We all know physical activity is important to health. For decades, it has been strongly linked to lowered risk of heart disease (the nation's leading cause of death at 614,000 deaths annually), but the full benefits of sufficient exercise are much broader and more profound. Nowhere is this more evident than in cancer, the nation's second leading cause of death — 592,000 deaths nationally each year — but projected to eventually rise to No. 1. In some states, it already has, including California and, more specifically, San Diego County.
Although much remains to be learned, physical activity is believed to lower cancer risk by, among other things, controlling weight, reducing levels of key sex hormones and insulin and strengthening the immune system. It can also boost the quality of life for patients undergoing cancer treatment.
Earlier this year, the American Cancer Society and the National Cancer Institute published a study that specifically linked exercise with lowered risk in 13 specific types of cancer: colon, breast, endometrial, esophageal, liver, stomach, kidney, myeloid leukemia, multiple myeloma (another kind of blood cancer), head and neck, rectum, bladder and lung.
Of course, preventing cancer is far more effective than treating cancer after the fact or diagnosis. To that end, I'm pleased to report that Jacqueline Kerr, Ph.D., in the Department of Family Medicine and Public Health at UCSD School of Medicine, has joined Moores Cancer Center as head of the Cancer Prevention Program.
Kerr's work and career have been built upon the idea that improved health is most likely to occur in concert with a supportive community —one that makes it easy for individuals to be active and make healthy choices. In recent years, working with James Sallis, Ph.D., Distinguished Professor in the Department of Family Medicine and Public Health, and others, Kerr has published major studies describing physical activity in different cities around the world and the implications for public health.
In April, for example, she and colleagues reported in The Lancet that how a neighborhood is designed — whether its streets were walkable, there was adequate public transit and plentiful parks — played a crucial role in reducing heart disease, obesity and diabetes. The work was based on research conducted in 14 cities around the world involving nearly 7,000 adults. She's continuing that work with an on-going study called Community of Mine, which is investigating how neighborhood places like parks, restaurants, grocery stores and recreation centers impact the lives of San Diegans. You can participate in the study by visiting communityofmine.ucsd.edu
Kerr is also training older adults to lead walking groups and become community advocates though the Peer Empowerment Program for Physical Activity, an on-going clinical trial at 12 senior centers in San Diego. (For more information, contact Khalisa Bolling at firstname.lastname@example.org
And she is leading a clinical trial to reduce sedentary behaviors among post-menopausal Latinas. Sitting is the new smoking. It's increasingly linked to a host of ailments, including cancer. Kerr is investigating the relationship between sedentary behavior and health risks in Latinas, who have a disproportionately higher chance of developing heart disease than the general population. Many cancers also affect Hispanic women and men disproportionately, something we're also addressing at Moores Cancer Center through the Reducing Cancer Disparities program under the leadership of Elena Martinez, Ph.D., and John P. Elder, Ph.D.
In the days, months and years to come, Kerr and colleagues will be working hard to figure out the connections between physical activity and cancer risk and, more importantly, how to translate them into good advice and healthier lives. The good news for the rest of us is that we don't have to work all that hard to be healthy. Current guidelines recommend 150-300 minutes of moderate-intensity exercise or 75-150 minutes of vigorous-intensity exercise each week. Even the max means just giving up one binge session of Game of Thrones.
But a study published last year in JAMA Internal Medicine found that individuals who did just the minimum amount of exercise each week experienced a 31 percent lower risk of dying than persons who did not exercise at all. Indeed, people who exercised even a little bit had a 20 percent lower mortality risk than those exercised not at all — and those who exercised more than the recommended minimum showed an almost 40 percent reduction in mortality risk.
All of which reminds me to remind you about Pedal the Cause, the annual bike ride to raise funds for local cancer research, Nov. 12-13. You can learn more at sandiego.pedalthecause.org
— Scott M. Lippman, MD, is director of UC San Diego Moores Cancer Center. His column on medical advances from the front lines of cancer research and care appears in the La Jolla Light each month. You can reach Dr. Lippman at email@example.com