Cancer is the second leading cause of death among U.S. men and women, accounting for nearly 600,000 deaths each year as well as ~$250 billion in annual health care costs. The top 5 leading causes of cancer death for U.S. men and women¹ are shown below in Table 1.

Table 1. Leading causes of cancer death in U.S. men and women.

Men	Annual Number of Deaths		Women	Annual Number of Deaths
Lung	~87,000		Lung	~73,000
Prostate	~28,000		Breast	~40,000
Colorectal	~27,000		Colorectal	~25,000
Pancreatic	~20,000		Pancreatic	~20,000
Liver	~15,000		Ovarian	~14,000

A common statement that I frequently hear is that ‘everything causes cancer, there’s nothing that you can do’. While it is true that genetics cannot be controlled and exposure to environmental carcinogens cannot always be controlled, there are a number of lifestyle factors that have a very significant effect on cancer risk¹:

Tobacco Use: The use of tobacco accounts for 30% of all cancer deaths and nearly 90% of all lung cancer deaths in the U.S. Exposure to environmental radon gas, genetics, and poor diet are thought to account for the remaining 10% of lung cancer deaths. Smokers are 25 times more likely to develop lung cancer than non-smokers. Tobacco use also increases the risk for developing cancers of the nose, mouth, esophagus, larynx, pharynx, stomach, pancreas, kidney, bladder, uterus, cervix, colon, and ovary. All forms of tobacco should be avoided, including secondhand smoke.

High Alcohol Intake: While it is true that a light to moderate alcohol intake can significantly decrease the risk of cardiovascular disease, many people are surprised to learn that a high alcohol intake is a major risk factor for cancers of the mouth, esophagus, larynx, pharynx, breast, colon, and liver. Adults who consume alcohol are advised to limit their intake to no more than 2 drinks per day for men and no more than 1 drink per day for women. A drink is defined as 12 ounces of beer, 5 ounces of wine, or 1.5 ounces of hard liquor. Women who are pregnant should not consume alcohol, and adults who are currently non-drinkers are advised to remain non-drinkers.

Obesity:  One of the best measures of obesity is waist circumference (WC). A WC of >35 inches in women or >40 inches in men is a widely-accepted criterion for obesity. Obesity is a cause of breast, colorectal, esophageal, endometrial, kidney, and pancreatic cancers, and likely raises the risk of other cancers. Of interest, research published by The Cooper Institute^2,3 showed that the risk of cancer death in obese individuals was much lower in those with a moderate to high level of cardiorespiratory fitness than in obese individuals with a low level of cardiorespiratory fitness.

Sedentary Lifestyle: Only ~20% of American adults meet the minimal current public health guidelines for physical activity (at least 150 minutes per week of moderate intensity aerobic activity and at least 2 days per week of resistance training). Physical activity may reduce the risk of several types of cancer including breast, colon, endometrial, and prostate. Cooper Institute data ^2,3 has shown a marked reduction in cancer mortality among men and women with moderate to high levels of cardiorespiratory fitness compared to those with low levels of fitness.

Diet: There are a number of myths and misconceptions regarding diet and cancer risk. What we do know about diet and cancer is summarized by the following guidelines from the American Cancer Society (ACS)¹:

• Processed meat (bacon, sausage, hot dogs, lunch meat) and red meat (beef, pork, and lamb) should be limited in the diet.
• Individuals are advised to choose fish, poultry, or beans instead of red meat.
• Farm-raised fish, as well as shark, swordfish, tilefish, and king mackerel may contain high levels of mercury, dioxins and other pollutants. Young children, as well as women who are pregnant or breast feeding should not consume these fish.
• Intake of fruits, vegetables, and whole grains should be increased, while refined grain products (pastry, sugar-sweetened cereals) should be limited in the diet.
• Irradiated foods are not a cancer risk since radiation does not remain in these foods.
• Despite public perception, it is largely unknown whether organic foods carry a lower risk of cancer because they are less likely to be contaminated by compounds that might cause cancer.
• Plant-based foods such as vegetables, fruits, legumes, and whole grains should form the central part of a person’s diet, regardless of whether they are grown conventionally or organically.

The ACS also states that although genetically modified foods (GMO’s) should continue to be assessed for safety, there is no proof that consumption of GMO’s such as corn or soy would either increase or decrease cancer risk. Finally, there is no proof that sugar substitutes such as aspartame and saccharin cause cancer in humans. More detailed information from the ACS on diet and cancer risk can be found at http://www.cancer.org/acs/groups/cid/documents/webcontent/002577-pdf.pdf

So there you have it. Following the above recommendations is associated with a marked reduction in the risk of developing several types of cancer. The ACS has long-stated that “for individuals who do not use tobacco, diet and physical activity remain the most modifiable determinants of cancer risk.”

To learn more about lifestyle changes and disease prevention, consider taking the Nutrition for Health and Fitness course live in Dallas or online offered by The Cooper Institute.

 

References

¹Kushi, L.H., et al. American Cancer Society guidelines on nutrition and physical activity for cancer prevention. (2012).  CA: A cancer journal for clinicians. 62(1):30-67.

²Farrell, S.W., Cortese, G.M., LaMonte, M.J., and Blair, S.N. (2007). Cardiorespiratory fitness, different measures of adiposity, and cancer mortality in men. Obesity. 15(2):3140-3148.

³Farrell, S.W., Finley, C.E., McAuley, P.A., and Frierson, G.M. Cardiorespiratory fitness, different measures of adiposity, and total cancer mortality in women.  (2011). Obesity. 19(11):2261-2267.