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How Useful is the VCS test?

In introduction to the VCS test

The Visual Contrast Sensitivity test, hereby referred to as the VCS test, is a 10-minute test that aims to determine how well you can tell between shades of grey. This is different to an ‘eye test’, which tests for visual acuity, and instead is testing a function conducted by the superlateral rim of the optic nerve. This is an area known to be vulnerable to the accumulation of biotoxins, hence the gradual increase in popularity of the VCS test.

I started tentatively using the VCS test in 2016 and, following some very interesting results, I decided that it justified a ‘roll-out’ to recommend it to all clients that I was working with; after all, the test cost £8 and took only a few minutes to complete. From spring 2017, I began asking every incoming individual to take it.

This Survey: Motivation and Methodology

“Do I really need to do anything about this? Can’t we just do everything else and then, you know, come back to this later?”

Those who have read my website and those who have worked with will likely be clear that I like data. I am in my element when I have a large chunk of labwork to investigate; blood test, urine tests, stool tests… these are what has driven my clinical work for many years. Of course, the VCS test does not adhere to any of these categories and naturally threw up more questions. There’s one other big factor to consider here: if we take the results of the VCS test at face value, this means a) identifying the source of biotoxins (eg. mould) and b) taking action. This can be hugely inconvenient or hugely expensive (eg. moving out of a property, should it be rented, or paying out, should it not be).

Given that this was the most left-field of all the testing procedures I had I had a number of questions about the VCS test, as to how reliable it was, how best it predicted outcomes for my clients and the biggest question of all that clients asked me: “I get it… this weird little test has told me there’s an issue… do I really need to do anything about this? Can’t we just do everything else and then, you know, come back to this later?”

These are important questions. So I did the following:

  • I brought out the file for all individuals who took their first VCS test between the end of October 2017 and the end of April 2018. This gave me a total of 27. I selected this range so that we could undertake a ‘where are they now’ comparison based on their progress in exactly 12 months after taking. This avoided unfair comparisons (as, if I had chosen a different date range, we may have inadvertently been comparing people six months into their mould journey against those who have had 12 months). All comparison were made on when that specific individual reached their own 12 month point, rather than a set date, so we were comparing like-for-like.
  • I also noted who had Continued with treatment, versus those than had Withdrawn. The main question I wanted to answer relied upon comparing the results of those that received ‘standard’ nutritional treatment against those that received this same treatment but also attended to any mould issues. It was therefore important to identify those that had not received comparable treatment (eg. those that had withdrawn). I categorized this a binary issue, with those that completed three or more treatments after the test classified as Continued, with those that only completed two or less classified as Withdrawn. Given that mould can wreak havoc upon the metabolism, and that treatment often requires both treatment of the environment and the individual and then further steps to deal with any ‘legacies’ it has left behind, it would be unrealistic to expect a suitable outcome without several follow-ups; for this reason, I felt three sessions represented a ‘minimum’ number to give individuals a chance at getting somewhere.
  • Separated the groups into those that Took Action on my recommendations versus those that Did Not Action. I made this a binary issue, and those that Took Action were those that had a) identified the source of mould exposure and, if this was ongoing, undertook mould remediation then b) used binding agents (eg. 3.75g of Spirulina and 4g of Glucomannan) for 5 months. There were two individuals that had taken partial steps, both of which were included into the Did Not Action group.
  • I then separated the individuals into three groups, based on their feedback. For this, I used the same grouping system as my CFS Survey of 2017. This saw the first group labelled as “No response, or little response”.
  • For additional information, I then looked into my files for all individuals that had every undertaken follow-up lab testing to corroborate the VCS test. Of the 28, seven undertook this screening. Follow-up testing was classified as either the Biotoxin Panel, a combination of six lab markers that I run through The Doctors Laboratory in London, or the Mycotox Profile, which I run through Great Plains Laboratory in Kansas.
  • I then crunched the numbers. The results are below…

Q1. When confronted with the results of the VCS test, how many people take action?

