Issues

The cover image is adapted from Fig. 1 in the article, “Impact of Moderate—Vigorous Physical Activity Trajectories on Colon Cancer Risk Over the Adult Life Course”, by Christopher and colleagues. Moderate–vigorous physical activity (MVPA) reduces colon cancer risk; however, it is unclear how the timing of MVPA throughout the adult life course impacts colon cancer risk. The purpose of this study was to evaluate whether maintenance of and changes in MVPA between late adolescence and later adulthood, measured as life course trajectories, are associated with colon cancer risk. Figure 1 shows the average leisure time physical activity (LTPA) in hours per week for each trajectory. “Maintainers” consisted of three distinct trajectories: low (referent}, high, and moderate. Increasers included two trajectories: early in life, and later in life. “Decreasers” included two trajectories: early in life and later in life. The authors evaluated whether maintenance and changes in MVPA levels over time are associated with colon cancer risk. In total, 293,198 adults aged 50 to 71 years in the NIH-AARP Diet and Health 9 Study were assessed. Compared to those who maintained low MVPA levels, participants who maintained high and moderate levels of MVPA had a lower risk of colon cancer. Those who decreased MVPA early in adulthood had an increased risk of colon cancer. The results suggest that consistent participation in MVPA throughout life may reduce colon cancer risk. For more information, see the article beginning on page 30.