Can Brazil nuts cause you to lose your hair?

The short answer?


However, I recently read something suggesting exactly that. As with most things that contain a grain of truth, or misunderstanding of a concept (keep reading to see where this idea came from), it inspired me to put this article together and help clear up any confusion you may have had about this.

In general, these kinds of questions remind me how important it is to get the best of everything from your supplements, your diet, and more. It is why I created products like the Daily Reset Packs, to help you get more of your daily micronutrients. It is best to get a combination of 100 mcg of selenium from a form of selenium called selenoexcel and an additional 50-100 mcg from the diet.

So, let’s break down the full story behind Brazil nuts, the research behind them, and whether you should be concerned about them causing hair loss…

Selenium & Brazil Nuts Through The Years

In past writings, I talked about the benefits of Brazil nuts (Read More: Supplements To Take and Ones To Avoid).

When I first shared the research, I was cautious in having you use moderation when consuming Brazil nuts (suggesting maybe having one or two at a time and not overdoing things).

That is because there can be a high amount of variance of selenium in some batches of Brazil nuts. Some could have more than others, and because selenium can be toxic in high amounts, this is worth keeping in mind.

After recently doing additional research, I wanted to present you with the most updated findings and clear cut guidance as to how you should approach Brazil nuts, selenium, and the worries concerning selenium toxicity.

What Is Selenosis?

Let’s start off with the basics. Selenosis is the other term for what we understand as selenium toxicity. Back in the late 90’s, I even diagnosed a case of selenosis myself.

In this case, a gentleman I had seen was taking extremely high doses of antioxidant pills. They were labelled as having far more selenium than you would expect, per pill, and he was taking a lot of those pills.

As it happened, he had symptoms that looked just like lead poisoning. This included:

  • Purple lines along the gums
  • Abnormal blood chemistries

At first blush, I thought it was lead poisoning. But, all the symptoms didn’t add up. And when your symptoms don’t add up, you have to keep digging, or find a doctor who will.

Turns out this patient had been overdosing on selenium before coming to see me. Thankfully we caught it in time and his symptoms improved when he went to an appropriate dose.

Selenium In Recent History

In the recent past, though, selenosis has also appeared in others. In the last few decades, it has appeared only in cases of poorly-manufactured vitamins (Read More: Why You Should Avoid Vitamins With Iodine).

For example, there were a few batches that came out that had way more selenium than intended. In those cases, people tragically had rapid and complete hair loss.1

This was a big deal, and they were also sick in more ways than simply hair loss. Thankfully, though, it was promptly identified and, by and large, they did get better.

Keep In Mind: Paradise Nuts & Brazil Nuts

In order to expand our thinking on this topic a little bit more, I want to introduce another nut that you may not have heard about before: paradise nuts.

These come from South America, and there have been some causes where they have caused selenosis (as well as the complications that come from it).2

Important to note, though, is that paradise nuts are not commercially available in the United States. They are also not the same as Brazil nuts. They are completely different.

We now know that they contain a different type of selenium. The proper term for it is seleno cystathionine.

This is different from selenocysteine that one can find in Brazil nuts. That’s important for you to know because there have been multiple documented cases of hair loss after only eating seven paradise nuts (due to this seleno cystathionine).3

Key Insight: Consider paradise nuts like selenium growing on a stem. It is a bad idea to eat them, as the kind of selenium, in particular, can result in rapid hair loss.

Can Brazil Nuts Be Toxic?

So, with that added context, let’s get down to the heart of the matter.

Brazil nuts have been shown to be rich in selenium, well absorbed, and the range can be as much as 7-200 micrograms per nut. Most hover around 25 mcg.

Most literature out there will recommend 2-4 Brazil nuts per day as a good option for everyone, but here’s one of the studies that caused my view on Brazil nuts to change…

This is a study that was done, funnily enough, in Brazil. Researchers took a large group of children, around preschool age, who were in a relatively-impoverished area. They were:

  • Malnourished to begin with.
  • Likely had micronutrient deficiencies.
  • Were slow as far as their growth was concerned.

