More exercise ‘very likely’ to reduce breast cancer risk, study finds – The Irish Times
Increasing physical activity levels and reducing time spent sitting are “very likely” to reduce breast cancer risk, according to new research.
The findings, published online Tuesday in the British Journal of Sports Medicine, were generally consistent across all types and stages of the disease, prompting researchers to recommend a greater emphasis on exercise as a way to prevent breast cancer. breast.
“These findings are very important for cancer control efforts around the world,” said one of the authors of the research paper, Associate Professor Brigid Lynch from the Cancer Council Victoria’s Division of Cancer Epidemiology in Australia.
“To date, the fight against cancer has not focused on increasing physical activity and this research shows that we need to, literally and metaphorically, step it up,” she said. .
The research paper notes that observational studies have reported that active lifestyles are associated with lower breast cancer risk, but it has not been possible to conclusively determine from these whether the activity is the protective factor.
This study provides “strong evidence” that higher levels of physical activity and less sedentary time are likely to reduce breast cancer risk, with generally consistent results across all breast cancer subtypes, according to the item.
The study used Mendelian randomization, a technique that uses genetic variants as a proxy for a particular risk factor, to assess whether physical activity and time spent sitting across the lifespan might be related in some way. causal to the risk of breast cancer in general, and specifically to different types of tumours.
They included data from 130,957 women of European ancestry. Of these, 69,838 had tumors that had spread locally and 6,667 had tumors that had not yet. The rest was a comparison group of 54,452 women who did not have breast cancer.
The women participated in 76 studies under the aegis of the Breast Cancer Association Consortium (BCAC), a forum of researchers interested in the hereditary risk of breast cancer.
The researchers then drew on previously published studies to genetically predict the degree of physical activity or physical inactivity of their own study participants. The next step was to estimate the overall risk of breast cancer, depending on whether or not the women were postmenopausal; and by type, stage and grade of cancer.
Data analysis showed that an overall higher level of genetically predicted physical activity was associated with a 41% lower risk of invasive breast cancer, largely independent of menopausal status, type, stage or grade of the tumour.
Genetically predicted vigorous physical activity on three or more days of the week was associated with a 38% lower risk of breast cancer, compared with no self-reported vigorous activity. A higher level of genetically predicted sitting time was associated with a 104% higher risk of triple-negative breast cancer.