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Flaxseed Nutrition and Testosterone: Do Not Eat These Seeds

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When you look up any blog or listicle outlining the top 10 superfoods, you can almost be sure that flaxseeds will be on the list. Indeed, flaxseed nutrition is something to behold. The seeds are chockfull of antioxidants, vitamins and minerals. BUT – and it’s a big but – the seed is absolutely ruined (for men at least) due to the presence of a single compound that is detrimental for testosterone production.

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Flaxseed Nutrition 101

Why exactly are flaxseeds touted as this amazing wonder-food, anyway? For starters, a study published in the Journal of Clinical Cancer Research showed that flaxseeds may fight off malignant tumors and offset the risk of ovarian and breast cancer. In addition, flaxseeds are also high in insoluble fiber, not to mention they’re gluten-free, making them a tempting source for anyone with gluten-sensitivity.

So, What’s the Problem with Flaxseeds, Then?

Flaxseeds contain a polyphenol known as lignans. We’ll put it this way: if your main goal is increasing testosterone, then flaxseed lignans are your worst nightmare. Why? They are EXTREMELY estrogenic.

Here is a shocking fact: flaxseeds contain 800 times the amount of lignans than any other food known to man.

Lignans have been proven in multiple human studies to lower both total and free testosterone. They also increase circulating estrogen and limit the activity of 5-alpha reductase. If you’re not familiar with the latter, it’s an enzyme that converts testosterone to dihydrotestosterone.

That’s not all. Lignans also increase sex hormone binding globulins (SHBG). This glycoprotein binds to testosterone molecules and makes them inert. In other words, the testosterone becomes useless.

In addition, flaxseeds, like soy, contain phytoestrogens. This compound has been classified by some as an endocrine disruptor. Chemicals that cause endocrine disruption have been linked to disturbances in the immune system and neurodevelopment disorders.

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What the Studies Show

Study #1

In a 2007 study, a 31-year-old woman diagnosed with hirsutism was given a flaxseed supplement. Hirsutism is a disorder that causes an abnormally high production rate of testosterone in women. Hirsutism leads to undesirable traits, such as a deep, manly voice and body hair.

READ MORE: 3 Foods That Kill Testosterone Levels

After four months of supplementation, the woman’s total serum testosterone levels dropped by an astounding 70 percent while free testosterone dipped by an even more impressive 89 percent. In this case, the testosterone decrease for the subject was a good thing. However, this should naturally lead men to wonder what the implications are if they were to consume flaxseeds.

Study #2

Okay, you may think that the study is not fully valid because it was done on a single subject who is also female. Fair enough. Here then, is a 2001 study involving 25 male subjects. The men were diagnosed with prostate cancer. As part of their treatment, they were given a flaxseed supplement, which they consumed 30 grams daily for an average of 34 days. The aftermath? Total testosterone dropped by 15 percent and free testosterone decreased by 20 percent.

While the decrease may not be as dramatic as that of the woman with hirsutism, it’s still pretty significant. Would you be okay with having 15 percent less testosterone?

Study #3

Here’s one more study if you’re still on the fence. In this study published under Science Direct, male Wistar rats that consumed flaxseed-infused milk had higher levels of the estradiol hormone and also had a smaller corpus spongiosum compared to the control group. The corpus spongiosum is a mass of erectile tissue that lines the inner penis.

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Are All Flaxseed Types the Same?

Flaxseeds come in several variations. They’re available as whole seeds, as grounded mill, as oil and as a dietary supplement in capsule form. Regardless, they’re all flaxseeds and contain the same mega-high lignan content.

Flaxseeds may also be labelled as brown or golden flaxseeds. The color distinction is due to the climate in which they’re grown. The nutritional content is more or less the same. That includes the same lignan profile.

In stores, you may see flaxseed products with labeling that read:

  • Milled flax
  • Flaxseed meal
  • Ground flaxseed
  • Cold milled ground flax

Regardless of the different name iterations, treat all flaxseed nutrition as the same. In other words, if it has the word “flax,” then keep it out of your shopping cart.

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A Final Word About Flaxseeds

We want to make it clear that we’re not suggesting that flaxseeds are as bad as processed chocolate cake or deep-fried Twinkies. Flaxseeds are good in many aspects — just not good in others. The problem is that modern health circles only look at one element. They may look at flaxseed nutrition and proclaim it to be universally healthy just because it contains insoluble fiber.

LEARN MORE: Can Women Benefit From Boosting Testosterone?

Likewise, researchers may examine the lignan profile and proclaim the polyphenol to be healthy. Lignan, after all, has been shown to protect against cardiovascular and breast cancer. In this respect, lignans are healthy. However, this does not mean it’s universally good for everyone. Flaxseed lignans can throw hormonal health out of balance in men.

You Have Plenty of Other Food Options

You’re not missing out on any healthy stuff by eschewing flaxseed nutrition. Nutrients like magnesium, selenium and phosphorus are all found abundantly in other foods that don’t contain outrageous concentrations of lignans. They are also available in ample amounts via supplementation. Consider supplements like Testro-X or any of the foods listed in our dozens of past blog posts and videos.


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Ryan Tronier

Ryan Tronier is a writer and editor who has worked with NBC, ABC, and USA Today.
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