Thursday, August 21, 2025

Weird Immunological Science

Instapundit links to a Washington Post article echoed at Yahoo.com, the topic is the lack of allergies among the Amish.

Only 7 percent of Amish children had a positive response to one or more common allergens in a skin prick test, compared with more than half of the general U.S. population. 

“Generally, across the country, about 8 to 10 percent of kids have asthma. In the Amish kids, it’s probably 1 to 2 percent,” said Carole Ober, chair of human genetics at the University of Chicago. “A few of them do have allergies, but at much, much lower rates compared to the general population.”

The “hygiene hypothesis” - first proposed in a 1989 study by British immunologist David Strachan - suggests that early childhood exposure to microbes protects against allergic diseases by contributing to the development of a healthy immune system.

The study found that hay fever and eczema were less common among children born into larger families. Children who grow up with more household pets are less likely to develop asthma, hay fever or eczema. Perhaps even more beneficial than having older siblings or pets, however, is growing up on a farm.

In a study of 60 schoolchildren by Ober, Vercelli and their colleagues, the prevalence of asthma was four times lower in the Amish as compared with the Hutterites, another U.S. farming community with a similar genetic ancestry and lifestyle.

The main difference between these two populations seemed to be the amount of exposure as young children to farm animals or barns. “The Hutterite kids and pregnant moms don’t go into the animal barns. Kids aren’t really exposed to the animal barns until they’re like 12 or so, when they start learning how to do the work on the farm,” Ober said. “The Amish kids are in and out of the cow barns all day long from an early age.”

It seems the "farm" needs to have livestock to be beneficial. I grew up in a commercial orange orchard where the sum total of our 'stock' was a barn cat. I have had hay fever since forever (sniffle, sneeze). 

Who would guess a generous exposure to literal bullsh*t, at an early age, is the key to an allergy-free life?