Exposure to Germs Fights Germs
Here's a topic I've touched on before but never actually focused on. Cleanliness may be next to godliness, but it may not necessarily be all that good for your health--despite what you've been told by all the purveyors of antibacterial soaps. A new study has just come out that once again confirms you need regular exposure to dirt and germs to keep your immune system in top shape. We'll explore the larger issues associated with the topic, but let's start by taking a closer look at the new study, which deals with the health effects of thumb-sucking and nail-biting.
Thumb-sucking and Nail-biting
Yes, there are problems associated with thumb-sucking (it can cause a child's teeth to misalign) and nail-biting (it can facilitate the spread of germs), but it turns out there is a huge upside to putting dirty fingers in your mouth. According to a study published in the Pediatrics, those germs on your fingers train and strengthen your immune system, and help condition your body to minimize allergic reactions down the road.1 And that's a key point. The problems may occur in childhood, but the consequences can manifest, not only in childhood, but all the way through adulthood.
Unfortunately, thanks to our obsession with cleanliness, children are losing their exposure to germs in their formative years. And the problems associated with that germophobia are growing. The prevalence of food allergies in children, for example, has increased 60% in the last two decades from about 3.4% in 1997 to about 5.4%, and the occurrence of skin allergies has increased from 7.4% to 11.6%.2 Allergies associated with asthma and hay fever are the sixth leading cause of chronic illness in the United States, and more than 50 million people nationwide suffer from allergies each year, according to the CDC.3 Understanding why so many people have allergic disease, then, is important.
The traditional "hygiene hypothesis" was proposed to explain why children from larger families and those with older siblings are less likely to develop hay fever. It was hypothesized that this could be explained if "allergic diseases were prevented by infection in early childhood transmitted by unhygienic contact with older siblings, or acquired prenatally from a mother infected by contact with her older children." The hypothesis is supported by evidence showing that children who grow up in large families are at greater risk of coming into contact with more infections, promoting T helper (TH)-1 immune responses, whereas children from smaller families are more likely to have TH-2 type responses and a higher risk of developing a hereditary allergy.4 The hygiene hypothesis remains controversial, however, as it, so far, has been unable to fully explain many associations, including the rise of allergies in "unhygienic" inner-city environments, and why probiotics are ineffective at preventing allergic diseases.5
As it turns out, the theory may indeed be valid, but just might need to be tweaked a bit. Which brings us to thumb-sucking and nail-biting.
Thumb-sucking and nail-biting are common oral habits among children. These habits have the potential to increase the exposure to environmental microorganisms independent of any contact with siblings, and, in fact, have been associated with the oral ingestion of various pathogens such as E. coli and intestinal parasite infections.6, 7, 8, 9, 10 According to the study's researchers, it seems likely that thumb-sucking and nail-biting would introduce a wide variety of microbes into the body, thus increasing the diversity of the child's microbiome. If the hygiene hypothesis is correct, it is plausible that thumb-sucking and nail-biting would also influence the risk for allergies. This would bridge the current gap in the hygiene hypothesis. Until now, there has been no evidence as to whether thumb-sucking and nail-biting influence immune function or risk for allergy. The researchers set out to establish that connection.
As it turned out, thirty-one percent of the 1013 children who provided data in the study were frequent thumb-suckers or nail-biters at 1 year old and up. These children had a lower risk of skin allergies at ages 13 and 32 than those who did not thumb-suck or nail-bite. These associations persisted when adjusted for multiple confounding factors. Children who had both habits had only a 31% chance of being allergy sensitive as adults vs 48% for those who had neither habit.
No associations were found for nail-biting, thumb-sucking, and asthma or hay fever at either age. Such an association, if found, would obviously have made the case stronger. But the fact that so many other studies support the same conclusion more than makes up for it. Let's look at some of those studies.
