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Does Modern Living Cause Asthma?

Does Modern Living Cause Asthma?

In 1733, Dr. George Cheyne published a book called “The English Malady” in which he suggested nervous ailments like hay fever and asthma were caused by modern living. While we now understand asthma is not nervous, there are some modern theories that likewise suggest our modern living causes allergies and asthma. Here are three of them.

Hygiene Hypothesis. Exposure to certain bacteria, especially in the first months of life, helps the immune system mature properly. Historically, this was accomplished through natural birth, breastfeeding, large families, and living on farms.

Our modern way of living has changed the way we live. Many infants are born by c-section, formula feeding is common, families tend to be small, and most people don’t live on farms. Not only that, but we also use sanitizers, antibiotics, and vaccines, all of which decrease exposure to germs.

The idea here is that lacking certain germs causes the immune system to develop an abnormal response to otherwise innocuous substances, such as allergens (dust mites, pollen, cockroach urine, animal dander, mold spores, and certain foods). This is what causes asthma and allergies.1

Microflora Hypothesis. All of us have normal flora (probiotics), or microbes that live on and in our bodies, some of which work with our immune system to keep us healthy. This inspired researchers to postulate that certain microbes in the intestinal tract assure the immune system stays healthy.

However, Lacking these bacteria, or a reduction of them, may result in an imbalance of microbes in your gut resulting in the abnormal immune response leading to asthma and allergies.

A suspected culprit here is broad spectrum antibiotics used to treat infections. While they may fix the infection, they may also wipe out bacteria needed to maintain a healthy immune response. Another culprit may be me our modern diets, which tend to be low in probiotics. This may be because many of the foods we eat are processed, refined, and tend to be low in fiber.2,3

Fetal Origins Hypothesis. Physicians once thought the placenta protected infants from anything inhaled or ingested by the mother. However, after various observations, researchers now suspect that this is not true. They now believe the environment of the mother has a significant impact on the growth and development of the unborn baby.

Air pollutants, such as vehicle exhaust and cigarette smoke, may cause metabolic changes resulting in a small birth weight. This may also result in gene mutations predisposing children to chronic diseases later in life, such as diabetes, hypertension, heart disease, allergies, asthma, and COPD.

This hypothesis has already resulted in some changes. For instance, in 1960, expecting mothers were often encouraged to smoke and drink, and were often discouraged from gaining too much weight. Now women are discouraged from smoking and drinking, and a healthy diet and exercise are encouraged.4,5,6

What does this mean? It probably means that some things we take for granted may need to be re-considered. For instance, these three hypotheses may inspire educational campaigns focused on educating physicians and patients about the advantages of:

  • Fewer births by c-section. Natural birth through the vaginal canal exposes the baby to norma flora needed for normal immune development.
  • More breast feeding: There are many benefits to breastfeeding, and one might be obtaining probiotics needed to maintain a healthy immune system.
  • More specific antibiotic use: The medical community is already making concerted efforts to change the way antibiotics are used. They would prefer the specific bacteria causing an infection be isolated and treated with narrow spectrum antibiotics, as opposed to using broad spectrum antibiotics. Physicians should also limit antibiotic use for pregnant women and infants.
  • Changing the way we eat. Physicians may start recommending a daily diet containing whole grains, nuts, fruits, and vegetables to maintain a healthy microflora.
  • Supplementing diets with probiotics. Physicians may start recommending a daily regime of probiotic supplementation to replace the probiotics lacking in our daily diets. They may also start recommending probiotics in prenatal and infant diets.
  • A better emphasis on mom’s environment. Breathing clean air and eating healthy foods while pregnant may go a long way to preventing chronic diseases later in the infant’s life.

Note: Keep in mind that most researchers believe only people with an asthma gene, or gene mutations, will develop asthma. And, many such genes require some environmental trigger for them to be set into action, and this may occur at any point in a person’s life. So, that said, birth by c-section, bottle feeding, antibiotic use, poor diet, and inhaling pollutants may be such triggers.

Does modern living cause allergies and asthma? Perhaps. But it’s important to understand these are educated guesses aimed at helping researchers better understand asthma, and why asthma rates continue to climb in industrialized countries compared to developing countries where asthma rates remain stable. The hope is these will lead researchers to better wisdom needed to prevent, treat, and even cure asthma.

This article represents the opinions, thoughts, and experiences of the author; none of this content has been paid for by any advertiser. The team does not recommend or endorse any products or treatments discussed herein. Learn more about how we maintain editorial integrity here.

  1. Bloomfield, et al, “Too clean, or not too clean: the Hygiene Hypothesis and home hygiene,” Clin Exp Allergy. 2006 Apr; 36(4): 402–425,, accessed 5/24/16
  2. Huffnagle, Gary B., Mairi Noverr, editors, “Advances in Experimental Medicine and Biology, Volume 635: GI Microbiota and Regulation of the Immune System,” 2008, New York, Springer, page 114
  3. Noverr M.C., G.B. Huffnagle, “The ‘Microflora Hypothesis’ of Allergic Disease,” Clin Exp Allergy 2005; 35:1511–1520,, accessed 5/24/16
  4. Almond, Douglas, Janet Curie, “Killing Me Softly: The Fetal Origins Hypothesis,” J. Econ Perspec, 2011, Summer: 25(3), 153-172,, accessed 5/24/16
  5. Tedner, S.G., et al., “Fetal growth and risk in childhood asthma and allergic disease,” lin Exp Allergy. 2012 Oct; 42(10): 1430–1447,, accessed 5/24/16
  6. Xu, Xue-Feng, et al., “Effects of low birth weight on childhood asthma: a meta-analysis,” BMC Pediatr. 2014; 14: 275,, accessed 5/24/16


  • John Bottrell, RRT moderator author
    3 years ago

    Thanks, Richard!!! Thanks for the kind words and links. I particularly love your comment, “The root causes of asthma and what exactly turns-on the “switch” is one of the enduring mysteries of the condition.” It’s also the most complicated subject I’ve ever delved into.

  • Richard Faust
    3 years ago

    John, thanks so much for the well-researched article (as a researcher myself, I always appreciate your pieces). The root causes of asthma and what exactly turns-on the “switch” is one of the enduring mysteries of the condition. This previous article from the editorial staff examined some the same risk factors you discuss that may lead to asthma: Research into the changes in modern society that may contribute to the proliferation of asthma is an important avenue for potential breakthroughs. Best, Richard ( Team)

  • Kerri MacKay moderator
    3 years ago

    Great post! i have a “perfect storm” of contributing factors for asthma. In addition to family history (which I only learned of after my grandma was diagnosed in her 80s, several years after my diagnosis!)… So interesting to think, had I not had this genetic component, all of the other factors–prematurity, c-section birth, antibiotics early in life… you know, the works for premies… may not have had the same impact had I not had the genetic bit.
    …Not that I’m blaming anybody ;).

  • Richard Faust
    3 years ago

    Thanks Kerri! It is amazing how much is being learned about the genetic component of many conditions. For forum participants that may not have seen these yet, here are the latest articles John Botrell has contributed which look at the genetics and other root causes of asthma: This is a great conversation. Richard ( team)

  • John Bottrell, RRT moderator author
    3 years ago

    That would be an interesting idea of a post: “Why do you think you developed asthma?” With you it seems pretty obvious. With me it would be a little speculating. Mom said there was a lot of cold-like symptoms those first few years before a diagnosis was made. Perhaps antibiotics were used on me, and those activated my asthma genes, making them go all wacky and start recognizing dust mites as enemies… Interesting.

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