Açaí vs. Wild Blueberries for Artery Function

“Plant-based diets…have been found to reduce the risk of cardiovascular disease” and some of our other 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 açaí berries, just one plant, for brain health and performance?

Well, “foods rich in polyphenols…improve brain health,” and açaí berries contain lots of polyphenols and antioxidants, so perhaps that’s why they could be beneficial. If you’re only looking at polyphenols, though, there are more than a dozen foods that contain more per serving, like black elderberry, regular fruits like plums, flaxseeds, dark chocolate, and even just a cup of coffee.

As you can see at 1:02 in my video The Benefits of Açaí vs. Blueberries for Artery Function, in terms of antioxidants, açaí berries may have ten times more antioxidant content than more typical fruits, like peaches and papayas, and five times more antioxidants than strawberries. But blackberries, for instance, appear to have even more antioxidants than açaí berries and are cheaper and more widely available.

Açaí berries don’t just have potential brain benefits, however. Might they also protect the lungs against harm induced by cigarette smoke? You may remember the study where the addition of açaí berries to cigarettes protected against emphysema—in smoking mice, that is. That’s not very helpful. There is a long list of impressive-looking benefits until you dig a little deeper. For example, I was excited to see a “[r]eduction of coronary disease risk due to the vasodilation effect” of açaí berries, but then I pulled the study and found they were talking about a vasodilator effect…in the mesenteric vascular bed of rats. There hadn’t been any studies on açaí berries and artery function in humans until a study published in 2016.

Researchers gave overweight men either a smoothie containing about two-thirds of a cup of frozen açaí pulp and half a banana or an artificially colored placebo smoothie containing the banana but no açaí. As you can see at 2:26 in my video, within two hours of consumption of their smoothie, the açaí group had a significant improvement in artery function that lasted for at least six hours, a one or two point bump that is clinically significant. In fact, those walking around with just one point higher tend to go on to suffer 13 percent fewer cardiovascular events like fatal heart attacks.

As I show at 2:52 in my video, you can get the same effect from wild blueberries, though: about a one-and-a-half-point bump in artery function two hours after blueberry consumption. This effect peaks then plateaus at about one and a half cups of blueberries, with two and a half cups and three and a half cups showing no further benefits.

What about cooked blueberries? As you can see at 3:12 in my video, if you baked the blueberries into a bun, like a blueberry muffin, you get the same dramatic improvement in artery function.

Cocoa can do it, too. As shown at 3:30 in my video, after having one tablespoon of cocoa, you gain about one point, and two tablespoons gives you a whopping four points or so, which is double what you get with açaí berries.

One and a quarter cups’ worth of multicolored grapes also give 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? Researchers gave participants a “McDonald’s sausage egg breakfast sandwich and two hash browns.” They weren’t messing around! As you can see at 3:56 in my video, without the grapes, artery function was cut nearly in half within an hour, and the arteries stayed stiffened and crippled three hours later. But when they ate that McMuffin with all those grapes, the harmful effect was blunted.

Eat a meal with hamburger meat, and artery function drops. But if you eat that same meal with some spices, including a teaspoon and a half of turmeric, artery function actually improves.

What about orange juice? Four cups a day of commercial orange juice from concentrate for four weeks showed no change in artery function. What about freshly squeezed orange juice? Still nothing. That’s one of the reasons berries, not citrus, are the healthiest fruits.

For a beverage that can improve your artery function, try green tea. Two cups of green tea gives you that same effect we saw with cocoa, gaining nearly four points within just 30 minutes. And, as you can see at 5:05 in my video, that same crazy effect is also seen with black tea, with twice as powerful an effect as the açaí berries.

So, why all the focus on just that one plant? Why açaí berries? Well, the real reason may be because the author owns a patent on an açaí-based dietary supplement.


How do the antioxidant effects of açaí berries compare to applesauce? See The Antioxidant Effects of Açaí vs. Apples.

What about the effects of other foods on artery function? Coronary artery disease is, after all, our leading cause of death for men and women. See:

What else can blueberries do? Check out:

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

70% Taking Common Antidepressants Suffer Sexual Side Effects

What’s the latest on treating depression with the spice saffron? Years ago, I covered a head-to-head comparison of saffron versus Prozac for the treatment of depression in my video Saffron vs. Prozac, and saffron seemed to work just as well as the drug. In the years since, five other studies have found that saffron beat out placebo or rivaled antidepressant medications.

