Brazil Nuts & Testosterone

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Medically approved by Dr Earim Chaudry
BMBS MMedSc Dip ENDO, TRT Expert
iconLast updated 16th February 2024

Testosterone is the male sex hormone which controls all the manly stuff like your muscle mass and fat distribution, facial and body hair, and your sex drive and ability to get an erection.

Testosterone levels naturally decrease as men age, however, suffering from low testosterone can have a negative impact on your sexual, physical, and mental health. Many men may look toward easy treatments to boost their testosterone levels and spare any embarrassing conversations, despite lack of scientific evidence.

Brazil nuts contain a very high concentration of the mineral selenium, which is said to naturally boost testosterone levels.

While selenium has many benefits, including antioxidant anti-inflammatory properties and helping thyroid hormone production (which is important for a bunch of other things too), we can’t say for sure that Brazil nuts will increase your testosterone levels or have any impact on your sex drive.

Approved treatments — generally known as testosterone replacement therapies (or TRT) — and positive life changes are the best way to tackle your low-T problem head-on.

The irony isn’t lost on us. The rumour that eating Brazil nuts can help the health and function of your own nuts — it sounds like a set up to a particularly bad dad-joke. Yet, while research into this suggestion is plentiful, we can’t say for certain that eating Brazil nuts will increase testosterone levels.

Some believe that a serving size as small as 6 nuts a day can make a difference to your testosterone levels, and for you to see a positive impact on your sex drive and fertility. And while there’s no harm in trying (so long as you’re not pinning all your hopes on it) the facts are relatively sketchy.

Low testosterone impacts many men — as many as 1 in 4 of us over the age of 30. Lots of guys would admit that looking for an easy, convenient and discreet natural remedy is preferable to awkward conversations at the doctors, or in the bedroom. However, before you start snacking on these tasty treats, can eating Brazil nuts seriously increase testosterone?

Here we will talk you through what we know. But first, how do you know if you’re suffering from low-T?

What Is Testosterone?

Testosterone is the male sex hormone. Your levels peak in early adulthood and slowly decline once you pass the age of 30, as part of the natural ageing process. Decreasing testosterone levels can be a reason why lots of guys may find it harder to keep in shape, and keep up in the bedroom, as they get older.

The scientific link between testosterone and erections is still a bit of a grey area, so how will you know if you have low-T? 

We know that guys with low-T are more likely to suffer from low libido, erectile dysfunction (the inability to get and keep an erection long enough for sex), and infertility. You may suffer from one or a few of the most common symptoms of low testosterone, which, aside from sexual dysfunction, can affect other parts of your body too. You might notice weight gain (especially on your chest), your muscle mass decreasing, and generally feeling weaker.

Although not always a precursor to hair loss, low testosterone levels can also increase your chances of suffering from male pattern baldness. Furthermore, men with serious health conditions, such as diabetes, obesity, or liver or kidney disease are more likely to have lower testosterone levels.

It can come as a bitter pill to swallow to find you have low-T, even though it’s a common problem. Studies have shown that most men with borderline low-T levels suffer from depression, low moods and energy levels. Unfortunately, our reluctance to talk about such problems means we’re more inclined to eat a handful of nuts and hope for the best rather than seek proper medical advice and treatment.

So, here’s the lowdown on whether Brazil nuts actually have anything to do with boosting testosterone.

How Can Brazil Nuts Increase Testosterone Levels?

The science behind the claims of Brazil nuts boosting testosterone levels is all based around a mineral called selenium. Brazil nuts contain a whopping amount of the stuff — around 174% of the recommended daily value per 5g nut.

Selenium is a mineral we need for many bodily functions. It can be found in a variety of foods as part of a healthy diet or it can be taken as a supplement. The amount of selenium we need is pretty tiny, only 55 micrograms, but it packs a punch.

It’s a powerful antioxidant which means it can help combat chronic conditions such as certain cancers and heart disease, as well as keeping your immune system in good nick.

But, most importantly for us, it has been said that selenium can raise low testosterone levels and boost men’s fertility by improving sperm mobility and quality. For most men living in wealthy, westernised countries, it is pretty rare to have a selenium deficiency, but those who do may see an improvement in their testosterone levels after supplementation.

In one study, it was found that 56% of subfertile men with low selenium levels recorded an increase in sperm mobility, however, this was based on taking selenium supplements, rather than eating foods high in selenium, such as Brazil nuts. In another study, it was concluded that selenium was a positive treatment for infertility thanks to it improving semen quality.

However, there is no evidence to suggest that eating Brazil nuts will specifically boost testosterone levels in men already getting enough selenium in their daily diet. A direct link between eating Brazil nuts and increased testosterone levels has not been scientifically proven.

