With the disintegration of Xitter, I’ve turned my social-media attention to what appears to be far more useful waste of time: Reddit. Reddit is amazing in that there’s a subreddit for every possible topic you can think of. The content is human- and not bot-generated, and the best comments rise to the top – based on reader votes. One of the subreddits that I enjoy following is called Cleaning Tips, which is pretty much exactly as described – people ask for advice on how to clean different objects, and other people comment. Some of the before and after photos are both horrifying and satisfying. One of the major concerns of the community seems to be black mold, something that everyone has likely seen but some people are truly frightened of. I thought it was just odd and didn’t think much about it until one of my regular podcast listens, Unbiased Science dedicated an entire episode to debunking fearmongering about black mold. Listening to it I learned that there’s a growing concern about black mold, fueled by social media. Google searches bear this out. The podcast made me reflect back on earlier in my pharmacy career, when just of school, I learned (acccording to my local pharmacy’s customers) that the root of all illness was just one thing: Candida, a yeast. Is black mold the new Candida?
Old School yeast fears
Concerns about Candida – yeast – seemed common over 20 years ago. Most chronic diseases could be traced back to Candida, patients informed me. And pharmacies did little to dissuade it – some even sold “Candida removal” kits. These didn’t contain antifungal drugs – most were combinations of laxative and purgatives, combined with psyllium and bentonite clay, all promising to sponge up toxins and Candida and restore health. There was a strict diet to be followed, too: No sugar, no bread – anything it was thought the yeast would consume. While you can still find these kits for sale, the enthusiasm for them seems to have waned. Whether consumers have caught on that these kits are useless, or have abandoned them because they don’t actually treat any underlying medical issues, isn’t clear.
New School mold fears
Molds and mold spores are are everywhere – indoors and outdoor. They are carried in the air and on your clothes. When molds encounter excessive moisture, typically in places like bathrooms, they will grow. Many materials inside our home can support mold growth, such as carpets, ceiling tiles, furniture, and drywall.
Moldy environments can cause a variety of health effects, but they are not certain to. Some people are sensitive to molds, and they may describe symptoms like congestion, wheezing and itchy eyes. Those with existing lung diseases, like asthma or chronic obstructive lung disease, may have more severe reactions. For these people, exposure to molds can lead to symptoms such as stuffy nose, wheezing, and red or itchy eyes, or skin. Some occupations may face regular exposure to significant amounts of mold (e.g., farming) and they may also experience more pronounced reactions.
Social media and influences appears to be driving fears about molds. Dave Asprey (the guy who puts butter in his coffee) writes about “mold poisoning” and promotes a long list of supplements to help you “recover” from “mold toxicity”.
Posts on black mold have millions of views on TikTok. Any form of mold, no matter how small, is blamed on any health-related concern. Mold is said to change how you will feel and even how you look. Weight gain is blamed on mold. So is weight loss. Celebrities blame mold for sickening their children. You can even find advice about how to keep mold out of the latest social-media-must-have, the Stanley Quencher.
Understanding molds
Mold is a common term used to describe a visible collection of fungi that develop as multicellular filaments or hyphae, which then come together to form web-like structures. Incredibly, while 100,000 fungi have been identified, the actual diversity of fungi is thought to be at least 7 to 10 times greater. Millions of fungal species have not yet been described and classified.
Fungi in the soil and on plants play crucial roles in breaking down organic matter, making essential nutrients like nitrogen and phosphorus available to other organisms. The survival of many plants relies on mycorrhiza, a symbiotic relationship between a fungus’s mycelium and a plant’s roots, facilitating the supply of water and essential nutrients to the plant.
Yeasts (which are single-celled fungi) and molds are critical to foods like bread and certain cheeses, as well as delicious beverages like beer and wine. They also serve as sources for medications, including antibiotics, immunosuppressants, and the statin drugs.
Both outdoor and indoor environments have microbiomes of molds, with their levels indoors being strongly influenced by their outdoor counterparts. Molds and other fungi are everywhere. They cannot be avoided – they live on our skin and in our mouths – and we are constantly exposed to them.
