Diet and Cancer Risk
Abramson Cancer Center of the University of Pennsylvania
Last Modified: March 23, 2012
While the media often reports on foods that "prevent cancer" and we would love to be told that eating one particular food will prevent cancer, it is unlikely that such a food exists. It is more likely that a combination of good foods may have a preventive effect. Studies over the years have looked at our diets and what foods, if any, will lead to a lower risk of cancer. Fruits and vegetables, whole grains and unprocessed foods have all been promoted as reducing cancer risk. Unfortunately, studies have not consistently proven this to be true. Expert panels state that a diet high in fruits and vegetables "probably" reduces cancer risk, but we just don't know for sure.
However, a healthy diet plays an important role in a sort of "triangle" of cancer prevention. A healthy diet, combined with regular physical activity and maintaining a healthy weight has been shown to reduce cancer risk. This triangle is thought to be the second most important step, after not smoking, to preventing cancer. The following foods have been shown to increase cancer risk and are worth paying closer attention to their presence in your diet.
Red & Processed Meats
A diet that includes a high consumption of red meat (beef, pork and lamb) and processed meats (hot dogs, bologna, bacon and lunchmeat) has shown a strong link to colon and rectal cancers. Red meat may also increase one's risk of developing endometrial and pancreatic cancer. Red meat is not all bad, and eating some in moderation likely does not increase risk of cancer. The AICR recommends that people eat no more than 18 ounces (cooked weight) of red meats, including beef, pork and lamb, per week to reduce cancer risk.
Processed, Cured & Fermented Meats
Processed (hot dogs, bologna and lunchmeat) and cured or fermented meats (sausage, salami) have been linked to colon, rectal, esophageal, nasopharyngeal, and gastric cancers. There may also be a link to endometrial and pancreatic cancers. These foods, as a result of how they are prepared, contain nitrosamines, nitrate and N-nitroso-compounds (NOCs), which have been shown to be carcinogens (cancer causing).
Carcinogenic (cancer causing) compounds [Heterocyclic Amines (HCAs) and Polycyclic Aromatic Hydrocarbons (PAHs)] form as a result of cooking meats at high temperatures and/or for long periods of time. In turn, eating lots of charred (or burned) meat has been shown to increase the risk of developing colon, rectal, esophageal, and gastric cancers.
White Breads, Rice and Processed Grains
Eating white bread, white rice and processed grains may increase your risk for colon, rectal, and endometrial cancers because of their link to obesity. Try replacing these foods in your diet with whole grains and brown rice.
Benefits of Vegetarianism
Studies have found that vegetarians and vegans have lower rates of colon cancer, as well as reduced rates of heart disease, diabetes, high blood pressure and obesity. It is not clear if these benefits are strictly diet related, as vegetarians tend to lead healthier lifestyles overall (more exercise, not smoking) and it may be a combination of factors that leads to better health.
Resources to learn more about how diet, physical activity and weight are related to cancer
A healthy diet, regular physical activity and maintaining a healthy weight have been linked to a lower risk of developing cancer. These three components make up the "cancer prevention triangle". They are strongly inter-related and working to improve one can often lead to improvements in another. Use the links below to learn more about this prevention triangle and ways to work towards a healthier you.
- Eat Healthy and Get Active at the American Cancer Society website.
- Reduce Your Cancer Risk at the American Institute for Cancer Research.
- American Cancer Society Guidelines on Nutrition and Physical Activity for Cancer Prevention.
- Dietary Guidelines for Americans, 2010 from the USDA.
- The US Department of Health & Human Services 2008 Physical Activity Guidelines for Americans.
- NIH AARP Diet & Health Study: a study developed at the National Cancer Institute of the National Institutes of Health to improve our understanding of the relationship between diet and health.
- The European Prospective Investigation into Cancer & Nutrition (EPIC): A large study by the International Agency for Research on Cancer investigating the relationships between diet, nutritional status, lifestyle and environmental factors and the incidence of cancer and other chronic diseases.