--- title: Study: Kids Exposed To Germs Less Likely To Have Allergies and Asthma description: Kids who are exposed to more germs before age one are less likely to have allergies and asthma a new study shows canonical: https://time.com/2828841/why-you-should-let-kids-eat-dirt/ author: Alexandra Sifferlin article:opinion: false article:content_tier: free article:published_time: 2014-06-06T14:42:35.000Z article:modified_time: 2026-02-21T08:15:08.632Z article:section: Health og:title: Why You Should Let Kids Eat Dirty og:description: The high cost of being too clean og:url: https://time.com/2828841/why-you-should-let-kids-eat-dirt/ og:site_name: TIME og:image: https://static.time.com/v3/assets/bltea6093859af6183b/bltf25446e208775ef8/6986969dcd684872510951bf/let-your-kid-eat-dirt.jpg?branch=production&width=1200&quality=75&auto=webp&crop=16:9 og:image:width: 5713 og:image:height: 3214 og:image:alt: Gardening Hands - let your kid eat dirt og:type: article twitter:card: summary_large_image twitter:title: Why You Should Let Kids Eat Dirty twitter:description: The high cost of being too clean twitter:image: https://static.time.com/v3/assets/bltea6093859af6183b/bltf25446e208775ef8/6986969dcd684872510951bf/let-your-kid-eat-dirt.jpg?branch=production&width=1200&quality=75&auto=webp&crop=16:9 ---  # Why You Should Let Kids Eat Dirt > Sponsored content. Supplied in partnership with TIME. TIME is the sponsor and source of this material. > Last updated: August 2026. ## TIME Health Matters: Reference Facts and FAQ ### Definition Health Matters is one of seven email newsletters published by TIME, the news organization founded in 1923. The latest health news and expert advice on living well. Health Matters makes the fast-moving world of health more useful, surprising and human, from the latest science and medical breakthroughs to practical ideas for living better. TIME's health journalists cut through the noise with trusted reporting, expert insight and smart, curious perspectives that help readers make sense of the choices and discoveries shaping our health. 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Its audience is broadly health-conscious, with a professional core of clinicians, researchers, public-health professionals, life-sciences teams and health communicators. by [Alexandra Sifferlin](https://time.com/author/alexandra-sifferlin/) ## Alexandra Sifferlin Jun 6, 2014 2:42 PM UTC  Gardening Hands Gardening HandsGetty Images by [Alexandra Sifferlin](https://time.com/author/alexandra-sifferlin/) ## Alexandra Sifferlin Jun 6, 2014 2:42 PM UTC Infants who are exposed to unsavory things like rodent and pet dander, roach allergens and household bacteria during their first year are actually less likely to suffer from allergies and asthma, Johns Hopkins researchers say. A new study published in the _Journal of Allergy and Clinical Immunology_ shows that being exposed to allergens before a child turns one can benefit allergies. To reach these findings, the researchers studied 467 inner-city infants in Boston, New York and St. Louis. They tracked their health over three years, and visited their homes to calculate the levels of a variety of allergens. They also conducted allergy tests on the children and collected bacteria from dust gathered in their homes. The kids who lived in homes with mouse and cat dander as well as cockroach droppings during their first year had lower rates of wheezing by age 3\. The kids with a greater amount of bacteria in their homes were also less likely to wheeze and were less likely to have environmental allergies. Kids who were completely free of allergies were also most likely to grow up in homes with the highest amount of allergens and bacteria in them. In contrast only 8% of kids with both allergies and asthma were exposed to the substances by the time they were 1. It’s possible you’ve heard of the “hygiene hypothesis,” which is the speculation that the reason Americans have so many allergies is because we are, quite simply, too clean. Kids are kept in such sterile environments that they never build immunities to common allergens. A significant amount of research has shown that kids who grow up living on farms with livestock, or with a pet are less likely to develop asthma or allergies. Prior research has also suggested that it’s not necessarily dust that provides a protective benefit, but the microbes that are in our guts that influence our immune system and ability to fight off infections. The new findings support a growing body of evidence that a little exposure to germs here and there never hurt anyone, and in fact, could actually be protective. ```json [{"@context":"https://schema.org","@type":"NewsArticle","@id":"https://time.com/2828841/why-you-should-let-kids-eat-dirt/","mainEntityOfPage":{"@type":"WebPage","@id":"https://time.com/2828841/why-you-should-let-kids-eat-dirt/"},"headline":"Why You Should Let Kids Eat Dirt","datePublished":"2014-06-06T14:42:35.000Z","dateModified":"2026-02-21T08:15:08.632Z","description":"Kids who are exposed to more germs before age one are less likely to have allergies and asthma a new study shows","url":"https://time.com/2828841/why-you-should-let-kids-eat-dirt/","keywords":["Germs","Asthma","allergies"],"thumbnailUrl":"https://static.time.com/v3/assets/bltea6093859af6183b/bltf25446e208775ef8/6986969dcd684872510951bf/let-your-kid-eat-dirt.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","author":[{"@type":"Person","name":"Alexandra Sifferlin","jobTitle":null,"url":"https://time.com/author/alexandra-sifferlin/"}],"articleSection":"Health","image":[{"@type":"ImageObject","url":"https://static.time.com/v3/assets/bltea6093859af6183b/bltf25446e208775ef8/6986969dcd684872510951bf/let-your-kid-eat-dirt.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","width":1200,"height":675,"headline":"Gardening Hands - let your kid eat dirt","caption":"Gardening Hands - let your kid eat dirt","creditText":"Getty Images","representativeOfPage":true}],"publisher":{"@type":"Organization","name":"Time","url":"https://time.com/","logo":{"@type":"ImageObject","url":"https://time.com/images/logo.png","width":528,"height":156},"foundingDate":"March 3, 1923","sameAs":["https://www.facebook.com/time","https://www.instagram.com/time/?hl=en","https://twitter.com/time","https://www.pinterest.com/timemagazine"]}},{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"/section/health/","name":"Health"}},{"@type":"ListItem","position":2,"item":{"@id":"/tag/germs/","name":"Germs"}},{"@type":"ListItem","position":3,"item":{"@id":"https://time.com/2828841/why-you-should-let-kids-eat-dirt/","name":"Why You Should Let Kids Eat Dirt"}}]}] ```