Doctors now say women double the risk of breast cancer from eating more than one meal of red meat a day.
This especially means processed red meat, like hamburgers and sausages.
The female hormones oestrogen and progesterone are important for bodily functions but also stimulate growth in 70 per cent of breast cancers – those known as hormone receptor positive.
Eunyoung Cho, associate professor of medicine at Harvard Medical School, said the reasons red meat triggered this type of breast cancer were the treatment of cattle with hormones to speed growth, carcinogens made when meat was cooked at high temperatures and a certain form of iron. Women who ate more than 1½ servings of red meat a day were 97 per cent more likely to have positive breast cancer than those who ate fewer servings a week.
Women who had meat in processed form more than three times a week were 2.3 times more likely to get cancer than those who ate them less than once a month. Those who ate hamburgers between one and three times a week were 71 per cent more likely to get cancer than those who did so less than once a month.