A 2009 study published in the Proceedings of the Royal Society found that children who were exposed to more animal feces and had more cases of diarrhea before age 2 had less incidence of inflammation in their bodies as they grew into adulthood.11 As a result, the researchers surmised that the very development of anti-inflammatory regulatory networks in response to early microbial exposure ends up imbuing the developing anti-pathogenic defenses of the immune system with greater flexibility. And it is this process that explains the children's lower levels of inflammation producing C-reactive protein as they grew into adulthood. This is a big deal as inflammation, of course, has been linked to many chronic adulthood illnesses, such as heart disease, cancer, diabetes, and Alzheimer's.
And just last year in 2015, Pediatrics published a study that found that in families who wash dishes by hand, allergic diseases in children are less common than in children from families who use automatic dishwashers.12 And more astonishingly, they found that children who grew up in homes that used automatic dishwashers had a 400-percent higher incidence of asthma than the children who grew up in homes where the dishes were washed by hand. Vive la germs!
Meanwhile, the medical community has "discovered" over the last several years that gut bacteria play an important role in the development of the immune system, and an imbalance in these organisms can affect health, including an increased risk of allergic diseases.13 A more recent discovery, however, is that microbial colonization of young infants is affected by the delivery mode at birth (vaginal VS Cesarean), and that the consequent alterations of gut microbiota in early life as a result of those modes of birth affects the development of allergic diseases.14 And then there was the study published just a couple of months ago that pretty much put everything in one package by concluding that early-life events, including mode of delivery and type of feeding (breast VS bottle), siblings, and gender, shape the developing gut microbiota.15
The bottom line is that it's important to keep in mind that having a strong immune system isn't just about health and nutrition. It's also about having memory of disease so that your body has a built-in defense. Perhaps Jimi Hendrix was talking about your immune system when he asked, "Are you experienced? Have you ever been experienced?" As a side note, adults, since they've been exposed to more germs during the course of their lives, have more built-in defenses. That is, of course, until you become a senior citizen. The immune systems of seniors do indeed have even more memories, but the increased experience is outweighed by the drop in immune system strength that usually--but not always--comes with age.
So what conclusions and practical steps can we take from this? And the simple answer is that being obsessed with cleanliness plays havoc with our health in multiple ways:
- Exposure to germs trains your immune system and causes it to build defenses in response to that exposure. Germophobes like Howard Hughes16 have it wrong. Avoiding all contact with germs doesn't protect you from illness; it weakens you. Although it may lessen your chances of getting a particular cold or flu, it makes it more likely that when you inevitably come down with those illnesses, they will strike you with far more devastating consequences because your immune system will be totally unprepared.
- There's actually nothing surprising here. The same holds true in the world of plants. If you look at antioxidants, which the plants use to defend themselves against insects and pathogens, you will notice a huge difference between conventional and organic produce. To put it simply, if you're dousing plants with herbicides and pesticides that eliminate all potential threats, then the plants have nothing to defend against since the toxic chemicals do it for them. As a result, they cut back on their own production of antioxidants since they are no longer necessary. It's simple conservation of energy.
- Exposure to beneficial bacteria builds your intestinal and skin flora--your microbiome. These account for 60- 70% of your immune function. In fact, there is an emerging theory that postulates that, at its heart, disease fundamentally is caused by a disruption in the "crosstalk" between the microbes in the human gut and other cells involved in the immune system and metabolic processes.17
- Foods fresh harvested from the ground or stalk as opposed to scrubbed and sterilized for sale in the supermarket are loaded with soil based probiotics that help build immune function. Super clean produce does not provide that benefit.
- Drinking chlorinated water and consuming antibiotics in your food destroys the beneficial bacteria in your gut and weakens your immune system.
- The use of antibacterial soaps destroys the beneficial bacteria on your skin which serve as your first line of defense against pathogens such as flesh eating bacteria. In fact, 33% people have some level of staph colonization on their skin as is,18 but the MRSA bacteria are held in check by the presence of beneficial bacteria, which keep the MRSA from growing into a devastating flesh eating infection. How effective is that protection? Only 1% develop into actual MRSA infections. In other words, your odds of getting a devastating MRSA infection increase the more you use antibacterial soaps. In fact, even the very presence of triclosan increases your risk of infection.19 When you wash, just use regular soap and water.
