A 39% reduction in the risk of colorectal adenoma, a precursor to colorectal cancer, has been observed in people practicing physical exercise for one hour a day from adolescence.
The benefits are cumulative: one hour of physical exercise a day from adolescence and throughout life would reduce by 39% the risk of colorectal adenoma – polyps likely to evolve into colorectal cancer. This is the main conclusion of an epidemiological study published in the British Journal of Cancer and conducted by researchers from the Faculty of Medicine of Sao Paulo in Brazil and Harvard in the United States.
“The links between physical activity, adenomas and colorectal cancer are well understood, but this is the first study demonstrating the cumulative effects of physical activity from adolescence onwards”, explains Leandro Rezende, Brazilian researcher and author of the study.
Physical activity, according to the results of this study, would reduce the risk of carcinogenesis by reducing body fat, inflammation and insulin levels.
Physical activity, a public health priority
For the researchers, this study confirms the importance of policies aimed at encouraging physical activity as a public health priority.
“Colorectal cancer is one of the most common types of cancer and science shows that physical activity alone is a key factor in reducing the risk of adenoma. However, it should be kept in mind that “an adenoma is not cancer. In other words, we have shown that physical activity helps to prevent the disease because it reduces the risk of developing a precursor”, specify the authors of the study.
Sedentary behavior in adolescence has been a major concern for them, particularly with regard to colorectal cancer: “Although in most cases the disease appears after the age of 60, the number of patients under age 50 is on the rise. We are not sure if this is due to more people being diagnosed or having colonoscopies or if early exposure to risk factors such as a sedentary lifestyle may be causing early incidence of adenoma or colorectal cancer”.
28,500 women aged 25 to 42
The study consisted of an analysis of data from 28,500 women residing in the United States and aged 25 to 42 included in a work on the health of nurses, one of the largest research on risk factors of the main chronic diseases ever conducted.
This questionnaire was the first to include items relating to physical activity, diet and obesity during adolescence, ie between the ages of 12 and 22.
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