Can eating well-cooked meats raise a woman’s risk of getting breast cancer? A decade worth of science has yet to provide conclusive results.
In 1998, a team of researchers at the University of Southern California, lead by Wei Zheng, M.D., Ph.D., found that women who eat well-cooked meats were four times more likely to have breast cancer. Over cooking meats by frying or grilling can create carcinogenic compounds called heterocyclic amines (HCAs), which have been linked to some cancers, including stomach and colorectal.
Although Zheng’s study was relatively small (only 273 breast cancer cases were included), the results were intriguing. Heterocyclic amines had been shown to produce mammary cancers in laboratory rats, but few studies had looked at the compounds in humans.
Zheng’s findings, however, were soon contradicted. In 2000, a UC Irvine College of Medicine study found that well-done red meat does not appear to increase a women’s risk of breast cancer. The researchers found no significant associations of breast cancer with red meats at any level of doneness.
Well, which is it?
“We have published a number of papers since then (1998) showing that some genetic factors may modify the association of HCA exposure and breast cancer risk,” writes Dr. Zheng, now at Vanderbilt University Medical Center. “But the studies are small and results inconclusive.”
Although the relationship between HCA’s and breast cancer has yet to be clarified, it does not mean there isn’t one. Instead, it may mean the relationship is more complex than originally thought.
One of the complexities that Zheng is studying is polymorphisms, or genetic changes that vary across a population. Genetic polymorphisms can affect how a person metabolizes heterocyclic amines and may therefore need to be taken into account when trying to find out if well-cooked steaks and pork chops increase one’s risk of breast cancer.
In addition, heterocyclic amines may not be the only toxic compound found in well cooked meats.
“The assumption is that heterocyclic amines are the causal agents in these meats; however, a variety of different types of genotoxic compounds are potentially present in grilled meats,” notes Robert Turesky, Ph.D., research scientist and Associate Professor at the New York State Department of Health.
