Black Soybean Tea Article

? Black Soybean Tea – Secret Worth Keeping – Dear Davey H

Executive Summary

Despite my efforts to make the Karma Sense Wellness blog a snark-free zone of positive energy, my readers taunt me with questions about some of the wild claims they experience on the web while avoiding work and the latest political blah-blah-blah on social media.

In this installment of Dear Davey H, I examine the super-secret diet drink from Japan, black soybean tea. This post serves the few people who are already in on the secret. It also targets readers interested in the process used to dissect the nutrition nonsense encountered in your daily life.

Dear Davey H

While perusing hyperspace, I was presented this post that posits the people of Japan are hiding a potent potion that prevents possible portliness. Is this possible? Please respond.



Black Soybean Tea – The Precise Picture

Dear P,

As much as I love a good alliteration, I need to break your streak as the spray from my mouth while I read this out loud makes a mess on my computer screen (I doubt anyone is surprised that I move my lips while I read).

P, I’m a big fan of the humble bean and believe it has amazingly healthful properties. It is a nutrient dense source of calories and is worthy of its veneration in the many cultures that adopt the legume as a staple.

Readers of The Karma Sense Eating Plan (an exclusive club that you can help democratize by getting your copy at this link), know how beans saved me from a summer of starvation. The bean is so important to me that it was the source of one of my spate of nicknames.

Yes, while many know me as “Davey H”, other PG-rated monikers include Big Poppa Pump, Tim (it’s true, some call me Tim)

Black Soybean Tea Tim

and finally, the relevant, Sir Rounded By Limas.

So P, as much as I would like to think it’s true that there is yet another brew made of freshly roasted beans with the miracle qualities described in the referenced article, I think not. But, before examining the article’s claims let’s look at the tea’s recipe:
Black Soybean Tea Recipe

And what does this buy you?

It Can Reduce Fat

The Short Story

Despite the articles claims, there is no food or drink in the world that absorbs body fat.

The Long Story

The article cites a study published in the Journal of Medicinal Food that demonstrates the anthocyanin in black soybeans “absorbs fat from the body.” There is no other information given but after a superficial search, I found the study at this link to be the only thing remotely close.

The good news is that the author seems to reference bona fide research. Sadly, that research doesn’t support the author’s case.

In the referenced experiment, the researchers fed each of four different groups of rats either a normal diet (ND), a high-fat diet (HFD), a high-fat diet that was high in black soybeans or a high-fat diet that included anthocyanins extracted from black soybeans.

In the end, rats fed an HFD with anthocyanins kept their weight in line with rats fed an ND. Rats fed black soybeans on an HFD gained weight but not as much as rats on an HFD without black soybeans.

What does this experiment prove? Black soybeans and pure anthocyanins extracted from the beans are somehow associated with limiting weight gain in rats.

What does the experiment not prove?

  1. That it’s the anthocyanin in black soybeans that limits weight gain in rats. If could be any number of factors in black soybeans that cause that effect. It could be the combination of black soybeans and the other contents in the HFD.
  2. That humans respond to black soybeans and pure anthocyanins the same way that rats do.
  3. That anthocyanin “absorbs fat from the body.” I don’t even know what that means but no known chemical reaction supports that statement.

Anthocyanins may help control weight. But you don’t have to drink some exotic bean tea to take advantage of them. Eat berries if you prefer. They’re loaded with anthocyanin.

It Suppresses Hunger

The Short Story

The alleged feature of black soybean tea that suppresses hunger is its fiber content. If you follow the recipe in the article, the tea has no fiber. So how does it suppress hunger?

The Long Story

The author claims that the fiber in black soybean tea slows digestion and that helps to stave off hunger.

That’s a well-known quality of fiber and black soybeans are a high fiber food (7g fiber in ½ cup or 121g serving).

Still, I don’t understand the mechanism that transfers fiber from roasted beans steeped in boiled water. It’s possible that some fiber of the soluble form find it’s way into the hot liquid. But most if not all is still in the bean and not in the cup of tea. I’m calling bullcrap on this one.

It Helps You Reduce Your Sugar Intake

The Short Story

This is subjective. There is no evidence for this claim.

The Long Story

The author maintains that black soybean tea is mildly sweet and satisfies your sweet tooth.

Someday I may taste this concoction. I haven’t yet. Until then, I’ll take the author’s word.

