Is a mycotoxin test worth it? An integrative doctor's view

What are mycotoxins, and what are the symptoms of mould exposure?

When people talk about mould and health, four different things are often mixed together: damp buildings, fungal infection, mycotoxins in food, and chronic illness from mycotoxins in indoor air. And the evidence varies from being established and recognised by official bodies to proposed and yet to be established.^1–7 The following is my attempt to disentangle all of this in an understandable way.

What is a mycotoxin?

Mycotoxins are metabolites produced by fungi and moulds, which can cause or contribute to a number of symptoms and illnesses that humans and animals can suffer from.^{8, 9} We are exposed to mycotoxins through a number of foods we eat, as well as the air we breathe, particularly in water-damaged buildings in our homes, our work, and our schools.^{1, 7, 10, 11}

There are possibly millions of fungal species on Earth, and the large majority live in harmony with humans.¹² We have studied some mycotoxins that can cause, trigger, or contribute to a number of conditions, from allergies and asthma to hypersensitivity reactions and cancer.^{5, 12} We know of over 400 individual mycotoxins, produced by several hundred species of fungi.^{13, 14} One mould species may produce many different mycotoxins, and several species may produce the same mycotoxin.¹⁵ Some of these, such as aflatoxin, ochratoxin, and trichothecenes, have evidence linking them to cancer, kidney disease, and gastrointestinal disease, to name a few.^{4, 5, 16}

Where do they come from?

Mycotoxins can enter our body through what we eat, what we breathe, and what comes into contact with our skin.⁸ Mould can grow in a number of foods, such as nuts, cereal products, and fruit.^{4, 9, 11} When animals eat contaminated food, it can pass to us through eggs, milk, and meat.¹⁶ We can also be exposed to mycotoxins in water-damaged buildings where mould can grow, and we can then breathe in its spores.^{1, 17, 18}

Whilst in many cases we can eliminate them without any health consequences if our body is in balance, in some cases, if we take in too much, these mycotoxins can lead to symptoms in multiple organ systems.^{4, 6, 7, 9}

What can mould cause?

We know in conventional medicine that patients can commonly present with fungal infections of their skin and nails, and we treat them with antifungal agents.^{12, 19} We also know that individuals exposed to mould, including in their occupation, can have a number of patterns, such as farmer’s lung and aspergillosis.^{3, 12, 20} Aspergillus, the fungus behind aspergillosis, is found in crops, soil, food, damp buildings, air conditioning systems and bedding.^{3, 21} Those most at risk typically have a weakened immune system or a condition such as asthma or COPD.³

Whilst the US Institute of Medicine (IOM) and the World Health Organization (WHO) have only found enough evidence for respiratory outcomes,^{1, 2} the biggest question is: does it make sense to limit this to conditions affecting the lungs?

The symptoms

The symptoms you get, of course, depend on various factors, such as which mycotoxin you’re exposed to, how you’re exposed to it, and how much of it you are exposed to. They also depend on your overall health status and immune system.²¹ It potentially makes sense for mould to contribute to issues beyond the airways, and research has examined this. Studies have reported associations between damp or mould-affected housing and cognitive,^{22, 23} musculoskeletal,^{24, 25} mental health^26–28 and skin^{29, 30} problems, and some mycotoxins in contaminated food cause digestive illness.^{31, 32} Whilst certain correlations are interesting, I think translating this to clinical practice means understanding the contributory factors in each case, such as housing conditions, fungal exposure or a particular mycotoxin, other physical illness, financial strain and other factors.^{26, 27} Therefore, these symptoms can overlap with a large number of conditions, from the common cold to anxiety and chronic fatigue syndrome, which is why symptoms alone cannot tell us whether mould is the cause.

These symptoms also overlap with fatigue that rest does not fix, anxiety held in the body, and gut patterns where the environment and the terrain both matter.

