This week, we are going clinical with Dr. Tom Guilliams. This is a new podcast segment that we’re doing called Controversies in Nutrition, and in each session, we are going to take some big controversies that have been brought to us by listeners and ask Dr. Tom Guilliams about them. If you’re not familiar with Dr. Guilliams’ work, he’s been a central mythbuster in the field of functional integrative medicine for more than a decade. In this episode, we got into N-acetyl cysteine, strontium and fish oil.

Highlights include:

  • N-acetyl cysteine: what it does, its uses and why it’s a controversial nutrient right now
  • The controversies surrounding strontium citrate and what the research says about this nutrient
  • The rancidity of fish oil on the market and whether or not it’s helpful for health
  • And so much more!

Controversies in Nutrition: NAC, Strontium and Fish Oil

James Maskell: Welcome to the Evolution of Medicine podcast, the place health professionals come to hear from innovators and agitators leading the charge. We cover the latest clinical breakthroughs in health technology, as well as practical tools to help you transform your practice and the health of your community. This podcast is brought to you by the Lifestyle Matrix Resource Center, who provide a range of options to help you deliver successful, effective, functional, and integrative medicine. To find out more and to get started, go to That’s

Hello and welcome to the podcast. This week, we are going clinical with Dr. Tom Guilliams. This is a new podcast segment that we’re doing called Controversies in Nutrition. And in each session, we are going to take some big controversies that have been brought to us by listeners like you and ask Dr. Tom Guilliams about them. If you’re not familiar with Dr. Guilliams’ work, he’s been a central myth buster in the field of functional integrative medicine for more than a decade. His work with adrenal fatigue and really sort of, I guess, bringing that myth and many other myths to an end in our space has been super helpful. He’s a great lecturer, has a lot of quality information. And in this episode, we got into it with regards to N-acetyl cysteine, strontium and fish oil. I think there’s some really interesting content in here that you’ll enjoy. All right, take it away. So a warm welcome back to the podcast, Dr. Tom Guilliams. Welcome Doc.

Tom Guilliams: Hey James. Good to be with you again.

.James Maskell: So we’re super excited to have you on for maybe what might become a regular segment, which is looking at controversies in nutrition. And we reached out to our community to ask them what did they want to know? And we had a real range of questions. I think some of which were a good fit for you. And maybe some that weren’t, some super broad and maybe some that could be a whole podcast by themselves, or maybe a whole day of lectures by themselves. And we’ve only got half an hour to jump into it. So we’ve picked out some of the things that we think would be most relevant for you and most interesting for our community and things that came up the most often. So why don’t we just start with N-acetyl cysteine, it’s been in the news. And so Amazon has decided to stop the sale of any products with N- acetyl cysteine in it. So I know that this is something that you know a lot about. So why don’t you tell us a little bit about N-acetyl cysteine what it does, its and why this is coming up now.

Tom Guilliams: Yeah this was actually a pretty big surprise for us and for a lot of people. The middle of last year, amongst a number of other warning letters that FDA sent out, they had this little line in one of the warning letters to one of the companies saying that the use of N-acetyl cysteine, NAC as we often call it is not a lawful dietary ingredient because it had been approved as a drug back in 1963. And of course that sent sort of this little ripple around the industry and around really the US market primarily wondering how is it possible? People have been using N-acetyl cysteine in dietary supplement ingredients, thousands and thousands of them since before the passage of the Dietary Supplement Health Education Act, DSHEA. And it was assumed I think by everyone that it was grandfathered in and whatnot. Of course N-acetyl cysteine is a modified sustained molecule, primarily used as an antioxidant or a disulfide breaker.

