We now have strong evidence that an individual’s risk of developing cancer can be substantially reduced by healthy behavior: not using tobacco, getting sufficient physical activity, eating healthy foods in moderation, and participating in cancer screening according to recommended guidelines. The American Cancer Society estimates that of the 565,650 cancer deaths expected in 2008, about 170,000 cancer deaths will be caused by tobacco use alone, and another third can be attributed to poor eating habits, overweight and obesity, and physical inactivity. If we can effectively promote healthy behaviors, much of the suffering and death from cancer can be prevented or reduced.

“Despite irrefutable evidence that modifiable behaviors are linked to numerous types of cancer and the implementation of a multitude of programs to combat risk-promoting behaviors, many millions of Americans continue to practice unhealthy lifestyles.”
– Letter to the President, 2007
President’s Cancer Panel

Healthier behavior could also reduce death and suffering from other diseases, such as type 2 diabetes, hypertension, coronary heart disease, and strokes. In 1993, researchers documented that modifiable behavioral risk factors had contributed substantially to the number of deaths that occurred in this country in 1990. Tobacco use accounted for 19% of all deaths, poor diet and physical activity accounted for 14%, and alcohol consumption accounted for 5%. Risky sexual behaviors and illicit use of drugs also contributed significantly to mortality. The researchers concluded that roughly half of all deaths that occurred in 1990 could be attributed to a limited number of “largely preventable behaviors and exposures.”

A decade later, another team of researchers found that tobacco use, poor diet, physical inactivity, and alcohol consumption were among the leading causes of death; combined, the first three accounted for more than one-third of all deaths in the United States. In addition to mortality, these unhealthy lifestyle behaviors impose significant burdens on society, such as disability, diminished quality of life, and increased health care costs.


Tobacco use is a known risk factor for 15 types of cancer. Decreased tobacco use has reduced cancer deaths among men by at least 40% from 1993 to 2003. Although much has been accomplished, a considerable amount of work remains to be done. In 1964, 42.4% of adults in the United States smoked. Now, the CDC reports that 21.5% of adults in the United States are smokers, and 17.5% of adults are daily smokers. About 4 out of 10 smokers (42.4%) attempted to quit smoking in 2005, but the majority were unsuccessful. Of the daily smokers, only 40.2% were successful. Recently, smoking rates among adults and high school students have leveled off, possibly because of increased tobacco industry spending on marketing and promotion.

“There are well-agreed-upon standards for basic nutrition and minimum levels of physical activity for sustaining good health. However, much less is known about how to effectively encourage people to make healthy choices.”
– F as in Fat: How Obesity Policies Are Failing in America
Trust for America’s Health, 2007

Physical Activity and Food Intake

Increasing evidence has accumulated showing that physical activity helps prevent cancer, and yet 38% of adults in the United States do not engage in any physical activity in their leisure time. Only 1 in 8 adults engages in vigorous physical activity in their leisure time for the recommended 5 times a week.

Lack of exercise and poor nutrition are major factors in the growing obesity problem in this country. Almost two-thirds of adults in this country are overweight or obese, and the numbers are expected to grow dramatically if the present trend continues unabated. A 2005 study estimated that 112,000 deaths in the United States were associated with obesity, making it the second-leading contributor (after tobacco) to premature death. Obesity and physical inactivity may account for 25 to 30% of several major cancers, including colon, post- menopausal breast, endometrial, kidney, and cancer of the esophagus.

Cancer Screening

Breast cancer deaths have been decreasing since 1990, with breast cancer screening playing a significant role. Unfortunately, the percentage of women who report that they have had a mammogram in the past 2 years has leveled off, remaining at the same level since 2000. If we can increase the number of women who have mammograms, more women will be diagnosed with breast cancer at an earlier stage, which dramatically increases their chances of surviving cancer.

Although colorectal cancer screening not only results in earlier detection, but also can actually prevent cancer from developing, less than half of Americans age 50 and older are current for colorectal cancer screening.

The President’s Cancer Panel

“In the . . . immediate term, the principal causes of lung and numerous other cancers are amenable to change through behavioral and policy/environmental interventions, which offer the best chance of substantially reducing the cancer burden.”
– Promoting Healthy Lifestyles
2006-2007 Annual Report of the President’s Cancer Panel

The President’s Cancer Panel recently released a report that summarized the findings of four meetings convened between September 26, 2006 and February 27, 2007 to discuss behaviors that affect cancer risk. These meetings examined the evidence regarding the effects of diet, nutrition, physical activity, tobacco use, and tobacco smoke exposure on cancer risk. The meetings also discussed actions – ongoing and potential – that could reduce the burden of cancer by promoting healthier lifestyles. The panel’s report commented that most of the federally sponsored cancer prevention research emphasizes genetic and other biologic factors, but this important work needs to be accompanied by research that addresses the macroenvironment and the physical, social, and cultural contexts in which food choices, physical activity, and tobacco use occur.