Eating a large amount of red meat in early adulthood could be associated with an increased risk of breast cancer, a new study suggests.
Substituting red meat with legumes — such as peas, beans and lentils — nuts, poultry and fish could reduce the risk, they found.
Studies thus far have found no significant association between the consumption of red meat and breast cancer, but the team of US researchers said that most previous research has been based on diet during mid and later life.
So they decided to assess the dietary habits of 89,000 pre-menopausal women aged 26 to 43 in 1991.
Their study, published on bmj.com, examined frequency of red meat intake as well as other foods. The authors also assessed the women's adolescent food intake.
In the 20-year follow-up period, medical records identified 2,830 cases of breast cancer. The researchers estimated that for each step-by-step increase in the women's consumption of red meat, there was a step-by-step increase in the risk of getting breast cancer.
Higher intake of red meat was associated with a 22% increased risk of breast cancer overall.
And each additional serving per day of red meat was associated with a 13% increase in risk of breast cancer, they said.
Substituting one serving of red meat each day of combined legumes, nuts, poultry and fish was associated with a 14% lower risk of breast cancer, they 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 of breast cancer," the authors concluded.
But other experts cautioned that the findings should be interpreted with caution.