And so it’s been used as an antioxidant. It’s been used as a recharger for glutathione, and it’s also used as a mucolytic, which breaks up mucus because of the breaking of the disulfide bonds. So the industry group CRN in particular, the Council for Responsible Nutrition, has been engaging FDA and kind of saying, hey, where did this come from? This is sort of left field, but in the midst of that Amazon, which has also been going through a cleanup of its quality program. So it initiated last year, a more rigorous quality program for a dietary supplements on its website on the Amazon site. And they decided to … FDA says CBD ingredients are no longer or were never lawful. And so you really can’t find a true CBD product on Amazon, a lot of hemp oil, but not CBD. Well they then took it upon themselves to say, well, if FDA has sent out this warning letter, that NAC is unlawful, we are going to stop the use of NAC ingredients.

So they literally just expunged all the products that had N-acetyl cysteine in them off of their … from purchase. So, you know, that was a pretty dramatic move and actually CRN and others have challenged Amazon actually on this saying they’re acting a little bit like a police and when FDA hasn’t really even … FDA hasn’t pulled the products, hasn’t told people to pull them off the shelf. They’ve not sent other warning letters since then, even though there’s thousands of products out there. So it’s going to be interesting to see. So people have asked, well, does it mean it’s NAC is unsafe? No, N-acetyl cysteine is not unsafe. It’s just that there’s a technicality in the dietary supplement health education act that says if a product has been a drug or is a drug, the FDA or the Secretary of Health and Human Services has the option of removing it as a dietary ingredient.

We’ve got a lot of things that are both drugs and supplements like niacin, for instance, our fish oil is a classic example. So we have approved drugs and products that are dietary ingredients. What makes them different is essentially the claims that can be made about `them. So you can make claims about Niaspan. You can make claims about fish oil, like bacopa that you can’t make about the dietary supplement ingredient, but really, there’s no fundamental functional difference between those ingredients except for the claims that can be made about them. So when it comes to NAC, we’re going to have to see how this pans out. It would seem, in my opinion, quite unusual for FDA to all of a sudden say that an ingredient has been used for this long this safely is now going to be banned as a dietary ingredient. And, but when you have Amazon and other retailers like that, that may take it on their own to sort of police the industry or to give their opinion, let’s say before FDA rules on this in a final way, it does complicate things. So I don’t think that the clinicians or people should avoid the use of NAC, but we’re going to have to wait and see what happens. We’re hoping that this obviously doesn’t get removed because it’s a very, very beneficial ingredient for a whole host of reasons.

James Maskell: Yeah, it’s really interesting. It seems to me like there’s many reasons not to have your patients get their supplements on Amazon. And here’s maybe just one more reason why professional grade and using services that are designed around health practitioners makes a lot of sense here too.
Tom Guilliams: Yeah. I mean, obviously people are concerned about lawsuits and obviously Amazon is getting larger. I think they’re now considered the largest retailer in the US if not in the world. And so they’re doing some different things, which just like we see with some of the online social media platforms that are able to sort of police things, whether we like that or not, the way they’re policing things, certainly now retailers that are controlling retail are going to be able to police things for good or for bad.

James Maskell: Interesting. All right. Well, that was one topic and I’m glad we looked at that and I know that that is a widely used supplement in our community. So I’m glad to clear up a little bit of that. Similar kind of issue is with strontium citrate. So this isn’t something that I’m that familiar with, but do you want to just talk about strontium citrate and how it’s been used and then some of the controversies around it?

Tom Guilliams: Yeah, I mean, there’s actually a similar, I mean, in some ways a similar idea with NAC in the fact that strontium has been used as both a drug and a supplement, not in the US, not as not approved as a drug in the US but strontium is basically a mineral that has very similar properties as calcium. So if you look at it, if you have a periodic table and you see calcium is right above strontium, strontium is about twice as heavy as far as its molecular weight as calcium, but it functions and acts very similar to calcium when taken into the body. And this has been known, actually, this was actually documented in 1870s, that when you gave animals strontium it increased their bone mineral density because it’s a stronger heavier molecule. The first publication of the use of strontium in humans was published in the Mayo Clinic proceedings in 1959.

So quite a few years ago before you were born I think even-

James Maskell: Quite a few years actually.

