Diet, along with other lifestyle factors such as level of activity, exerts a major influence on cancer risk. Apart from the specific actions of specific chemicals found in foods, which can be important, diet is crucial because it determines your weight. Being overweight or obese relates clearly to cancers of the breast (for women who have experienced menopause), colon, kidney, esophagus and uterus, according to the American Cancer Society, and is likely related to several others, including the cervix, ovary and pancreas. Maintaining proper nutrition is one of the most important steps you can take to lower your chances of cancer.
Effects
Through "healthy patterns of diet, physical activity and weight maintenance," about a third of cancer cases in high-income countries and a quarter of cases in low-income countries are preventable, the World Cancer Research Fund (WCRF) reported in 2009. For example, in the United States, about 45 percent of bowel cancer cases and 38 percent of breast cancer cases are preventable by these methods, according to the WCRF.
What to Eat
The American Cancer Society recommends a diet that limits calories to an amount that will allow you to maintain a healthy weight. It also advises eating at least five servings of fruits and vegetables each day. Produce contains antioxidants that include vitamin C, vitamin E and carotenoids, which may protect against cancer, according to the society. For carbohydrates, the group recommends eating whole grains such as those found in wheat bread, and for protein, it advises choosing fish, poultry and beans.
What to Avoid
Foods to avoid include those high in calories, fat and sugar, according to the American Cancer Society. That means foods such as cheeseburgers, french fries, pizza, ice cream, sweets and regular sodas should play little or no role in your diet. Refined carbohydrates like sweetened breakfast cereals and pastries should be kept to a minimum, as should red meat. Since alcohol is linked with a variety of cancers, including liver, throat and esophagus, intake should not exceed two drinks a day for men and one for women.
Misconceptions
Myths about the causes of cancer abound. Substances that people frequently ask questions about include aspartame, bioengineered foods, coffee and food additives---those that enhance color, flavor and texture. In some cases, older studies and news reports may have suggested links. But current evidence does not suggest a cancer link for any of these substances, according to the American Cancer Society.
Predictions
Worldwide, cancer deaths could reach 17 million per year in 2030 compared with 8 million in 2007, according to a report by the International Agency for Research on Cancer in 2008. Lifestyle factors, including obesity that results from an increasingly Westernized diet and smoking, will supersede chronic infection as the primary cause of cancer in low- and middle-income countries, according to the organization.
