Toxic mold is the latest pseudoscience diagnosis
Toxic mold is the latest pseudoscience diagnosis
As usual, celebrity attention and wellness industry disinformation exploit health anxiety
Toxic Mold is all the rage in wellness circles lately. Social media influencers, chiropractors, naturopaths, “functional medicine” practitioners, and even celebrities claim that mold toxicity is causing a myriad of symptoms and is the root cause (yet another wellness buzzword that means nothing) of almost every ailment under the sun.
What’s worse is it is being amplified and legitimized by various online outlets, most recently in an article in Women’s Health insinuating that toxic mold illness is incredibly common and to blame for symptoms from brain fog, anxiety, GI issues, blurred vision, headaches, vertigo, joint pain, and more.
Recently, Dave Asprey - who is not qualified to speak on any science or health related topics - had a double whammy: he spread misinformation about Lyme disease AND toxic mold.
Let’s clear things up: mold toxicity is quite rare, especially associated with molds purportedly in your home.
If you didn’t know, I write a monthly column for Skeptical Inquirer, called Inside Immunity. My piece in May focused on this very topic, but as I’ve gotten more questions from folks who likely haven’t seen it, I wanted to share some key details from the column itself, but also some extra information about molds that didn’t make it into that piece. That being said, I encourage you to read my entire Skeptical Inquirer column.
Molds are everywhere and the vast majority pose no risk to you.
Mold is a catch-all term for fungal species that form visible colonies when they grow in suitable environments. There are over 100,000 different species of fungi that can form molds.
Fungi are a kingdom of organisms that include yeasts, mushrooms, slime molds, and mold. Fungi reproduce and grow by spreading spores, small reproductive structures that spread through the air or in water. These spores can be dormant for extended periods of time, and only germinate and start to grow when they encounter suitable conditions. Individual spores are too small to be seen by the naked eye, but when spores attach to porous organic material, they grow into visible colonies: mold.
Molds have existed far longer than you have.
Molds have been on the planet for millions of years and are found ubiquitously around the world. They particularly love warm and humid environments, so can be found pretty much anywhere those conditions exist in nature. Fungi are decomposers which means they digest organic matter to use for energy but also play critical roles as recyclers, so you’ll find molds in tree debris like dead branches, leaf litter, woodpiles, etc. They don’t discriminate, so if you have organic material in your home and have a warm and humid ecosystem, they can grow there too. Places like a poorly-ventilated basement, bathrooms that accumulate moisture: these are some of the usual suspects.
Residential mold can cause respiratory irritation for certain people when found at high levels.
Molds spread when microscopic spores float in the air and attach to a matrix that facilitates their growth. When they grow into large visible colonies, this means that there is a high density of mold spores on that structure. It also means that more spores may detach and float around in the air, which, for people with risk factors, can cause some respiratory symptoms. This is particularly true of people with asthma or allergies.
Symptoms include watery and itchy eyes, coughing or difficulty breathing, headaches/migraines, sinus issues (including sneezing and congestion), and rashes. Mold allergies are estimated to occur in about 3 percent of the population.
In rare instances, mold allergies may cause hypersensitivity pneumonitis, which can present with shortness of breath, tiredness, and persistent coughing. It is important to note that this typically only occurs in individuals who are severely immunocompromised.
Mold toxicity from inhaling spores does not have evidence to support it.
Respiratory-associated symptoms are very different than the claims circulated by the wellness industry. But yet again, they use a nugget of truth to capitalize on their pseudoscience.
The toxic mold claims relate to the fact that molds can produce chemicals as a way to deter predators. These chemicals, broadly called mycotoxins, can exert effects on some species, humans included.
Proponents of toxic mold illness claim inhaling mycotoxins from molds in your home cause a myriad of symptoms.
The wellness industry uses the word mycotoxin to create fear and attribute nonspecific symptoms to this “extended exposure” to mold in your home. Some practitioners have even fabricated unsupported diagnoses such as Chronic Inflammatory Response Syndrome (CIRS), which they claim is caused by exposure to mold and other biotoxin producers.
Symptoms run the gamut: fatigue, headaches, “brain fog,” insomnia, anxiety, depression, bloating, joint pain, edema, mood swings, weight loss, incontinence, diarrhea, excess thirst, nose bleeds, sweet cravings. People claim that mold exposure can lead to autoimmune disorders, cognitive decline, and endocrine issues.