Of the individuals who took action on mould (7), all of them continued with treament. There were no withdrawals.
Of individuals who Did Not Take Action (20), only 7 persisted with a treatment protocol

The figures:

  • Of the 27 individuals I tracked, only 7 (26%) actually applied my recommendations on resolving the mould issues. None of these withdrew from treatment
  • Of the 20 (74%) that did not fully apply my recommendations, 13 soon chose to withdraw from treatment and 7 chose to persist with a treatment program (but not the aspects that addressed mould).

I was very aware that a failed VCS test tended to split the crowd; some were relieved to see that there was a reason for the problems they were facing (and that they had options to deal with it), yet others were dismayed (because the discovery meant that their protocol was not going to be as simple as they had hoped).

I also knew that a lot of individuals could not find the motivation to continue if such issues were flagged; many openly acknowledged that, even though they’d read my CFS Survey and knew that that 67% of incomers were found to have mould issues, they simply didn’t have the capacity to take action and had simply hoped that they were in the 33% who showed no issues. Failing the VCS test was therefore a huge blow to their hopes. Sometimes it purely came down to lack of appetite for the steps I had laid out, other times due to the financial costs of mould remediation (if they owned the home) or the logistical difficulty in moving out (if they rented).

The main headline is, of course, that more than half withdrew from treatment quickly after the failed VCS test. Almost all of these had one or two further sessions, and none reported any improvements in this time. In this light, it’s actually quite understandable that so many withdrew. It seems illogical to continue if a) they are not getting progress and b) I share pessimistic expectations (and I told all that I was not expecting much progress if they have not taken action on mould). It is interesting to compare this to the group that did take action; these all recorded varying responses in the months that followed but all persisted with treatment (no withdrawals).

This gave us three basic groups; those that withdrew from treatment within three sessions, those that undertook a ‘halfway house’ (metabolic support but without mould remediation) and those that went all the way (metabolic support and mould remediation).

Summary: it appears that a Failed VCS Test + Lack of Action = very low chance of improvements and a high chance of losing the faith. Of course, we must also acknowledge the role of the practitioner-client relationship and that, right or wrong, my pessimistic (realistic?) outlook may have actively killed motivation and therefore distorted the results.

However, there were seven individuals who embarked upon a ‘halfway house’ treatment plan versus seven that introduced the full protocol. And this gives us the opportunity to make some like-for-like comparisons in their trajectory…

Q2. Once identified, how important is it to deal with mould issues?

As I touched on above, it was clear that there was an interesting comparison to be made between the progress achieved by two specific groups; namely, those that had pursued treatment for ‘everything but mould issues’ vs those that had followed my recommendations fully. For those that had asked me how necessary it was to deal with mould issues, this was obviously a key question. The answer would lie in their responses.

I separated the two groups into Not Addressing Mould (shown below in orange) and those Fully Actioned (shown below in blue). I then gauged the responses of each individual, and added them into one of three categories based on their response exactly 12 months after taking the VCS test.

  • No response, or little response. We may have seen some positives, but not enough to consider any symptoms ‘gone’ and certainly no meaningful change in wellbeing. This group are listed in red.
  • Moderate response. In this category, we see individuals who have seen their sleep improve, seen their digestive movement change (eg. no longer constipated) or other symptoms disappear… we have seen measurable success in the metrics but they do not feel dramatically changed overall. This group are listed in yellow.
  • Significant response. This relates on to anyone reporting that they ‘feel much better’, ‘totally different’, ‘like myself again’, or similar. This group appear in the third column.
Taking action on mould appears to make a huge difference to outcomes


  • Of those who did not address mould issues, only 1/7 (14%) recorded any measurable progress and NONE recorded significant improvements
  • Of those who took action, 6/7 (84%) made some sort of progress and 3/7 had achieved a dramatic change in their health

Even before auditing the results, I continually make mental notes of the responses I am seeing. So I was already aware of the differences between those that took action on mould (resolving their environment and using binders) compared to those who did not. However, I did not expect the result to be so emphatic.

