Lactating Women Should
Avoid Charred Meat,
Study Shows

By Lori Bona Hunt

Breast-feeding mothers who consume charred meats are probably passing dangerous environmental contaminants on to their children, according to a first-ever study by U of G researchers.

Heterocyclic amines - the mutagenic and carcinogenic products formed during frying, broiling and grilling of meats - were found in human milk during tests conducted by Prof. David Josephy and post-doc researcher Lillian DeBruin of the Department of Chemistry and Biochemistry and Perry Martos of Laboratory Services.

"There have been a number of studies that have found a link between consuming charred meats and an increased risk of breast cancer," Josephy says. One investigation concluded that women who ate red meat that was "very well done" had a 4.6-fold increased risk of breast cancer compared with those who usually ate meat that was "rare" or "medium."

"But this is the first time analysis of these compounds has been conducted on human milk," Josephy says. "We can say with some certainty that most of these environmental chemicals are also being absorbed by nursing infants, and as a rule, infants are more susceptible than adults."

The research is reported in the journal Chemical Research in Toxicology, publishedby the American Chemical Society, the word's largest scientific society. The pilot study included samples from 11 lactating mothers living near Guelph, 10 of whom are meat eaters. The environmental chemicals that result from eating grilled meats were detected in nine of the 11 samples, with one of the two exceptions being the milk of the vegetarian donor.

"The presence of these environmental chemicals in human milk means this is possibly a human mammary carcinogen," says DeBruin.

Josephy adds that animal meat is the most likely source. "The chemicals are formed by heating creatine with amino acids, and creatine is found almost exclusively in muscle." This includes red meat, fish and chicken. "Reducing the intake of overly cooked meats might minimize exposure to these compounds," he says.

The chemicals have a relatively short lifespan in the body - between eight and 24 hours - so cutting back on consumption even just while breast-feeding might have a positive effect, he says.

Although the study was a pilot project intended to test the methodology of analysing milk samples for these contaminants, Josephy says the findings are provocative. "We will now embark on a more comprehensive study."

That work will include more detailed analysis of women's dietary habits and is being funded by the Canadian Breast Cancer Foundation.