Tom Guilliams: And they actually used strontium lactate at that time, and they gave quite a high dose. So like six grams, a little over six grams, but they had this case series where they showed that bone mineral density and bone strength increased in the people that were given the strontium lactate. And so most of the strontium compounds, strontium chloride, strontium citrate, strontium lactate were not patentable. So a drug company started looking at this in the nineties using strontium ranelate, which is a salt form of ranelic acid. And so the publications looked really promising. This was done in Europe in the nineties and animal studies and human studies, big publications came out phase two, phase three clinical trials in the early two thousands. And so it actually was approved as a osteoporotic drug in most of Europe in I think the year 2004.

And so people started using that and they showed obviously fracture risks going down and bone mineral density going up. And all the things you’d expect at all the major points of bone mineral density increase. And at that time, a lot of people started using in the United States strontium citrate again. So they started using that data because we knew from the mechanisms that it was the strontium part, not the ranelic acid part. So going back to the strontium lactate data, the strontium citrate, and strontium chloride data, we knew it was the strontium component that was really affecting both the benefit of the change in what we call the osteoclast, osteoblast mechanisms that promote bone growth, but also strontium incorporates itself into the bone and increases the bone mineral density and strengthens the bone.

Then, so it was basically used in Europe for about 10 years. And in around 2013, there was a publication that came out looking at some of the data. And in Europe, actually, I’m writing a [inaudible 00:12:15] paper on this kind of right now. And so in Europe, they had this pharmico vigilant risk assessment committee, it’s part of the European medicine agency, and they kind of looked at some of the data. They pulled some data from about 75, 100 post-menopausal women, and they determined that there was an increased of myocardial infarction, MIs with some of these women using strontium ranelate. So that was published in about 2013 and that kind of changed the calculus. They came out and said that women who had risk for cardiovascular disease shouldn’t use strontium ranelate. Well, obviously that became a concern. And so you started seeing people concerned about the use of strontium ranelate in particular.

And as it turns out, we now know, after looking at all this post market surveillance, looking from 2004 all the way to 2013, that the data that they were using was I wouldn’t say flawed, but it was limited. And when you started looking more broadly, publications started coming out and saying there was no increased risk for cardiovascular risk or some of these other risks that they had in the broader population of people taking the drug. But by that time, the recommendation not to use it in women that had cardiovascular risk, the use of was going down and down and down, even though there was other publications showing that there was no more risk with strontium ranelate than with bisphosphonates, which is the kind of thing, other main osteoporotic drug. But by that time, the use had gone down enough by 2017, the company that was producing it decided it’s not worth it anymore.

We’re going to just stop making it because we don’t have enough people buying it anymore. It never was a huge, huge drug in Europe. And so they just stopped making it. So there was this assumption that it had been taken off the market, which it really hadn’t been taken off the market. It just was stopped being produced. And now we actually have another company, a drug company called Aristo I think it is, that is now producing strontium ranelate, selling it in the UK and other places in Europe. So it’s still available as a drug. As it turns out, so the question is, okay, what does that mean about how we’re using strontium citrate, which is the typical dietary supplement ingredient in the United States? Well, there’s very good data, actually did an animal study where they compared the absorption and the incorporation of strontium in the bones using strontium ranelate versus strontium citrate.

It turns out strontium citrate in this animal study was able to absorb into bones better than the ranelate form. But I would expect them to perform pretty much the same because it’s the strontium component. So if you just take that full circle to where we are with the use of strontium citrate from the standpoint of safety, the standpoint of its use in the United States as a dietary ingredient, as a dietary supplement, I would say that strontium citrate is as safe, I would say it’s probably as safe as calcium, and we know that calcium taken in high doses can also increase risk … has been shown an increased risk for coronary artery disease or other things, especially when not taken with vitamin D. So I would say strontium is probably the same in very similar in it’s safety risks as calcium.

James Maskell: So what does it do? What’s the mechanism of action for strontium citrate and what are doctors prescribing it for?

