Gut, Thyroid and Heavy Metals

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Gut, Thyroid and Heavy Metals

Understanding lab test ranges & when to treat with Dr. Tommy Wood.

Lab test results can seem solid and unquestionable. But what do the lab test ranges of “normal” or “abnormal” really indicate, and where do they come from? Are thyroid lab tests or gut tests indicating abnormal levels always something to be concerned about? Conversely, are all blood lead levels marked “normal” actually out of the danger zone? Dr. Tommy Wood shares his take on when and how to act, along with other health tips for fitness and longevity.

Episode Intro

Dr. Michael Ruscio, DC: Hi everyone and welcome to Dr. Ruscio Radio. This is Dr. Ruscio. Today I’m here with Dr. Tommy Wood, a long-awaited connection. We had a couple of scheduling snafus and boy, it’s been probably two years leading up to this conversation! But Tommy, I’m really happy to have you here. Thanks for being on the show.

Dr. Tommy Wood, BM BCh, PhD: So happy to be here. Thanks for having me. I’m a long-time listener, so it’s really nice to be on the show.

[Continue reading below]

Dr. R’s Fast Facts Summary


  • Not all markers are useful
  • TPO should be examined in relation to other markers
  • It’s ok to act, but not obsess over markers


  • Try to be in bed for at least 8 hrs
  • Eat 1-2 hrs before bed
  • Wear blue blocker glasses or eliminate use of screens before bed
  • Night owls are most likely driven by their environment


  • Athletes tend to have increased ferritin
  • High ferritin could be a slight genetic disturbance


  • Screen for pathogens and potential pathogens
  • Gut markers can help tell the story but treating for specific markers is not recommended
  • You don’t need a lab to tell you to change the diet

In this episode…

Episode Intro … 00:00:40
Interpreting Thyroid Markers … 00:06:09
Adding Patient Context to Thyroid Labs … 00:11:07
Defining Hypothyroidism … 00:21:09
How to Act on Thyroid Labs: Sleep & More … 00:26:47
Ferritin Levels & Health … 00:33:31
What Can You Learn From Gut Labs? … 00:40:13
Examining Ranges for Lead Levels in Blood … 00:47:50
What to Do for Heavy Metal Detox … 00:51:04
Episode Wrap-up … 00:57:58

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Hey guys, this is Dr. Ruscio with a huge favor I’d like to ask you. If you could take literally 15 to 20 seconds and fill out a survey that we’re running to help better understand you, our audience, I would deeply, deeply appreciate it. If you’re on the go and you’re just listening to your podcast player conveniently, the link to the survey is located in the description on your podcast player. It’s also of course located in the transcript associated with this sphere if you’re reading this and if you want to know what the direct link to the survey is, it’s This is super short. Five-ish questions will take you 15 to 20 seconds, but it’s very helpful in allowing me to better understand our audience and better serve you guys. So if you would take just a moment, I promise it is super short, super quick, super easy, but it will be very helpful for me. So if you could do that, I would really appreciate it.

Again, the link is in the podcast description on your players. It’s also embedded on the website with the transcript post, and it’s directly accessible through Okay. Thanks.

DrMR:   And (for our audience) what I’m really excited to get your perspective on, Tommy, is some of the ranges for lab values that you’re coming away with and some of the pearls that you’re extracting in working with the population that you’re working with, which is more—I guess you’d say—athlete-performance and longevity-based.

This is where I think you’ll be able to provide us a nice couple of talking points, in terms of, this is where we can say there’s a disease. And if someone’s trying to perform their best, here’s perhaps where this range for a marker might be ideal.

So I’m excited to offer this for people who are hopefully at a point along their health journey where they’re not feeling sick anymore, and now they’re trying to perform better or have more optimal function. Not in that they’re trying to be able to eat FODMAPs as an example, but that they’re able to run a mile 30 seconds faster than they could a month ago or so. So I’m excited to dig into the other end of the spectrum here.

DrTW:   Yeah, that’s great. And I think it’s important before we start out, just to mention that nothing that we talk about here is really worth getting super focused on. And with the client base that I spent a lot of time working with, that’s often really easy to do, right? You get hyper-focused on specific values or specific targets and try to make them as perfect and optimal as possible.

I think that way lies craziness. So, I think using more accurate ranges when you’re looking at your blood tests has a huge amount of importance, and maybe just allows you to think your way through ideas in a slightly different way. But in reality, all the important things that you talk about—in terms of just general lifestyle and health management—are always going to be the main basis. And then maybe use some of these things to tweak certain aspects. But it’s definitely not ever going to be the end-all and be-all of long-term health.

DrMR:   Yeah. And I’m glad you said that, because what we want to prevent people from doing is just obsessing over a given marker. That can make someone feel stressed and interfere with their health endeavors, probably more than the marker in some cases. So we want to use these things as guideposts but not necessarily end-all be-all.

DrTW:   Absolutely. I completely agree.

DrMR:   Can you tell people briefly about your background before we launch in?

DrTW:   Sure. So I spent most of my life living in the UK. I now live and work in Seattle in the US. I’m a research assistant professor at the University of Washington in the Department of Pediatrics. My day job is mainly researching ways to treat newborn babies with brain injury.

But along the way I trained as a doctor in the UK, worked in central London for a couple of years, then went to Norway, did a PhD. And that entire time (I guess for the last 15 years or so), I’ve been an athlete myself, working, coaching athletes and then increasingly interested in this area of integrative medicine.

How can you treat the whole human and have them live and perform as long and as well as possible? That’s branched out into these various side businesses and areas, and people that I work with to try and help them do that.

DrMR:   And for the audience… Tommy, you’re in tip-top shape, so you are clearly practicing what you preach. I remember when we met at AHS, I was like, “Wow, this guy’s got broad shoulders, big biceps, low body fat,” and you can tell you’re really embodying what you’re doing.

And I think it’s just important to mention that, so people understand that you’re clearly walking the talk. But you’re also pursuing this from an academic perspective. So you really bring that rich involvement of multiple facets of the healthcare sphere into this conversation.