On the other hand, I have tasted the hipster-friendly nitro cold-brewed coffee. It too has a natural mild sweetness. And still, I see people emptying packets of sugar, both real and fake, into their drink. They accompany those drinks with giant pastries.

Sweet tooths are phenomena that tend towards stimulation as opposed to satisfaction. This claim seems like a throwaway to me.

It Boosts Metabolism

The Short Story

Once again, no evidence but even if you assume an above average effect, the impact is negligible.

The Long Story

Okay campers, time for some math.

Let’s say, for example, your total metabolism burns 2500 calories a day. Part of that 2500 is the thermic effect of food (TEF), which is the segment of your overall metabolism that responds to the food and drinks you take in. The average TEF is only about 15% of your total metabolism or 375 calories. Even if black soybean tea boosted your TEF 5%, which would be a Nobel Prize-worthy discovery, that’s a generous metabolism boost of 20 calories per day. If you make no other adjustment to your diet or activity, you can maintain your weight and have the luxury of adding three M&Ms to your diet. Another option is to forsake those M&Ms and you’ll lose one pound every six months. Is that a big enough boost for you?

If you want to increase your metabolism, do muscle building exercises.

It Can Make You Look Younger

The Short Story

If there is ever an award for “Most Content Free” passage in a health and wellness article, I will nominate this paragraph.

A good physique combined with good looks is a dream, but it can truly be achieved by drinking this natural drink. It contains compounds known as polyphenols that work as anti-aging agents to help keep you looking young and fresh.

The Long Story

Longtime followers of Karma Sense  know that no single food or drink makes a person literally look younger. Anyone who believes otherwise already moved on from this blog and went back to watching Dr. Oz.

Normally I would give a writer a pass for taking poetic license like this. After all, I’m the guy who claims that following the guidelines in The Karma Sense Eating Plan helps you be healthy, be happy and, oh yeah, save the world!

But in that book, I devote over 300 pages of research-based narrative and poopy jokes to demonstrate that “Be Healthy. Be Happy. Save the World!” is more than just a catchphrase.

I highlighted the phrase above because it is at least partially factual. Like thousands of other readily available plant-based foods, black soybeans have polyphenols. The predominant polyphenol in black soybeans is the aforementioned fat-absorbing anthocyanin.

P, there is no evidence that:

  • A good physique combined with good looks is a dream,
  • This dream can truly be achieved by drinking black soybean tea, or
  • Polyphenols keep you looking young and fresh (and before you ask, there were no studies that proved they kept you young or fresh, either)

and there never will be.

There is some evidence for the claim about polyphenols. For example, in this experiment, the investigators extracted anthocyanins  from black soybeans and applied them to mouse cells. This application appeared to reverse DNA damage. That’s actually pretty cool. For mice.

But for humans reading this post, it doesn’t prove much. Not only because we’re not mice but because we don’t consume anthocyanins in isolation. The anthocyanins in black soybeans share real estate with thousands of other compounds that interact with our human cells in ways that are very different from how any one of those compounds would on its own.

Speaking of real estate. I spent way too much of this post’s real estate on this specious claim so let me move onto the last one.

It Is Easy To Find

The Short and Long Story

Okay, when it comes to this claim, black soybean tea is better than Waldo.

Black Soybean Tea Waldo

But if it’s so easy to find, how could it be a Japanese Diet SECRET? If it’s east to find, it’s not a secret.

In Summary

The Bullcrap detector for this article about black soybean tea is pegged in the red zone.


But, Dear P

Don’t assume I dismiss black soybean tea in total just because this article is bullcrap. I’m a huge believer that tonics with massive health benefits exist and that black soybean tea may be one. If the author of this article took the time to state a logical case, I’d feel better about these claims. There is probably nothing wrong with drinking black soybean tea and would encourage people to do so if they enjoy it. But just know, that I could easily write a fact-based article that asserts that black soybean tea is the worst thing ever to come out of Japan since those giant nuclear monsters. But I wouldn’t do that. Because, well…beans.

Yours in Good Karma,

Davey H


If you agree with thousand of others, that 300 pages of research-based narrative and poopy jokes focused on the topic of “Be Healthy. Be Happy. Save the World!” can be more than just a catchphrase, it’s not too late to get your copy of The Karma Sense Eating Plan. I donate ALL PROFITS to Alice’s Kids, a charity that protects the dignity of America’s school children living in poverty.
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