I once had a horse who developed an allergy to the dust and molds in hay at the ripe old age of 23.
Are you allergic to these?
Are you allergic to these? iStockphoto.com
At least I think that's what happened — as she aged, she had more and more problems breathing. The veterinarian said any results from a skin test were likely to be hard to read, and pretty inconclusive.
Turns out human food allergies are also pretty hard to pinpoint. That makes it difficult for consumer groups and doctors to give clear advice on how to deal with them.
In the current issue of JAMA, researchers from several California institutions report on their efforts to divine the science behind food allergies. They looked at 72 reports published between 1988 and 2009, and found little consensus from study to study.
The literature revealed no clear best way to diagnose food allergies. Skin testing, blood testing and food challenges were equally popular in the studies, and all were prone to over-diagnosis. The researchers also found no conclusive evaluations of a couple of drug treatments, how effective dietary restrictions are, or whether (and how) foods can be reintroduced.
They were able to conclude one thing, sort of — food allergies affect anywhere from 1 to 10 percent of the population. The National Institute of Allergy and Infectious Diseases puts the figures at 6 to 8 percent of kids, and about 4 percent of adults. But because of the imprecision of allergy tests, the researchers weren't able to say whether the prevalence is increasing or decreasing.
And I thought veterinary science was a little behind!
As for my horse with the hay allergy — I put her out to pasture, where she breathed freely, eating grass and rolls of hay that were washed through by every passing rain, til she died at 27.