DrTW:   Thanks. I think that’s something that, actually, I’d like to say both of us portray in that arena, even though we work with different people. I think walking the talk is important and it helps to know what works and what doesn’t.

Interpreting Thyroid Markers

DrMR:   Yup, absolutely. So let’s start with thyroid. I know this is something that you’ve wanted to give your take on and talk through the pros and cons of the way functional medicine looks at things, the way that conventional medicine looks at things. So where do you want to start with the conversation? Obviously, there’s so much that we can talk about.

DrTW:   Yeah, I think the conversations that you’ve had about thyroid on your podcast are hugely important, particularly the risks of overtreatment, where people are overanalyzing and maybe worrying too much about certain markers.

Where I come from is trying to take all the markers that I see in front of me. You could say thyroid antibodies—as an example—just tell me something about what’s happening inside the person, rather than something that I’m going to try to treat and actively fix, be that with a sudden intervention or thyroid medication or something like that.

The reason why I think that that is useful is because a lot of these markers are not necessarily particularly useful when you’re trying to compare one person to another. Thyroid antibodies are a great example. There’s the study that I know you’ve talked about a few times, where they looked at thyroid antibodies and risk of later hypothyroidism. Unless your TPO antibodies are over 500, you don’t really have an increased risk of hypothyroidism.

And there’s loads of interesting stuff in this paper for a number of reasons. One thing is that a certain number of antibodies in a certain person doesn’t really correlate with TSH or thyroid level at all, right? So if you’re trying to create this aggregated assessment based on a single number, you’re not really going to get anywhere. One antibody level doesn’t tell you anything about what’s being affected. It doesn’t tell you anything about the thyroid hormone levels. It doesn’t tell you anything about the faithfulness of the signaling once that thyroid hormone hits a receptor.

But you can use some of these things to look over time. And one thing that I’m concerned about when people say, “Oh, you don’t need to worry about risk of hypothyroidism until you get to X level,” is that you can then slowly have these things increasing over time, but you’re letting yourself feel okay about it because you’re not going to worry about it until it hits a certain level.

In my mind, that’s like saying, “I’m not going to worry about my blood sugar until I have type two diabetes.” I know that’s an extreme example, but just seeing how these things change over time in response to various aspects of lifestyle and environment is very important to me. Again, doesn’t mean I’m necessarily going to worry about it, but it gives me something to think about.

The other side of that is that in this particular study—and this is very common throughout the research—they say, “What’s your risk of hypothyroidism?” So they say that you are technically hypothyroid when your TSH hits 4.2. Who made that decision that 4.2 is the level where you suddenly become hypothyroid? Because it doesn’t necessarily correlate with thyroid hormone levels. It doesn’t necessarily correlate with symptoms.

The way that those things are generally established is that they take an average population and the 95th percentile becomes the cutoff. And for TSH that’s somewhere around 4, 4.2, 4.6 depending on the lab. So what you’ve done is you’ve said, “Right, so under that or in that range, 95% of people exist.”

There’s been a lot of discussion in the research, as I’m sure you know, where people say, “Well, above 2.5, maybe those are people with some kind of thyroid disease that just hasn’t been diagnosed yet.” That’s certainly possible. I’m not saying that it’s right or wrong. I’m just saying when there’s so much discussion about it, it’s very difficult for us to say whether we really know what’s going on there.

So if we take a bigger step back, all the normal ranges that we’re using in standard medicine or even in other types of tests—maybe you get a blood metals test from Genova or something like that, or you just get a standard CBC from your doctor, a normal reference range again is very similar—are constructed one of two ways, but it basically are designed so that you capture whatever is seen in 95% of the population.

But if you look at the US population, there was a recent study that came out looking at average Americans from the NHANES data set, more than 80% have one of the symptoms that’s on the way towards metabolic syndrome.

So normal ranges are constructed from datasets of sick people. The average person in the US is prescribed at least one medication, has at least one chronic disease. So when you’re trying to compare yourself to a whole population of people who we know are sick, that makes it very difficult to then figure out whether this is the right thing to do or not.

And then when you boil that down and use those cutoffs in research, I think it gets really muddy in terms of whether you’re actually going to do yourself or your patients a disservice by then just relying on those very rigid cutoff points.

Adding Patient Context to Thyroid Labs

DrMR:   Well, there’s a whole podcast right there! So let’s jump on a few of them. I think you make a lot of very important points. And there’s this balance, which is, we want to be progressive, we want to maybe look at nuanced patterns in someone’s blood work, thyroid panel (in this example), to help indicate where attention may be needed.

DrTW:   Yeah.

DrMR:   Unfortunately, what I think happens more often—and maybe I just end up championing this message because it’s more reactionary to what I think is a lot of overzealousness in the field—is you see (or at least I see) someone who’s on a paleo-type diet, their exercise is dialed in, they’re tracking their sleep to have excellent sleep hygiene. They might even be meditating. They’re taking some supplements, vitamin D, selenium, fish oil, and they’re not in bad shape.

And the overzealous provider tells them, “Well, your TPO antibodies are 225. Now you’ve got to go on the autoimmune paleo diet and we’ve got to make sure you’re taking these other four supplements.” So in that context of an otherwise in fair health person with really good attention paid to their diet and lifestyle, I’m a bit circumspect about going into a lot more aggressive treatment for the antibodies. But that’s one end of the spectrum.

The other end is if, let’s say, someone’s not feeling well, and they have an elevation of their antibodies and other supporting data showing that thyroid function is looking to become suboptimal. Let’s say they have an elevated TPO antibody, combined with a marginal elevation of their TSH.

So let’s say they’re subclinical hypothyroid and they’re 5.1, and they’re a little bit tired. Now we start to see this picture of, “Okay, there are things here that can be remedied, diet, lifestyle, maybe some supplementation.” One of the systems that may be negatively affected by these things that the person is doing incorrectly could be their thyroid. And that person could then be motivated to act by this emerging trend in the system of thyroid that may indicate where their symptoms are coming from.