It may be the spice’s red pigment, crocin, since that alone beat out placebo as an adjunct treatment, significantly decreasing symptoms of depression, symptoms of anxiety, and general psychological distress. Perhaps, its antioxidants played a role in “preventing free radical-induced damage in the brain.” The amount of crocin the researchers used was equivalent to about a half teaspoon of saffron a day.

If the spice works as well as the drugs, one could argue that the spice wins, since it doesn’t cause sexual dysfunction in the majority of men and women like most prescribed antidepressants do. SSRI drugs like Prozac, Paxil, and Zoloft cause “adverse sexual side effects” in around 70 percent of people taking them. What’s more, physicians not only significantly underestimate the occurrence of side effects, but they also tend to underrate how much they impact the lives of their patients.

Not only is this not a problem with saffron, the spice may even be able to treat it, as I explore in my video Best Food for Antidepressant-Induced Sexual Dysfunction. “In folk medicine, there is a widely held belief that saffron might have aphrodisiac effects.” To test this, men with Prozac-induced sexual impairment were randomized to saffron or placebo for a month. By week four, the saffron group “resulted in significantly greater improvement in erectile function…and intercourse satisfaction,” and more than half of the men in the saffron group regained “normal erectile function.” The researchers concluded that saffron is an “efficacious treatment” for Prozac-related erectile dysfunction. It has all been found to be effective for female sexual dysfunction, as well, as you can see at 2:35 in my video. Female sexual function increased by week four, improving some of the Prozac-induced sexual problems but not others. So, it may be better to try saffron in the first place for the depression and avoid developing these sexual dysfunction problems, since they sometimes can persist even after stopping the drugs, potentially worsening one’s long-term depression prognosis.

This includes unusual side effects, such as genital anesthesia, where you literally lose sensation. It can happen in men and women. More rarely, antidepressants can induce a condition called restless genital syndrome. You’ve heard of restless legs syndrome? Well, this is a restless between-the-legs syndrome. These PSSDs, or Post-SSRI Sexual Dysfunctions, meaning dysfunctions that appear or persist after stopping taking these antidepressants, can be so serious that “prescribing physicians should mention the potential danger of the occurrence of genital (e.g., penile or vaginal) anesthesia to every patient prior to any SSRI treatment.” If you’re on one of these drugs, did your doctor warn you about that?

All hope is not lost, though. Evidently, penile anesthesia responds to low-power laser irradiation. After 20 laser treatments to his penis, one man, who had lost his penile sensation thanks to the drug Paxil, partially regained his “penile touch and temperature sensation.” However, he still couldn’t perform to his girlfriend’s satisfaction, and she evidently ended up leaving him over it, which certainly didn’t help his mood. But, before you feel too badly for him, compare a little penile light therapy to clitoridectomy, clitoris removal surgery, or another Paxil-related case where a woman’s symptoms only improved after six courses of electroshock therapy.

Pass the paella!


For more on the spice, check out:

Those drug side effects sound devastating, but depression is no walk in the park. However, when one balances risk and benefit, one assumes that there are actually benefits to taking them. That’s why the shocking science I explored in Do Antidepressant Drugs Really Work? is so important.

What else may boost mood? A healthy diet and exercise:

For more on sexual health generally, see:

What else can spices do? Here’s just a taste:

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

How to Treat Polycystic Ovary Syndrome (PCOS) with Diet

Given the role that oxidant free radicals are thought to play in aging and disease, one reason fruits and vegetables may be so good for us is that they contain antioxidant compounds. As you can see at 0:20 in my video Benefits of Marjoram for Polycystic Ovary Syndrome (PCOS), different vegetables and herbs have different antioxidant content. When making a salad, for example, spinach, arugula, or red leaf lettuce may provide twice the antioxidants as butterhead lettuce, and choosing purple cabbage over green, or red onions over white can also boost the salad’s antioxidant power.

Fresh herbs are so powerful that even a small amount may double or even quadruple the antioxidant power of the entire meal. For instance, as you can see at 0:50 in my video, the total antioxidants in a simple salad of lettuce and tomato jump up by adding just a tablespoon of lemon balm leaves or half a tablespoon of oregano or mint. Adding marjoram, thyme, or sage not only adds great flavor to the salad, but effectively quadruples the antioxidant content at the same time, and adding a little fresh garlic or ginger to the dressing ups the antioxidant power even more.

Herbs are so antioxidant-rich that researchers decided to see if they might be able to reduce the DNA-damaging effects of radiation. Radioactive iodine is sometimes given to people with overactive thyroid glands or thyroid cancer to destroy part of the gland or take care of any remaining tumor cells after surgery. For days after the isotope injection, patients become so radioactive they are advised not to kiss or sleep close to anyone, including their pets, and if they breathe on a phone, they’re advised to wipe it “carefully” or cover it “with an easily removed plastic bag.” Other recommendations include “avoid[ing] splatter of radioactive urine,” not going near your kids, and basically just staying away from others as much as possible.