Overall, these were not healthy kids.

In the study, they took one group of these children and simply monitored them with no changes. The other, though, received a pretty high amount of Brazil nuts.4

Researchers monitored the health of both groups in multiple ways, and measured their selenium in a lot of ways, too. It’s also worth noting that when I say “a pretty high amount of Brazil nuts,” I mean a lot.

If you were to convert what these kids ate into an adult dose, you would be looking at around 32 Brazil nuts a day. And, when you consider that Brazil nuts are way bigger than almonds, that equates to 20-30% of these kids’ caloric intake coming from Brazil nuts.

What Were The Results?

What happened was that, when compared to their peers, these kids absolutely flourished. They showed improvements in their:

  • Health
  • Immune function
  • Antioxidant capacity

Their selenium markers were also fascinating. For quick context, you can measure selenium in the blood, the urine, the hair, and the nails. As a generalization, though, the body works hard to keep the blood levels steady.

So, if you ever get too much, you will keep the blood levels steady, but the extra levels will leave in all of those other tissues. In cases of toxicosis, there is so much that you cannot get it out fast enough and the blood levels get high, too.

For these kids who were essentially living on Brazil nuts, their blood levels were great! They were fine, right where they should be, and better where they were before the study (and not even the least bit high).

This goes back to our previous conversation around the kind of selenium found in Brazil nuts, selenocysteine. So, while you may still get variable amounts of it in Brazil nuts, your body has a much easier time sorting itself out using this kind of selenium.

How Should You Feel About Brazil Nuts?

While at one point I was cautious about the amounts of Brazil nuts, studies have shown that the kind of selenium you can find within them is pretty safe for your body.

On top of that, Brazil nuts have been shown to be beneficial in other ways that selenium (when found in other sources) cannot be on its own.

Specifically, those who are lower in selenium can get better benefits from Brazil nuts than they otherwise could with supplementation or from other food sources.

For those without known selenium deficiencies, adding a single Brazil nut to the daily diet is an effective means of preventing issues from too little selenium.

The practice of eating two Brazil nuts per day has been clinically proven to be an effective way to increase selenium status in areas that have low levels of selenium in the soil.

In one clinical trial, two Brazil nuts were twice as effective as selenium supplements. The nuts, which averaged 53 mcg worked as well as 100 mcg of selenium from supplements.5

Key Insight: In short, you should feel completely confident and secure in enjoying a couple of Brazil nuts per day, without worry!

What Else Can Cause Hair Loss?

If you are looking at an explanation for recent hair loss, though, you may need to dig a bit deeper to get to the root cause. Click this link if you’re curious about hair loss and what you can do to fix it.

While I would not be wary about Brazil nuts being the culprit, I would seek out clarity on the following to try and get to the bottom of any issues surrounding hair loss:

  • Dysthyroid
  • Fe
  • PCOS – androgens
  • Pregnancy
  • Protein (Low protein + weight loss)
  • Biotin
  • Vitamin A overdose

So please feel confident in enjoying some Brazil nuts because it is a safe food that will not lead to hair loss. Please avoid paradise nuts, though, but enjoy the benefits that come from Brazil nuts and ensuring that your selenium levels are in check.

If you are concerned about hair loss, or the overall status of your thyroid-related to a host of symptoms, please consider taking the Thyroid Quiz today. It can help unlock so much about your health, so I would love for you to give it a try today.


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P.S. Whenever you are ready, here is how I can help you now:

1. Schedule a Thyroid Second Opinion with me, Dr. C, Click Here for Details
2. Download and use my Favorite Recipes Cookbook Here
3. Check out my podcast Medical Myths, Legends, and Fairytales Here

Dr. Alan Glen Christianson (Dr. C) is a Naturopathic Endocrinologist and the author of The NY Times bestselling Adrenal Reset Diet, The Metabolism Reset Diet and The Thyroid Reset Diet.

Dr. C’s gift for figuring out what really works has helped hundreds of thousands of people reverse thyroid disease, lose weight, diabetes, and regain energy. Learn more about the surprising story that started his quest.