And that obviously would be happening more in a population that’s not quite so robustly health enthusiasts. But that’s how I look at this. The context is really important in terms of the individual. Are they already doing a bunch of stuff to improve their health? If they are, how much more can we optimize a given marker? I’m not sure!

And I question, if we try to go too far toward a “perfect lab finding,” at what point do we cross over to that law of diminishing returns, where now we act more robustly, yet the person doesn’t feel any better? The study published by Robert Abbott—where he took patients who are already mostly gluten-free and then put them on the autoimmune paleo diet—saw no changes in their TPO antibodies. They did feel better, and this likely was because they also had community support, but the antibodies didn’t improve anymore.

So there’s that balance between knowing when the person has some low-ish hanging fruit that could be improved in order to help them feel better. And then knowing when, “Gosh, this guy is already doing a whole heck of a lot.”

Let’s say this guy is starting a business, he’s in a family with two young kids, he’s got a lot going on, he’s exercising, he’s eating paleo, he’s getting time in nature, he’s a little bit tired, and his TPO antibodies are marginally elevated. Are we best serving him by maybe recommending that he goes on the autoimmune paleo diet and incur maybe more stress from a dietary perspective than he can handle? Or do we say, “Hey, let’s watch this, and if this trend continues then we can act.”

So that’s some of the nuance. But what are your thoughts there, Tommy? You’re seeing a different population. So I’m wondering, are you seeing a lot of benefit for someone who’s doing a lot well and then, using the example of maybe going from paleo to AIP, is that something that is very beneficial? Are you finding this plays out differently in terms of when you make a recommendation for what type of person?

DrTW:   So I think you and I are in complete agreement. From my perspective, when people are using published research—and this maybe is something we can get into later—to make “evidence-based recommendations,” the problem is that the people doing the research probably don’t know very much about statistical analysis. And I see that very frequently. And then the people who are interpreting that research also don’t know whether the analysis was done correctly or not.

And when you then try to use that to say whether something should or shouldn’t be done, I get very wary. So it’s really important for me to try to share with people how much they should really look into the actual studies that are being done, and that they’re then using to make recommendations one way or another.

The context of the person in front of you is, of course, absolutely paramount. Again, this is one of those things where you could do or not do a thing based on a study and you think it’s evidence-based, but actually, you’re doing that but you’re switching off your gray matter and not actually applying it to the person in front of you.

So that’s where I worry that a specific study or not, using a specific cutoff or not, then stops you really doing the basic work of any integrative medical practitioner. It really should start with a history and seeing how your patient functions and feels. And when it comes to say, transitioning from paleo to AIP, it is something that we do in certain people and it’s almost always based on symptomatology.

So I would never do that in response to a given, say, isolated raised antibodies in the blood. I don’t work at Nourish Balance Thrive anymore, but when I was working there, there was a lot that we built, interpreting or building machine learning predictions based purely on people’s symptoms. There’s a huge amount that you can learn just on somebody’s symptoms.

So really being guided by how that person feels and performs is where I think most of the benefit is going to come from, rather than focusing on simple lab values. But I just worry about going the other way, which is that we defer to the evidence, and actually the way that the evidence is built is on shaky ground because the people who did it didn’t analyze it properly, and the people who are interpreting it don’t know how to interpret it properly.

DrMR:   I agree. I think the evidence there—especially with the thyroid antibodies predicting someone’s risk of hypothyroid—is certainly in its nascency. So we don’t have the volume of data to be able to say that the 500 cutoff is highly definitive.

But again, if we come back to our agreed context, the provider will be looking at a number of things in conjunction and decide, “Okay, does this person need to do more or take more supplementation?” or “Is this something that we can just wait and see?” or is it maybe something where, “Okay, this is a somewhat anomalous or non-meaningful finding in an individual”?

I think we’re on the same page there. But no matter what perspective you’re coming from—trying to warn against overzealousness in functional medicine, or also trying to warn that we don’t look at labs too literally and maybe not act when we should act on an early warning sign—if we juxtapose either position on the spectrum with looking at the context of the person, that should help us from making an error. And I think we’re in agreement on that, right?

DrTW:   Yeah, absolutely.

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Defining Hypothyroidism

Okay. The other thing that we should talk about is defining hypothyroid. Obviously this is something that there’s debate about. This is in alternative medicine. Conventional medicine is also going through this debate.

I think to best understand how we can define hypothyroidism (as would be defined, meaning that one would need to start on thyroid medication), looking at the debate regarding subclinical hypothyroid really helps. Just for the audience, true hypothyroidism is high TSH plus low T4. Subclinical hypothyroid is when you only have high TSH. So this is this gray area finding, where there’s quite a bit of controversy over, “Do these patients need treatment? Do they not need treatment?” I think the more conventional medicine research community has filled in a lot of the grays here.

Tommy, I’m definitely curious to get your thoughts—where you agree, where you disagree, where you’d modify—where there does seem to be a cut off value for TSH. When the TSH becomes high enough, then that person has a higher probability of benefiting from thyroid medication. And if the TSH is not high enough, the probability that they could benefit from thyroid medication diminishes.

And this should be mentioned in the context and the backdrop of (depending on what research study you read) roughly half of the cases of subclinical hypothyroidism will spontaneously revert back to total normalcy. So the question then is when do we act? And it seems that, generally speaking, when TSH is above 10 (although some recommend a little bit higher than 10), that may indicate someone will benefit from thyroid hormone replacement.

Also, the older someone is, the less important elevation is. So in those who are over 65, that elevation of 10, 11, 12 may not be cause for alarm or cause for action. If someone is 25, 35, and they’re at nine, that might be a call for action. So the older you get, the more TSH tends to creep up.

Then in certain populations, clearly in women who have had a history of infertility or are pregnant, this subclinical hypothyroidism should be treated.

