Transcription
One nut once a week. That's it. I'm pretty sure that this nut can do your taxes and trim your dog's toenails, too.
But it is one nut that restores this one particular enzyme that determines whether your metabolism actually runs or starts to crash. I mean, it really is. It sounds like an exaggeration, but it's actually real.
Without this enzyme, your body cannot convert the stored hormone into an active form that drives your energy, drives your overall metabolism, drives your body temperature, and ultimately drives your fat burning. There was an RCT that found that just two of these nuts matched the effectiveness of a pharmaceutical-grade supplement.
So, a lot of people would either ignore this because it sounds almost too good to be true or they'll load up on it and then they'll overshoot the safe range and take way too much because this is one nut that you can consume too much of. But the thing is, even if you nail this piece and you eat this nut and you get that exact amount of the nutrient that you need, there's also a stress hormone that shuts down this whole same conversion process from a completely different direction. So, then we need to counterbalance with that. And it sounds complicated, but it's actually very simple. We just need to address both things simply through diet and a little bit with timing.
So, what we'll cover today is I'm going to explain why selenium deficiency is so much more common than anyone would realize, even in very developed countries with established diets, and why a lot of blood work ends up missing it. And this is why a Brazil nut, just one per week, can have a huge effect. Secondly, we'll get into the thyroid conversion problems. And this is what happens when selenium drops and T4 cannot become what's called T3. Even if your thyroid panel looks totally normal, if you can get blood work done, your thyroid can look normal and this can still be happening. And then I'll show you how cortisol can attack that same conversion step from a different angle and the chain reaction that ends up leading to visceral fat. Then lastly, we'll land on more of a practical piece like why Brazil nuts are a very efficient fix, why eating them daily could actually be dangerous, and why you may want to focus on more of a once a week protocol that sort of threads that needle.
Now, I want to start with the really important stuff, which was a big study that was published in the Lancet that laid out three really important things. And before I get into that, something that might help you out just in general, because Brazil nuts can be kind of pricey. I put a link down below for Thrive Market. That's a 30% off discount link. I mentioned it because yes, they do absolutely carry a bunch of different varieties of Brazil nuts, but it's really just a place that you can just get your groceries. Like it's an online membership based grocery store, but they sift through different products and they only put products that have clean ingredients on their website. So, it's like grocery shopping that's already been vetted and then it gets delivered to your doorstep. So, it really does make things so easy, especially as they've just continued to expand the products that are on their digital shelves. Not to mention, they've expanded into frozen and even fresh for some people. Not everyone gets those, but still, it depends on where you are. Bottom line is that it is really awesome and super convenient and the ingredient quality is hardcore good, right? So that is a 30% off discount link plus a free $60 gift whenever you use that special link that is exclusive here. So that link is in the top line of the description.
Okay, this was published in the Lancet. It laid out three things. First, the scale. Selenium deficiency affects hundreds of millions of people. Hundreds of millions. Okay, and the reason is soil period. If the soil where your food was grown is low in selenium, it does not matter how clean your diet is. You are still short in it. Secondly, selenium gets built into 25 different selenoproteins. Those enzymes run very critical systems, mainly like the thyroid hormone. Thirdly, the dose response curve is U-shaped, which means that people who are low benefit from more of it, but people who are already adequate can be harmed by pushing higher. And that becomes really important when we talk about Brazil nuts because Brazil nuts are very easy to overeat.
So even if you test for it, the standard panel can be misleading because a standard blood panel is measuring total serum selenium. That can look totally fine while functional selenoprotein activity is running below capacity. So you can be told your selenium is normal and still have a very impaired enzyme function. So selenium status is typically declining with age as well. So this isn't just like a developing country problem. Like we see the UK, we see a lot of Europe, parts of New Zealand and a lot of the US like the Northwest and Northeast specifically have very structurally low selenium soil.
Now, the reason that this matters to your thyroid so much is because the thyroid gland produces mostly T4, which is the storage form of thyroid for your metabolism. That is super weak. For your body to actually use thyroid, it needs to convert it. So, in order to actually regulate your metabolism, speed up your metabolism, speed up your body temperature, increase your energy, increase your mood, it has to convert T4 to T3, which is the active form. So, the enzymes that perform that conversion are called deiodinases. Deiod1 and Deiod2. These are perfect examples of selenoproteins like I mentioned. So without enough selenium those enzymes don't get built all the way or they're super weak and they underperform.
So if we look at a study in clinical pediatric endocrinology they looked at patients that had selenium deficiency and with no prior like thyroid disease at all and they found that there was a ratio that directly reflected how well the conversion is working and this ratio was very much elevated in the selenium deficient group. So basically they were not converting T4 to T3. Like the worse the deficiency, the worse the conversion. When they supplemented them with selenium, TSH, thyroid stimulating hormone normalized. They also found that T4 came back to normal. They actually dropped and T3 went way up. So the ratio balanced out. So the conversion problem was entirely reversible.
