The Antioxidant Power of Açaí vs. Apples

There are so many açaí products on the market now, from frozen pulp in smoothie packs to freeze-dried powder and supplements. How is it eaten traditionally? “In the Brazilian Amazon, the Indian tribes of the forest cut down the tree and eat the palm heart…then urinate on the rest of the tree to attract a species of palm beetle to lay its eggs inside the tree. Several weeks later, they return to harvest 3–4 pounds of beetle grub larvae….” I think I’ll just stick to my smoothie pack.

“Despite being used for a long time as food and beverage” in the Amazon, açaí berries have only been researched scientifically since the beginning of this century. A number of years ago, I reviewed that research in my video Clinical Studies on Açaí Berries, starting with in vitro studies showing that açaí could kill leukemia cells in a petri dish at levels you might expect to find in the bloodstream after eating one or two cups of açaí pulp and could also cut the growth of colon cancer cells in half.

Unfortunately, as I discuss in my video The Antioxidant Effects of Açaí vs. Apples, subsequent published studies have failed to find such benefits for that particular type of colon cancer, a different type of colon cancer, or an estrogen-receptor negative form of breast cancer. An açaí extract did appear to kill off a line of estrogen-receptor positive breast cancer cells, but to achieve that level of açaí nutrients in your breast, you’d have to eat about 400 cups of açaí pulp.

The problem with many of these petri dish studies is that they use concentrations that you could never realistically achieve in your bloodstream. For example, as you can see at 1:48 in my video, açaí berries may exert a neuroprotective effect, blocking the buildup of amyloid fibers implicated in Alzheimer’s—but only at a dose reached by drinking about 2,000 cups at one time. They may also have an anti-allergy effect or decrease bone loss—at a mere 1,000 cups a day.

In my previous video Clinical Studies on Açaí Berries, I also talked about a clinical study in which subjects were asked to drink less than a cup a day of açaí in a smoothie. They appeared to get significant improvements in blood sugar, insulin levels, and cholesterol. Now, there was no control group and it was a small study, but there’d never been a bigger study trying to replicate it until a study published in 2016.

As you can see at 2:37 in my video, researchers gave subjects the same amount of açaí for the same duration as the previous study, but they found no significant improvements in blood sugars, insulin, or cholesterol. Why did this study fail to show the benefits seen in the first study? Well, this study was publicly funded with “no conflicts of interest,” while the first study was funded by an açaí company, which always makes you suspect that perhaps it was somehow designed to get the desired result. And, indeed, the participants in that first study were not just given açaí smoothies, but they were explicitly told to avoid processed meat, “for example bacon and hot dogs.” No wonder their numbers looked better at the end of the month. Now, the new study did find a decrease in markers of oxidative stress in the participants’ bloodstreams, a sign of how rich in antioxidants açaí berries can be.

Those who hock supplements love to talk about how açaí consumption can “triple antioxidant capacity” of your blood. And, if you look at the study they cite, you’ll find that the antioxidant capacity of participants’ blood did actually triple after eating açaí—but the same or even better tripling was achieved after consuming just plain applesauce, which the researchers used as a control that happens to be significantly cheaper than açaí berries or supplements. You can see the graph at 3:42 in my video.

A new study has shown significant improvements in artery function after eating açaí berries, but are they any more effective than other common fruits and vegetables? You can learn more about that in my video The Benefits of Açaí vs. Blueberries for Artery Function.


What’s so great about antioxidants? Check out:

Where else can you get them? See Flashback Friday: Antioxidants in a Pinch and Antioxidant Power of Plants vs. Animal Foods.

What are the nutritional aspects of those grub-kabobs? See Bug Appétit: Barriers to Entomophagy and Good Grub: The Healthiest Meat.

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:

Does Aspartame Cause Lymphoma?