But there have been many other studies looking at, will treatment of subclinical hypothyroid and people who aren’t above 10, lead to improved cardiovascular outcomes, improve fatigue, other improvements in thyroid-related symptoms? And that seems to be really a no. Those patients don’t seem to respond. It’s not to say that we wouldn’t want to look at that TSH in conjunction with a bunch of other markers, like their thyroid antibodies, and decide if they need to clean up their diet and their lifestyle.

That, fully agreed. We should always be looking to that, right? Where can we find a pattern to help motivate someone to improve their diet and their lifestyle, and maybe use some choice supplementation? I guess the thing that I’m more concerned about is a lot of people in natural medicine who are saying, “Well, your TSH is 7.2, let’s put you on levothyroxine.” And then there’s never a follow-up.

That person ends up in my office four years later, only to have the conversation and check their initial lab work and they were never really hypothyroid to begin with. And they’ve been on medication for a while and they didn’t realize that that medication wasn’t even really treating the underlying cause of the symptoms. You get this whole mess, where now someone’s angry that it wasn’t explained that they weren’t truly hypothyroid. And here they are.

But what there, Tommy, do you agree with, what would you modify?

DrTW:   So, I’d agree with everything you say, in terms of when and where subclinical hypothyroidism should be treated.

I think the most important thing that comes out of that—and again, this is where antibodies can potentially be useful regardless of where they are in a range—is that when you see they’re elevated or they’re moving in a certain direction, looking at those things over time, I think, is potentially beneficial (and the levels change from day to day, within a day, so just testing and retesting, there’s always going to be some error, in terms of whether they go up or down). It tells you that there’s some underlying process that maybe yet hasn’t been addressed, as much as it could have been.

And this is classic from Rob Abbott’s paper. He knows, I was actually one of the peer reviewers when this was published. I was one of the people who reviewed it in the publication process.

DrMR:   Oh, nice.

DrTW:   And actually, I think NBT probably ended up giving like 10 or 20% of the funding for the study because we really wanted it to happen. So I’m really glad to see that it came out great in the end.

But you can see that even though antibodies didn’t change, symptoms improved dramatically. And you see that, again, on the other side, which is that when people have elevated antibodies, they are at greater risk of depression or they’re at greater risk of having lower quality of life scores. So when this thing is happening, it’s telling me that there’s still some underlying process that hasn’t been addressed yet.

So it’s not that I want to do something because TSH is elevated or because the antibodies are elevated specifically, but because it tells me that something that hasn’t been addressed yet. So I think you can still bring these in, and maybe sometimes be conservative in terms of when it is that you might think about doing something. But for me, that’s almost never recommending treatment. It’s usually in the lifestyle, environment, diet kind of realm.

How to Act on Thyroid Labs: Sleep & More

DrMR:   So let’s go through a couple of examples, because I think patients and providers alike would be curious, how do you navigate. Okay, let’s say you have a couple of different scenario patients come to see you, all with a similar lab finding.

How do you navigate when to act? And then when, conversely, to perhaps recommend, “Okay, this finding combined with everything else tells me that the thyroid is not the cause of the problem. You’ve done enough and you don’t have to worry about this”? I think that’s a key distinction that needs to be made, which is, when is this something where, “Okay, I need to perk up in my chair and listen and act,” and when is this something not to worry about?

DrTW:   So…

DrMR:   Not the easiest question.

DrTW:   No, it’s really difficult. And it’s also very dependent on the person. Often people come, and like you say, they’ve already been started on a certain medication. Then one of the hardest things for any clinician to do is to mess with somebody else’s prescription, right?

People feel really uncomfortable with doing that. And it’s something that we need to do, but it’s sort of wired into us that it’s difficult to do that. Usually, the more somebody has done in a given area already, the less worried I am about that specific area.

And what I see, talking in generalities, is that if we think about the four or five things that seem to be really crucial to long-term health—movement, sleep and circadian rhythm, diet, the absence or the presence of the correct nutrients or environmental toxins, and some kind of distress tolerance or stress modification, whatever you want to call it—when people ignore one or more of those areas, they usually have to pull one of the other levers even harder to see benefit, right? So if the diet has been the area that’s gotten a huge amount of attention from this person, then it’s time to step back and look at where there might be other areas that are worth working on.

And, upfront, is that the most scientific way to do it? Is there a marker that tells me that I should be shifting focus? No, there isn’t. It just comes from the knowledge of the person in front of you. And in general, for NBT and some of the other clients that I work with, gut issues is absolutely where the problem comes from.

Like you’ve said multiple times, if you just improve the function of the gut, you’re less likely to need some thyroid medication. Or you’re able to reduce your doses because you’re improving conversion, improving uptake, improving response or signaling fidelity. So that’s often an area. But very frequently, people have done literally everything for their gut or tried everything, and haven’t made any headway. And that’s usually, or often, because there’s some area of their diet or lifestyle that they haven’t taken the time to look into, or just the act of being hyper-focused on one area has caused stress that’s then causing those downstream effects.

DrMR:   Right. And that’s one of the key things that I’m always trying to warn people against. There’s an old saying, “Don’t make yourself miserable in attempts to be healthy.”

That’s why I’m always trying to help strike this balance. Are there some other areas that you find commonly imbalanced? I’m assuming sleep is a big one. But what are the areas that you find people are prone to neglect more?

DrTW:   Sleep is a huge one. And the timing of food around sleep makes a big difference. And sort of extending that fasting period before sleep, and making sure that you’re getting to sleep at a decent time, those can just make huge differences to people.

DrMR:   Can you give us specifics for both of those? Like, what’s your fasted window pre-bed, and what do you think the latest someone should be going to bed is?

DrTW:   Yeah, absolutely. So there are some data on differing chronotypes, evening versus morning, verses when people are more likely to get good quality sleep, and wake up and feel that they’re functioning ultimately.

There’s always going to be some preference in there. If you take out all the modern environment, all the modern light, those do tend to come closer together. So people who think they’re night owls, probably some major proportion, 70, 80% is due to the environment.

DrMR:   Interesting.

DrTW:   And then the rest is due to some slight difference there in terms of natural chronotype. But it’s something simple. I often recommend people start winding down for bed, at least, by 9:00 PM.

But in reality, you just want to be in bed for at least eight hours. So knowing when you’re going to wake up, then making sure that you’re in bed for at least that eight-hour period, and then maybe making sure that you’re not exposed to any bright blue light. Or wear blue-light-blocking glasses, f.lux, all that stuff, for one to two hours before then, and then maybe an hour or two before that you have your last meal.

So basically the easiest way to do it is work backwards from when you know you’re going to wake up, and then that gives you the best buffer over all that time period.

DrMR:   That makes sense. Okay. That’s interesting what you say about the night owl, because I used to be more of a self-proclaimed night owl. And it’s funny, I just connected this dot as you were saying that, but over the past several years, as my sleep hygiene has gotten better, I’ve found myself becoming, and have become, much less of a night owl.

But I think one of the things I would love to do is—and it’s so obvious now—I’d go to a coffee shop at night, have a little bit of espresso… and with all the lights and my blue screen on my computer, I’d think I was a night owl, but I was just getting so much stimulation then.

And when I finally really was using the blue light blocking, and using either candlelight or more often just a soft yellow light bulb that had minimal blue light, I noticed I would get tired earlier. So I think that’s really interesting what you say, that there could be this bias, where for night owls, it’s their lifestyle driving that predilection, rather than that being more genetic or what have you.

DrTW:   Yeah, so, my friend, Dr. Greg Potter did his PhD in circadian rhythms. And I’ve sort of hypothesized with him—I didn’t think he thought I was entirely wrong—that people who are night owls are for some reason more affected by the modern light environment. So they’re more likely to be shifted in terms of the circadian rhythm by all the modern blue lights and things that we are exposed to.

So that might be the interaction between the modern light and any genetic susceptibility they have to a shift in the circadian rhythm.

Ferritin Levels & Health

Gut, Thyroid and Heavy Metals - 240F241528843ONTuMk8ZqUbjiv6v8cLTd2JjHgzisQl7DrMR:   So shifting gears for a minute, I want to get your take on ferritin quickly. I think we’re seeing differences, especially now that I’m looking and I’m flagging in my mind, if ferritin below 100 as something to consider. And just really quick for the audience to get you up to speed, ferritin is a marker of iron status. Soppi, a researcher in Finland, published one really fascinating study. He found that for hypothyroid women on medication and not feeling well, who had ferritin below 100 and were then supplemented to above 100, 70% of them saw a resolution of their fatigue and other thyroid-related complaints.

And there is this physiological mechanism that may tie this together. We know that (depending on the study) 30-ish percent of hypothyroid women will have autoimmunity to the parietal cells in the stomach that make hydrochloric acid. So there might be this overlap, thyroid autoimmunity to stomach autoimmunity. And that stomach autoimmunity affects the absorption of iron through diminishing the output of hydrochloric acid. So some of these pieces here fit. Now that I’ve been looking for it, I do see quite a number of women who have ferritins below 100.

But I haven’t connected yet, from my own personal clinical experience, how many of them seem to respond dramatically. It’s too early to tell. But it seems like, Tommy, you’re seeing more people on the other end of the spectrum. So just curious what your general take on iron and ferritin is.

DrTW:   That’s a really good question. So, Chris Kelly and I started looking at iron overload in athletes, maybe three or four years ago now. Then it seemed to be everywhere. And obviously it’s worth bearing in mind that ferritin is also an acute phase protein. So it’s increased in people in during the inflammatory response. That can make things a little trickier to look at.

But people tending towards iron overload certainly seems more frequent, so higher ferritins than you might like. And there are multiple reasons for this. It could be the fact that they have a slight genetic disturbance that increases iron absorption. So, the HFE gene. There’s the H63D SNP which slightly increases iron overload. There’s the C282Y, which if you have two of those, you’re more likely to get true hemochromatosis, which is basically like, iron in all of your organs and massive organ dysfunction at its worst.

Gut, Thyroid and Heavy Metals - 240F18654162549LM3W5rGdrkrZJTPxPVLa8ih9u6D808And actually those also predispose you to being better athletes on average. You have more iron, you make more red blood cells. And hemoglobin is one of the best predictors, particularly, of endurance performance. So that may be why in the athletic population we see more of that, because successful athletes just have that tendency.

We have recently increased where we might start to think about worrying about ferritin. So previously, we targeted under 100 or under 150 for men or under 70 for women. Those were the targets that people were using in the integrative medicine space. But when you really look at the data—so if you look at what ferritin people have and then their long-term health outcomes—you don’t really see any detrimental effects until maybe a ferritin over 200 in men, 115 in women. And you obviously run risks of making people iron deficient if you go too far in the other direction.

When you talk about supplementing iron, bringing up ferritin and women who are hypothyroid, I also think about the risk of pernicious anemia. Obviously all these autoimmune disorders are going to come together. So then they’re also potentially at risk of a B12 deficiency.

I think one of the nicest and easiest ways to sort this stuff out, and where I would always start, is just look at CBC with differential. Look at your RDW red cell distribution. If that is elevated in any way and you compare that with the size of the red blood cells, that can give you a huge amount of information in terms of nutritional status, other things that people need to worry about. And obviously, thyroid. If you’re hypothyroid, that changes the way your red blood cells look, because it’s important in terms of making red blood cells.

So there’s a huge amount that you can get just from those really, really simple and cheap markers. That’s always where I’d start for almost any kind of nutritional intervention, or anything that I think is going to affect inflammation, immunity. Looking at a CBC with differential. There’s a huge amount of information you can get out of that.

Gut, Thyroid and Heavy Metals - 240F282275908xvDhTZcGjDqF2XWmoakpb7bJLCh3vmZjDrMR:   Yup, agreed. And there have been some cases where the ferritin was quite high. Then as one of the first things you do, more for the clinicians here, do you cross-reference that with, do they flag for the diagnostic criteria for hemochromatosis?