The treatment can be very effective, but all that radiation exposure appears to increase the risk of developing new cancers later on. In order to prevent the DNA damage associated with this treatment, researchers tested the ability of oregano to protect chromosomes of human blood cells in vitro from exposure to radioactive iodine. As you can see at 2:25 in my video, at baseline, about 1 in 100 of our blood cells show evidence of chromosomal damage. If radioactive iodine is added, though, it’s more like 1 in 8. What happens if, in addition to the radiation, increasing amounts of oregano extract are added? Chromosome damage is reduced by as much 70 percent. Researchers concluded that oregano extract “significantly protects” against DNA damage induced by the radioactive iodine in white blood cells. This was all done outside the body, though, which the researchers justified by saying it wouldn’t be particularly ethical to irradiate people for experimental research. True, but millions of people have been irradiated for treatment, and researchers could have studied them or, at the very least, they could have just had people eat the oregano and then irradiate their blood in vitro to model the amount of oregano compounds that actually make it into the bloodstream.

Other in vitro studies on oregano are similarly unsatisfying. In a comparison of the effects of various spice extracts, including bay leaves, fennel, lavender, oregano, paprika, parsley, rosemary, and thyme, oregano beat out all but bay leaves in its ability to suppress cervical cancer cell growth in vitro while leaving normal cells alone. But people tend to use oregano orally—that is, they typically eat it—so the relevance of these results are not clear.

Similarly, marjoram, an herb closely related to oregano, can suppress the growth of individual breast cancer cells in a petri dish, as you can see at 3:53 in my video, and even effectively whole human breast tumors grown in chicken eggs, which is something I’ve never seen before. Are there any clinical trials on oregano-family herbs on actual people? The only such clinical, randomized, control study I could find was a study on how marjoram tea affects the hormonal profile of women with polycystic ovary syndrome (PCOS). The most common cause of female fertility problems, PCOS affects up to one in eight young women and is characterized by excessive male hormones, resulting in excess body or facial hair, menstrual irregularities, and cysts in one’s ovaries that show up on ultrasounds.

Evidently, traditional medicine practitioners reported marjoram tea was beneficial for PCOS, but it had never been put to the test…until now. Drinking two daily cups of marjoram tea versus a placebo tea for one month did seem to beneficially affect the subjects’ hormonal profiles, which seems to offer credence to the claims of the traditional medicine practitioners. However, the study didn’t last long enough to confirm that actual symptoms improved as well, which is really what we care about.

Is there anything that’s been shown to help? Well, reducing one’s intake of dietary glycotoxins may help prevent and treat the disease. Over the past 2 decades there has been increasing evidence supporting an important contribution from food-derived advanced glycation end products (AGEs)…[to] increased oxidative stress and inflammation, processes that play a major role in the causation of chronic diseases,” potentially including polycystic ovary syndrome (PCOS). Women with PCOS tend to have nearly twice the circulating AGE levels in their bloodstream, as you can see at 0:33 in my video Best Foods for Polycystic Ovary Syndrome (PCOS). 

PCOS may be the most common hormonal abnormality among young women in the United States and is a common cause of infertility, menstrual dysfunction, and excess facial and body hair. The prevalence of obesity is also higher in women with PCOS. Since the highest AGE levels are found in broiled, grilled, fried, and roasted foods of “mostly animal origin,” is it possible that this causal chain starts with a bad diet? For instance, maybe eating lots of fried chicken leads to obesity, which in turn leads to PCOS. In that case, perhaps what we eat is only indirectly related to PCOS through weight gain. No, because the same link between high AGE levels and PCOS was found in lean women as well.

“As chronic inflammation and increased oxidative stress have been incriminated in the pathophysiology [or disease process] of PCOS, the role of AGEs as inflammatory and oxidant mediators, may be linked with the metabolic and reproductive abnormalities of the syndrome.” Further, the buildup of AGE inside polycystic ovaries themselves suggests a potential role of AGEs contributing to the actual disease process, beyond just some of its consequences.

RAGE is highly expressed in ovarian tissues. The receptor in the body for these advanced glycation end products, the “R” in RAGE, is concentrated in the ovaries, which may be particularly sensitive to its effect. So, AGEs might indeed be contributing to the cause of PCOS and infertility.

