Peter Vadas, M.D., Ph.D., of St. Michael s Hospital, University of Toronto, Ontario, and colleagues conducted a clinical investigation at two North American hospitals from March 1999 to October 2000 to find out if maternal dietary peanut protein passes into breast milk during lactation. The authors tested breast milk samples from 23 healthy, lactating women aged 21 to 35 years. According to background information cited in the article, peanut allergy is a significant public health problem. Approximately 1 percent of British and U.S. preschool children are sensitized to peanuts. It starts early in life, is often associated with severe or life-threatening reactions, and is rarely resolved.
Peanuts account for the majority of food-induced anaphylactic fatalities.
Between 72 percent and 81 percent of individuals who have reactions to peanuts do so on their first known exposure. Potential but unproven routes of hidden exposure include exposure in the womb and exposure to peanuts transferred from maternal diet via breast milk during lactation. The authors measured the presence in breast milk of total peanut protein and two major peanut allergens. Peanut protein was detected in 11 of 23 subjects. It was detected in 10 subjects within two hours of ingestion and in one subject within six hours, the authors write.