And if we actually compare that to like pharmaceutically, like if you're on levothyroxine, like synthetic T4, like a lot of times people still feel lousy. It's because selenium is still a missing piece. Like levothyroxine gives you T4, but you still need functional deiodinases to convert it. So if selenium is low, that conversion is compromised even on medication because it's actually screwing up that ratio even more. So you're taking levothyroxine, your T4 is going way up and then like it's not converting it because you don't have selenium. So now, wo, you have a way messed off ratio.
So selenium is not the only thing that cuts down that conversion though. Cortisol actually does this too. Like I mentioned earlier in the video and we look at a 2025 study in JRSM, it found that glucocorticoids, okay, like cortisol, these decrease the activity of five deiodinase, which is the same enzyme family that converts T4 to T3. So if you're chronically stressed, then cortisol suppresses the conversion. Okay, so it's it's a wild hairy world.
And the progression kind of plays out like this. You have less T3 available. So your body produces more reverse T3, biologically inactive form that actually blocks T3 receptors to protect you. So you're not just making less of the active hormone. The inactive version is sitting in the receptor sites where T3 is supposed to go. So now you have T3 being lower, but what little amount is there can't even bind. From there, your reduced T3 decreases all kinds of different like mitochondrial oxidative phosphorylation. So it's metabolizing carbs and fats way worse. Thermogenesis drops. Lipolytic enzyme activity gets blunted. So you're not burning fat. Your body becomes less efficient and you start storing visceral fat. So the chain is chronic stress raises cortisol. Cortisol suppresses T4 to T3. Uh reverse T3 ends up climbing. That blocks the receptors and over time you gain fat, particularly visceral fat.
So Brazil nuts, the dosing matters very much. And if we look at an RCT in the American Journal of Clinical Nutrition, 59 humans, adults, they were in New Zealand, which is a region with well documented low selenium. They put them into three groups. Two Brazil nuts per day, 100 micrograms of selenomethionine tablets or a placebo. 12 weeks later, the Brazil nut group raised plasma selenium just as effectively as the supplement group. Two nuts matched 100 micrograms of the standard supplemental form.
So the bioavailability is comparable to pills, but selenium content in Brazil nuts isn't fixed. So a typical nut can range from like 50 to 90 milligrams. But we have analysis that actually found sometimes individual nuts as low as one microgram and get this as high as over 500. So if you're eating two nuts a day from a high selenium batch, you could be getting over 1,000 micrograms in a single serving, which is nearly three times the tolerable upper limit of 400. You do that daily and you are in serious chronic selenosis territory. Like way too much selenium. It happens within days to weeks.
So the resolution is not to avoid them, but it's to reduce the frequency. If you do one to two nuts per week, it's giving you 80 micrograms, which is enough to meaningfully contribute to selenium status without risking accumulation. The trial data supports this significantly. Selenium from Brazil nuts stayed elevated for weeks after supplementation stopped because it incorporates slowly into tissues. And then we have a weekly dose that accounts for that.
So I want to tie it all together and talk about how you can actually apply this. Okay? Because basically right now all we've got is maybe I should just eat a few a week. First consider testing before supplementing because like a serum selenium or GPX activity test will tell you whether you're clinically deficient. But with a U-shaped curve, you don't want to really push higher if you're already adequate. So it is important to kind of get a test.
Secondly, if you are low, start with one Brazil nut per week, okay? Not even daily. The long tissue half-life means that the weekly dosing is actually sufficient. This protects you from that nut to nut selenium variability. And then you have to thirdly support the system around selenium. So there's an interesting review. Okay, it established that selenium, iodine, and iron as sort of a triad for thyroid function, and they should be assessed together. So you really want to look at like eating whole foods, right? But if you're going to take a Brazil nut, you should also be considering uh maybe even some seaweed for the iodine and maybe some red meat for the iron.
Now, additionally, we don't want to overlook protein because selenoprotein synthesis shares machinery with the amino acids like sulfur containing amino acids. So, like when protein intake is low, you can have a lot of selenium but still not build the enzymes itself. So, eggs, meat, fish, and dairy plus your selenium, right? Brazil nut.
And then fifth, you need to manage cortisol. So, cortisol suppresses that same deiodinase enzyme that selenium builds. There's a triple blind crossover study in neurology and therapy found that a single 200 milligram dose of theanine produced over a 40% decrease in salivary cortisol within an hour after stressful events. So if stress is just part of your life, which it is for many of us, theanine is a practical tool to protect that conversion from the cortisol side.
So one to two nuts once per week. That is the protocol that respects all this stuff. Have it along with some seaweed. Have it along with some red meat or some eggs. Your thyroid needs selenium to do its most basic jobs. And most people are quite frankly ignoring it or they're overdoing it. So now that you have the middle ground, it can kind of help you out because taking too much is a problem.
So if you're someone that loves nuts and you want to have more than like one nut a week, there is a nut that you can eat every single day and it provides an entirely different set of metabolic benefits. So I actually did a full 30-day experiment eating an ounce of macadamia nuts every day and I tracked what happened. So that video is linked right here. That'd be a great one to watch if you're a nutty person. So check it out here and I'll see you.