Eating Contaminated Great Lakes Sport Fish Does Not Inhibit Lactation, UB Study Finds

ATHENS -- A study by University at Buffalo reproductive epidemiologists has found no association between eating DDE-contaminated sport fish from Lake Ontario and the length of lactation in nursing mothers.

The research is part of the New York State Angler Study, which is assessing the health effects of eating sport fish from Lake Ontario, the most contaminated of the Great Lakes. UB's portion of the study concentrates on the relationship between sport-fish consumption and adverse reproductive events.

"DDE is a potential endocrine disrupter, which means it could interfere with production of hormones that control lactation," said Bridget McGuinness, UB project coordinator for the New York State Angler Study and principal author of the lactation study. She presented results here today (Sept. 6, 1999) at the joint meeting of the International Society for Environmental Epidemiology and the International Society of Exposure Analysis.

"There is some thinking that the presence of DDE in the diet of women of child-bearing age could decrease the duration of lactation," McGuinness said. "However, we found the opposite of what we expected to find."

Results showed that women who had eaten sport fish during the study period did lactate for a shorter period than women who had not eaten sport fish, she said. But they had lower levels of DDE in their breast milk than their non-fish-consuming colleagues.

The study cohort was composed of 54 first-time mothers enrolled in the New York State Angler Study who gave birth between 1991 and 1993. During the initial data collection, which ended in 1991, enrollees provided information on consumption of sport fish from Lake Ontario and their intentions to conceive.

Milk samples later were collected from all new mothers, along with their histories of breast feeding, but only first-time mothers were included in the study. Lactation is known to help eliminate contaminants from breast milk over time, so women who had no previous children -- and therefore logged the least amount of breast-feeding time -- were considered the best candidates to assess DDE's effects, McGuinness noted.

Milk samples were analyzed for DDE concentration and compared with length of breast-feeding. Results showed that the first-time mothers who reported they ate Lake Ontario fish during the initial study period breast fed for an average of 12 weeks less than women who did not eat contaminated sport fish. But the fish-eaters were found to have DDE concentrations about 47 percent lower than women who ate no contaminated sport fish during the initial study period.

"Our study suggests no direct relationship between DDE concentrations in breast milk of first-time mothers who eat sport fish and a shortened duration of lactation," McGuinness said.

Also contributing to the study were John Vena, Ph.D., Germaine Buck, Ph.D., and John Weiner, Dr. P.H., of the UB Department of Social and Preventive Medicine; Pauline Mendola, Ph.D., formerly of UB, now with the Environmental Protection Agency, and Hebe Greizerstein, Ph.D., and Paul Kostyniak, Ph.D., of the UB Department of Pharmacology and Toxicology.

The study was funded in part by the Great Lakes Protection Fund and the Agency for Toxic Substances and Disease Registry.