Intense exercise, just 45 minutes, three times a week, has shown the potential to reduce cancer risk in individuals with Lynch syndrome, a genetic condition known for its propensity to cause cancer at a young age. Researchers at the University of Texas MD Anderson Cancer Centre have discovered that this level of exercise can enhance the immune system’s ability to combat cancer cells.
The study, led by oncologist Eduardo Vilar-Sanchez, MD, PhD, involved a focused approach: 45 minutes of high-intensity cycling, performed three times a week. According to Vilar-Sanchez, the goal was to offer specific recommendations, moving away from vague lifestyle advice like “just exercise.”
This research, although involving a small group of just 21 participants, builds upon a significant body of evidence supporting the link between regular exercise and a reduced risk of cancer, particularly colorectal cancer. However, the MD Anderson researchers delved further into understanding how exercise influences cancer risk.
Exercise and the immune system
All 21 participants had Lynch syndrome and were divided into two groups. One group underwent a 12-month exercise programme, while the other did not. The scientists assessed their cardiovascular and respiratory fitness and monitored immune cells in the blood and colon tissues, specifically natural killer cells and CD8+ T cells.
“These immune cells play a pivotal role in combating foreign entities like cancer cells,” explained Vilar-Sanchez. “In the exercise group, these cells exhibited higher activity.”
In addition to increased immune cell activity, individuals in the exercise group also experienced a decrease in levels of the inflammatory marker prostaglandin E2 (PGE2). This decline was closely connected to the heightened immune cell activity. Both of these changes suggest a more robust immune response, possibly boosting the body’s “immune surveillance” system to detect and eliminate potentially cancerous cells.
Building on previous research
Existing scientific evidence strongly supports the notion that regular exercise can help reduce cancer risk. A comprehensive systematic review conducted in 2019, comprising over 45 studies and millions of participants, revealed that exercise could decrease the risk of various cancers, including bladder, breast, colorectal, and gastric cancers, by up to 20%.
However, the study at MD Anderson is the first to establish a direct link between exercise and changes in immune biomarkers. As the director of the GI Cancer Prevention Programme at Yale Cancer Centre and professor of medicine at Yale School of Medicine, Xavier Llor, MD, PhD, remarked, “One thing is having the epidemiological correlation, but it’s another thing to know the biological basis.” Two previous studies explored exercise and inflammation markers in both healthy individuals and those with a history of colon polyps but failed to produce significant results. The success of this recent study may be attributed to the higher-intensity exercise regimen and advanced technology enabling more sensitive measurements.