1 in 4 Breast Cancers Could Be Prevented
Shocker, right? Exercise is good for you! The reason why exercise could lower breast cancer risk is because it may lower levels of hormones (such as estrogen), and it also can affect the immune system and your metabolism.
For postmenopausal women, frequent physical activity — including “occupational, recreational, walking and household activity” — likely offers 13% lower risk of breast cancer compared to women with the lowest amounts of exercise. The evidence is considered “probable.”
Postmenopausal women who engage in vigorous physical activity — including running or cycling — have a 10% lower risk, while premenopausal women have around a 17% lower risk. The evidence is considered “probable.”
There is limited data on whether or not physical activity is associated with a decreased risk of premenopausal breast cancer, so the evidence there is considered “suggestive.”
Evidence is suggestive that eating dairy (including milk, butter, cheese, and yogurt made from cow, sheep, and goat products), vegetables, and foods high in carotenoids offer protection against cancer. This is likely due to the minerals and vitamins they contain. Evidence is also suggestive that increasing your calcium intake offers some protection.
Unproven Or Unlikely Risk Factors
Some factors were researched and determined not to affect cancer risk. These have been deemed unlikely or unproven risk factors. Fruit, tea, coffee, and caffeine are not proven to offer a decreased breast cancer risk. Phytoestrogens (which naturally occur in certain fruits and vegetables, grains and seeds, and red wine), soy products, and wearing a bra do not increase risk.
Increased stress levels, aspirin, and progesteron-only contraception are also unproven risk factors, as well as using hair dye and deodorant.