How mycotoxins can cause symptoms throughout the body

The proposed mechanism by which these mycotoxins can damage our body is through processes such as oxidative stress, inflammation, mitochondrial dysfunction, and disruption of the immune system.^{14, 33} This means that they affect our health at the level of our cells, impairing our body’s ability to produce energy, as well as the structure and function of various organs and tissues throughout the body. This is the thinking behind why some claim this can lead to what is described as chronic inflammatory response syndrome, or CIRS.³⁴

CIRS and sick building syndrome

CIRS

CIRS, or chronic inflammatory response syndrome, is a term typically used to describe eight or more clusters of symptoms across multiple systems, together with a range of advanced tests, many of which I describe in the following section.³⁴ It was first described by Dr Ritchie Shoemaker in the 1990s, after observing fishermen and other patients developing a cluster of symptoms following exposure to biological toxins, including toxic mould.^{6, 7, 35, 36}

To this day, some argue that CIRS is an underrecognised and underdiagnosed multi-system, multi-symptom illness,³⁴ with further research indicating that it can also be caused by bacteria and various viral infections.^{36, 37}

However, it is not an accepted diagnosis in standard healthcare,^{6, 7} it appears yet to be independently validated,^{6, 7} and it should not be confused with SIRS (systemic inflammatory response syndrome), which is a well-defined concept amongst doctors.³⁸

Whilst this specific condition may be debated by different healthcare practitioners and scientists, mould and fungal growth as a concept is known to play a role in human disease through well-defined mechanisms, from asthma, allergic rhinitis and sinusitis^{1, 2, 39} to fungal skin and nail infections,^{12, 19} and liver cancer from aflatoxin in food.^{5, 32}

Sick building syndrome

Sick building syndrome describes symptoms associated with time spent in a building when a specific illness or cause has not been identified.^{40, 41} Assessment may involve ventilation, pollutants, dampness and other building conditions,⁴⁰ and Dr Shoemaker also described it, focusing on water-damaged buildings, where he proposed that fungi and bacterial antigens affect multiple organ systems and trigger allergic responses in susceptible individuals.^{19, 37, 42}

Increased awareness of these concepts could improve work environments for employers, the living conditions of those with mould in their home, and the environment of those working in schools and offices, as mould can not just produce health issues, but can physically destroy the building material on which it grows, produce offensive odours, and look unsightly.¹⁹

Therefore, the most logical conclusion after this is: what tests are available, and are they worth it?

Mycotoxin testing: urine, blood and environmental tests

There are a number of tests available to measure mycotoxins, such as through your urine, through your blood, and through your environment. The most important next step, if you suspect mould or fungi may be contributing to your issue, is to understand how these tests work and therefore whether they are useful.

Urine mycotoxin testing

The most common commercial panels claim to detect mycotoxins through urine.¹¹ The rationale given by the laboratories is that a lot of mycotoxins are stored in your fat, so the urine shows the toxins and their breakdown products as the body excretes them, including past exposure. However, different mycotoxins appear to behave differently, with some leaving the body within a day or two, whilst others travel bound to proteins in the blood, so urine also can reflect recent exposure.^{7, 42}

These tests are typically offered as commercial panels, for example Great Plains Laboratory MycoTOX and RealTime Labs Mycotoxin, using methods such as advanced mass spectrometry and ELISA. The main question really is: even if this can show you that you’ve been exposed to mycotoxins, we also know that the result can vary based on your diet, your body’s capacity to regulate, and hydration, amongst others.^{7, 42, 43}

Blood tests: antibodies and fungal DNA

In conventional medicine, we use blood tests to help diagnose conditions such as allergic bronchopulmonary aspergillosis and extrinsic allergic alveolitis.^{45, 46} Therefore, an IgG or IgE blood test, which looks for the antibodies produced in an allergic or immune response to mould, does make some potential sense.^{6, 47}

A blood DNA test can detect tiny fragments of fungal DNA shed into the bloodstream. In hospital patients with suspected serious fungal infections, it matched tissue biopsy much of the time.⁴⁸ It is a test for fungal infection, not for mould illness from a damp building.

Other biological tests

Other tests that are sometimes done:

• The visual contrast test, proposed as a screen for the effects of biotoxins on vision.^{10, 48, 49}
• HLA-DR genotyping and methylation markers such as MTHFR, which some practitioners use when discussing the body’s ability to clear toxins.
• Tests used within the Shoemaker protocol, developed largely in his own clinic and partly in patients exposed to a fish toxin (ciguatera):^50–52
  • inflammatory markers such as VEGF, MMP-9, C4a, MSH and TGF-beta;
  • transcriptomic testing, which looks at the genes involved in the inflammatory pathways;
  • nasal swabs.