4 Other Benefits of Brazil Nuts for Men’s Health

While the headline news linking Brazil nuts and testosterone is thanks to their selenium content, there are actually a few other reasons why they’re a good choice of snack for us guys.

While eating healthily will help keep your sperm healthy in general, here are the other benefits of Brazil nuts:

1. Good for Heart Health

We all know that a healthy heart means good blood flow, and we all also know that good blood flow means good erections. Which is great news for us all! Brazil nuts are a great source of monounsaturated fats and polyunsaturated fats, which in turn help maintain a healthy cholesterol level and reduce the risk of heart disease and stroke. Cholesterol is needed for testosterone production, so this is a really important way Brazil nuts may help boost testosterone.

2. High in L-Arginine Amino Acids

Why is this alien-sounding compound important? Well, this amino acid boosts nitric oxide production in your body, and when it comes to erections, nitric oxide is the chemical that does the hard work. As our resident Dr Chaudry explains:

“When you are aroused, your brain sends nerve signals to promote nitric oxide-mediated vasodilation of the blood vessels supplying the penis. This engorgement of blood promotes the extension and contraction of the erectile tissues within the penis. Additionally, the muscles compress the veins (i.e. the blood leaving the penis), so this maximises the blood within the penis.”

3. Promotes Healthy Thyroid Function

Your thyroid tissue has the highest concentration of selenium in your whole body. This selenium promotes healthy levels of thyroid hormone production which is needed to maintain a healthy metabolism and testosterone levels. One study found that those with low selenium levels were more at risk of thyroid disease and hypothyroidism than those with normal selenium levels.

While in general thyroid problems are more common in women than men, both an under- and overactive thyroid can cause problems for men in the bedroom. With an overactive thyroid, or hyperthyroidism, men can find themselves losing weight and suffering from hair loss, anxiety, and elevated levels of testosterone. Whereas with an underactive thyroid, or hypothyroidism, you are more likely to experience weight gain, low moods, and low libido and erectile dysfunction.

4. Contains other Important Micronutrients

Brazil nuts are chock full of the good stuff; a great addition to a plant-based diet, as they are rich in protein and dietary fibre. They’re also a great source of other micronutrients, not just selenium, including magnesium, copper and zinc. All important for healthy blood flow and blood pressure (and good erections), zinc especially is a testosterone friendly mineral thanks to its testosterone regulating properties.

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Key Takeaways

In short, while there’s no harm in chowing down on a handful of these nuts for their multiple health benefits, we just can’t say for sure that Brazil nuts increase testosterone.
Approved testosterone replacement therapy treatment and lifestyle changes are more likely to improve your testosterone levels. So, if you think you have the symptoms of low-T, it’s best to get checked out by a medical professional. They will be able to point you in the right direction of treatment if you need it.


Endocrine Society – Most Men with Borderline Testosterone Levels May Have Depression:


Healthline – Selenium Deficiency:


R Scott, A MacPherson, R W Yates, B Hussain, J Dixon (1998). The effect of oral selenium supplementation on human sperm motility:


Mohammad Reza Safarinejad , Shiva Safarinejad (2008). Efficacy of selenium and/or N-acetyl-cysteine for improving semen parameters in infertile men: a double-blind, placebo controlled, randomized study:


Medical News Today – What are the benefits of eating Brazil nuts?


Men’s Health – A Growing Gut, a Sinking Sex Drive, and 7 Other Signs Your Thyroid Hormones Are Too Low:


Bárbara R Cardoso, Graziela B Silva Duarte, Bruna Z Reis, Silvia M F Cozzolino (2017). Brazil nuts: Nutritional composition, health benefits and safety aspects:


Ali Fallah, Azadeh Mohammad-Hasani, and Abasalt Hosseinzadeh Colagar (2018). Zinc is an Essential Element for Male Fertility: A Review of Zn Roles in Men’s Health, Germination, Sperm Quality, and Fertilization:


Qian Wu, Margaret P. Rayman, Hongjun Lv, Lutz Schomburg, Bo Cui, Chuqi Gao, Pu Chen, Guihua Zhuang, Zhenan Zhang, Xiaogang Peng, Hua Li, Yang Zhao, Xiaohong He, Gaoyuan Zeng, Fei Qin, Peng Hou, Bingyin Shi (2015). Low Population Selenium Status Is Associated With Increased Prevalence of Thyroid Disease:

While we've ensured that everything you read on the Health Centre is medically reviewed and approved, information presented here is not intended to be a substitute for professional medical advice, diagnosis, or treatment. It should never be relied upon for specific medical advice. If you have any questions or concerns, please talk to your doctor.

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