are you too cleanOver 25% of adults in America self-report having seasonal allergies. Additionally, over ten percent have a positive antinuclear antibody (ANA) which is an indicator of autoimmune disease. These concerning numbers only seem to be growing.

Both disorders are caused by an immune system that is malfunctioning. Allergies are an immune response that confuses a harmless substance with a dangerous one. Autoimmune diseases occur when an overactive immune system creates antibodies that attack the body.

Why are cases of seasonal allergies and autoimmune diseases growing? Is there something in our modern world that leads to their development? What can we do about it? 

It is a complicated topic with lots of nuances, so be sure to read to the end where application steps will be suggested.


Hygiene Hypothesis

One theory is called the “hygiene hypothesis.” It was originally based on a study in Britain where immunologist David Strachan found a lower prevalence of hay fever in children being raised in large families than those in small ones. He concluded that the germs they were exposed to from older siblings at an early age increased the effectiveness of their immune system protecting them from allergies. 

In 1968, Kiviloog L. Irnell studied the difference in asthma rates between those living in rural areas and those living in urban areas in Sweden. He found the prevalence of asthma was lower for those living in rural areas (1). Similar results were found when comparing native tribes living traditionally in rural areas of Canada and Caucasian Canadians in urban areas. It was found that the native population had a lower frequency of allergies and a higher prevalence of helminth infestation (2).

One especially interesting study looked at those in Eastern and Western Germany after the “Fall of the Iron Curtain.” Researchers thought the increased pollution in Eastern Germany would result in more cases of allergies. Surprisingly they found the opposite. Better sanitation and hygiene were “positively associated with atopic diseases (3)".

Many scientists interpret these findings to indicate that there is a benefit of increased exposure to microorganisms. They believe the diversity in gut flora and helminth parasites that are a result of this exposure, act as protective agents. Please know that this does not mean we should stop valuing cleanliness or intentionally expose ourselves to illness. Keep reading to understand the practical steps that you can take to apply this knowledge responsibly. 


The Value of Microorganisms 

In the case of allergies, the immune system over-responds to harmless substances like certain foods and environmental substances.  With autoimmunity, the body begins to attack its own cells resulting in diseases such as diabetes, rheumatoid arthritis, psoriasis, multiple sclerosis, lupus, celiac, and Hashimoto disease. 

Some scientists believe that since our bodies evolved with the presence of microorganisms, they are used to processing them. Scientist Graham Rook calls these microorganisms “Old Friends." With lower levels of microorganisms in the body, the immune system does not have enough to do and overreacts. Other scientists believe that these early exposures simply train the immune system not to overreact. Either way, preventing the immune system from responding excessively will lead to better outcomes.



Applying This Knowledge

Though it may seem simple, this is an extremely nuanced topic. It is crucial to use this information properly with guidance from experts. Applying it without a thorough understanding can cause health problems. You should not stop washing your hands or try to introduce a bunch of microbiomes to your system. Doing so can actually increase your likelihood of allergies, autoimmune diseases, and infections.

However, these results should make us question our society’s obsession with sanitation. Do we need to use hand sanitizer multiple times a day or continuously clean surfaces with Lysol wipes? There are a lot of benefits from the hygiene practices we have adopted, but we need to be balanced. 

With the research in mind, consider... 

  • eating a real food diet - Your diet directly impacts the diversity of your gut flora. Focus on eating whole grains, omega 3’s, lots of phytonutrients, and soluble fiber. 
  • getting a dog (not a cat) - Having a dog in your home will expose you to beneficial microorganisms. According to research, cats do not provide this advantage.
  • growing natural plants - Children with natural plants growing around their house were found to have increased microbial diversity on the skin. This is associated with lower atopic skin conditions and asthma
  • using a sponge - Washing dishes with a sponge will introduce you to more microorganisms than a dishwasher would.
  • accepting antibiotics when necessary to kill pathogens - Many people are afraid to take antibiotics, but they are a tool to handle illness when necessary. A good diversity of microorganisms in your environment will help your microbiome recover. 
  • limiting your use of hand sanitizer - We need to sanitize our hands after using the washroom, handling raw meat, or being exposed to pathogens. However, we might not need to use sanitizer multiple times throughout the day.
  • getting rid of the Lysol mindset - For most people, living in a completely sterile environment is not healthy. Clean responsibly, but don’t get carried away.


This topic requires balance, especially in a post-Covid society. We want to take a responsible approach, but maybe that doesn’t mean stressing about sanitation all day.

Dr. Jamie

P.S. If you are interested in understanding the nuance of this theory, check out Dr. Ruscio’s podcast where he interviews Dr. Manoff on the matter (Hygiene, Environment & Autoimmunity with Moises Manoff - Author of Epidemic of Absence)

  1. Bronchial asthma and chronic bronchitis in a Swedish urban and rural population. With special reference to prevalence, respiratory function and socio-medical condition - PubMed (
  2. Serum IgE levels in white and metis communities in Saskatchewan - PubMed (
  3. Trends in prevalence of atopic diseases and allergic sensitization in children in Eastern Germany - PubMed (