From a scientific viewpoint, it is important not to consider this a definitive outcome; the sample sizes are small, so we cannot rule out sampling error. Equally, could there be confounding factors, eg. if an individual is willing to sidestep a recommendation that I had made on mould, would they be less likely to comply in my recommendations elsewhere (such as sleeping enough or following my dietary guidelines)? This is a difficult factor to control for.

However, it is relevant that the only individual on the No Action on Mould was one of the few that I had difficulty classifying, as she had moved out of her mouldy home but not yet introduced binders (which help support the removal of accumulated mycotoxins). So there were grounds to place this woman in the other group, something that would separate the two groups even further, although I stuck with the original definition to avoid ‘combing’ the results.

Summary: the information indicates that, while taking action on mould issues does not guarantee a perfect outcome, not taking action appears to severely limit your chances of progress. In other words, resolving this issue is necessary to have a ‘fair chance’ of progressing.

Q4. How does the VCS test compare to the available lab tests for mould issues?

This is a very understandable question. It’s a test that we take at home, a test that takes little time and is not administrated to us by scientists in lab coats. It also feels non-specific and throws up the all-important question, “how can we trust it?”

One of the first steps following a failed VCS test is to undertake an inspection of the client’s local environment. This always means home and often means work. Around 70% of people who fail the VCS test quickly find the source of mould (which is obvious to the naked, untrained eye).

When the presence of mould is so clear, clients very rarely undertake further testing because there is no longer any need. Why spend £227 on a urinary test to see if you’ve been exposed to mould, when you can already see a colony of black mould a metre from your bed? Or if you had just spent a year sneezing in a mouldy flat in East London?

There is more of a conundrum when there is no visual evidence. On these occasions where we cannot immediately corroborate the results of the VCS test, there is obviously a great benefit in running back-up tests. These tests are:

  • An in-sight survey of the home with ERMI air testing, conducting by mould remediation experts (around £750)
  • Mycotox profile, via Biolab (urinary test for mould metabolites, £227). This is a urinary test that screens for exposure to six common types of mould, using 11 metabolites to do so.
  • Biotoxin profile, via TDL, £707. This is a customized panel that replicates 6/7 markers of the standard biotoxin panel studied by Dr Shoemaker (a US doctor who has spent two decades exploring the science of biotoxins in the body).
Powerful correlations between the VCS test and other lab tests


  • Of those who conducted air sampling in their home, 100% (6 out of 6) showed toxic levels of mould spores
  • Of those who submitted urine samples, 100% (5 out of 5) showed raised mould metabolites
  • Of those who took the biotoxin panel, 100% (3 out of 3) showed disturbances consistent with mould exposure

While we should always be aware of problems with small sample size such as 14 people, it was interesting to note that not a single discrepancy was found across any tests. Regardless of the testing method, all tests were in accord with one another.

Summary: based on purely correlation with lab results, I am very confident in the predictive value of the VCS test.

FINAL NOTES: The wording that I have chosen above would imply that the VCS test is only useful for identifying mould issues. This is not entirely true, as any biotoxin exposure would be expected to trigger similar results. This includes certain types of food poisoning and infection from Borrelia bacteria (normally referred to as ‘Lyme Disease’). However, most likely due to the geographical dispersion of my clientele, there have been only two confirmed cases of Borrelia in the last 2 years and none of these were in the individuals included in this survey. For this reason, I determined that it would be more helpful to my clients to keep terminology more simple and refer solely to mould exposure.

A WORD ON THE SCIENCE: This is not a case-controlled cohort study. This is a survey conducted by myself and should not be considered as definitive in any way. There has been no attempt to control for confirmational bias held by the individual running the numbers (me) and the sample size is too small to rule out sampling error. What am I saying here? This is useful information and one that should drive further testing and analysis, while providing support for my prior observations.

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