There are lots of things we want to do in life. Climb a mountain, write a song, watch our grandchildren grow up. But guess what? We can’t do any of those things if we don’t have our health.
Welcome to the Nutrition Facts Podcast. I’m your host Dr. Michael Greger. And I’m here to bring you evidence-based research that takes the mystery out of the best way to live a healthier, longer life.
Today on the show we continue our series on potential super foods. And today’s show is looking at the Acai berry. Whenever a new so-called superfood hits the market, the first thing researchers tend to look at its chemistry and antioxidant capacity. Based on one measure of antioxidants, the Acai berry had “the highest of any food reported to date,” in a report from 2006.
In our first story, we look at the antioxidant content of 300 foods by serving.
The average antioxidant content of much of what Americans eat—peas and carrots, corn, lettuce, bananas—just as a reference.
Let’s go in reverse order for the top dozen superfoods, starting with #12: a tablespoon of cocoa powder, which I talked about in my 2007 review. #11: a half-cup of blueberries. Blueberries didn’t even make the top ten this year! In tenth place, a pomegranate. Ninth, one black plum. Eighth, a handful of pecans. Seventh, one pear. Sixth, a half-cup of cranberries. Fifth, an apple. Fourth, a teaspoon of cinnamon. Third, an artichoke. The runner-up: a half-cup of goji berries. And, if you were given the choice to eat a single serving of any food on the planet, in terms of antioxidant power, you wouldn’t be going to the Himalayas for gojis, you’d go to Brazil. Way off the charts. Nearly 75,000 antioxidant units, a half-cup serving of açai berries.
They’re so purple, they’re black. In fact, the color is so intense that they sometimes actually give these berries to people before abdominal MRIs, because it actually stains the inside of your intestines, and can kind of act as contrast.
Okay, a few observations on our dozen. First, every food you don’t see on the list has an antioxidant per serving level between about 400 and 4,000 which just underscores how amazing these foods are.
Second: artichokes? That was a surprise. Ever since I’ve learned that, I always keep a can of artichoke hearts in our pantry, and try to add them wherever we can. That’s basically how it works. I come back from a long day of research at the National Library of Medicine, and go straight to the grocery store to put it into practice, whatever I find out.
And finally, check it out: plums, pears, and apples. You don’t have to go to the other side of the world or order exotic fruit over the internet. We hear how amazing pomegranates are, but one plum, one pear, one simple, humble apple beats them out. Which brings up an important point: cost.
You can pretty much walk into any big natural food store, go to the frozen section, and buy a pound of açai berries. But it may cost five or ten dollars! So, in terms of practicality, I calculated not only antioxidants per serving, but antioxidants per dollar.
In our next story we explore how an independent review of the effects of açaí berries was published, that included studies on immune function, arthritis, and metabolic parameters.
An “Evidence-Based Systematic Review of Açaí” berries was recently published by the Natural Standards Research Collaboration, an impartial scientific body that refuses to take support from product manufacturers cited by the World Health Organization as one of the most authoritative sources on such matters.
What did they find? Whenever a new purported superfood hits the market, the first thing researchers tend to do is look at its chemistry, such as antioxidant capacity, which was done back in 2006. Based on one measure, it had “the highest antioxidant capacity of any food reported to date”. A remarkable finding I reported at the time, arguing that, despite its cost, frozen açaí pulp represented one of the best antioxidant bangs for one’s buck. But, still, we didn’t know what it did outside of a test tube.
The next step is to go from test tube to petri dish, and try it out on some human cells. They dripped the concentration of açaí berry phytonutrients one would expect in one’s bloodstream after eating them on some blood cancer cells taken from a woman with leukemia, and saw a dramatic rise in cancer cell mortality. In fact, about twice what was found previously, using similar concentrations of hibiscus tea, on the same cancer.
Açaí was also found to boost immune cell function at extremely low doses. Slowly but surely, researchers began piecing together the mechanism by which açaí affected cellular function.
Still no human studies, though. Researchers moved from cells to animal models. Who could forget the “Addition of açaí to cigarettes has a protective effect against emphysema in mice.” Instead of adding berries to their cigarettes, though, it might be easier to just encourage the mice to quit smoking. But then, finally, starting in 2011, studies on actual people.
“Pain Reduction and Improvement in Range of Motion After Daily Consumption of an Açaí” in about a dozen folks with painful conditions, like osteoarthritis. After three months, antioxidant levels went up, and pain levels went down. Though since there was no blinded control group drinking like some artificially açaí-flavored Kool-Aid, the placebo effect could not be excluded.
And, finally, one last pilot study. The “Effects of Açai on Metabolic Parameters.” Ten overweight folks were given two packs of frozen açaí pulp every day for a month. And, even though they were allowed to take it with sugar, their fasting blood sugars dropped, as did their insulin levels, and cholesterol. And, it significantly blunted the sugar spike caused by a standardized meal all without any observed adverse effects. In fact, the only theoretical concerns cited in the new review may be that it might work too well. If you’re on diabetic blood sugar-lowering medications, it could potentially drop your blood sugar too low. Or, if you have an autoimmune disease, or are on immunosuppressants, it could stimulate your immune system too much.
But, what about the case report of the guy whose muscles started dissolving after using this açaí berry supplement? Turns out, there was no açaí berry in it, at all! That’s the problem with taking supplements. They’re so poorly regulated, you never know what you’re getting.
