Acai Controversy

July 16, 2010 Written by JP    [Font too small?]

Much of the potential and risk associated with the natural health industry involves the issue of responsibility. Who is responsible for ensuring the efficacy and safety of natural remedies? In terms of oversight, consumers must rely on watchdogs within the natural health industry itself and the US Food and Drug Administration (FDA). However, many people feel let down by this agency. That’s why we consumers need to get involved in the process. I think the best way is to become informed about the actual research behind these products rather than the glossy marketing and superficial propaganda put out by detractors and proponents alike.

Buying questionable and/or unsafe supplements promotes a commercial environment that encourages the future sale of similarly disreputable products. For better or worse, the natural health industry is largely driven by sales trends. It should be about more than that, but often it is not. Once you accept that reality, you can begin playing a part in shaping the current state of the industry. Supporting legitimate products and shunning those that are promoted in an irresponsible manner is the most impactful way to accomplish this goal. But the first step is to identify which camp each product falls into.

Acai berries (Euterpe oleracea) are either a miracle “superfruit” or an outright fraud depending on who you ask. If you visit health food stores regularly or read natural health magazines you’ve surely come across juices and supplements containing extracts of this Amazonian palm fruit. It’s quite possible that you’ve even had a friend or neighbor offer to sell you a bottle of acai because it’s a regular fixture in the multi-level marketing community as well.

The hype involving acai (ah-sigh-EE) primarily has to do with its unique chemical composition. The pulp of the fruit is a rich source of antioxidants, dietary fiber and health promoting fatty acids. This much is well established in the medical literature and forms the basis for the optimism revolving around this supplement. What’s more, scientists are continually discovering previously unknown elements in acai which may confer some of the potent antioxidant activity demonstrated in numerous laboratory experiments. (1,2,3,4,5,6,7,8,9)

Clinical studies conducted in animal and human models go a long way toward establishing the validity of a functional food or nutritional supplement. Intervention trials involving human volunteers are naturally preferable, but they’re also quite expensive and relatively rare. So let’s examine the most noteworthy in-vivo studies that have been published in peer-reviewed, scientific journals over the past several years:

  • The July-August 2010 issue of the journal Nutrition reports that adding 2% acai pulp to the diets of rats with high cholesterol effectively lowered LDL (“bad”) and total cholesterol and select markers of oxidative stress including carbonyl proteins and superoxide dismutase activity. Another inquiry indicates that acai extracts stimulate vasodilation in rats and may, therefore, be of value in the natural management of cardiovascular disease. (10,11)
  • Preliminary experiments in animals suggest that acai berry extracts may: a) inhibit esophageal tumor progression; b) protect the brain from oxidative stress which may contribute to neurological conditions including Alzheimer’s and Parkinson’s disease and; c) protect the kidneys and liver from chemically induced DNA damage. It’s worth noting that the esophageal cancer study builds upon a few test tube experiments in which acai was shown to selectively combat the growth of colon cancer and leukemia cells. (12,13,14,15,16)
  • In 2008 a study was published in the Journal of Agricultural Food Chemistry that examined the ability of 12 human volunteers to absorb the antioxidants contained in acai juice and pulp. The juice and pulp resulted in significant increases in plasma antioxidant activity of up to 3-fold compared to baseline readings. (17)
  • An additional human trial also from 2008 found that a juice blend containing acai elevated serum antioxidant concentrations and reduced lipid peroxidation. The latter is of value because high levels of lipid peroxides can result in cell damage and dysfunction. (18)
An Acai Component (C3G) May Combat Cancer Growth
Source: The Journal of Biological Chemistry, 281, 17359-17368. (link)

New research appearing in the May 2010 edition of the journal Toxicology supports the overall image of acai as relatively non-toxic. However, there are a few caveats to keep in mind. Firstly, the safety evaluation was conducted in-vitro and in an animal model – 220 rats were the study subjects. More importantly, the form of acai used in the experiment was an “acai pulp enriched fruit and berry juice”. Mixing small quantities of acai with other fruit juices is a common practice because consumers tend to prefer the taste of diluted acai (4% to 5%) as compared to more concentrated acai blends (20% to 40%). Observing this taste preference may be appealing to consumers and manufacturers, but it makes it nearly impossible to determine the safety of pure acai extracts which are common in the marketplace. (19,20,21)

While researching today’s blog I tried to get a sense of where other natural health experts stood on this issue. Dr. Andrew Weil hasn’t addressed this topic on his popular web site for a number of years. However, in 2006 he essentially took the position that acai simply didn’t have enough evidence to support it’s use over other berries. This more conservative point of view is not entirely shared by Dr. Mehmet Oz who considers acai to be one of the top “anti-aging” foods because of it’s hefty antioxidant content. Even the famed dermatologist, Dr. Nicholas Perricone, has weighed in on this topic. He’s a big fan of acai and notes the relatively high proportion of oleic acid contained therein. This is the same monounsaturated fatty acid which is believed to contribute to the health benefits attributed to olive oil. (22,23,24)

The measure of how I feel about any given supplement is whether or not I recommend it to my family and friends. To date, I have yet to suggest acai to anyone. On occasion I use a “chocolate green superfood” drink that includes acai as one of many ingredients. That doesn’t disturb me in the least. In fact, I’m not particularly concerned that acai will pose a danger in regular users. However, I have a big problem when certain manufacturers promote acai as a weight loss aid. This claim appears to be completely unfounded. Beyond that, the bottom line is that I’ve found little evidence that acai provides any health benefits beyond those found in better researched foods and supplements. As an example, an experiment from 2008 determined that pomegranate juice and several other beverages including black cherry juice and red wine possessed significantly higher antioxidant activity than acai juice. Factor in the higher price of acai juice and I think you’ll find that it’s just not a very good deal according to the evidence. (25)

Note: Please check out the “Comments & Updates” section of this blog – at the bottom of the page. You can find the latest research about this topic there!

