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:

The Best Dried Fruit for Osteoporosis

“We are in an epidemic of osteoporosis. There can be no doubt about that.” Ten million Americans have it, and one in three older women will get it. “We urgently need public health strategies to maintain bone health throughout the life cycle and to prevent osteoporosis in later life.” Might fruits and vegetables be the unexpected natural answer to the question of osteoporosis prevention? My video Prunes for Osteoporosis sought to find out.

Evidence from a variety of studies “strongly points to a positive link between fruit and vegetable consumption and indexes of bone health,” such as bone mineral density, and the “size of the effect in the older women [is] impressive: doubling the fruit intake” is associated with a 5 percent higher spine mineralization. The same relationship exists with young women, too. And, eating lots of fruit in childhood may protect bones throughout life—something that was not found for milk intake, as I’ve explored before in my video Is Milk Good For Our Bones?

Bone health isn’t just about calcium. There are several key nutrients found in vegetables, fruits, and beans that are associated with better bone mineral density, but does that translate into lower hip fracture risk? The Singapore Chinese Health Study found that a “diet rich in plant-based foods, namely vegetables, fruit, and legumes such as soy, may reduce the risk of hip fracture.” But, why?

“The underlying mechanism in postmenopausal osteoporosis (PO) is an imbalance between bone resorption [disappearance] and formation,” and oxidative stress may play a role in this balance.

There are two types of bone cells: “the bone-forming osteoblasts and the bone-dismantling osteoclasts.” Osteoblasts are continually laying down new bone, while osteoclasts chisel away old bone, using free radicals as the molecular chisel to chip away our bone. Too many free radicals in our system, though, may lead to excessive bone breakdown. Antioxidant defenses appear “markedly decreased in osteoporotic women,” and “elderly osteoporotic women had consistently lower levels of all natural antioxidants tested than controls.”

“Because excessive [free radicals] may contribute to bone loss, it is important to elucidate the potential role antioxidant-rich fruits play in mitigating bone loss that leads to the development of osteoporosis.” The thought is that fruits up-regulate the bone building cells, and down-regulate the bone-eating cells, tipping the balance towards greater bone mass. So, let’s put a fruit to the test. Which one do we pick? Dried plums were chosen because they have among the highest antioxidant ranking among commonly consumed fruits and vegetables—and because the researchers received a grant from the California Dried Plum Board!

When you think of prunes, you think of bowels, not bones, but, over a decade ago, researchers at Oklahoma State tried giving a dozen prunes a day to a group of postmenopausal women, using a dozen dried apple rings as a control. After three months, only the subjects who consumed the prunes had significant elevations in an enzyme marker of bone formation, although prunes didn’t seem to affect markers of bone breakdown. So, prunes may help more with building bones than preventing bone loss. However, the reverse was found with almonds, so maybe a little prune-and-almond trail mix is in order. 

With this bump in bone formation indices, one might expect that if they did a longer study, we would actually see an impact on bone mineral density. And nine years later, just such a study was done: 12 months on dried plums versus apples. Both dried fruit regimens appeared to have “bone-protective effects,” though the prunes seemed to work better in the arm bone and spine.

So, the dried plum marketing board wants everyone to know that dried plums are “the most effective fruit in both preventing and reversing bone loss,” but only two fruits have ever been tested: plums and apples. If this pans out for other plants, though, “a ‘fruit and vegetables’ approach may provide a very sensible (and natural) alternative therapy for osteoporosis treatment, one that is likely to have numerous additional health-related benefits.” All we have to do is convince people to actually do it.

For more on bone health, see:

What else can prunes do for us? Check out Prunes vs. Metamucil vs. Vegan Diet.

Apple rings have their own benefits. See Dried Apples vs. Cholesterol.

In health,
Michael Greger, M.D.

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

How to Avoid Fatty Liver Disease

In the documentary Supersize Me, Morgan Spurlock eats exclusively at McDonald’s for a month and predictably his weight, blood pressure, and cholesterol go up, but so do his liver enzymes, a sign his liver cells are dying and spilling their contents into the bloodstream. His one-man experiment was actually formally replicated. A group of men and women agreed to eat two fast food meals a day for a month. Most of their liver values started out normal, but, within just one week, most were out of whack, a profound pathological elevation in liver damage.

