Study Links Sedentary Lifestyle to Young-Onset Colorectal Cancer

Overview of Colorectal Cancer

Recent research conducted by teams from China, Korea, and the United States has investigated the correlation between sedentary lifestyles and the incidence of young-onset colorectal cancer. This form of cancer, which arises in the colon or rectum, is generally diagnosed in older individuals. However, cases diagnosed before the age of 50 are on the rise globally. Young-onset colorectal cancer often presents differently and at more advanced stages compared to late-onset cases, leading to increased years of life lost among younger patients. The underlying reasons for this worrisome trend have remained unclear until now.

Research Findings

In a study published in the JNCI Cancer Spectrum, the researchers focused on the escalating prevalence of young-onset colorectal cancer in relation to sedentary behaviors. Sedentary lifestyles have emerged as the fourth leading mortality risk factor worldwide and are associated with numerous chronic conditions, including cardiovascular disease, cancer, and diabetes. Alarmingly, in 2013, over 75% of Canadian adults and more than 90% of children and youth failed to meet recommended physical activity guidelines, which advocate for at least 60 minutes of moderate-to-vigorous activity daily for youth and 150 minutes weekly for adults.

Contributing Factors to Sedentary Lifestyles

The rise in sedentary behaviors can be linked to an increase in office-based work and passive media consumption, particularly television. Individuals who comply with the minimum exercise recommendations may still face health risks if they spend a significant portion of their waking hours inactive.

Study Participants and Methodology

The study monitored 89,278 women aged 25 to 42 over a span of 22 years, tracking their sedentary behaviors, including television viewing time, and the incidence of young-onset colorectal cancer. Throughout the study period, researchers identified 118 cases of this cancer.

Television Viewing and Cancer Risk

The findings revealed that women who watched more than one hour of television daily had a 12% increased risk of developing young-onset colorectal cancer. Those watching over two hours per day experienced a nearly 70% heightened risk, with the association being particularly strong for rectal cancer compared to colon cancer. Women with higher screen time also exhibited increased rates of diabetes, lower multivitamin usage, reduced physical activity, and poorer dietary habits.

Impact of Body Mass Index and Lifestyle

The results were consistent across various patients, regardless of body mass index (BMI) and other common risk factors for colorectal cancer. However, individuals with higher BMI, those who smoke, and those who are less physically active were found to be at an elevated risk for young-onset colorectal cancer.

Importance of Active Lifestyles

These findings underscore the necessity of maintaining an active lifestyle to mitigate chronic disease risks. By reducing periods of inactivity, individuals can lower their chances of developing young-onset colorectal cancer and enhance their overall health. The study also highlights the need for targeted screening and intervention for those identified as high-risk.

Future Research Directions

Further research is essential to understand how a sedentary lifestyle may induce biological changes that contribute to cancer development and to identify preventive strategies for younger individuals at risk.

References

American Cancer Society. What is colorectal cancer? Atlanta, GA: ACS; [updated 2018 Feb 21; cited 2019 Feb 17]. Available from: https://www.cancer.org/cancer/colon-rectal-cancer/about/what-is-colorectal-cancer.html

Nguyen LH, Liu P, Zheng X, Keum N, Zong X, Li X. Sedentary behaviours, TV viewing time, and risk of young-onset colorectal cancer. JNCI Cancer Spectrum [Internet]. 2019 Jan; [cited 2019 Feb 17];2(4). Available from: https://academic.oup.com/jncics/article/2/4/pky073/5301781 doi: 10.1093/jncics/pky073

Government of Canada. How healthy are Canadians? Physical inactivity [Internet]. Ottawa, ON: Government of Canada; [updated 2017 Apr 11; cited 2019 Feb 17]. Available from: https://www.canada.ca/en/public-health/services/publications/healthy-living/how-healthy-canadians.html#s3-1-2

Public Health Agency of Canada. Health status of Canadians 2016: report of the Chief Public Health Officer. Ottawa, ON: Public Health Agency of Canada; 2016. 64 p. Cat. No.: 978-0-660-05480-3.