Physical Activity In Adolescence Reduce The Risk Of Colorectal Adenoma

The effects of more than 60 minutes of moderate daily physical activity, such as walking, accumulate throughout life and are associated with a 39% reduction in the risk of advanced adenomatous polyps, a precursor of colorectal cancer, the third most frequent type of cancer in Brazil. This is the main finding of an epidemiological study published in the British Journal of Cancer.

Population include women

The study was conduct by researchers in the Department of Preventive Medicine at the University of São Paulo’s Medical School (FM-USP) in Brazil and colleagues elsewhere, specifically Harvard University in the United States. It was support by a Research Internship Abroad Scholarship (BEPE) from FAPESP.

The authors analyze the data of 28,250 women include in the Nurses’ Health Study II (NHS II); one of the largest investigations into risk factors for major chronic diseases ever conduct. The sample population include women age 25-42 years who were employ as nurses and medical residents in the United States.

It was one of a series of prospective cohort studies conduct to examine the etiology of chronic diseases and the long-term effects of physical activity, nutrition, hormones and the environment, among other factors, on health and disease development. The study publish this year in the British Journal of Cancer analyze the association between physical activity; during adolescence and risk of adenoma later in life and adjust for such know risk factors as smoking, diet, alcohol intake, and family history of colorectal cancer.

Impact of physical activity

According to Rezende, the small difference between the impact of physical activity in adolescence alone and in adulthood alone reflects the different lengths of the two periods. “The reduction is actually similar in each case,” he said. “This tendency suggests that there is a cumulative effect of physical activity as life goes on. Whether it’s during adolescence or adulthood, the more physical activity we get; so the lower the risk of developing adenoma in adulthood becomes.”

The Nurses’ Health Study II began in the late 1980s, with a target population of nurses between 25 and 42 years of age. Each set of two year cohort members receive a follow-up questionnaire with questions about diseases and health relate topics; which including smoking, hormone use, pregnancy history, and menopausal status. The 1997 questionnaire was the first to include items relating to physical activity, diet; also obesity during adolescence (when they were between 12 and 22 years of age).

Follow-up continue until 2011, when the questionnaire include further items on lifestyle habits; between the ages of 23 and 64 – a period in which the nurses respond the questionnaire every two years. To participate in the study, the nurses had to have undergone; so at least one sigmoidoscopy or colonoscopy, since polyps and adenomas are asymptomatic.