Breast cancer

One in eight women in the UK will develop breast cancer at some point in their lives. Women with breast cancer are more likely to survive the disease now thanks to screening programmes, early diagnosis and improved treatment. However, more women than ever before are getting the disease with 150 women diagnosed every day. Men can get breast cancer too; at least one man is diagnosed every day in the UK. 

Only 5-10 per cent of breast cancers are caused by genes (inherited in the family). Most cases are linked to environmental or lifestyle factors including diet. The fact that breast cancer rates vary hugely around the world also shows the powerful role diet and lifestyle has.

Women with breast cancer have higher levels of certain hormones in their blood. This may be due to obesity or alcohol consumption. However, the Western diet (rich in meat and dairy foods) increases levels of the hormones found in women with breast cancer.

Two thirds of milk in the UK is taken from pregnant cows with the remainder coming from cows that have recently given birth. The high levels of hormones in cow’s milk are designed to help a young calve grow into a fully-grown cow in just one year. Milk is not suited to human infants or adults. No other species drink milk beyond weaning. 

Cow’s milk boosts production of a growth hormone called IGF-1 in the body. People who drink milk have higher levels of IGF-1 in their blood and vegans have lower levels. IGF-1 can make cancer cells grow in the laboratory and it increases the risk of several cancers including those of the breast, bowel and prostate.

Women who eat a lot of meat have a higher risk of breast cancer – this may be due to the chemicals used in processed meats and produced in red meat and chicken when it is cooked at high temperatures. It’s hard to say whether it’s the unhealthy saturated fat, the hormones or the chemicals in meat and dairy that increases the risk of breast cancer. But a diet rich in one tends to contain the others. Why take the risk? 

Research shows that women who eat a healthier diet made up mostly of fruit, vegetables, wholegrains and pulses (peas, beans and lentils) have lower rates of breast cancer. One study found that substituting one serving of red meat a day for pulses can slash the risk of breast cancer by 15-19 per cent! Official dietary advice should include how a low-fat, high-fibre, meat-free and dairy-free diet consisting mainly of fruits, vegetables, whole grains and pulses can result reduce your risk of breast cancer.

Read more about breast cancer and dairy products and breast cancer and diet in general.

Soya and breast cancer

Women who regularly eat soya when they’re growing up are less likely to develop breast cancer as adults compared to those who eat no soya. Also, women who already have breast cancer may have a better outcome if they consume soya.

Read more about soya and breast cancer and the general safety of soya.



Viva!Health examines the lastest science on soya.

Previous studies show that soya protects against breast cancer. This study looked at the diets of 34,028 women in the Singapore Chinese Health Study among whom there were 629 breast cancer cases. Results showed that postmenopausal women who consumed the most soya, fruits and vegetables had a 30 per cent lower risk of developing breast cancer compared with those who consumed the least. The longer they had consumed these foods, the lower their risk of developing breast cancer.