DrTW:   Yeah.

DrMR:   And some cases they will not fully fit the profile when you do a followup genetic profile. We’ll have some of the genes but not really all the genes to be diagnostic. So one of the things Dr. Abbott had mentioned recently in a conversation was perhaps there’s subclinical hemochromatosis, which certainly there may be.

That’s one way you can try to distinguish, is the ferritin elevated somewhat in isolation (meaning it’s an acute phase reactant as part of the inflammatory process), or could this be genetic over-absorption, so to speak, of iron? So yeah, we want to strike a fine balance with ferritin. We don’t want to go too high with ferritin, we also don’t want to go too low.

Do you find that athletes are more prone to supplement with iron, or just take more vitamins in general? And do you suspect maybe part of this is just due to pill popping?

DrTW:   I don’t think that’s the case. I mean, depending on what seems to be required, we’ll often recommend a multivitamin in athletes of certain types. And I don’t think it’s too much, that they’ve added a huge amount of iron into their diet. Historically, there was this recommendation, “Oh, you know, you’re tired, take this iron supplement.” And obviously that’s just nonsense, right?

But that’s kind of where people are in the vitamin and supplementation space. In reality, your body is very good at regulating iron stores unless there’s something else going on, be it a genetic preponderance or some significant change or ability in terms of how you absorb it.

So I think it’s less likely that people are just taking a load of iron. I think it’s more to do with changes in handling or genetic predisposition to how people handle iron.

What Can You Learn from Gut Labs?

Gut, Thyroid and Heavy Metals - 240F242108182EjirCBD4Zv6uMkz7lcdyL69FroxyFmoKDrMR:   Right. What about gut? I’d be remiss if I didn’t get your thoughts on anything in gut that you wanted to expand upon. Maybe something that you’re finding to be more common or more impactful out of the various things that you assess and work with?

DrTW:   Yes, I’ve been back and forth so many times, in terms of what we can glean from assessing the gut microbiota. There was this time when I was super excited about it. There’s all this stuff that you could get by just looking at as much as you get from the different genus and species levels, maybe down to the strain. Some tests claim to do that.

And the more time I spent looking at that, the more it felt like tasseography, which is reading the tea leaves. Just trying to extract some useful information out of something that we just don’t know enough about. I say the same thing with us working with genetics and doing things based on genetics.

So what has been impactful is making sure that there are no pathogens lurking. And that might be E. coli. We see a lot of H. Pylori, Blastocystis hominis, whether or not in a certain person it correlates with symptoms is sometimes tricky, whether it’s worth treating. But making sure there’s not something that you can actually actively target, that you know is a pathogen, I think that’s really important and I’ve seen a lot of benefit there.

But then when you try uBiome and alpha diversity and all that kind of stuff, I’ve yet to be convinced that that’s really useful at all.

So there’s definitely a lot that you can do. And a lot of it can be empirical. It could be benefits that you get just by changing diet, just by empirically trying probiotics, antimicrobial herbs, or antibiotics if needed. But equally, you can try to dig down a little bit and see what’s in there. But trying to go any further than that, I think, again, that way lies crazy town.

DrMR:   Well, it’s nice to hear you say that, because I feel like five years ago I was the one perceived nut saying, “We can’t really look at these tests and glean that much!” I felt like I was the only person saying that. And understandably so, there was a lot of information there. I happened to be writing a book on this at the same time. So I had the luxury of spending three to five hours a day just sifting through this.

And like you said, the longer you look at the data, the more you come away with, “Well, there are just so many inconsistencies here that it’s hard to really make a strong recommendation about this one way or the other.” In fact, I was just writing up a study for our clinicians newsletter where they found that patients who had dysbiosis—as they defined it via a duodenal aspirate—actually had lower levels of Prevotella.

Low FODMAPAnd Prevotella, many have claimed, is a bad player and you shouldn’t see much Prevotella in the gut. I talked about this in Healthy Gut, Healthy You. Prevotella, if you look at all the data, can really go one way or the other depending on the context of the gut. But your self-proclaimed online gut guru will tell you that Prevotella is always bad… and yet, in this finding, the patients who had dysbiosis had less of the bad player.

Just another data point showing that we really don’t have all this sorted out yet, because it is just so complicated. But I totally agree with you, looking for pathogens and potential pathogens is probably the best way to go. And much beyond that, although it’s interesting, we can’t really do much with it.

I think you also alluded to something very important, which is the confirmation bias/placebo effect that can occur here. Which is, someone comes into a doctor’s office, they’re not eating very well, they do a stool test, they have low diversity. So they say, “Well, you need more fruits and vegetables in your diet.”

And they come back and they go, “Oh my God, I feel so much better.”

The clinician says, “Yes, I knew this new gut test they gave me, the microbiota mapping, was going to be the new craze and the new big thing!”

I think we see a lot of that, where we think the labs are guiding the recommendation. In some cases, it’s actually helpful. So then we proclaim it’s because of the labs. But you can have someone change their diet in any direction and you don’t really need a lab to tell you that.

DrTW:   Yeah, I go back and forth and whether this is sort of ethical or not, but a lot of people will respond to a lab test, where you say, “Well, because of this lab test, you have to do this thing.” And then that means they finally do the thing that you want them to do before that they didn’t do, and they get the benefit out of it. But the test didn’t necessarily give you that answer.

DrMR:   Yeah, I would be open to selectively doing that perhaps. Especially if you had a cheap test. Maybe the best way to do that would be to run the pathogen test. And then oftentimes, with the pathogen tests, there’s a few of these things tacked on anyway. If you’re going to point to some of these gray area findings, you could easily find something on almost any GI panel that would be a potential problem that you could twist to motivate someone.