Tom Guilliams: Yeah. So the mechanism… there’s actually a lot of debate about this because we have a lot of information about how it works in vitro showing that strontium is able to increase the bone turnover, which it increases the kind of turnover between the osteoclasts, which are sort of taking away, creating the beginning of bone resorption, and then the osteoblasts, which then fill in and create new bone. So there’s a lot of data to suggest that strontium has that direct ability, but it seems like probably the most important fact is that strontium incorporates itself into bones and by doing so because it’s slightly different than calcium, it only can take about 10% of the calcium sort of molecules within the bone itself can be replaced with strontium. And of course that takes years and years and years, maybe decades for that to actually go from 0% up to 10%.

But as it does that, as it incorporates into bone, we know that it strengthens the bone and it strengthens the bone building process. So strontium is actually added to a lot of implants, both dental implants, and other implants as part of the matrix because when it incorporates, when they fuse that into a bone, the strontium in there increases the ossification, the connecting between the bone and the implant. And so this has been known, strontium has been used in dental work for many, many years, and also both in the implants themselves, or taken orally, increases the benefit of connecting to the bone. And so, because of that, and this is one of these other anomalies that you’ll see, some people call it an artifact, and it is a little bit confusing is that when you incorporate strontium in the bone, you change, obviously the bone mineral density, you change the strength of the bone, but because we’re typically using DEXA scans, which is dual x-ray through the bone, x-rays essentially are looking for density.

And when you incorporate strontium in the bones, you make it more dense immediately because the strontium molecules absorb electrons different than calcium. And all the DEXA scan machines and all the data that we have is indexed based on the density of calcium. So people will say, well, yeah, if I put strontium in your bones, it’s going to give an artifact as if it’s more dense because you have this artifact, strontium is more dense. And I would not call it an artifact, but I would say, yes, that’s true. Once you start incorporating strontium in the bones, you are going to affect the DEXA scan more. It’s going to affect it more than it would if you just added calcium. And so some people say, well, that’s a red flag because now this is all false density.

I would say a couple of things. One, we know that that’s not true. We’ve got a number of other ways of measuring the amount of strontium in bones and actually in animal studies showing that the strength of the bones get stronger. So we know it’s not just an artifact of the DEXA scan itself. We know this from a number of different studies, including human studies, animal studies, fracture risk, so fractures go down. So we know that strength of the bone is getting better. But I would say that rather than being an artifact, it’s actually evidence that when you take strontium orally, it’s getting to the bone. Most people don’t realize that strontium, radioactive strontium, usually in the form of strontium chloride is used as a palliative care for cancer metastasis to the bone. The reason they do that is because they know if you take strontium, even if it’s radiolabeled strontium, it’s going to go in orally and it’s going to go to the bone.

And then that radiation will benefit those who’ve got a metastasis to the bone. So we know that strontium goes to the bone. We know that it strengthens the matrix and changes the strength of the matrix in the bone. And the DEXA scan is just evidence that that’s happening. The only place that this becomes, let’s say an issue is that once a person has been taken strontium for a while, they can’t really use the traditional Z scores. So the traditional way of measuring DEXA scan, bone mineral density numbers. So what I tell people is that if you are … a goal of the clinician is not to increase DEXA scan scores, the goal of the clinician it’s to strengthen the bone. So it’s unfortunate that we can’t do a biopsy of the bone to find out how much strontium is there, which is what you’d need to do if you’d want to back calculate how much of that is actual incorporation versus how much is there.

It’s just the increased density between the strontium and the calcium. But if the goal is to reduce fracture risk and to strengthen bone, then an increase in the DEXA scan caused by strontium is actually evidence that you have strontium incorporation in the bone, which is what the goal of taking strontium is in the first place. So I don’t see this anomaly or artifact as being a negative thing. I actually see it as being a positive way to know that there’s incorporation of strontium into bone. There’s been a couple researchers in Canada that have looked at this, and they’ve looked at a couple of other ways of measuring this, not just using DEXA scans. And they show that strontium increases after taking strontium citrate, even six, seven, eight years into taking it. It’s still increasing amount of strontium in the bone. So we don’t know when that actually maxes out, depending on how much you take.