These symptoms have many potential causes, and there is no evidence that mold is one of them.
But vulnerable people are drawn in by promises of having a culprit for frustrating and persistent symptoms, and like many other pseudoscience diagnoses, mold is an easy target. This has led to the growth and expansion of a lucrative market aimed at people who are struggling with health issues.
Health impacts actually related to mycotoxins are a result of ingestion of these toxins through contaminated food products.
Mycotoxins can pose a health risk to us, but not from household exposure. Rather, if we consume foods that have high levels of mycotoxin-producing mold species. For example, aflatoxins produced by certain Aspergillus species can contaminate improperly stored nuts, seeds, and grains, and consuming those at high levels can cause adverse effects. However, the FDA regulates food products and monitors for these types of contaminations and has set safety thresholds for these chemicals.
The color of a mold doesn’t correspond to potential harms
I often hear that it isn’t mold per se, but it’s the “black mold” that is harmful. Let’s put that to bed, while we are at it.
The color of a mold colony has no direct relationship to whether that species of mold can be potentially harmful. Fungi possess different pigment chemicals, these chemicals help dictate their color. Remember: everything is chemicals! These chemicals contribute to many characteristic colors of molds, but they also serve important biological functions.
Many assist in protection from ultraviolet radiation, metabolism, and yes, protection from predators. That is why some of these chemical compounds can be considered mycotoxins: these fungi are trying to survive and prevent predators from eating them!
For example, Penicillium molds can appear blue, green, and yellow as a result of secondary metabolites produced by the fungi. These include compounds like citrinin, patulin, penicillic acid, viridicatin and viridicatol.
On the black mold side, Aspergillus niger and Stachybotrys chartarum appear black because they produces dihydroxynaphthalene (DHN) melanin. While not the same as human melanin, it serves a similar role in fungi: protecting against UV radiation.
Other factors that impact the color of a mold are age of the mold, what substrate they are growing on, what material they are using as a food source, and the environment they’re growing in. Molds growing in higher levels of sunlight may be photobleached compared to the same species growing in darker conditions.
Tests marketed to diagnose you with mold illness or test the air in your home are unproven and inaccurate.
As is the case with all the pseudoscience medical issues, there’s a lucrative market of tests, both for you and for your home. I discuss those in detail here, but the takeaway is that none of these have evidence to support their use or their accuracy. In fact, there is quite a bit of data to suggest they are completely inaccurate. That’s why none are approved by the FDA for diagnostic purposes.
Air quality tests are not going to tell you anything useful about the levels of mold, whether those molds pose a health risk, and whether you need to be concerned. It is pretty much a guarantee your house has mold in it, because you are tracking in molds from the outdoors anytime you leave your house.
Urine tests for mold are also not accurate. Urine is a waste product, and whether you detect something in that or not doesn’t demonstrate a health implication. But more than that, you eat mold and fungal species all the time, so of course there would be waste products in your urine. Cheese, yogurt, breads, soy sauce, tofu, beer? All of these foods and more contain fungal species.
As usual, the wellness industry profits off pseudoscience.
Of course, if you have large colonies of visible mold in your home, you want to dry it out and get them removed, but they are not causing the illnesses and symptoms celebrities and unqualified influencers claim they do.
But by causing undue health anxiety and manufacturing a condition to pair with a wide array of symptoms, they create a profitable market to sell vulnerable people predatory tests, unproven treatments, and unregulated supplements that don’t have evidence to support them. Unfortunately, this is not a new pattern for them, but merely, recycling the same tactics that are used too often to create fear and erode trust in evidence-based science. Please steer clear of these people and be wary of these types of claims.
Thanks for joining in the fight for science!
Thank you for supporting evidence-based science communication. With outbreaks of preventable diseases, refusal of evidence-based medical interventions, propagation of pseudoscience by prominent public “personalities”, it’s needed now more than ever.
Stay skeptical,
Andrea
“ImmunoLogic” is written by Dr. Andrea Love, PhD - immunologist and microbiologist. She works full-time in life sciences biotech and has had a lifelong passion for closing the science literacy gap and combating pseudoscience and health misinformation as far back as her childhood. This newsletter and her science communication on her social media pages are born from that passion. Feel free to follow on Instagram, Threads, Twitter, and Facebook, or support the newsletter by subscribing below: