Three times a week, 45 minutes of intensive exercise can reduce the risk of cancer, particularly forms associated with Lynch syndrome, say scientists.
Previously, it was known that exercise could prevent the onset of cancer, and now scientists have discovered how it happens and how much exercise is needed. A study conducted by the MD Anderson Cancer Center at the University of Texas, on a group of people with Lynch syndrome, an inherited condition associated with an increased risk of several types of cancer, showed that 45 minutes of intensive exercise (in this case, cycling) three times a week could lower that risk.
Precise recommendations
“We wanted to provide very precise exercise recommendations and link them to a specific effect because people won’t accept advice that says ‘just exercise.’ It turns out that this type of exercise, designed for the study, makes the immune system more capable of eradicating cancer cells,” said study leader, oncologist Eduardo Vilar-Sanchez.
The study was small, involving 21 participants, but it provided substantial evidence linking regular exercise to a reduced risk of cancer, especially colon cancer. All participants, who had Lynch syndrome, were divided into two groups: one received an annual exercise program, and the other did not. Scientists monitored everyone’s cardiac and respiratory fitness, as well as the levels of natural killer cells and CD8+ T cells in the blood and in the colon tissue. These immune cells are responsible for attacking foreign entities, such as cancer cells, and in participants who exercised, they were more active. The exercisers also had lower levels of the inflammatory marker prostaglandin E2, which was closely associated with the increase in immune cells. Both changes indicate a stronger immune response, and scientists believe they are linked to enhanced “immune surveillance,” which seeks out and eliminates cells that might otherwise become cancerous.
Biomarkers
It has already been proven that regular exercise can prevent cancer in about 20 percent of cases, including breast, bladder, colon, and stomach cancer. Earlier this year, American research showed that exercise can disrupt signaling within breast cancer cells, meaning that during muscle contractions, they release factors that can destroy cancer cells before they develop or at least slow their growth. This occurs even during lighter exercises such as dancing or walking. However, the MD Anderson study is the first to show a connection between exercise and immune biomarkers, not just an epidemiological correlation. Vilar-Sanchez has not yet linked the study’s results to the broader population beyond those with Lynch syndrome, but he remains optimistic, saying that the public should be aware that engaging in some form of exercise will have some effect in cancer prevention.
