Cutting out one portion of red meat every day and replacing it with chicken can reduce the risk of developing breast cancer by almost a fifth, a study suggests.
An extra, or second, daily serving of beef, lamb or processed red meat such as sausage increases the risk of breast cancer, according to research which examined the diets of thousands of women.
The study by Harvard School of Public Health found that replacing one serving - about 85g or three thin slices of roast beef - a day with poultry reduces the risk of such cancer by 17 per cent.
Substituting red meat for a combination of fish, chicken, nuts and legumes, such as peas, beans and lentils, also lowers the risk by 14 per cent.
The impact is even greater for postmenopausal women whose risk of breast cancer could be cut by almost a quarter if they swapped red meat for poultry.
Dr Maryam Farvid, author of the study, said: "Higher red meat intake in early adulthood may be a risk factor for breast cancer, and replacing red meat with a combination of legumes, poultry, nuts and fish may reduce the risk."
The study involved 88,803 women and was completed over 20 years.
"It found eating high amounts of red meat increases risk by 22 per cent overall, and every extra daily serving carries a 13 per cent increased risk," said Farvid.
"When this relatively small relative risk is applied to breast cancer, which has a high lifetime incidence, the absolute number [the number of cancer cases developing over a certain time period] of excess cases attributable to red meat would be substantial, and, hence, a public health concern."
The risk could stem from the fact that red meat contains more saturated fat, which can raise levels of cholesterol and hormones causing tumours.
When red meat is cooked at very high temperatures, as is the case with sausages and burgers on a barbecue, harmful chemicals are released.
The study, published in the British Medical Journal, used data from women between the ages of 26-45.