What’s happening is non-alcoholic fatty liver disease (NAFLD), the next global epidemic, as I discuss in my video How to Prevent Non-Alcoholic Fatty Liver Disease. Fatty deposits in the liver result in a disease spectrum from asymptomatic fat buildup to non-alcoholic steatohepatitis (NASH), which can lead to liver scarring and cirrhosis, and may result in liver cancer, liver failure, and death.

NAFLD is now the most common cause of chronic liver disease in the United States, affecting 70 million Americans, nearly one in three adults. Fast food consumption is a great way to bring it on, since it’s associated with the intake of soft drinks and meat. Drinking one can of soda a day may raise the odds of NAFLD by 45 percent, and those eating the equivalent of 14 chicken nuggets’ worth of meat a day have nearly triple the rates of fatty liver compared to those eating 7 nuggets or less.

It’s been characterized as a tale of fat and sugar, but evidently not all types of fat are culpable. Those with fatty hepatitis were found to have eaten more animal fat and cholesterol, and less plant fat, fiber, and antioxidants. This may explain why adherence to a Mediterranean-style diet, characterized by high consumption of foods such as fruits, vegetables, whole grains, and beans, is associated with less severe non-alcoholic fatty liver disease. It could also be related to the presence of specific phytonutrients, like the purple, red, and blue anthocyanin pigments found in berries, grapes, plums, red cabbage, red onions, and radicchio. These anthocyanin-rich foods may be promising for the prevention of fatty liver, but that’s mostly based on petri dish experiments. There was one clinical trial that found that drinking a purple sweet potato beverage seemed to successfully dampen liver inflammation.

A more plant-based diet may also improve our microbiome, the good bacteria in our gut. “‘We are what we eat’ is the old adage but the modern version might be ‘we are what our bacteria eat.’” When we eat fat, we may facilitate the growth of bad bacteria, which can release inflammatory molecules that increase the leakiness of our gut and contribute to fatty liver disease.

Fatty liver disease can also be caused by cholesterol overload. The thought is that dietary cholesterol found in eggs, meat, and dairy oxidizes and then upregulates liver X receptor alpha, which can upregulate something else called SREBP, which can increase the level of fat in the liver. Cholesterol crystals alone cause human white blood cells to spill out inflammatory compounds, just like uric acid crystals in gout. That’s what may be triggering the progression of fatty liver into serious hepatitis: “the accumulation of sufficient concentrations of free cholesterol within steatotic hepatocytes [fatty liver cells] to cause crystallization of the cholesterol.” This is one of several recent lines of evidence suggesting that dietary cholesterol plays an important role in the development of fatty hepatitis—that is, fatty liver inflammation.

In a study of 9,000 American adults followed for 13 years, researchers found a strong association between dietary cholesterol intake and hospitalization and death from cirrhosis and liver cancer, as dietary cholesterol can oxidize and cause toxic and carcinogenic effects. To limit the toxicity of excess cholesterol derived from the diet, the liver tries to rid itself of cholesterol by dumping it into the bloodstream. So, by measuring the non-HDL cholesterol in the blood, one can predict the onset of fatty liver disease. If we subtract HDL from total cholesterol, none of the hundreds of subjects followed with a value under 130 developed the disease. Drug companies view non-alcoholic fatty liver disease as a bonanza, “as is the case of any disease of affluence…considering its already high and rising prevalence and…[its] needing continuous pharmacologic treatment,” but maybe avoiding it is as easy as changing our diet, avoiding sugary and cholesterol-laden foods.

“The unpalatable truth is that NAFLD could almost be considered the human equivalent of foie gras (loosely translated from French as ‘fat liver’). As we overeat and ‘force-feed’ ourselves foods that can result in serious health implications, however, having such a buttery texture in human livers is not a delicacy to be enjoyed by hepatologists [liver doctors] in clinical practice!”

Like my video Preventing Gout Attacks with Diet, How to Prevent Non-Alcoholic Fatty Liver Disease covers an important topic worth the extensive coverage the video provides.

For more on how bad added sugars are for us, see:

For more on how bad cholesterol can be, 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, year-in-review presentations: