Higher levels of aerobic fitness may reduce inherited risk of breast cancer, according to a new study published in Carcinogenesis. The study, conducted by researchers from Colorado State University, Memorial Sloan Kettering Cancer Center in New York City and the University of Michigan, linked aerobic fitness to a lower risk of breast cancer development, although the reason for the relationship is not yet clear.
The study’s authors believe that being physically fit increases the ability of cells to defend themselves against cancer.
Higher Endurance, Lower Risk
The study observed the ability of cells of aerobically fit female rats to fight off cancer after being exposed to carcinogens. Researchers exercised the rats used in the study on treadmills. The rats were evaluated for endurance, and researchers bred the male and female rats with high levels of endurance together.
The offspring, or pups, of the rats with higher levels of endurance showed a greater level of fitness than the offspring of the rats with low levels of endurance. Researchers did not exercise the pups and linked their fitness level solely to their genetics.
Both the groups of pups were exposed to a chemical known to cause breast cancer before they reached puberty. The researchers then monitored the pups as they transitioned into adults for both tumors and changes in their cells that may indicate cancer.
The Bigger Picture
The results of the research showed significant differences between the two groups of rats. The group of rat pups with low endurance had four times greater risk of developing breast cancer than the group of rats with high endurance. Cancer was also likely to develop earlier in the low-endurance group.
Further examination of the rats found that the high-endurance group had lower rates of cell replication than the low-endurance group. Uncontrolled cell division is a common indicator of cancer.
The rat research is exciting for Dr. Mona Alqulali, M.D., F.A.C.OG, Ph.D. Alqulali is a Clinton, Iowa, OB-GYN.
"Researchers and physicians have investigated the link between fitness and health for the last few years. This study shows how genetics and exercise contribute to health. This study can yield potential new strategies to help prevent or reduce the risk of developing diseases like breast cancer," Alqulali said.
According to The Komen Foundation, a woman with a first-degree female relative, like a mother or sister, with breast cancer has almost twice the risk of developing breast cancer than a woman without a family history. More than one first-degree female relative with a history of breast cancer increases the risk of developing breast cancer by three or four times.
Other Cancer Contributors
In addition to family history, other factors, including behavior and habits, increase the chance of developing breast cancer.
"Smoking, overconsumption of alcohol and exposure to some carcinogens are well-known factors that increase an individual's risk of developing breast cancer, but obesity, a poor diet, nutritional deficiencies and a sedentary lifestyle are also contributors," Alqulali said.
Researchers estimate that 30 to 40 percent of all cancers develop as a result of poor diet.
"Avoiding overconsumption of red meat, sodium, and high-fat and processed foods can help lower your risk of developing cancer and other diseases," Alqulali said.
Exercise may not only be a cancer preventative, but it could also improve outcomes for women living with a breast cancer diagnosis. The American Cancer Society suggests that women with breast cancer benefit from four to seven hours of regular exercise a week to increase their chance of survival and lower their risk of developing new cancers.
The New York Times. Fitness May Lower Breast Cancer Risk. New York Times. 6 September 2017.
The Komen Foundation. Family History of Breast, Ovarian or Prostate Cancer. 10 October 2016.