James Maskell: So who is a good candidate for strontium then? Is it sort of the same person or the same kind of patients that would be prescribed calcium for preventive osteoarthritis or arthritis cares. Is it that same patient base?

Tom Guilliams: Yeah, I think there’s a lot of questions about is strontium a nutrient? Should we think of it as a nutrient like we think of calcium? And I would say, I think the data suggests we should reserve the use of strontium for post-menopausal women who have evidence of osteopenia or osteoporosis. I don’t necessarily … I think of it a little, even though it’s a mineral and it’s very similar to calcium, I still see it more like a therapeutic mineral than a nutrient mineral. So I would say that strontium shouldn’t be given to young women as they’re building their bone mineral density. I think it should be reserved as the research suggests for post-menopausal women who have bone mineral density deficits. And then I think then you’re dealing with where the research shows it’s benefits going to be.

James Maskell: Beautiful. Okay.

Tom Guilliams: And I would just add that you would also want to add calcium and vitamin D and because strontium and calcium absorb using the same sort of mechanisms and they compete with each other, you’d want to try to take your calcium and strontium apart, or at least most of it apart, it’s sometimes hard to do, obviously if you’re taking calcium in your diet, but if you’re supplementing calcium and vitamin D you want to do calcium separate from strontium at least a little bit.

James Maskell: Okay. All right. So one thing you mentioned earlier, we had a few questions on it was fish oil, that it had been a drug and a supplement. One question that came up was this conversation about the rancidity of fish oil on the market and whether or not fish oil is rancid and therefore whether or not it’s helpful for health. I’d just love to get your take on that.

Tom Guilliams: Yeah. So, I mean fish oil has come a long way and there’s been a lot of quality issues. And here, of course, we have the same issue with fish oil. We have a lot of forms of fish oil that are a dietary supplement ingredients around the world, are nutrient ingredients. And then there’s a handful of products, which are essentially the same or very similar and sold as pharmaceuticals. So years and years ago, this goes back almost 20 years now, CRN, and then the Council for Responsible Nutrition, and then a group that merged or came out of CRN, GOED, which is the Global Organization for EPA and DHA, created a monograph. And in that monograph, they stipulated all the different ways that fish oil should be measured, including the oxidation or what we … the rancidity, but a couple of different tests for its oxidation.

And once that came out and we started using the peroxide, what we call the peroxide value and then anicidine which is sort of a secondary way to measure rancidity in fish oil, those measures together, which you would call the total toxic, or Totax, the total oxidation measurement are kind of the industry standards. And most of the fish oil around the world, including the let’s say the high end fish oils used by most clinicians come out of a handful of manufacturers that really do know what they’re doing. They’re part of GOED, they’re part of the … they’re using technologies that purify the EPA and DHA and maybe other fatty acids. They can modify them to ehtylesters or re esterify them back to triglycerides, and they can really keep the oxidation low. And they do that obviously through a number of different processes, including using nitrogen at various stages. Where you may end up having problems is if they’re using, if some of these companies are using, let’s say they get a drum that, I mean, some of this comes to like 55 gallon drums of oil that are purified, EPA, DHA type products.

And those would be extremely low oxidized oil. It’s where it goes from that product to a bottle. If it’s going to be a liquid, or if it’s going into a soft gel. IF those companies aren’t protecting it with nitrogen or doing it properly, it is possible that some of those products may be oxidized and or rancid, we might call it. And probably the best way use the smell test. If you open up your fish oil and it doesn’t smell right, it smells really fishy like a day old tuna sandwich or something, then that means you probably have oxidation. But a lot of that can be done by the consumer. If you leave a bottle of fish oil open on a counter for a long time and oxygen gets in there and it’s warm, you need to protect that fish oil.