Does this mean we should just cut down on AGE-rich foods, such as meat, cheese, and eggs? Or hey, why not come up with drugs that block AGE absorption? We know AGEs have been implicated in the development of many chronic diseases. Specifically, food-derived AGEs play an important role because diet is a major source of these pro-inflammatory AGEs. Indeed, cutting down on these dietary glycotoxins reduces the inflammatory response, but the “argument is often made that stewed chicken would be less tasty than fried chicken…” Why not have your KFC and eat it, too? Just take an AGE-absorption blocking drug every time you eat it to reduce the absorption of the toxins. What’s more, it actually lowers AGE blood levels. This oral absorbent drug, AST-120, is just a preparation of activated charcoal, like what’s used for drug overdoses and when people are poisoned. I’m sure if you took some ipecac with your KFC, your levels would go down, too.

There’s another way to reduce absorption of AGEs, and that’s by reducing your intake in the first place. It’s simple, safe, and feasible. The first step is to stop smoking. The glycotoxins in cigarette smoke may contribute to increased heart disease and cancer in smokers. Then, decrease your intake of high-AGE foods, increase your intake of foods that may help pull AGEs out of your system, like mushrooms, and eat foods high in antioxidants, like berries, herbs, and spices. “Dietary AGE intake can be easily decreased by simply changing the method of cooking from a high dry heat application to a low heat and high humidity…” In other words, move away from broiling, searing, and frying to more stewing, steaming, and boiling.

What we eat, however, may be more important than how we cook it. At 4:00 in my video, I include a table showing the amounts of AGEs in various foods. For instance, boiled chicken contains less than half the glycotoxins of roasted chicken, but even deep-fried potatoes have less than boiled meat. We can also eat foods raw, which doesn’t work as well as for blood pudding, but raw nuts and nut butters may contain about 30 times less glycotoxins than roasted, and we can avoid high-AGE processed foods, like puffed, shredded, and flaked breakfast cereals.

Why does it matter? Because study after study has shown that switching to a low-AGE diet can lower the inflammation within our bodies. Even just a single meal high in AGEs can profoundly impair our arterial function within just two hours of consumption. At 4:54 in my video, you can see the difference between a meal of fried or broiled chicken breast and veggies compared with steamed or boiled chicken breast and veggies. Same ingredients, just different cooking methods. Even a steamed or boiled chicken meal can still impair arterial function, but significantly less than fried or broiled.

“Interestingly, the amount of AGEs administered [to subjects] during the HAGE [high-AGE] intervention was similar to the average estimated daily intake by the general population,” who typically follow the standard American diet. This is why we can decrease inflammation in people by putting them on a low-AGE diet, yet an increase in inflammation is less apparent when subjects switch from their regular diet to one high in AGEs. Indeed, they were already eating a high-AGE diet with so many of these glycotoxins.

Do we have evidence that reducing AGE intake actually helps with PCOS? Yes. Within just two months, researchers found differences from subjects’ baseline diets switched to a high-AGE diet and then to a low-AGE diet, with parallel changes in insulin sensitivity, oxidative stress, and hormonal status, as seen at 5:54 in my video. The take-home learning? Those with PCOS may want to try a low-AGE diet, which, in the study, meant restricting meat to once a week and eating it only boiled, poached, stewed, or steamed, as well as cutting out fast-food-type fare and soda.

What if instead of eating steamed chicken, we ate no meat at all? Rather than measuring blood levels, which vary with each meal, we can measure the level of glycotoxins stuck in our body tissues over time with a high-tech device that measures the amount of light our skin gives off because AGEs are fluorescent. And, not surprisingly, this turns out to be a strong predictor of overall mortality. So, the lower our levels, the better. The “one factor that was consistently associated with reduced [skin fluorescence]: a vegetarian diet.” This “suggests that a vegetarian diet may reduce exposure to preformed dietary AGE…potentially reduc[ing] tissue AGE,” as well as chronic disease risk


What’s so great about antioxidants? See my videos:

Just how many antioxidants do we need? Check out:

For a few simple tips on how to quickly boost the antioxidant content of your food with herbs and spices, see my video Antioxidants in a Pinch.

I touched on the benefits of spearmint tea for PCOS in Enhancing Athletic Performance with Peppermint. Another sorely under-recognized gynecological issue is endometriosis, which I discuss in How to Treat Endometriosis with Seaweed.

Because of AGEs, I no longer toast nuts or buy roasted nut butters, which is disappointing because I really enjoy those flavors so much more than untoasted and unroasted nuts. But, as Dr. McDougall likes to say, nothing tastes as good as healthy feels. For more on why it’s important to minimize our exposure to these toxic compounds, see:

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations: