Published January 25 2016
Everyone is exposed to environmental toxins. But not everyone reacts the same to these chemicals. For example, one person might not experience any overt symptoms when exposed to numerous chemicals, while another person might experience severe symptoms when exposed to smoke, perfumes, fragrances, cleaning products, and other fumes. And some people are sensitive to the ingredients in certain medications, nutritional supplements, and herbs. But why are some people highly sensitive to certain substances? Well, there can be a few reasons, and I will discuss some of the more common ones in this article.
Multiple chemical sensitivity (MCS) is an acquired multi-organ condition, and some of the most common symptoms include muscular weakness and fatigue, memory loss, depression, dizziness, general anxiety, panic disorders and post-traumatic distress, respiratory distress, chronic bronchitis and asthma, ear-nose-throat disturbances, autoimmune disorders, gastrointestinal and genitourinary tract malfunction, and migratory joint pains (1)  (2)  (3) . A population-based survey in 1995 which was administered to 4,046 subjects reported that 253 (6.3%) had been diagnosed with multiple chemical sensitivity, while 643 (15.9%) of the participants said that they were unusually sensitive to everyday chemicals (4) . Another study involving 1,582 people looked to investigate the prevalence of hypersensitivity to common chemicals, and the study found that 12.6% reported being hypersensitive to common chemicals (5) .
The common feature of products that appear to be responsible for these sensitivities is that they have a strong smell and include: solvents, paint, glue, tar, oil, pesticides, perfume, cosmetics and spray products (6) . However, there might be an increased hypersensitivity to heavy metals, including elevated levels of mercury in patients with MCS (7) . In addition, in my experience it’s not uncommon for people with this condition to have an increased sensitivity to certain foods, along with nutritional supplements and herbs. But it does seem to depend on the person, as I have worked with patients who have had sensitivities to perfumes, cleaning products, and other chemicals, but not have a problem when eating most foods, or when taking supplements and herbs. On the other hand, some people with MCS are unable to tolerate many supplements and herbs, and so it does depend on the person.
What Causes Multiple Chemical Sensitivity?
There are numerous factors which can cause someone to be sensitive to many different chemicals. Here are some of the most common ones:
Exposure to a large amount of environmental toxins. One reason someone might have sensitivities to certain chemicals is because they are exposed to an overwhelming amount of them. For example, most people are regularly exposed to arsenic, but if someone happens to be exposed to a lot more arsenic than their body can tolerate then this can result in toxic overload, which might not only cause the person to be sensitive to arsenic, but can also make them sensitive to other environmental toxins as well. Even though I gave arsenic as an example here, this of course can apply to other environmental toxins as well. When dealing with someone who has multiple chemical sensitivities, while exposure to large amounts of toxins can be a factor, this usually isn’t the main reason why someone will develop this condition. And so while you no doubt will want to reduce your exposure to environmental toxins, you definitely want to focus on the other factors I’ll be discussing below.
Poor job of eliminating toxins. While the amount of toxins someone is exposed to can definitely be a factor, if someone does a poor job of excreting toxins then this also can cause problems. So for example, if someone is dealing with constipation, then this will prevent them from eliminating toxins on a frequent basis. And while many people who have multiple chemical sensitivities move their bowels a few times per day, if constipation is an issue then this is usually the first priority. For more information on how to address this problem I would refer to an article I wrote entitled “Chronic Constipation and Natural Treatment Methods “. Since we also release toxins in the urine, keeping well hydrated is something else that is essential.
Having bile metabolism issues can also lead to the accumulation of toxins. When thinking about environmental toxins, many people just think of heavy metals and other chemicals. But it’s important to understand that the body also considers an excess of hormones to be toxic. As a result, if someone is taking large doses of bioidentical hormones, or if they are exposed to high amounts of xenoestrogens, then this can result in bile that is thick and sluggish, which in turn can affect the detoxification process. For more information on how to have healthy bile metabolism I would refer to my blog post entitled “The Importance of Bile In Thyroid Health “.
Nutrient deficiencies. Not surprisingly, having certain nutrient deficiencies can lead to many health issues. But how can being deficient in certain nutrients cause problems with detoxification? Well, certain nutrients are important for both phase one and phase two detoxification. For example, vitamins B2, B3, B6, B12, and folate are all required to support the phase one detoxification pathways. And the amino acids taurine, glycine, glutamine, cysteine, and methionine are all necessary for phase two detoxification. Selenium is an important cofactor for glutathione production, which plays a key role in the detoxification pathways. Magnesium also plays a role in phase 2 detoxification. Being deficient in just one of these nutrients can make it very challenging to eliminate toxins.
Intestinal dysbiosis. Why is a healthy gut necessary for healthy detoxification? Well, there are a few different reasons, but one of the main ones is because certain nutrients are necessary to support proper detoxification, which of course relates to the previous factor I just discussed regarding nutrient deficiencies. This includes amino acids, the B vitamins, and minerals such as zinc, magnesium, selenium, and iron. As I mentioned earlier, some of these nutrients are essential for glutathione formation, which is necessary for the detoxification of chemicals. Many people have an iron deficiency, and iron is required for the formation of all of the CYP450 enzymes, which are responsible for metabolizing approximately 75% of all drugs. And of course having an imbalance of the gut flora can affect the absorption of these nutrients, which in turn will affect both phase 1 and phase 2 detoxification. Having low stomach acid and digestive enzymes can also lead to a deficiency of certain nutrients, which in turn can have a negative effect on detoxification.
Genetic polymorphisms. Certain genetic polymorphisms can affect detoxification. One study found a significantly higher frequency of polymorphisms CYP2C9∗2, CYP2C9∗3, CYP2C19∗2, CYP2D6∗4 and CYP2D6∗41 in patients with environmental sensitivity-related illnesses (8) . Another study investigated the effect of genetic polymorphisms in patients with multiple chemical sensitivity (9) , and found that these patients were more significantly associated with SOD2 polymorphisms. Keep in mind that ethnicity can also play a role, as the first study I included here involved Italian subjects (both male and female), while the second study involved Japanese male workers.
How Does MCS Relate To Thyroid Health?
Although it doesn’t seem as if having a thyroid condition directly leads to multiple chemical sensitivity, it is common to find thyroid hormone imbalances in people with MCS (10)  (11) . And so it does seem that MCS is more likely to be present in those with thyroid hormone imbalances, although there are many people who have a lot of sensitivities who don’t have a thyroid or autoimmune thyroid condition. So this is yet another area where more research is needed.
What Can Be Done To Overcome This Problem?
Reduce your toxic load. Of course you want to do everything you can to minimize your exposure to environmental toxins. This can be accomplished by eating mostly organic foods, as well as by using natural household cleaners, cosmetics, along with body creams and lotions. Although you can’t control the outside environment, there is a lot you can do to improve your home environment, as I discussed in an article entitled “Indoor Air Pollution and Thyroid Health “. You also want to do things to help eliminate toxins from your body. Eating broccoli, kale, cabbage, garlic, and drinking green tea and a small amount of pomegranate juice can all help to support the detoxification pathways. Cilantro and chlorella can help bind to heavy metals, and some supplements that can be beneficial include milk thistle, N-acetylcysteine, alpha lipoic acid, dandelion, and there are other supplements and herbs that can help with detoxification. Infrared sauna therapy and colon hydrotherapy can also aid in the elimination of environmental toxins.
Move your bowels on a daily basis. One can argue that moving one’s bowels is the most important factor, as if you don’t have at least one or two bowel movements per day on a regular basis then this of course will increase your toxic load. Earlier I provided a link to an article I wrote on chronic constipation. This admittedly can be challenging to overcome, and it usually takes some time. And while sometimes just drinking more water or adding more fiber to your diet will correct this problem, many times it isn’t this simple.
Correct any nutrient deficiencies. I mentioned earlier how certain nutrients are necessary for proper detoxification. For example, selenium is a cofactor for glutathione, which is an antioxidant that plays an important role in detoxification. As a result, if someone has a selenium deficiency then they might have problems eliminating toxins. Amino acids are important for phase 2 detoxification, and so if someone isn’t consuming enough protein then this also can affect detoxification. Eating nutrient dense foods is of course important, but if someone has moderate to severe nutrient deficiencies then supplementation is usually required.
Heal the gut. Since certain nutrients are essential to support the detoxification pathways, and because conditions such as intestinal dysbiosis or a leaky gut can affect the absorption of these nutrients, it is important to have a healthy gut for proper digestion and absorption to take place. Some gut healing foods and supplements include fermented vegetables (i.e. sauerkraut), bone broth, cabbage juice, L-glutamine, vitamin A, zinc, and slippery elm. Eating fermented foods and taking a probiotic supplement can help with some cases of intestinal dysbiosis. However, if something is causing gut inflammation, such as a food allergen or an infection, then of course this needs to be removed in order to restore the health of the gut. Some people might also need to take betaine HCL and/or digestive enzymes.
Consider getting genetic testing. Although you can’t change your genes, if you have sensitivities to a lot of chemicals then it still can be beneficial to get some genetic testing done, as this can provide some important clues as to why someone might have a difficult time eliminating toxins. This is especially true for someone who has a lot of chemical sensitivities yet has followed many of the recommendations I have given in this article. Many people are familiar with the 23andme genetic test, which is a low cost solution to getting genetic testing done, although there are other companies which provide this type of testing as well.
In summary, although everyone is exposed to environmental toxins, some people are extremely sensitive to these chemicals. And some people are also sensitive to the ingredients found in certain medications, along with nutritional supplements and herbs. Some of the common causes of chemical sensitivities include exposure to a large amount of chemicals, doing a poor job of eliminating toxins, having nutrient deficiencies, intestinal dysbiosis, or certain genetic polymorphisms. So in order to improve one’s tolerance to chemicals one of course wants to address these problems, as they will want to reduce their toxic load, make sure they are moving their bowels regularly, correct any nutrient deficiencies, have a healthy gut, and be aware of any genetic polymorphisms they may have.