That I’m more on board with, rather than… some of my poor patients come in and they’ve done one of the microbiome mapping tests. And some of these are getting expensive now, where they’re close to a thousand dollars. And it’s just like, “Boy, we could have done to two to three…”

Gut, Thyroid and Heavy Metals - 240F122026635SSFpzom2TiM6CUrNuSOkFZeAHOdeYz5qDrTW:   The Prevotella thing, going back to that, is super interesting in the athlete population. I’m thinking about one study—Lauren Petersen was the first author—where they looked at elite and professional cyclists. And basically, as you go up the cyclist categories, in terms of how good you are as a cyclist, the more Prevotella you have in your gut.

So it seems to be definitely a beneficial adaptation to exercise. Whereas the other side, people would say that elevated Prevotella causes rheumatoid arthritis or whatever.

And within the same paper they showed that particularly elite level professional cyclists had a dramatic elevation in Methanobrevibacter smithii. Which we would think: methane-dominant SIBO and constipation. The theory there is that that particular archaebacteria helps slow down gut transition time, which helps you absorb nutrients while you’re on the bike a bit, and then may also manipulate carbohydrate metabolism.

So it’s actually a beneficial adaptation in those guys. The downside of that is, I think you often see athletes who are like, I can’t go to the bathroom or can’t pass stool unless I exercise. Maybe that’s an interaction of the downside of that adaptation.

So some of this stuff where you think, “Oh, this is a pathogen,” in certain scenarios actually becomes beneficial. I think it’s not good or bad. It’s just interesting.

DrMR:   Yep. That’s actually fascinating. And again, context here will really help one navigate these decisions, these markers, and what to do about a given marker. You reminded me of another thing that was published in the same paper I just referenced. They found that a fair number of healthy non-symptomatic patients who were eating high-fiber diets actually tested positive for SIBO via a breath test.

So you might see small intestinal bacteria populations increase in a non-harmful or non-symptom-causing way in someone who’s eating a high fiber diet. And that wouldn’t be a bad thing. So again, coming back to the context, we don’t want to take a SIBO breath test and think that always means it’s something that we have to act on.

DrTW:   Absolutely.

DrMR:   Any final point you want to hit, as we start moving to a close?

Examining Lab Ranges for Lead Levels in Blood

Gut, Thyroid and Heavy Metals - 240F155484475mg7nid7DltcUYUF8OP4VZbZyRHGj2TveDrTW:   I think one of the things that I just briefly wanted to talk about, going back to some of the normal ranges… when people try to interpret lab tests either for themselves or for their patients, I think it’s really useful to look at what a value really means in terms of the long-term health of that person.

This is something that we try to do more and more of. And it could be that we end up—because of the published research,—worrying less than we did previously. Or it could help guide us in terms of what we might want to help that person do.

And instead of just using the reference ranges as they’re published in the lab test… another one I’m thinking about is blood lead levels. We created, or Chris made, some mortality models looking at NHANES data and levels of lead in the blood. Basically if you’re looking at a graph, it goes through zero, zero. So the lowest mortality is when there’s the lowest amount of lead in the blood.

But because there’s so much of it going around, the normal reference range goes up well into the point where you’d start to see problems with long-term health. And this isn’t just a thing that I’m going crazy trying to scare people about. There was a paper that came out, and it was in the Lancet Public Health last year, which basically showed that the lead in people’s blood was causing as much cardiovascular disease as smoking was.

Between the two of them, they calculated it accounted for two-thirds of ischemic heart disease in the US. That’s huge. So just because something’s within the normal range doesn’t mean it’s safe. That’s something that we might want to think about. So looking at how a given level might affect some of these long-term health risks… A lot of these things are published. I think it’s really worth looking at. And again, I’m not trying to get people scared about lead, but filter your water, please, because that’s where most of it is coming from.

But this is just a reminder that there’s so much you can get out of cheap tests. And I go back to blood tests because they are cheap and we understand them well. Before you start going into all these other fancy tests, there’s a huge amount you could learn. Particularly if you pair that with just some basic look at the research, in terms of what people’s long-term health outcomes are for a given level of a very basic test.

I really would encourage people to do that, because there’s Gut, Thyroid and Heavy Metals - 240F126865695p0tjL4Y4TT61aRxmr087VydaL2PaY4CDso much more you can get for your patients, clients, in terms of cost-effectiveness, if you just pair those two things together rather than just by going by what the lab tells you to do, in terms of taking a supplement or doing a detox or whatever.

DrMR:   So in this Lancet paper, they were finding that the elevations were within the normal range, but they were enough to cause as much cardiovascular complications as smoking?

DrTW:   Yes, absolutely. And so if you look at that NHANES data, basically the lowest mortality is going to be if your lead is under probably one microgram per deciliter. But the normal range would go up to around three. And so, even within the normal range, you’ll see they’ve calculated–

DrMR:   And this is a standard, non-provoked–

What to Do for Heavy Metal Detox

DrTW:   Non-provoked, just whole blood lead. So just worth bearing in mind. And it’s a simple test you can do. You can do it through Quest for not very much money. And if it’s elevated, just filter your water.

DrMR:   Right. And I’m so glad that you tied that together. Because the follow-up question in anyone’s mind then is, well, what do we do about elevated lead? Do I need to do a DMPS suppository or DMPS orally? Which I’m certainly open to if there’s ample evidence for that. But it seems that the primary intervention for toxins should be avoidance.

DrTW:   Absolutely.

DrMR:   And then second to that would be hitting all the diet and lifestyle basics that we harp on, including gut health. And especially if you get some exercise in, that seems to be a pretty darn good way, especially according to Walsh. If you can exercise in this semi-fasted state, light exercise of course, and then follow that up with some type of sauna or steam therapy, that seems to be a great way to start.

How are you tackling this lead? Are you doing detox or can you get there with some basics?

Gut, Thyroid and Heavy Metals - 240F65499848tYeyjL5jEXYVl2ZCZiIJrbO9NYox62upDrTW:   No, exactly the same way. I think if you have extremely high levels of lead outside of the normal range, then I would see a toxicologist who would help you with chelation therapy or something like that. But beyond that, you’re right, the basics are always going to be the first point to work on.

