The Farm Effect: What Amish Communities Can Teach Us About Allergy Prevention

Despite the increasing prevalence of allergies and allergic sensitizations in the United States, one group appears largely unaffected: the Amish. A study of Amish children living in northern Indiana showed a 50% reduction in prevalence of allergic sensitizations and a considerably lower level of sensitization at 7.2%. Researchers hope these findings can be used to develop protective treatments for children.

Amish children with adult walking | Image Credit: © MMerellinn - stock.adobe.com

The Rise of Allergies in the US

In the past few decades, allergies and asthma have become more common across industrialized nations. According to the CDC, over 25% of US adults and nearly 20% of children report seasonal allergies, food allergies, or asthma. Researchers point to genetics, environmental pollutants, and lifestyle changes as potential contributing factors. However, one widely discussed explanation is the hygiene hypothesis, which suggests that reduced exposure to microbes in early childhood weakens the immune system’s ability to regulate allergic responses.^1-3

The Farm Effect

The "farm effect" is a term researchers use to describe the protective impact of growing up on traditional farms—especially around livestock, barns, and raw farm environments—on the development of allergies and asthma. In early childhood, the immune system is still developing, and research suggests that exposure to a wide variety of microbes helps the body learn to distinguish between harmful and harmless substances.^3,4

In modern, highly sanitized environments, this microbial exposure is reduced. The “hygiene hypothesis” suggests this lack of microbial training leaves the immune system prone to overreact, leading to allergies and asthma. The farm effect expands on this idea, showing that early, continuous exposure to farm microbes acts almost like a natural immune training program.³

Although the term initially originated from Europe, “the farm effect” gained significant popularity following a paper published by Ober and Sperling in the Current Opinion in Immunology. The paper reflected on findings from a prior study evaluating asthma risk and immunity in Amish and Hutterite communities. The Amish and Hutterite communities have very similar lifestyles and history; however, Amish communities continue to practice traditional farming methods rather than industrial ones—as the Hutterites do. That study found that the prevalence of asthma and allergies in Amish children were comparatively lower (4 to 6 times) compared with Hutterite children, despite having higher exposure to endotoxins, namely farm dust.^3-5

“Children who grow up in traditional farm environments are protected from developing asthma and allergy,” wrote Ober and Sperling. “This ‘farm effect’ can be largely explained by the child's early life contact with farm animals, in particular cows, and their microbes.”

The Indiana Study

Researchers set out to examine whether Amish children in northern Indiana experienced the same “farm effect” observed in Amish communities elsewhere in the US and Europe. They specifically wanted to measure allergic sensitization and asthma prevalence in a community that maintains traditional farming practices, minimal use of technology, and limited outside environmental exposures.⁶

The study involved over 60 Amish children from a farming community in northern Indiana, whose blood samples were collected and analyzed for allergen-specific immunoglobulin E (IgE), a marker used to determine allergic sensitization. The children and their families also completed health questionnaires to record asthma symptoms, family history, and environmental exposures. These data were then compared to children in the broader US population using data from the National Health and Nutrition Examination Survey (NHANES).⁶

The authors reported that Amish children are significantly protected against both asthma and allergic sensitization, and only 7.2% tested positive for IgE, compared with 25% to 30% of US children. Asthma rates were also dramatically lower. Although nearly 8% of US children are diagnosed with asthma, only isolated cases were found among the Indiana Amish cohort. The authors attribute these protections to early-life exposure to farm environments, particularly microbial exposure from barns, animals, and traditional farming practices.⁶

“The prevalence of asthma and allergic sensitization continues to rise in the Westernized populations,” the authors concluded. “Although we have not determined specific mechanisms, this study continues to support the effect of early farm exposures and their impact in significantly reducing the prevalence of asthma and allergic sensitization.”⁶

The Next Step

The Indiana study adds to a growing body of research suggesting that the “farm effect” offers powerful protection against asthma and allergic sensitization. Although the exact mechanisms remain under investigation, consistent findings across Amish and European farm communities point to the importance of early and continuous microbial exposure in shaping immune development. Insights gained from Amish communities could guide the development of new strategies—such as microbial-based therapies, probiotics, or environmental interventions—that mimic the protective benefits of traditional farm exposures.

REFERENCES

1. Diagnosed allergic conditions in adults: United States, 2021. CDC. January 2023. Accessed August 22, 2025. https://www.cdc.gov/nchs/products/databriefs/db460.htm?utm_source=chatgpt.com

2. Diagnosed allergic conditions in children aged 0–17 years: United States, 2021. CDC. January 2023. Accessed August 22, 2025. https://www.cdc.gov/nchs/products/databriefs/db459.htm?utm_source=chatgpt.com

3. Kim M. Allergies seem nearly impossible to avoid — unless you’re Amish. The Washington Post. July 20, 2025. Accessed August 22, 2025. https://www.washingtonpost.com/health/2025/07/20/allergies-amish-hygiene-thesis/

4. Ober C, Sperling A, Mutius E, et al. Immune development and environment: lessons from Amish and Hutterite children. Current Opinion in Immunology. August 29, 2017. doi:10.1016/j.coi.2017.08.003

5. Stein M, Hrusch C, Gozdz J, et al. Innate immunity and asthma risk in Amish and Hutterite farm children. N Engl J Med. August 4, 2016. doi: 10.1056/NEJMoa1508749

6. Holbreich M, Genuneit J, Weber J, et al. Amish children living in northern Indiana have a very low prevalence of allergic sensitization. Journal of Allergy and Clinical Immunology. April 19, 2012. doi: 10.1016/j.jaci.2012.03.016