For example, a study was done on 27 supplements of another purported superfruit, pomegranate. “Of the 27 supplements tested, only 5 appeared to be what they actually said.”
Fine, you say, no pills, you’ll just stick to the juice. “45 commercial pomegranate juice samples from 23 different manufacturers in the United States.” They all said they contained 100% pomegranate juice, on the label, but most of them lied; only 6 out of 23 were what they said they were. The only source you can be guaranteed to get authentic pomegranate juice has no label at all.
Finally today, what are the effects of açai berries, cooked and raw blueberries, grapes, cocoa, green tea, and freshly squeezed orange juice on artery function?
“Plant-based diets have been found to reduce the risk of” some of our leading causes of death and disability. “Studies have shown that the longest living and least dementia-prone populations subsist on plant-based diets.” So, why focus on just this one plant for brain health and performance, açai berries? Well, “foods rich in polyphenols appear to improve brain health,” and açai berries have lots of polyphenols and antioxidants; so, maybe they’d help.
But, if you’re just looking at polyphenols, there are over a dozen foods that have more per serving, and it doesn’t have to be black elderberry. Regular fruits, like plums, have more; a few spoonfuls of flax seeds, a few squares of dark chocolate, or even just a cup of coffee, has more.
In terms of antioxidants, yes, açai berries may have ten times more antioxidant content than more typical fruits, like peaches and papayas; five times more than strawberries, but comparable to blackberries. In fact, blackberries appear to have even more antioxidants, and are cheaper and more widely available.
Ah, but açai berries don’t just have potential brain benefits; for example, protecting the lungs against “harm induced by cigarette smoke.” But you all remember that study, right? That’s the one where “addition of açai berries to cigarettes has a protective effect against emphysema in smoking mice.” That’s not very helpful. There’s this long list of impressive-looking benefits, until you dig a little deeper.
For example, I was excited to see “reduction of coronary disease risk due to a vasodilation effect,” but less excited when I pulled the study, and found out that they were talking about a “vasodilator effect in the mesenteric vascular bed of the rat.” But, there hadn’t been any studies on açai berries and artery function in humans, until now.
Give some overweight men a smoothie containing about two-thirds of a cup of frozen açai pulp, and a half a banana, versus an artificially-colored placebo smoothie with the banana but no açai; you get a significant improvement in artery function within two hours of consumption, which lasts at least for six hours. That one or two-point bump is clinically significant. Those walking around with just a point higher go on to have 13% fewer cardiovascular events like fatal heart attacks.
You can get the same effect from wild blueberries, though, about a point-and-a-half bump two hours after wild blueberry consumption. An effect peaking and plateauing at about one-and-a-half cups of blueberries, with two-and-a-half or three-and-a-half cups showing no further benefits.
What about cooked blueberries? Here’s the same wild blueberry drink effect we saw before. But what if you baked the blueberries into a bun, like a blueberry muffin? Same dramatic improvement in artery function.
Cocoa can do it, too. One tablespoon of cocoa gets you about a point, and two tablespoons is like a whopping four points. That’s like double the berries.
One-and-a-quarter cups worth of multicolored grapes gave a nice boost in artery function, but enough to counter an “acute endothelial insult”; a sudden attack on the vulnerable inner layer of our arteries? They decided on a sausage-and-egg McMuffin meal; they weren’t messing around. Without the grapes, that meant cutting artery function nearly in half within an hour, and the artery stayed stiffened and crippled three hours later. But, eat that McMuffin with all those grapes, and hardly any effect.
Eat a meal with hamburger meat, and artery function drops after the meal. But, eat that same meal with some spices, including a teaspoon and a half of turmeric, and your artery function gets better.
What about orange juice? Four cups a day for four weeks, and no change in artery function. Ah, but that was commercial orange juice from concentrate. What about freshly squeezed orange juice? Still nothing. That’s one of the reasons berries are the healthiest fruits.
Want a beverage that can improve your artery function? Green tea. Two cups of green tea, and you get that same cocoa effect, nearly four points within just 30 minutes. And, that same crazy effect you get with green tea, you get with black tea. Twice as powerful an effect as the açai berries.
So, why focus on just that one plant? Well, the real reason, presumably, is that the author owns a patent on an açai-based dietary supplement.
We would love it if you could share with us your stories about reinventing your health through evidence-based nutrition. Go to NutritionFacts.org/testimonials. We may share it on our social media to help inspire others.
To see any graphs, charts, graphics, images, or studies mentioned here, please go to the Nutrition Facts Podcast landing page. There you’ll find all the detailed information you need, plus links to all of the sources we cite for each of these topics.
For recipes, check out my “How Not to Die Cookbook.” It’s beautifully designed, with more than 100 recipes for delicious and nutritious meals. All the proceeds I receive from the sales of my books all goes to charity.
NutritionFacts.org is a nonprofit, science-based public service, where you can sign up for free daily updates on the latest in nutrition research via bite-sized videos and articles.
Everything on the website is free. There’s no ads, no corporate sponsorship. It’s strictly non-commercial. I’m not selling anything. I just put it up as a public service, as a labor of love, as a tribute to my grandmother, whose own life was saved with evidence based nutrition.
Thanks for listening to Nutrition Facts. I’m your host, Dr. Michael Greger.