So if you’re using liquid fish oils, I always tell people using liquid fishers, keep them in the refrigerator. You can even keep them in the freezer. They’re not going to freeze because they’re, they’re very fluid. You shouldn’t buy fish oil in the three months supply bottle, I mean, you should probably buy fish oil that takes maybe one or two months at the most, and you should consume them. So open them, consume them, open them, consume them, maybe even keep them in the refrigerator if you’re not certain about that. But yeah. So once you start opening a bottle, you’re introducing the oxygen to those. And even though most of these are in soft gels, soft gels do allow oxygen to penetrate. So you can’t just leave these out on the counter or in an open bottle for hours and hours and hours every day, and then expect your fish oil to be good continuously. You know, if you want to try it, if you take one of your fish oil capsules and bite on it, and if you have to spit it out because it tastes so fishy, then yeah you might have products that are starting to go. But I would say that that’s less and less common these days, especially when it comes to the higher end fish oil that most clinicians are using.

James Maskell: Yeah. That’s really helpful to understand too. I guess it gets hard to understand when you have flavored fish oils, now it’s hard to understand what’s going on, right?

Tom Guilliams: Well, yeah. So many of the companies, yeah, they’re adding some flavors. Look, if you’re taking fish oil, even if it’s pure, I mean, there’s some fish oil that I’ve taken and you can hardly even taste it. There’s a liquid fish oil, you can hardly even taste it. And yet it still, when it’s sitting in your stomach, if you burp, you’re still going to get a little bit of that flavor that’s going to come up. There’s almost no way that you’re not, if let’s say you burp for any reason. And so a lot of companies add sort of a vanilla taste or some other citrus taste or something so that when you burp up, you don’t get that really strong, fishy taste. And so that … it’s impossible to eliminate that, but that’s what they’re really trying to do. And even a hint of fish smell, for instance, in like prenatal, if a prenatal, a woman she’s pregnant, she doesn’t want to smell that fish. So sometimes they have that smell that gives a little more pleasant back smell rather than the fish oil smell. Awesome.

James Maskell: Awesome. Hey Tom, well, look, I want to thank you for being part of this podcast series. Maybe we’ll have you again in the future. I want to also thank everyone who put in that questions. Just as a caveat, if you did put in a question and we didn’t get to it today, there’s just certain questions that are a good fit for this format of podcast. And some that you probably have to come an all day Tom Guilliams lecture to get to. And some that probably couldn’t even be done in that kind of time, just because there’s so much to some of these issues, but I hope that this was useful. I was super interested honestly, to see about the N-acetyl cysteine for many reasons, one of which is that early on in the pandemic, I saw quite a few clinicians talking about it in their COVID stack.

And so I’ve been just interested to follow that nutrient particularly, but I think the strontium thing is super interesting and the fish oil. And so, yeah, maybe we’ll come back again soon and talk about some other controversies in nutrition. If you do write back to me on the email and ask for questions, we do read every email. So just know that we are following them. We’ll do our best to get back to you with good information if we can. But thanks so much for being part of the controversies in nutrition podcast Tom. I know that myth busting is one of your favorite pastimes.

Tom Guilliams: Yeah. I spent a lot of time on this. And these are relevant issues for clinicians and yeah, hopefully we can bundle some more questions like this together for one of these in the future.

James Maskell: Sounds good. All right. This has been the Evolution of Medicine podcast. I’ve been with Dr. Tom Guilliams. We’ll have more details about his work in the show notes. So you can find out more about what he’s up to, but in the meantime, thanks so much for tuning in and we’ll see you next time.

Thanks for listening to the evolution of medicine podcast. Please share this with colleagues who need to hear it. Thanks so much to our sponsors, the Lifestyle Matrix Resource Center. This podcast is really possible because of them. Please visit to find out more about their clinical tools like the group visit toolkit. That’s Thanks so much for listening and we’ll see you next time.


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