Environmental testing

There are a number of tests to detect spores and evidence of mycotoxins, both in the air and in dust. There are some home mould kits, for example, where you place a petri dish on a surface where you want to test, remove the top lid and leave it open to the air for one hour. Other companies test dust, such as that found in HVAC systems, carpets, or hard surfaces, using techniques such as Swiffer-style sampling.⁵⁴

There are a number of tools used to score a building, such as the ERMI (Environmental Relative Moldiness Index), which the EPA recommends for research use only,^{54, 55, 69} and the HERTSMI-2, proposed to help judge whether a building is suitable for someone with CIRS.

What Chinese medicine and Ayurveda add: dampness, kapha and ama

Chinese medicine and Ayurveda add another layer of thinking, both in terms of diagnosis and treatment. In both systems, the internal environment can reflect the external one.⁵⁶ Therefore, what we describe as dampness in Chinese medicine is similar to what we describe as excess kapha dosha in Ayurveda. In both, the earth element contributes, and it is more likely to occur in cold, damp weather, such as late winter and early spring.⁵⁶

However, in Chinese medicine and Ayurveda, we don’t just look at whether a person comes in with dampness or excess kapha. We understand and take into account more. For example, in Chinese medicine, external damp can come from the outside and invade the body, resulting in what we call Bi syndrome, a painful obstruction syndrome.⁵⁶ It can also occur internally, when spleen function is weak, which can be caused by a number of issues, such as a poor diet, overconsumption of raw foods, emotional stress, and irregular routines.⁵⁶ This can transform into heat, known as damp heat, and lead to a variety of symptoms.

In Ayurveda, excess kapha dosha can cause an accumulation of toxins, which we describe as ama, and this can impair the metabolic fire, which we describe as agni. This undermines nutrient absorption, leading to further sluggishness and inflammation.⁵⁷ We can then look at things like the pulse, which is typically slippery in Chinese medicine and slow in Ayurveda, and the tongue, which typically has a thick, white coating in both of these syndromes.⁵⁶ Therefore, a combined understanding of what can occur in the human body logically makes more sense.

The main question is: with all of these diagnoses and tests available from a functional medicine, an Ayurvedic and a Chinese medicine perspective, what can be done about it as a result?

Is a mycotoxin test worth it? My verdict

The honest truth is, I don’t really order this test to start with. But I think this information is important for patients to know, regardless, to understand both sides of the argument, because for some patients, this kind of testing can truly help.

What the official bodies say

The American College of Medical Toxicology has emphasised that diet is the most important source of human exposure to mycotoxins, and no FDA-approved or FDA-cleared urine mycotoxin test exists.^{7, 58} ACMT also states that even in mouldy environments, modelled inhalation doses of mycotoxins are generally orders of magnitude lower than demonstrated thresholds for adverse effects, and far below typical dietary exposure.⁷

It is currently argued by some that there is no evidence that the presence of mycotoxins in the urine or any other body tissue identifies disease, and that a positive result just proves that exposure to a mycotoxin-producing source has occurred, which is why some argue there is no need to test at all.^{58, 59} It is also argued that reference ranges vary between labs, results do not always correlate cleanly with symptoms, and there is no single most accurate mycotoxin test, because the different tests measure different things.^{42, 59}

Where I stand

The truth is, it depends on the extent of the mould in the building. To my knowledge, I do question how necessary it is to measure the presence of mycotoxins in the air. How can we be certain that these levels are at the level needed, in the individual at hand, to create or contribute to the symptoms they may be experiencing?¹⁹ Therefore, I can understand the rationale behind the current consensus that biological testing for people who work or live in water-damaged buildings is not recommended.⁵⁸

