Researchers in the Society’s Epidemiology Research Program have made and continue to make new discoveries related to nutrition and physical activity by analyzing data on an ongoing basis from Cancer Prevention Study II (CPS-II), which the Society began in 1982. Recent findings include:
- Peter Campbell, PhD, strategic director of Digestive System Cancer Research, led a new analysis examining liver cancer data from 14 prospective studies (including CPS-II) with more than 1.5 million participants. After accounting for age, sex, alcohol use, smoking and race, researchers found that obese body mass index (BMI) compared to normal BMI was associated with a 75% higher risk of liver cancer, with similar associations for waist circumference. These results suggest that the increase in obesity in the US might at least partially account for the parallel increase in liver cancer rates.
- Losing 10 or more pounds and keeping it off for at least 5 years might reduce breast cancer risk among postmenopausal women, according to a study conducted by Senior Epidemiologist Lauren Teras, PhD.
- Men and women with very large waists – 47 inches or larger in men and 42 inches or larger in women – have twice the risk of death from cancer, heart disease, and respiratory disease compared with those with the smallest waists – 35 inches or smaller in men and 30 inches or smaller in women, according to research conducted by Society researcher Eric J. Jacobs, PhD. This holds true even for men and women who were not overweight. So inches may be as important as pounds.
- Reducing the risk of cancer and heart disease is more than a matter of how much you exercise. Society researcher Alpa Patel, PhD studied data on 123,000 participants in the American Cancer Society Cancer Prevention Study II who had no history of cancer, heart attack, stroke, or lung disease. She found a strong relationship between the amount of leisure time spent sitting and the risk of death, especially in women, that was independent of levels of physical activity. Women who reported more than six hours per day of sitting were 37% more likely to die during the time period studied than those who sat fewer than three hours a day.
- Individuals who adhered closely to the Society’s nutrition and physical activity guidelines reduced their risk of dying of cancer by 25% to 30%, according to a study conducted by Society epidemiologist Marji McCullough, ScD, RD. McCullough examined data on 112,000 nonsmoking men and women who had participated in the American Cancer Society Cancer Prevention Study II.
- Weight cycling, which is the repeated loss and regain of body weight, has become very common as more people try to lose weight, and previous research from small studies suggests that weight cycling might increase cancer risk or premature mortality. In the largest studies conducted to date on this issue, Strategic Director Victoria Stevens, PhD, examined data from the CPS-II Nutrition Cohort and found that weight cycling did not increase overall cancer risk or risk of premature death from cancer or other cases. These findings support the encouragement of weight loss, even if that weight is regained.
- The Society’s newest multi-year cancer prevention study, CPS-3, will yield more findings about the relationship between nutrition and physical activity and cancer in the future.
In addition, Society researchers in other program areas are conducting different types of nutrition and physical activity studies. For example, Society researcher Kerem Shuval, Ph.D. recently discovered that physical activity may help work against some of the negative health effects of sitting too much. The Society’s Economic and Health Policy Research program is exploring the economics of nutrition, such as the effects of income on dietary quality. Applying the lessons learned from economic methods for tobacco control to the areas of nutrition and physical activity may offer solutions to the obesity epidemic and its accompanying cancer burden.