The approval of aspartame has a controversial history. The Commissioner of the U.S. Food and Drug Administration (FDA) concluded that “there is a reasonable certainty that human consumption of aspartame: (1) …will not pose a risk of brain damage resulting in mental retardation, endocrine [hormonal] dysfunction, or both; and (2) will not cause brain tumors.” However, the FDA’s own Public Board of Inquiry withdrew their approval over cancer concerns. “Further, several FDA scientists advised against the approval of aspartame, citing…[the aspartame company’s] own brain tumor tests…” Regardless, the Commissioner approved aspartame before he left the FDA and went on to enjoy a thousand-dollar-a-day consultancy position with the aspartame company’s PR firm. Then, the FDA actually prevented the National Toxicology Program (NTP) from doing further cancer testing. As I discuss in my video Does Aspartame Cause Cancer? we were then left with people battling over different rodent studies, some of which showed increased cancer risk, while others didn’t.

This reminds me of the saccharin story. That artificial sweetener caused bladder cancer in rats but not mice, leaving us “to determine whether humans are like the rat or like the mouse.” Clearly, we had to put the aspartame question to the test in people, but the longest human safety study lasted only 18 weeks. We needed better human data.

Since the largest rat study highlighted lymphomas and leukemias, the NIH-AARP study tracked blood cancer diagnoses and found that “[h]igher levels of aspartame intake were not associated with the risk of…cancer.” Although the NIH-AARP study was massive, it was criticized for only evaluating relatively short-term exposure. Indeed, people were only studied for five years, which is certainly better than 18 weeks, but how about 18 years?

All eyes turned to Harvard, where researchers had started following the health and diets of medical professionals before aspartame had even entered the market. “In the most comprehensive long-term [population] study…to evaluate the association between aspartame intake and cancer risk in humans,” they found a “positive association between diet soda and total aspartame intake and risks of [non-Hodgkin’s lymphoma] and multiple myeloma in men and leukemia in both men and women,” as you can see at 2:12 in my video. Why more cancer in men than women? A similar result was found for pancreatic cancer and diet soda, but not soda in general. In fact, the only sugar tied to pancreatic cancer risk was the milk sugar, lactose. The male/female discrepancy could have simply been a statistical fluke, but the researchers decided to dig a little deeper.

Aspartame is broken down into methanol, which is turned into formaldehyde, “a documented human carcinogen,” by the enzyme alcohol dehydrogenase.The same enzyme that detoxifies regular alcohol is the very same enzyme that converts methanol to formaldehyde. Is it possible men just have higher levels of this enzyme than women? Yes, which is why women get higher blood alcohol levels than men drinking the same amount of alcohol. If you look at liver samples from men and women, you can see significantly greater enzyme activity in the men, so perhaps the higher conversion rates from aspartame to formaldehyde explain the increased cancer risk in men? How do we test this?

Ethanol—regular alcohol—competes with methanol for this same enzyme’s attention. In fact, regular alcohol is actually “used as an antidote for methanol poisoning.” So, if this formaldehyde theory is correct, men who don’t drink alcohol or drink very little may have higher formaldehyde conversion rates from aspartame. And, indeed, consistent with this line of reasoning, the men who drank the least amounts of alcohol appeared to have the greatest cancer risk from aspartame.

A third cohort study has since been published and found no increased lymphoma risk associated with diet soda during a ten-year follow-up period. So, no risk was detected in the 18-week study, the 5-year study, or the 10-year study—only in the 18-year study. What should we make of all this?

Some have called for a re-evaluation of the safety of aspartame. The horse is kind of out of the barn at this point with 34 million pounds of aspartame produced annually, but that doesn’t mean we have to eat it, especially, perhaps, pregnant women and children.


For more information on the effects of aspartame, watch my videos Aspartame and the Brain and Aspartame-Induced Fibromyalgia. Interested in learning more about the effects of consuming diet soda? See, for example:

What about Splenda? Or monk fruit sweetener? I have videos on those, too—watch Effect of Sucralose (Splenda) on the Microbiome and Is Monk Fruit Sweetener Safe?.

I also do a comparison of the most popular sweeteners on the market, including stevia and xylitol, in my video A Harmless Artificial Sweetener.

Perhaps the best candidate is erythritol, which you can learn about in my video Erythritol May Be a Sweet Antioxidant. That said, it’s probably better if we get away from all intense sweeteners, artificial or not. See my video Unsweetening the Diet for more on this.

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 Foods With the Highest Aspirin Content

The results of a recent aspirin meta-analyses suggesting a reduction of cancer mortality by about one-third in subjects taking daily low-dose aspirin “can justly be called astounding.” Yet the protection from “Western” cancers enjoyed by those eating more traditional plant-centered diets, such as the Japanese, “is even more dramatic.” I examine this in my video Plants with Aspirin Aspirations.

