Can You Eat Mushrooms If You Have Mould Toxicity? Busting a Common Myth

By Lee Carroll, Medical Herbalist

Introduction

People with mould-related illness are often told to avoid mushrooms. The reasoning seems straightforward: moulds and mushrooms both belong to the fungal kingdom. But biology is rarely that simple. The available scientific evidence does not support avoiding mushrooms, and in some cases suggests they may offer protective benefits instead.

While mushrooms and moulds share a fungal classification, they are biologically and functionally very different. Importantly, research suggests that mushrooms contain compounds that support cellular resilience and antioxidant defences, helping the body better manage the physiological stress associated with mould exposure. This article examines what mould-related illness actually refers to, why individual responses vary, and the biological rationale for including, rather than excluding, mushrooms.

What Is Mould Toxicity?

There is no single, uniform condition that defines what is commonly referred to as “mould toxicity” [1]. Rather, mould exposure can manifest in several ways, depending on factors such as the type of mould involved, the nature of exposure, and individual susceptibility [1]. Some individuals may experience allergy-like symptoms in response to airborne spores [1, 2], while others may be exposed to mycotoxins; toxic secondary metabolites produced by certain moulds [3]. In rare cases, particularly among immunocompromised individuals, mould exposure can lead to fungal lung infections such as aspergillosis [4].

The term “mould toxicity” is often used as an umbrella descriptor for a range of reported symptoms related to respiratory and inflammatory response disorders [5]. While the scientific literature examining chronic mould-related illness in humans remains limited and, at times, contested, it is clear that responses to mould exposure are highly variable and not universally experienced [2].

Why Some People Are More Vulnerable

So why the variability, you ask? Part of it relates to how people are exposed to mould in the first place. Mould spores are commonly inhaled, which means the respiratory system may be the first place irritation or inflammatory stress is noticed. In some people, ongoing exposure and systemic inflammation may also show up at the level of the skin. How strongly someone reacts depends on how well their body manages stress and clears toxic by-products.

Many of these differences relate to how efficiently the liver and kidneys process and clear toxins, as well as how well the body maintains antioxidant defences under stress. Many mycotoxins drain glutathione, a key molecule that helps protect our cells from stress and keeps energy flowing [6]. When glutathione is low, cells are more vulnerable to oxidative damage, which can impair mitochondrial function and contribute to fatigue [7].

Genetics and immune strength also matter here. Variations in enzymes involved in detoxification, such as GST, might affect how efficiently individuals handle mycotoxins, helping to explain why some are more affected by mould exposure than others [8]. And, at its core, mould exposure acts as a cellular stress test, and individuals with weaker antioxidant defences are more likely to experience the physiological strain [7].

Mushrooms ≠ Mould

Some people believe mushrooms should be avoided if you’re dealing with mould issues, and I appreciate the apprehension, since on the surface it may seem like fighting fire with fire (or rather fungi with fungi). The truth, however, is a lot more nuanced. Culinary and medicinal mushrooms are very different from environmental moulds.

Moulds produce toxins such as aflatoxins and ochratoxin A, particularly under favourable environmental conditions such as high humidity, and commonly during contamination of grains and other agricultural products [9].

There’s no scientific evidence that suggests that eating mushrooms worsens mould-related issues. In fact, on the contrary, mushrooms provide nutrients and bioactive compounds that may actually help the body cope with the cellular stress caused by mould exposure, let me explain how.

Ergothioneine – The Forgotten Protector

Cue Ergothioneine (Ergo). Ergo is a remarkable amino acid found in abundance in mushrooms [10]. So, what makes Ergo special? Well, it has a knack for protecting our cells from oxidative stress, especially when glutathione levels are low, supporting cellular energy and overall resilience [10]. So, for those sensitive to mould, Ergo becomes especially significant, stepping in as a secondary line of antioxidant defence.

Research reveals that it gathers in stressed tissues, shielding mitochondria, proteins, and DNA from the ravages of oxidative damage. The body even boosts its Ergo transporter, OCTN1, during times of stress, so vulnerable cells can take up more of this protective compound when they need it most [11]. It’s an elegant example of how the body prioritises cellular protection under stress.

Some scientists even propose that it acts much like a vitamin, playing a vital role in supporting long-term health and resilience [12]. Research on ergothioneine is emerging, and new discoveries are exciting.

Beta-Glucans and Immune Support

Mushrooms are also a rich source of beta-glucans, which are complex polysaccharides that interact with immune receptors such as Dectin-1 and CR3 [13]. These compounds don’t simply boost the immune system; rather, they help modulate it, enhancing defence when needed and dampening inflammation when it is excessive [13].

Beta-glucans also function as fermentable fibres in the gut [13]. When metabolised by beneficial gut bacteria, they promote the production of short-chain fatty acids, such as butyrate, which support gut barrier integrity and immune tolerance. This gut–immune signalling pathway is particularly relevant in the context of mould exposure, where immune activation and inflammatory signalling may be persistently elevated. By supporting both immune regulation and gut barrier function, beta-glucans may help reduce inappropriate or chronic inflammation and restore physiological balance during ongoing mould-related stress.

Yet, the mythology continues

So why do people with mould issues still believe they should avoid mushrooms? Part of it comes down to a simple category error. Mushrooms get lumped in with mould. Add to that a natural desire for simple rules in the face of complex health challenges, and avoiding all fungi starts to feel intuitive.

There’s a lack of public awareness about compounds like ergothioneine and beta-glucans, so many don’t realise that mushrooms can actually play a protective role.

Unfortunately, myths often travel faster than nuanced science.

Final takeaway

So, what’s the verdict? Mushrooms are not the same as mould and don’t contain harmful mould chemicals when grown and stored properly.

In fact, mushrooms contain helpful substances that can protect cells, support the immune system, and support pathways involved in processing and clearing mould-related toxins from the body.

For people sensitive to mould, mushrooms might actually help the body get stronger. So, rather than seeing them as something to avoid, mushrooms can provide an edge for people dealing with mould issues.

References

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