Waseda University study links cardiorespiratory fitness to lower breast cancer risk

A research group led by Waseda University has identified that high cardiorespiratory fitness may mitigate the increased risk of breast cancer associated with genetic factors in postmenopausal women.

Using data from 15,199 postmenopausal women in the UK Biobank, the study analyzed the interaction between polygenic risk scores (PRS) and cardiorespiratory fitness, measured via VO2max. The findings, published in ‘Medicine & Science in Sports & Exercise’, show that while a high PRS significantly increases breast cancer risk, women with high cardiorespiratory fitness experienced a smaller increase in risk compared to those with lower fitness levels.

Specifically, in the group with high genetic risk but low-to-moderate fitness, the risk of breast cancer was 2.59 times higher than the baseline. However, for women with both high genetic risk and high cardiorespiratory fitness, the risk was reduced to 1.64 times. This protective effect was particularly evident in women aged 60 and older.