Before the Westernization of their diets, animal products made up only about 5 percent or less of the Japanese diet. At 0:37 in my video, you can see the difference in cancer mortality of U.S. men and women compared with Japanese men and women. “[A]ge-adjusted death rates from cancers of the colon, prostate, breast, and ovary were on the order of 5–10-fold lower in Japan than in the US at that time; mortality from pancreatic cancer, leukemias, and lymphomas was 3–4-fold lower in Japan. But this phenomenon was by no means isolated to Japan; Western cancers were likewise comparatively rare in other societies where “people ate plant-based diets.”

“The cancer protection afforded by lifelong consumption of a plant-based diet, in conjunction with leanness and insulin sensitivity (which tend to be promoted by low-fat plant-based diets)…may be very substantial indeed.” Therefore, a “lifestyle protocol for minimizing cancer risk” may include a whole-food plant-based diet.

If part of this cancer protection arises out of the aspirin phytonutrients in plants, are there any plants in particular that are packed with salicylates? Though salicylic acid, the main active ingredient in aspirin, is “ubiquitously present in fruits and vegetables,” the highest concentrations are found in herbs and spices.

Red chili powder, paprika, and turmeric contain a lot of salicylates, but cumin is about 1 percent aspirin by weight. Eating a teaspoon of cumin is like taking a baby aspirin. (See the table at 1:54 in my video for details on other herbs and spices, and their salicylate content.) “Consequently, populations that incorporate substantial amounts of spices in foods may have markedly higher daily intakes of salicylates. Indeed, it has been suggested that the low incidence of colorectal cancer among Indian populations may be ascribed in part to high exposure to dietary salicylates throughout life from spice consumption.”

“The population of rural India, with an incidence of colorectal cancer which is one of the lowest in the world, has a diet that could be extremely rich in salicylic acid. It contains substantial amounts of fruits, vegetables, and cereals flavored with large quantities of herbs and spices.” Some have proposed it’s the curcumin in the spice turmeric (which I discuss in detail in my video Turmeric Curcumin and Colon Cancer), but it may be the salicylic acid in cumin—and the spicier the better.

A spicy vegetable vindaloo may have four times the salicylates of a milder Madras-style veggie dish. As you can see from the chart at 2:55 in my video, after just one meal, we get an aspirin spike in our bloodstream like we just took an aspirin. So, eating flavor-filled vegetarian meals, with herbs and spices, may be more chemoprotective—that is, more protective against cancer—than regular, blander vegetarian meals.

We may also want to eat organic produce. “Because salicylic acid is a defense hormone of plants, the concentration…is increased when plants become stressed,” like when they are bitten by bugs (unlike pesticide-laden plants). Indeed, soups made from organic vegetables were found to have nearly six times more salicylic acid than soups prepared from conventionally grown ingredients.

We should also choose whole foods. Whole-grain breads, which are high in salicylic acid, contain about 100 times more phytochemicals than white bread: 800 phytochemicals compared to 8.

“Interest in the potential beneficial effects of dietary salicylates has arisen, in part, because of the extensive literature on the disease-preventative effects of Aspirin™. However, it should not be forgotten that plant products found to contain salicylic acid are generally rich sources of other phenolic acids…[and many] also have a marked anti-inflammatory and redox-related bioactivity [that is, antioxidant activity] in mammalian cells. Their potential protective effects should not be overlooked. In this context, the importance of dietary salicylic acid should not perhaps be over emphasised…Indeed, some believe that ‘salicylic acid deficiency’ has important public health implications and that it should be classed as an essential vitamin, namely ‘Vitamin S’.”

What they’re saying is that we should all eat a lot of plants.


If you missed the first two videos in this series, see Should We All Take Aspirin to Prevent Heart Disease? and Should We All Take Aspirin to Prevent Cancer?.

The drug-like anti-inflammatory power of certain plant foods may make them a risky proposition during pregnancy. See Caution: Anti-Inflammatory Foods in the Third Trimester.

Herbs and spices not only have some of the most anti-inflammatory properties, but they also are well-rounded protectants. 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: