Gastric Cancer: Nutritional Considerations

Stomach cancer is associated with the carcinogenic effect of nitrosamines, compounds derived from nitrates that are used to preserve meats. High sodium intakes appear to be responsible for the high rates of gastric cancer in cultures where processed (salted) fish and soy foods are consumed frequently. In epidemiologic studies, a protective effect has been noted for plant-rich diets, especially those high in fruits, vegetables, and whole grains.² Consumption of these foods is inversely related to stomach cancer mortality.³ In observational studies, the following dietary factors are associated with reduced risk:

Avoidance of animal products, particularly those containing nitrates. Cholesterol and animal protein intakes are associated with several subtypes of gastric and esophageal cancer.⁴ Nitrate-containing red meat and processed meat increase the risk for gastric cancer 3-fold, and frequent intakes of dairy products and fish are also associated with increased risk.⁵ In persons with a family history of gastric cancer and high red meat consumption, the risk for gastric cancer is roughly 25 times that of individuals with no history and low meat intake.⁶ Red meat contains particularly high levels of heme iron; individuals taking in the highest amount of this nutrient had roughly three times the risk for upper digestive tract cancer (predominantly gastric cancer) as those consuming the lowest amount.⁷

Eating more fruits and vegetables. Fruit intake is inversely related to gastric cancer incidence, and high vegetable consumption is associated with up to a 30% reduction in risk compared with low intakes.⁸ These apparent anticancer effects may be attributed to 3 factors: the inhibiting effect of vitamin C and other antioxidants on nitrosamine formation; the effects of carotenoids,⁹ flavonoids,¹⁰ and sulfur compounds in Allium species of vegetables, including garlic and onion;¹¹ and the total antioxidant potential of the diet, particularly in H. pylori-infected persons.¹²

Replacing refined grains with whole grains. Whole grain and dietary fiber intake are associated with greatly reduced risk for gastric cancer.^13,14 In contrast, several reports show that high consumption of carbohydrates from refined grain products increases risk,^15,16 possibly because fruit and vegetable consumption may be lower in these cases.¹⁷

Avoiding highly salted foods. Sodium is a gastric irritant, and table salt intake is associated with gastric cancer risk, especially in Asians, who frequently eat salted fish,¹⁸ processed or salted foods,¹⁹ and fermented soy foods with added sodium.²⁰

Maintenance of a healthy body weight. Obesity is a risk factor for adenocarcinoma of the gastric cardia and esophagus. Persons with a higher body mass index (BMI) have 2 to 4 times the risk of those with lower BMI, and the most obese have nearly 9 times the risk.^21,22 (See Obesity chapter.)

Diet and survival in gastric cancer. Although the role of diet in gastric cancer prognosis needs further study, data indicate that patients whose diets were lower in animal fat, animal protein, and nitrosamines before diagnosis had approximately half the risk of death from this cancer, compared with other patients.²³

Orders

See Basic Diet Orders chapter.

Limit intake of salted and pickled foods.

Avoid foods preserved with nitrates.

What to Tell the Family

Diet plays a critical role in the prevention of gastric cancer, which remains one of the leading causes of cancer-related death worldwide. Animal products, especially those preserved with nitrates, are associated with increased risk of gastric cancer and other cancers. A diet that includes regular servings of fruits, vegetables, and whole grains may reduce that risk, in addition to its other health benefits. The whole family would do well to incorporate these dietary changes into their lifestyle.