Science Nook: Association of Sedentary Behavior and Cancer Mortality Risk

by Jenna Koroly, MS, RD, CSOWM, CDN

The American Cancer Society guidelines on nutrition and physical activity for cancer prevention recommend “at least 150 minutes of moderate intensity or 75 minutes of vigorous intensity activity each week, or an equivalent combination, preferably spread throughout the week” [i]. Less than 25% of adults in the US meet these guidelines [Katzmarzyk PT, Lee IM, Martin CK, Blair SN, 2017 as cited in reference ii]. The below study examines sedentary behavior, levels of physical activity, and risk of cancer mortality.

Study

Association of Sedentary Behavior With Cancer Mortality in Middle-aged and Older US Adults

Journal: JAMA Oncology

This prospective cohort study included 8002 participants 45 years or older from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study. Participants wore an accelerometer device for 7 consecutive days during waking hours. Accelerometer measurements of 0-49 activity counts per minute were considered sedentary behavior, 50-1064 activity counts per minute light-intensity physical activity (LIPA), and at least 1064 activity counts per minute moderate- to vigorous-intensity physical activity (MVPA). A sedentary bout was consecutive minutes that the accelerometer showed fewer than 50 activity counts per minute. Cancer mortality was studied at 5 years of follow-up [ii].

Findings

The authors found:

1. Greater total sedentary time was associated with increased risk of cancer mortality

2. Longer sedentary bout was not associated with increased risk of cancer mortality for those who met MVPA guidelines

3. There was a significant trend between sedentary bout duration and risk of cancer mortality for those who did not meet MVPA guidelines

4. Replacing 30 minutes of sedentary time with 30 minutes of MVPA was associated with a 31% decreased risk of cancer mortality

5. Replacing 30 minutes of sedentary time with 30 minutes of LIPA was associated with an 8% decreased risk of cancer mortality [ii]

For the Patient and Caregiver

Begin incorporating more physical activity into your routine using guidance on cardiovascular and strength training workouts and breaking down barriers to exercise. With social distancing guidelines, it may feel more challenging to form an exercise routine for those that are motivated by going to the gym or to in person classes. Exploring creative options can be helpful:

1. Walk, jog, or bike in the early hours of the morning when there may be fewer people outside.
2. Use free weights, resistance bands, or even water bottles to do bicep and tricep curls. Or, try workouts using body weight: wall push ups, squats, and lunges.
3. Check out exercise apps such as 7 Minute Workout and Peloton for guided exercises and live classes.
4. Look up your favorite workouts on YouTube such as zumba, kickboxing, or yoga and do them with a loved one in person or over video chat.
5. Park further from the grocery store and take the stairs rather than the elevator when you can to decrease sedentary time and build physical activity into your routine.

For the Healthcare Team

Encourage patients to decrease sedentary time and increase physical activity. Suggest setting alarms for every hour to get up and walk for a few minutes for those that have sedentary jobs. Present the research, particularly to those with increased risk of cancer. Lastly, use motivational interviewing techniques to determine barriers and help form lasting behavior change.

References:

[i] Kushi LH, Doyle C, McCullough M, et al. (2012). American Cancer Society 2010 Nutrition and Physical Activity Guidelines Advisory Committee. American Cancer Society guidelines on nutrition and physical activity for cancer prevention. CA Cancer J Clin, 62(1):30-67. doi:10.3322/caac.20140

[ii] Gilchrist SC, Howard VJ, Akinyemiju T, Judd SE, Cushman M, Hooker SP, Diaz KM (2020). Association of sedentary behavior with cancer mortality in middle-aged and older US adults. JAMA Oncology, E1-E8. doi:10.1001/jamaoncol.2020.2045