A new study at Tel Aviv University found that aerobic exercise can reduce the risk of metastatic cancer by 72%. According to the researchers, intense aerobic exercise increases the glucose (sugar) consumption of internal organs, thereby reducing the availability of energy to the tumor.
The study was led by researchers from TAU’s Sackler Faculty of Medicine: Professor Carmit Levy from the Department of Human Genetics and Biochemistry and Dr. Yftach Gepner from the School of Public Health and the Sylvan Adams Sports Institute.
Levy said the study has led to an important discovery that may help prevent metastatic cancer, which is the leading cause of death in Israel. The paper was published in the journal Cancer Research.
Levy and Gepner explained that “studies have demonstrated that physical exercise reduces the risk for some types of cancer by up to 35%. This positive effect is similar to the impact of exercise on other conditions, such as heart disease and diabetes. In this study, we added new insight, showing that high-intensity aerobic exercise, which derives its energy from sugar, can reduce the risk of metastatic cancer by as much as 72%. If so far as the general message to the public has been ‘be active, be healthy,’ now we can explain how aerobic activity can maximize the prevention of the most aggressive and metastatic types of cancer.”
‘A rise in the number of glucose receptors’
The study combined an animal model, in which mice were trained under a strict exercise regimen, with data from healthy human volunteers examined before and after running. The human data, obtained from an epidemiological study that monitored 3,000 individuals for about 20 years, indicated 72% less metastatic cancer in participants who reported regular aerobic activity at high intensity, compared to those who did not engage in physical exercise.
The animal model exhibited a similar outcome, enabling the researchers to identify its underlying mechanism.
Sampling the internal organs of the physically fit animals, before and after physical exercise, and also following the injection of cancer, they found that aerobic activity significantly reduced the development of metastatic tumors in the lymph nodes, lungs and liver. The researchers hypothesized that in both humans and model animals, this favorable outcome is related to the enhanced rate of glucose consumption induced by exercise.
Levy noted that “our study is the first to investigate the impact of exercise on the internal organs in which metastases usually develop, like the lungs, liver and lymph nodes. Examining the cells of these organs, we found a rise in the number of glucose receptors during high-intensity aerobic activity — increasing glucose intake and turning the organs into effective energy-consumption machines, very much like the muscles. We assume that this happens because the organs must compete for sugar resources with the muscles, known to burn large quantities of glucose during physical exercise.”
Consequently, she continued, “if cancer develops, the fierce competition over glucose reduces the availability of energy that is critical to metastasis. Moreover, when a person exercises regularly, this condition becomes permanent: The tissues of internal organs change and become similar to muscle tissue.”
