There’s a few definitive things one can say about hypoallergenic formulas:
1) They smell like regurgitated rotten potatoes
2) In order to feed your baby with them for one year, you will need to take out a second mortgage, and
3) They are lifesaving, invaluable substances for kids with food allergies, and many parents are eternally grateful for their existence.
According to this study, though (and please note I have not been able to track down the actual study – it does not appear to be in the current issue of JACI as the articles have implied; maybe it is forthcoming? – I am only going on the media reports, which as we all know are sketchy at best), there is one thing you can’t say about hypoallergenic formulas: that they prevent allergies.
But wait. I forgot! There is one more thing you can say about hypoallergenics: partially hydrolyzed formulas – the kind this study was using – are not technically hypoallergenic. A partially hydrolyzed formula is something like your favorite brand’s “sensitive” formula. Or Nestle Good Start. These don’t smell as bad as Nutramigen or Alimentum. Nor do they cost as much. Most importantly, they don’t help one bit if your kid is actually suffering from a legit food intolerance or allergy.
Now, as far as I was aware, the evidence was mixed when it came to the actual hypos and allergy prevention. I’ve read some studies that have found a significant (remember, significant only means statistically significant; not necessarily significant in the way you or I might define the term) advantages to using a hydrolyzed protein formula in babies with a high risk of allergies. Others found no difference. But many studies have compared partially hydrolyzed to extensively hydrolyzed, and these have definitely found a difference between the two. This one, done in 2000, found that “the cumulative incidence of confirmed cow’s milk allergy was 1.3% (three of 232) in exclusively breast-fed infants, 0.6% (one of 161) in infants fed extensively hydrolyzed formula (Nutramigen or Profylac), and 4.7%(four of 85) in infants fed partially hydrolyzed formula (Nan HA). Partially hydrolyzed formula was found to be less effective than extensively hydrolyzed formula in preventing cow’s milk allergy, 0.6% vs. 4.7% (p=0.05), but because of the small number of cases the results should be interpreted with caution.” Another study, published in 2009, showed a significant difference in allergy incidence between those fed partially hydrolyzed versus extensively hydrolyzed.
Okay, so we’re clear that we’re talking apples and oranges here, right? The reporting of this study frustrates me, because most people are probably going to assume that the findings hold true for actual hypoallergenic, extensively hydrolyzed formulas, and this is simply not the case.
My frustration is much higher, though, because of how each and every article reporting these findings had to throw in the requisite breast-is-best message. Even though this study did not compare exclusively breastfed kids to those fed any of the formulas in question (rather, they compared those fed a milk-based, soy, or partially hydrolyzed formula), and we have no way of knowing if breastfeeding would have been any more preventative (or any less) than the so-called “hypoallergenic”.
I want to bring your attention to a Cochrane Review (the “gold standard” of metastudies) which looked at all the good-quality evidence for prevention of allergies by way of childhood nutrition. The review didn’t find much of an advantage to using hypos as a preventative, but it also didn’t find any advantage to breastfeeding in this particular case. Although it’s hard to know, because….
Sorry to interrupt, but, um… Two. As in a number my son could count to before he could walk.
Interestingly, though, the ‘authors’ conclusion then states, “There is no evidence to support feeding with a hydrolysed formula for the prevention of allergy compared to exclusive breast feeding.” This is a bit oddly phrased to me, because while it is certainly true, it seems a bit misleading. What their review actually found was that there were only a few studies actually comparing these two methods of feeding, and that neither fared particularly well.
Anyway – the takeaway message is that parents who want to prevent allergies in their kids might be wasting their money (and their nasal passages – both my kids had to be on hypos and the smell seriously haunts my dreams) on special hydrolyzed protein formulas. But there’s a few important things that I hope won’t get lost in the media dissemination of this study (gosh, I’m list-heavy tonight, aren’t I?):
1. This study had fudge-all to do with kids who are currently suffering from food allergies. THAT is what these formulas were designed for; the prevention thing was likely just a hopeful scientific extension of a marketing ploy (incidentally, this study was funded by Nestle…) And regardless, for those of us on extensively hydrolyzed formulas (like most with food allergies will be), the type of formula used in this study is not the same as what we are feeding our children.
2. Speaking of Nestle, this study also looked at one particular formula, made by everyone’s favorite company of ill repute. Formulas do vary, contrary to what you may have heard. Nutramigen and Alimentum, the two most popular commercial hypoallergenics in the States, are nearly identical – and yet any GI will tell you that many kids who can’t tolerate Enfamil’s option will do better on the Similac version. There are tiny, incremental differences in these two similar formula – I think soy products are more heavily used in one, and corn in another, or something like that (I’m sure one of you FFF’s knows about this and can fill us in). These tiny differences might matter if we’re talking about allergens/immunoresponse to allergens.
3. Just in case this gets used as anti-formula ammunition, let’s be clear: this study does not say that hypoallergenics make allergies worse than breastfeeding. All it says is that this particular type of hypoallergenic does not help prevent allergies.
Now if you will excuse me, I must go wash the scent of regurgitated potatoes out of my hair.