HTMA: The Accuracy/Validity Question
I ended my last post asking if we can trust HTMA for accurate results and what it can show us.
The short answers are “yes” and “quite a lot”.
Keeping in mind that, as with any test, lab results are only as accurate as the practitioner reading them, HTMA is mineral analysis by spectroscopy, which is a very standard laboratory procedure that’s been around for at least 75 years. The technology is used worldwide to assess mineral and metal content in geology, plant, animal, and human tissue. It’s used in situations where a person’s heavy metal exposure need to be evaluated, and it’s a useful tool for looking into one’s mineral balance and oxidative/metabolic state as well. You’ll find that in conventional medicine, acceptance of this test as a valid tool has been slowed by researchers who use it and disagree on how to best use the data.
There’ve been a few studies published that claim HTMA is inaccurate, but by and large they are due to inconsistency in how the hair is prepared for analysis when it is clipped and washed at home and even chemically washed at various labs, which can alter results, and is why practitioners who know their stuff use one of a handful of labs that are consistent and who do not use practices that alter the readings of the hair analysis. The inconsistencies merely point to the variations in preparation that do give inconsistent results, but they do not invalidate the test itself.
There are hundreds of studies that validate HTMA testing as an accurate picture of mineral and metal levels in the body. One of the major scientific reviews was done by the US Environmental Protection Agency, which published a 300-page review on hair analysis in 1979 which reviewed 400 studies – a meta-analysis of pretty much all the studies that had been done up till that time. Hair was declared an appropriate, meaningful tissue representative of soft tissue in general in the body that can be biologically monitored for most of the toxic metals, with the exception of those few that don’t naturally excrete through the hair. There are studies that demonstrate how mineral supplementation affect the minerals excreted in the hair, and studies that conclude that hair concentrations of minerals directly correlated with the extent of each individual’s chronic health complaints. A simple search for ‘hair tissue mineral analysis’ on PubMed pulls up 184 studies that illuminate how HTMA has been used and studied, with titles such as Hair Minerals and Metabolic Health in Belgian Elementary School Girls and Relationships of Hair Mineral Concentrations With Insulin Resistance in Metabolic Syndrome. (The search is simple, but crawling my way out of the rabbit hole once the search results came up proved to be quite difficult.)
In the US, all commercial hair testing labs are licensed and inspected annually by the federal government under the Clinical Laboratory Improvement Amendments Act, better known as the CLEA Act. The labs are given blind samples and they must meet stringent criteria for accuracy, or they are not allowed to operate. Reference ranges have been well established and are used in this inspection and licensing process.
Educated practitioners know that the hair mineral content can be affected by exposure to various chemicals such as certain shampoos, bleaches, or dyes, and to the use of water softeners, for example, and collection strategies include steps to factor this in to get the most accurate result. They also have learned that interpreting what is seen on test results is more complex than noting that a high level in one mineral means an excess; it can mean that the body is losing that mineral into the hair at a rate that is demonstrating a loss in the body, or that there is a large amount of that mineral that is building up, unusable by the body due to its bio-unavailability. Understanding the difference is very important to reading a test properly. Knowing how one mineral is synergistic or antagonistic with another and looking at the ratios with a trained eye and as a whole is the key to successfully interpreting the test results. With HTMA, we get a picture of what’s been going on for the previous 3-4 months, in a small sample of the hair in the inch or inch and a half closest to the scalp. Changes can be monitored and individual diet, lifestyle, and supplement recommendations tweaked with carefully timed retesting as the body begins to balance itself.
I’m beginning to venture into what HTMA can actually show us about our inner workings, but I’ve covered enough for one post talking about the accuracy question. Stay tuned!