So what’s your source? And say lead is the example, it’s probably your tap water. There’s a level in the municipal tap water which is considered safe and that’s just what you get exposed to. So filter your water as a super simple step. And then, depending on the metal or on whatever it is, if it’s a persistent organic pollutant or some kind of plasticizer or something, a lot of them come out in sweat, so just those things that you mentioned.

Light exercise, sauna, and then, yeah, supporting gut health, making sure that everything else is working correctly. So making sure you’re nutrient-replete in whatever way that requires, be it supplementation or just a nutrient-dense diet. That’s going to get you almost all of the way. And definitely, I know you interviewed Brian about detox on your podcast. If you were to go back and listen to that, he’s a brilliant thinker on that topic and there’s a lot to learn there.

DrMR:   Yeah, he is. And for our audience, if you want to get a deep dive, just go to our homepage or just go to Google and type in “Michael Ruscio, Brian Walsh toxins” and you’ll see his interview come up. We’ve also linked through towards his essentially caloric restriction combined with a couple of supplements, some dietary guidelines, and then you exercise in a semi-fasted state. And you follow that with sauna therapy.

That seems to be a great way to get all this rolling and get the detox pathways stimulated. Whereas I have a lot of concern about clinicians doing these heavily-provoked heavy metal tests. There has been, I believe, some litigation brought against these companies, where they were—said loosely—falsifying their lab ranges with really no supporting data, which is also tough because there’s not a lot of research on what normal for a provoked test should be. So all the culpability here may not fall in the labs. That may not have been something they were doing in a malicious fashion.

Gut, Thyroid and Heavy Metals - 240F91548621JL1l3MlhwSutjRyk3bzPTSq3KCr6YZhiBut I certainly get concerned when we’re using a test that hasn’t been validated, like a urine test with a heavy provocation before the urine test. And then providers who are using aggressive month and month and month long detox protocols.

There’s a time and a place for that, as you said, if someone has markedly elevated lead according to a more conventional test. But my fear is there’s a lot of people being detoxed who don’t really need it. And so here—and I think this is the best way to approach detoxification—get someone healthy, first avoid the exposure, and then focus on things like sweating and some of these lifestyle basics.

That pretty much turns the tide in your direction of being able to get these toxins out of your system.

DrTW:   Yeah, absolutely. I think the test that you’re talking about, they use a reference range from people unprovoked, and then they layer your provoked result on top, right? You’re very likely to create a false positive there.

DrMR:   If there’s any test where almost everyone comes back positive… haha.

DrTW:   Hahaha.

DrMR:  And that was adrenal testing for me. I was saying, everyone comes back positive and the sickest people don’t look any worse than the least unhealthy people.

When I was doing heavy metal testing, it was the same thing. Our field really needs to grow up. And I include myself in that criticism, because it shouldn’t be that easy, right?

If you’re like, “Oh yes, that seminar I went to really nailed it. Everyone has this problem,” that tells you that there’s probably some problem with the validity of the test. Not every person should be flagging positive for something.

Gut, Thyroid and Heavy Metals - 240F258496989BT2b0TAsl8r5uEhxeQwMWK2pPYpCsZFuDrTW:   Yeah, absolutely. And I think, right in line with that, if somebody is telling you that you’re good or bad at detox based on a genetic test, run a mile. Because there’s absolutely no way that they can know that.

I’ve spent some time digging in to what can you get out of nutrigenomics and 23 and Me. Just looking at the activity of an enzyme based on a SNP, the variability is huge.

So yes, if you have one specific thing on average in one study, it might show that it is increased or decreased. But how that works in you, you have absolutely no idea. People who have a specific SNP could have better function because of everything else that’s going on, compared to somebody who doesn’t have it. So do not, based just on your genetics, say, “Oh, I can and can’t detox stuff well,” because there’s no way to know that.

DrMR:   Yeah. Love it. Completely agreed.

View Dr. Ruscio’s Additional Resources

Episode Wrap-Up

So Tommy, where do you want to point people on the Internet if they want to hear more from you?

DrTW:   Yeah. I just joined Instagram, so come to @DrTommyWood on Instagram. It’s mainly pictures of my boxers… my dogs, not the ones that I’m wearing.

DrMR:   Yeah, I thought so. The ladies got really excited there for a minute though, Tommy.

Gut, Thyroid and Heavy Metals - drragnarDrTW:   But occasionally, there’s some science that goes up there that people might enjoy. My website is, which is in the middle of an overhaul. So it’s all a bit old now, but at some point it will come back online.

And then there’s a tool that I think I mentioned that we made with Brian Walsh, called the Blood Chemistry Calculator, which is trying to get the most out of a blood chemistry, mainly for practitioners. It comes with some education pieces and all that kind of stuff from Brian, and has it.

And if anybody has any questions, we’d be very interested to hear. We’re still in the process of putting it together. We’d never say it was finished or perfect, we’re just trying to help people get the most out of cheap and simple tests for their clients.

DrMR:   Yeah. I mean, I love that. And I love what you’re doing. There’s so much superfluous information out there, in terms of testing that’s not validated and recommendations that are overzealous. So I love what you’re doing and I apologize it took so long for us to have this conversation. Despite the fact that we agree on so much, it seems like our schedules are just in total opposition.

I would highly recommend everyone checking out Tommy’s work. I think he’s got his head on straight. He’s doing a good job. And I’ve certainly heard great things about the blood chemistry software and the fact that you and Walsh worked together on that. Walsh, another guy I highly respect, could only indicate that it is probably a pretty fantastic tool.

DrTW:   Yeah. Thanks for all of that. And thanks so much for having me on. Eventually we’ve had multiple good conversations both in podcast and in person, so it’s nice to be here.

DrMR:   Yeah. Well, thank you again, Tommy.

DrTW:   Cheers.

What do you think? I would like to hear your thoughts or experience with this.


I care about answering your questions and sharing my knowledge with you. Leave a comment or connect with me on social media asking any health question you may have and I just might incorporate it into our next listener questions podcast episode just for you!