Who has the research?

[wombatclay]

My best friend IRL is fairly mainstream but DEVOTED to breastfeeding despite several blocks (BF not the norm in her region, her extended family disapproves, her ped and medical community is horrible about breastfeeding, she works full time and has to travel frequently so she pumps 4-5x a day and on the road, she has had horrible supply issues with both babies, mastitis/thrush, etc) and she is currently tandem nursing her 2+yo and her 6mo.

We no longer live geographically close so we talk mostly by phone, and she mentioned the other day that the only children she knows with food allergies are the ones who were (or still are) being breastfed for at least a year. She is worried that maybe killing herself over breastfeeding was the wrong choice... that in terms of allergies putting her babes on formula may have been a better decision. I immediately said "no way...Breastfeeding helps prevent food allergies!"

But... my friend is a scientist and she'd like to see the studies. Which I figured wouldn't be to hard to find. And that's where I need help! Normally I can find just about anything (I was a reference librarian at a research university for years) but I'm drawing a blank. The studies I do find mostly say "breastfeeding for 6 months seems to help" reduce food allergies, and the sites that discuss extended breastfeeding/allergies don't seem to cite their sources for that specific factoid.

I'm really surprised, since I expected Kellymom or LLL or the Newman site to have a list of research on extended breastfeeding benefits (or even just data on a stronger breastmilk/allergy protection correlation) but I'm just not seeing it. Help!

Thanks!

[velcromom]

Try the LLL site, they have a document titled "Outcomes of Breastfeeding" that has summaries of research on the differences between ff and bf for a large variety of diseases/conditions. I would think there's something in there about allergies.

[wombatclay]

Thanks! The LLL page does site some studies which demonstrate that breastfeeding does reduce the prevalence of allergies, but mostly these are from the 80s and early 90s... not a lot of recent research. Which isn't really a problem since I just want the general data. But when I went to pubmed and read the abstracts/summaries for the studies listed none of them discuss extended breastfeeding? They all say thing like "exclusive breastmilk for 4 months" or "breastfeeding for at least 6 months".

And even the studies that say breastfeeding for 4-6 months reduces allergy or food sensitization usually then go on to say that no difference is seen in children who are breastfed longer (in terms of reduced prevalence of allergy), that the allergy benefits are mostly maxed out by 6 months. And a few retrospective studies suggest that prolonged breastfeeding (9mo+) can increase food sensitivities later on.

The pro-breastfeeding pages I find all seem to assume the allergy reduction benefits continue into toddlerhood, and my personal opinion is that allergies in breastfed babes are simply recognized sooner... a formula babe may not have as wide an exposure to different allergens (through mama's changing milk) so they may not demonstrate allergies till later, but those babes are getting whacked with dairy/soy allergens regularly and may develop more serious allergies in later years while the breastfed babes outgrow their sensitivities. And there are obviously plenty of other reasons to breastfed past 6 months (heck, if I didn't believe so strongly in breastfeeding I wouldn't be tandem nursing a 3yo and a new babe)!

I just can't seem to find the studies that actually look at extended breastfeeding and food allergies. Possibly because the sample set is too small (not enough extended breastfeeders to do a good study) but I feel bad... my friend has been through hell and back fighting for her right to breastfeed for as long as she and her babes want and I'd love to be able to validate that effort by giving her the reassurance she asked for.

ETA- still digging in the LLL site though... if you have a specific link please let me know! thanks!

[rrs]

Are you looking specifically for food allergies/sensitivities or allergies in general?

My pubmed search has revealed some current research, mainly about non-food allergies/asthma. Let me know if that would be helpful.

[wombatclay]

My friend specifically wondered about food allergies since both her children now show sensitivities... my dd2 seems fine but my dd1 has food allergies as well and the one other mother she knows who has breastfed past a year also has a lo with food allergies. So her IRL sample set is very small. I'm not much anecdotal help since although extended breastfeeding in my region isn't uncommon, food allergies are also through the roof.

I'm sending her some of the studies I found (mostly looking at atopic dermatitis) so if you could pm me with your search results I'll add those to the email. Thank you! But I think her main concern is that the studies don't seem to show a protective benefit in terms of food allergies with extended breastfeeding. Even the studies on the LLL breastfeeding outcome study look at the 6month or younger set, with mixed results. And seriously... I am extremely pro-breastfeeding but I don't know if I would have been able to carry on facing the same difficulties she has so it's killing me that the obvious studies don't seem to exist!

I think I may xpost this in health/allergies but I was hoping there was a "of course you should check..." lactivist studies page, kind of like the turk vbac site. Maybe I'll make a page with everything we can find so no one has to do this again!

[Mommal]

If your friend is a scientist, this article will probably appeal to her: Why We Develop Food Allergies, Brandtzaeg, P., American Scientist Jan-Feb 2007. It's all about the development of the immune system with regards to food allergies, and makes specific reference to the beneficial effects of breastfeeding.

[wombatclay]

Sweet! thanks! Yeah, she and her husband are engineers so they really like seeing controlled studies with hard numbers. I've tried to explain biology doesn't always work like that...

[TortelliniMama]

I've read stuff that suggests that babies with food allergies often resist solids (at least some of them). It could be that some of the babies she's seen are still nursing past a year because they resisted the move to solids. IOW, the toddler nursing is due to allergies, not the other way around.