From my perspective, these tests can show exposure, but what I think is more important is for healthcare professionals ordering such tests to strive to be more aware of the other factors related to them, and for patients to do the same to the best of their ability. For example, in one exploratory study, 93 per cent of patients with a prior chronic fatigue syndrome diagnosis had at least one mycotoxin detected in their urine, compared with previously published healthy controls.⁶⁰ Deoxynivalenol, a mycotoxin linked to cereals, was found in 296 of 300 adult urine samples,⁶¹ and ochratoxin was found in 51 and 35 per cent of children’s and adults’ samples respectively.⁶² And interestingly, studies of the general population have found mycotoxins in the urine of most people tested.^{43, 63}

If you test someone and they are likely to be positive for a toxin every time, the real question is: has the test given you the true cause of the issues you can treat, or what is the likelihood that you may go down a path which may not be optimal for the patient to get better? For example, what would happen if a patient or clinician wrongly believes the patient has mould toxicity, a test confirms it, the employer spends a lot of money to fix the building, and the patient continues to get worse, not better? Such instances could be propagated by commercial incentives, which can make their way into AI searches, social media algorithms, and then public and medical perception.⁶⁴

Therefore, I do think the clinician ordering the test, as well as the critical thinking of the patient, matters more than the test. Important questions before any test include what kinds of foods you eat, what symptoms you have, and whether you spend a lot of time around animals or in damp buildings. And if a test is then decided together, it is important to think about the extent to which it is likely to give you the true cause of the issues you can treat.

Who I would consider it for, and who I wouldn’t

I would consider a test only when it has been decided together, when the result is likely to change what we do next, and when that change has a likelihood of improving the outcome. Testing a building for insurance or legal purposes is a separate question from testing a person.

I would not order it:

• when you can see the mould: the priority is to remove it, or get it professionally removed, before chasing a urine panel;
• before a proper history has been taken;
• as a diagnosis in itself;⁵⁸
• when the result would not change what we do next.

What you can do, with or without a test

Irrespective of whether you do a test or not, there are a number of practical things you can do.

• Fix the moisture first. Fix the source of moisture and remove damaged material.^65–67 Simple things like increasing ventilation by opening windows, and running a dehumidifier, especially if you live near the sea or in very humid conditions.^{67, 68} If you see mould, you don’t need a test to confirm it.⁶⁸ A small area, roughly up to one square metre, can usually be cleaned yourself; anything larger, or damage from sewage or other contaminated water, needs professional help.⁶⁷
• Let the sun and fresh air work for you. Sunlight helps dry and freshen a home, in the same way drying laundry in the sun keeps mould from growing. Air the rooms you live in: dry, sunlit, well-ventilated spaces are hostile to mould, because mould needs moisture to grow.^{67, 68}
• Move and sweat. Regular exercise is a strong way to strengthen your immune system and support elimination through your lungs, lymph and skin.⁷⁰
• Protect sleep and settle the nervous system. Your immune system is much harder to regulate with an irregular sleep routine and stress.⁷¹ In both Ayurveda and Chinese medicine, chronic worry and overthinking weaken digestion,⁵⁶ and worry about toxins in our environment can itself shape how we feel symptoms.⁷² That is easier said than done, and one of the common things I do in clinic is help regulate the nervous system.

Choosing who to see

• Have a proper history taken by a healthcare professional knowledgeable on the topic. Understanding the cause and contributory factors for your issue will always be important.
• Think critically. It is very important for patients to think critically, take charge of their health and become as informed as possible, and to seek healthcare professionals who are at least as informed as they are on the topic at hand. This can prevent unnecessary cost and anxiety following a number of tests and expensive supplement protocols you may never have needed.
• Seek multiple opinions if necessary. Understand the thinking behind the healthcare professional you are going to. If you see a medical doctor, they are more likely to prescribe medications. If you see an acupuncturist, they are more likely to give acupuncture. If you see a herbalist, they are more likely to prescribe herbs. None of this may be inherently wrong, but it is important for you to understand the most likely treatments you will be given, and which align most closely with your current understanding and values.

As for the patient I described at the start, the honest truth is, she never proceeded with treatment, and to the best of my understanding, she is still suffering. Patients like her truly deserve an answer. Not only do I wish that for her, but for all patients in a similar situation. I hope articles like this can help. I wish you all the best.