Recently I listened to Dr. Josh Axe’s book “Eat Dirt” on Audible. As a side note, if you’re not familiar with Audible it’s something to check out, as I frequently listen to audiobooks while driving, working out, preparing my meals, etc. Anyway, getting back to Dr. Axe’s book, I thought it was very good and is worth reading (or listening to). He talks a lot about leaky gut syndrome, but he also talks about the hygiene hypothesis, and there is some evidence in the research that discusses how this might play a role in the development of autoimmune conditions such as Graves’ Disease and Hashimoto’s Thyroiditis.
Well before Dr. Axe wrote his book, there was an article released by the New England Journal of Medicine entitled “Eat Dirt-The Hygiene Hypothesis and Allergic Diseases” (1) [1]. This article starts out by discussing how there has been an epidemic of both autoimmune and allergic diseases, which is more common in Western, industrialized countries. And the basis behind the hygiene hypothesis is that we’re not being exposed to as many microorganisms (both good and bad), and this essentially weakens or suppresses our immune system. This in turn can make us more susceptible to developing infections, allergies, and autoimmune conditions.
This might seem to be counterintuitive to some people, as many believe that is a good idea to avoid all “bad” microorganisms. After all, this is one of the reasons why there are so many vaccines given during childhood these days, and why many people receive the flu shot on an annual basis. I’m not suggesting that it’s beneficial to get the flu, or serious illnesses such as polio or tetanus. However, we are going to extremes to avoid exposure to all of these microorganisms, and the hygiene hypothesis suggests that there can be negative consequences of taking this approach.
But why are we not being exposed to as many microorganisms? Well, there are a few reasons for this:
1. We spend too much time indoors and not enough time in our environment. This is true with both children and adults. As a child I didn’t have access to all of the electronics that are available these days, and so I frequently went outside to play with my friends. These days many children spend too much time on electronic devices (i.e. computers, video game systems, IPads, etc.), and not enough time exploring the environment. On average, adults are spending more and more time indoors as well. After all, who needs to go out and socialize when you can simply login to Facebook or chat with someone through Skype?
2. We are becoming too sanitary. Widespread access to clean water, soap, and chemicals to aid in cleaning dates back to the end of the 19th century (2) [2], and so this is unlikely to be a big factor in the development of autoimmunity. But one thing that has changed greatly is the use of hand sanitizers. For example, when I was a child there wasn’t the widespread use of hand sanitizers as there is today. And while soap was available, chemicals such as Triclosan weren’t in all of the soaps like they are these days. Not too long ago I wrote a blog post entitled “Hand Sanitizer, Triclosan, and Thyroid Health [3]“. Triclosan is commonly used in soaps and hand sanitizers, and while the post focused on some of the health risks associated with this chemical, perhaps the main concern is that overuse of this will lead to a decreased exposure to microorganisms, which in turn can have a negative effect on our immune system health.
3. The birth process. Most births take place in a hospital setting, and frequently the baby is bathed too soon. Babies are born covered in a white substance called vernix, and this is a protective material that helps to prevent common infections. So while this blog post has focused on how we should be exposed to a greater number of microorganisms, in this situation you want to delay bathing a newborn due to the antimicrobial properties of the vernix (3) [4]. This is why some hospitals enforce “delayed bathing.
The increase in Cesarean deliveries can also play a role in the development of autoimmunity related to the hygiene hypothesis (4) [5]. The reason for this is because being born via a C-section can potentially lead to a change in long term colonization of the developing intestinal tract, which in turn can alter the development of the immune system (4) [5]. Approximately one third of births in the United States are through cesarean delivery. And while some of these are necessary, many others are due to maternal request.
4. Vaccines. I’m not going to go into much detail about the controversy behind vaccines, but many more vaccines are given these days than in the past, which further reduces the chances of children and teenagers getting infections. I realize that some of these infections can be life-threatening, and everything of course comes down to risks vs. benefits. While it’s understandable for parents to be concerned about their children developing certain infections, they also should be concerned about the risks associated with vaccines as well, not only as they relate to the hygiene hypothesis, but also the additives included in them. According to the Center for Disease Control (who is in favor of vaccines), some of the common substances found in vaccines include aluminum, antibiotics, formaldehyde, monosodium glutamine (MSG), and thimerosal (5) [6].
So What Can You Do?
If the hygiene hypothesis is one of the factors responsible for the increase in autoimmunity over the last few decades, then what can be done to help prevent the development of autoimmune conditions? Here are a few suggestions:
Eat some dirt. Okay, so you probably won’t eat dirt, but I definitely would try to spend more time outdoors. This admittedly is something I need to do more of, as without question I spend too much time indoors.
Use more natural soaps and avoid soaps and hand sanitizers with Triclosan. If you frequently use antimicrobial soaps and hand sanitizers then I would encourage you to switch to more natural products. There are plenty of natural options with regards to soaps and hand sanitizers, including essential oils.
Sleep with your pet. If you have a dog or a cat that spends times outside then consider inviting him or her into your bed at night. This is especially true if you don’t spend much time outdoors.
Be cautious about taking antibiotics, and educate yourself about vaccinations. Once again, I’m not going to get into the vaccine controversy, but I will recommend to educate yourself about vaccines, especially if you have young children, or are planning on having children. Even if you are in favor of vaccinations, consider spacing them out.
Read Dr. Axe’s book. I’m not getting anything for promoting Dr. Axe’s book, but I do think it’s worth reading, or listening to on Audible like I did.
In summary, the hygiene hypothesis suggests that autoimmune conditions such as Graves’ Disease and Hashimoto’s Thyroiditis might be more common due to a decreased exposure to microorganisms. Some of the reasons behind this decreased exposure includes not spending as much time outdoors, using too many chemically-laden soaps and hand sanitizers, the birth process, and too many vaccines. So while there are many factors that can lead to the development of an autoimmune condition, with regards to the hygiene hypothesis, some of the things we can do to help prevent the development of autoimmunity include spending more times outdoors, using less soaps and hand sanitizers with Triclosan, sleeping with your pet, and being cautious about taking antibiotics and vaccines.