With molds ubiquitous, our immune system is naturally pretty adept at dealing with them. There are some cases where disease is known to occur. One example would be rare diseases like “farmers’ lung” or “pigeon breeders’ disease”. Infections can also occur in the immunocompromised – think untreated HIV, or patients being treated for some forms of cancer.
Evidence and expert opinion
Exposure to molds and the impact on health and in particular, air quality, have been examined. In 2004 the Institute of Medicine (IOM) found there was sufficient evidence to link indoor exposure to mold with upper respiratory tract (nose and throat) symptoms, cough, and wheezing in otherwise health individuals, with asthma symptoms in people with asthma; and with hypersensitivity pneumonitis (which is a rare immune-mediated condition) in susceptible individuals.
The World Health Organization also has a guideline on indoor air quality. It summarizes the evidence (as of 2009) on problems associated with moisture and exposure to molds. That review concludes that the most common effects are an increase prevalence of respiratory symptoms, allergies and asthma:
Our review of the epidemiological evidence presented in this report, the previous review by the Institute of Medicine and the quantitative meta-analysis of Fisk, Lei-Gomez and Mendell (2007) leads us to conclude that there is sufficient evidence of an association between indoor dampness-related factors and a wide range of respiratory health effects (Table 8), including asthma development, asthma exacerbation, current asthma, respiratory infections, upper respiratory tract symptoms, cough, wheeze and dyspnoea.
The CDC has a page on molds. It says,
Exposure to damp and moldy environments may cause a variety of health effects, or none at all. Some people are sensitive to molds. For these people, exposure to molds can lead to symptoms such as stuffy nose, wheezing, and red or itchy eyes, or skin. Some people, such as those with allergies to molds or with asthma, may have more intense reactions. Severe reactions may occur among workers exposed to large amounts of molds in occupational settings, such as farmers working around moldy hay. Severe reactions may include fever and shortness of breath.
Some molds are “toxigenic”, producing “mycotoxins”. Color is not an indication of how dangerous a mold may be, or if it produces mycotoxins. A review article from 2017, entitled “Mold and Human Health: a Reality Check” published in Clinical Reviews in Allergy and Immunology, provides an overview of concerns about molds and the accumulated evidence. It concludes:
Molds and fungi are ubiquitous and generally live in harmony with human beings. Only rare molds have been associated with human disease. The diseases that molds can cause are restricted to allergies, hypersensitivity pneumonitis and infection. There is no validity to the hype of “toxic black mold” and “mycotoxicosis.” Humans are not exposed to enough mycotoxins to develop illness, unless they ingest toxic quantities of mycotoxins or become exposed to intense organic dust storms.
Are molds the new…Candida? Or gluten?
When I started this post I saw the parallels between fears about black mold and worries about Candida. But there was something in between. Remember several years ago when all sorts of health ills were being blamed on gluten? This wasn’t previously-undiagnosed Celiac disease, or even subtle Irritable Bowel – it was the ascribing of vague health concerns health ills to a bogeyman in our diets. While the craze for gluten-free foods exploded (which was admittedly good for those with Celiac disease), my sense is that most people went back to breads and gave up on cauliflower pizza crust. Today, it looks like mold is that new substance that social media is hypervigilant about.
Like gluten, mold can be be potentially harmful in some circumstances, especially in individuals who may be predisposed. There is no argument from health organizations that mold, when identified in our homes, should be removed. We should look for evidence of mold whenever there is water damage, and clean or remove anything that is moldy. When there is mold growth in our carpets, walls or insulation, the only way to fix it is to remove it. It is also important to regulate moisture and humidity to reduce the likelihood of mold growth. However, it’s worth noting that the CDC does not recommend routine sampling for molds. There’s also no evidence that mold toxins cause diseases in people, so you don’t need to detox after mold exposure – you simply need to reduce your exposure. Unapproved or unvalidated diagnostic studies and treatments based on theoretical infections or suspected toxicity are both useless and potentially costly.
Like much pseudoscience, there is a kernel of truth at the heart of mold fears. Regrettably and also somewhat predictably, mold has become are marketer’s dream and the anxious consumer’s nightmare. I have no doubt that in a few years time, I’ll be describing some new product as “the new black mold”.