The study followed 42,012 American and Puerto-Rican women (35-74 years old), who have a sister or half-sister already diagnosed with breast cancer, to see if there was a link between the type of meat in their diets and their likelihood of developing the disease. 

During the follow-up period of more than seven years, 1,536 women taking part in the study developed invasive breast cancers. Postmenopausal women who consumed over 110.8 grams of red meat per day had higher risk of breast cancer. However, consuming an equivalent amount of lean (no skin) poultry was linked to lower chances of developing the disease. 

From this data, the researchers created a mathematical model to predict how diets containing different amounts of meat influence breast cancer risk. In this model, the total amount of meat in the diet remained the same, but the levels of red meat and poultry changed. Using this model, the researchers found that replacing red meat with poultry was linked to lower chances of developing breast cancer. 

The analysis accounted for other lifestyle factors that are known to influence someone’s chances of getting breast cancer, such physical activity, alcohol intake and smoking. However, the researchers noted that participants who ate more red meat had ‘worse health behaviours’ overall. 

Further research is needed to understand exactly why lean poultry may change someone’s breast cancer risk.

Dr Kotryna Temcinaite, Research Communications Manager at Breast Cancer Care and Breast Cancer Now, said: 

“While the potential protective effect of eating poultry needs to be investigated further, we know that limiting red meat in your diet can help all women lower their breast cancer risk by helping them maintain a healthy weight. Even small changes can be a good start, like reducing the number of times you eat red or processed meat each week.

“These findings add to the suggestion that regularly eating red meat may increase the risk of breast cancer in postmenopausal women, but the evidence has been inconsistent to date and more research is needed to understand why it might have an effect on someone’s likelihood of developing the disease, particularly as this study only looked at women with a family history of breast cancer. 

“There is never one single cause of breast cancer and, given our diets change over time and can be affected by our lifestyles, it remains very difficult to calculate how specific food groups influence an individual’s risk of the disease. 

“That said, consistent evidence has shown that a healthy and varied diet, rich in fruit, veg, pulses and grains and limited in red meat, can help women lower their breast cancer risk. There are also several well-established health benefits to reducing red meat in preventing heart disease and bowel cancer, and we’d encourage women of all ages to limit their intake as part of a balanced diet.”

Regarding the finding that eating poultry in moderation may help lower the risk of breast cancer, Dr Kotryna Temcinaite added:

“The potential protective effect of eating poultry in moderation on breast cancer risk is intriguing, but we now need further studies to confirm this finding as well as to understand the possible mechanisms at play. In the meantime, we know that all women can help keep their breast cancer risk as low as possible by maintaining a healthy weight, keeping physically active and drinking less alcohol.”