. The following information is mostly based on a recent review of current international guidelines on primary and secondary prevention strategies for stomach cancer published in the Journal of Gastroenterology and Hepatology in 2020.1
Salt
A high salt intake has been linked to an increased risk of stomach cancer, and it is associated with an increased risk of inflammation in the stomach (atrophic gastritis) that may lead to precancerous changes in the cells lining the stomach (intestinal metaplasia).2,3,4 Salt does make food taste better though, and you don’t have to avoid it completely, but consider adding less salt to your food and increasing flavour with anti-inflammatory herbs and spices, such as curry powder, parsley, and garlic powder, or experimenting with lemon, lime, vinegar, and ginger root, or even trying new cooking methods such as caramelizing and roasting food instead of boiling. If you only eat boiled vegetables, then you’re missing out!
Garlic
There are many garlic studies, with research dedicated specifically to looking at garlic intake and/or supplementation and stomach cancer risk and progression. The results so far have been controversial. Garlic contains organosulfur compounds that may help slow or prevent the development of cancer and modify cancer risk.5 The results from two large prospective cohort studies – 77,086 women from the Nurses’ Health Study and 46,398 men in the Health Professionals Follow-up Study – in the United States did not show a decreased risk of stomach cancer with increased garlic intake.5 It might help, but we don’t have the evidence to fully support that statement yet. If you enjoy using garlic in cooking, and you tolerate it well, then continue to try new recipes and products, including pesto, which is packed with garlic. Try adding pesto to scrambled eggs, fish, pasta, and soups.
Alcohol, Coffee, and Green Tea
A moderate or large consumption of alcohol is associated with a significant increased risk of stomach cancer that may, in part, be due to the toxic local effects of alcohol itself directly to the cells lining the stomach.6 When it comes to coffee and green tea, the research has shown inconclusive results, so there are no recommendations to reduce your intake of coffee or increase your intake of green tea at this time. However, green tea does have a strong and beneficial antioxidant called epigallocatechin gallate (EGCG), which protects against cell damage so, if you like drinking green tea, then please continue to enjoy it!
Vegetables, Fruits, and the Mediterranean Diet
Some studies have shown a significant association between a high intake of vegetables and fruit and the prevention of stomach cancer, but others not so much. If you smoke, you may benefit from eating even more vegetables and fruits, as they have been shown to have an even greater protective effect than in non-smokers.7 Interestingly, dietary fibre may help neutralize cancer-causing (carcinogenic) nitrites.8 One study showed that an increase of 10 g of dietary fibre per day (the amount you’d find in two pears) was associated with a 44% decreased risk of stomach cancer.9 The overall health benefits of having a high intake of vegetables and fruit is clear, so please continue to enjoy them daily. The Mediterranean diet, which is high in vegetable and fruit intake, and low in red and processed meats, has been associated with a significant reduction of risk of stomach cancer,10 and it can be healthy and enjoyable.
Citrus
Citrus fruits appear to have a protective effect against stomach cancer, likely due to their high flavonoid content, so consider enjoying a variety of citrus fruits more often, including oranges, tangerines, lemons, limes, and grapefruit. However, grapefruits can be harmful when taken with certain medications, so please check with your doctor or pharmacist in case you shouldn’t be eating them. Lemon, on the other hand, is a versatile and simple ingredient that you can enjoy more often. I like to add lemon to so many things, including fish, tahini sauces, blueberry bread, hummus, and salad dressings, but you can also keep it super simple and squeeze it into water or tea. It all counts!
Red Meat
A high intake of red and processed meat is associated with an increased risk of stomach cancer, as are smoked and/or charred meat. Processed meats usually contain nitrites, which may form carcinogenic compounds in the body. You may benefit from lowering your intake of red meat, especially avoiding processed meats that contain nitrites, and replacing those with other protein sources, such as eggs, chicken, fish, seafood, tofu, tempeh, and legumes, such as peas and hummus. I would personally love to see more studies on the differences between grass fed, wild, and/or organic red meat vs conventional red meat, because I strongly suspect that what the animal eats will affect how its meat helps or hurts our bodies.
Vitamins and Mineral Supplementation
Vitamin A, C, E, and the mineral selenium, are all antioxidants that have been studied in the prevention and treatment of stomach cancer. A low-dose vitamin supplementation of vitamin A (1.5 mg/d), vitamin C (100 mg/d), and vitamin E (10 mg/d) has been associated with a reduced risk of stomach cancer.11 A follow up study of the results of a randomized control trial that took place from 1995 to 2017 showed that the supplementation of vitamins C, E, and selenium demonstrated a significant reduction in stomach cancer mortality, so longer term supplementation may be beneficial for those at increased risk of stomach cancer.12
Conclusion
There are many potential nutrition strategies to consider in the prevention of stomach cancer, and the majority of them favour overall good health. Eat more fibre-rich foods, vegetables and fruits like garlic and citrus, and less alcohol, salt, and red and processed meats. As usual, more research is needed, but it certainly doesn’t hurt to incorporate some of these changes into your lifestyle to optimize your health today.