- Triclosan, the primary agent used in antibacterial soap, presents two problems. First, as stated by Tufts University microbiologist Dr. Stuart Levy, "The vast majority of bacteria are out there serving a purpose for us. Helping our intestinal track mature, helping our immune system mature."20 He went on to say, "Dousing everything we touch with antibacterial soaps and taking antibiotic medications at the first sign of a cold can upset the natural balance of microorganisms in and around us, leaving behind only the ‘superbugs." In other words, the regular use of antibacterial soap on your skin turns the bacteria on your skin into "superbacteria." And second, triclosan is dangerous in and of itself as a hormone disruptor, not to mention the fact that it helps breed superbugs as we've already mentioned.21
The bottom line is being obsessed with cleanliness only makes you more vulnerable to infection. Simple cleanliness with soap and water is more than enough to keep you clean. Avoid using antibacterial soaps, which harm your health and compromise your immune system. And keep that in mind when cleaning and bathing your children. Regular soap and water will do the trick. And don't obsess about a little dirt on their hands. Remember, exposure to a little dirt only makes them stronger.
For a better understanding of how your immune system really works, how to boost it, and how to use natural antipathogens to fight infection, check out:
- Anatomy and Physiology of the Immune System, Part 1
- Anatomy and Physiology of the Immune System, Part 2
- Anatomy and Physiology of the Immune System, Part 3
- Anatomy and Physiology of the Immune System, Part 4
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- 2. K. Jackson, L. Howie, and L. Akinbami. "Trends in Allergic Conditions Among Children: United States, 1997-2011." NCHS Data Brief 121. May 2013. http://www.cdc.gov/nchs/products/databriefs/db121.htm
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- 12. Bill Hesselmar, Anna Hicke-Roberts, Göran Wennergren. "Allergy in Children in Hand Versus Machine Dishwashing." Pediatrics Feb 2015, peds.2014-2968. http://pediatrics.aappublications.org/content/early/2015/02/17/peds.2014-2968.full.pdf+html
- 13. Neu J1, Rushing J. "Cesarean versus vaginal delivery: long-term infant outcomes and the hygiene hypothesis." Clin Perinatol. 2011 Jun;38(2):321-31. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3110651/
- 14. Lee E, Kim BJ, Kang MJ, et al. "Dynamics of Gut Microbiota According to the Delivery Mode in Healthy Korean Infants." Allergy Asthma Immunol Res. 2016 Sep;8(5):471-7. http://e-aair.org/DOIx.php?id=10.4168/aair.2016.8.5.471
- 15. Martin R, Makino H, Cetinyurek Yavuz A, et al. "Early-Life Events, Including Mode of Delivery and Type of Feeding, Siblings and Gender, Shape the Developing Gut Microbiota." PLoS One. 2016 Jun 30;11(6):e0158498. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4928817/
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- 18. "MRSA and the Workplace." CDC NIOSH. Last updated 14 July 2016. http://www.cdc.gov/niosh/topics/mrsa/
- 19. Adnan K. Syeda, Sudeshna Ghoshb, Nancy G. Loveb, Blaise R. Bolesa. "Triclosan Promotes Staphylococcus aureus Nasal Colonization." mBio 8 April 2014 mBio vol. 5 no. 2 e01015-13. http://mbio.asm.org/content/5/2/e01015-13.full
- 20. Antibacterial Cleasers Can Hurt Immune System. ABC News July 17, 2016. (Accessed 29 Jul 2016.) http://abcnews.go.com/Health/story?id=118140&page=1
- 21. Allison E. Aiello, Elaine L. Larson, and Stuart B. Levy. "Consumer Antibacterial Soaps: Effective or Just Risky?" Clin Infect Dis. (2007) 45 (Supplement 2): S137-S147. http://cid.oxfordjournals.org/content/45/Supplement_2/S137.long