Eating processed meats like bacon, sausages and ham could increase the risk of breast cancer, a study has said.
Regularly consuming the foods was linked with a 9% higher risk of breast cancer, according to an analysis of previous studies looking at over 1.2 million women.
The findings follow previous research from the World Health Organization, which categorized processed meat as a carcinogen after finding that its consumption can cause various types of cancer.
Processed meats are those that have been preserved by smoking, curing or salting.
"This systematic review and meta-analysis study reports significant positive associations between processed meat consumption with risk of breast cancer," the authors wrote.
"Cutting down processed meat seems beneficial for the prevention of breast cancer," added lead author Dr. Maryam Farvid, of the Harvard T.H. Chan School of Public Health.
But scientists did not suggest people cut processed meats from their diets entirely, and experts warned that the study should be met with caution.
"Individual risk is small"
The paper leaves "many questions unanswered" and does not prove that increased processed meat intake led directly to breast cancer in the women studied, according to Kevin McConway, emeritus professor of applied statistics at the UK's Open University.
"I just can't tell you how many more cases of breast cancer there would be if everyone ate an extra bacon sandwich a day -- this research just can't give that information," added McConway.
The study's authors accepted that the previous studies into the connection between processed meat and breast cancer had produced "inconsistent" results.
Gunter Kuhnle, associate professor in nutrition and health at the University of Reading, said that "while the evidence for classifying processed meat as a carcinogen is strong, the actual risk to the individual is very small and it is more relevant on a population level."
"Whether this [study] justifies a change in the current [UK] recommendation of 70 grams of red and processed meat is questionable," he added.