Hello Cynthia

Have just one study about this precise subjets. In the abstract, they don't
give the lengh of persistence of allergens in breast milk (perhaps they give
it in the integral study... ) :


Detection of Peanut Allergens in Breast Milk of Lactating Women

Peter Vadas, MD, PhD; Yvonne Wai, MD; Wesley Burks, MD; Boris Perelman, PhD.
JAMA. 2001;285:1746-1748

Context Most individuals who react to peanuts do so on their first known
exposure. A potential but unproven route of occult exposure resulting in
sensitization to peanut is via breast milk during lactation.

Objective To investigate the ability of maternal dietary peanut protein to
pass into breast milk during lactation.
Design and Setting Clinical investigation conducted at 2 North American
hospitals from March 1999 to October 2000.
Patients Twenty-three healthy, lactating women aged 21 to 35 years.
Intervention Each woman consumed 50 g of dry roasted peanuts, after which
breast milk samples were collected at hourly intervals.
Main Outcome Measures Presence in breast milk of total peanut protein,
analyzed by a sandwich enzyme-linked immunosorbent assay, and 2 major peanut
allergens, Ara h 1 and Ara h 2, detected by immunoblot analysis.
Results Peanut protein was detected in 11 of 23 subjects. It was detected in
10 subjects within 2 hours of ingestion and in 1 subject within 6 hours. The
median peak peanut protein concentration in breast milk was 200 ng/mL (mean,
222 ng/mL; range, 120-430 ng/mL). Both major peanut allergens Ara h 1 and
Ara h 2 were detected.
Conclusions Peanut protein is secreted into breast milk of lactating women
following maternal dietary ingestion. Exposure to peanut protein during
breastfeeding is a
route of occult exposure that may result in sensitization of at-risk
infants.

Kindly
Françoise Railhet
[log in to unmask]
Manager of the LLL France Medical Associates Program

             ***********************************************

To temporarily stop your subscription: set lactnet nomail
To start it again: set lactnet mail (or digest)
To unsubscribe: unsubscribe lactnet
All commands go to [log in to unmask]

The LACTNET mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software together with L-Soft's LSMTP(TM)
mailer for lightning fast mail delivery. For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html