Be well!


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Posted in Diet and Weight Loss, Food and Drink, Nutritional Supplements

7 Comments & Updates to “Acai Controversy”

  1. Blake Says:

    Great article. The truth is, until some human trials are published on acai it will remain not much more than an overblown fad. Thanks for giving a balanced view of the research on it.

  2. Mark Says:

    I appreciate the effort in every post and this one is no different. I have read many articles on acai and most all were touting it’s super antioxidant powers. Supplement catalogs are packed with items of questionable quality and use. The government would do the public a huge service by researching supplements, but the cost I’m sure would be prohibitive.

  3. JP Says:

    Thank you, Blake and Mark. Much appreciated! 🙂

    Be well!


  4. JP Says:

    Update 06/11/15:

    Biol Sport. 2015 Jun;32(2):161-8. doi: 10.5604/20831862.1144419. Epub 2015 Mar 15.

    Effects of supplementation with acai (Euterpe oleracea Mart.) berry-based juice blend on the blood antioxidant defence capacity and lipid profile in junior hurdlers. A pilot study.

    The purpose of this pilot study was to examine whether regular consumption of an acai berry-based juice blend would affect sprint performance and improve blood antioxidant status and lipid profile in junior athletes. Seven junior hurdlers (17.5±1.2 years) taking part in a pre-season conditioning camp were supplemented once a day, for six weeks, with 100 ml of the juice blend. At the start and the end of the camp the athletes performed a 300-m sprint running test on an outdoor track. Blood samples were taken before and immediately after the test and after 1 h of recovery. Blood antioxidant status was evaluated based on activities of antioxidant enzymes (superoxide dismutase [SOD], catalase [CAT], glutathione peroxidase [GSH-Px], glutathione reductase [GR]), concentrations of non-enzymatic antioxidants (reduced glutathione [GSH], uric acid), total plasma polyphenols, ferric reducing ability of plasma (FRAP), thiobarbituric acid reactive substances (TBARS) and activities of creatine kinase (CK) and lactate dehydrogenase (LDH) as muscle damage markers. In order to evaluate potential health benefits of the acai berry, the post-treatment changes in lipid profile parameters (triglycerides, cholesterol and its fractions) were analysed. Six weeks’ consumption of acai berry-based juice blend had no effect on sprint performance, but it led to a marked increase in the total antioxidant capacity of plasma, attenuation of the exercise-induced muscle damage, and a substantial improvement of serum lipid profile. These findings strongly support the view of the health benefits of supplementation with the acai berry-based juice blend, mainly attributed to its high total polyphenol content and the related high in vivo antioxidant and hypocholesterolaemic activities of this supplement.

    Be well!


  5. JP Says:

    Updated 02/18/16:

    Nutrition. 2015 Dec 29.

    Açai (Euterpe oleracea Mart.) pulp dietary intake improves cellular antioxidant enzymes and biomarkers of serum in healthy women.

    OBJECTIVES: The aim of the present study was to evaluate the effect of açai pulp (Euterpe oleracea Martius) intake on the prevention of oxidative damage by measuring the activity of antioxidant enzymes and biomarkers of protein oxidation in women.

    METHODS: A nutritional intervention study was conducted with thirty-five healthy women who were asked to consume 200 g/d of açai pulp for 4 wk. Blood samples were collected, and blood pressure and anthropometric parameters were measured before and after the experimental period. Antioxidant enzymes, superoxide dismutase, catalase, glutathione, production of reactive oxygen species, and total antioxidant capacity were evaluated in polymorphonuclear cells. Serum concentration of protein carbonyl and sulfhydryl groups were also determined.

    RESULTS: The açai intake increased catalase activity, total antioxidant capacity, and reduced the production of reactive oxygen species. Furthermore, it reduced serum concentration of protein carbonyl and increased total serum sulfhydryl groups.

    CONCLUSIONS: These results show the antioxidant benefit of dietary açai for the healthy women included in the present study, and may increase understanding of the beneficial health properties of this fruit.

    Be well!


  6. JP Says:

    Updated 09/30/16:

    Am J Clin Nutr. 2016 Sep 28.

    Consumption of a flavonoid-rich açai meal is associated with acute improvements in vascular function and a reduction in total oxidative status in healthy overweight men.

    BACKGROUND: Açai (Euterpe oleracea) is a polyphenol-rich fruit marketed as beneficial for health. Experimental data showing improvements in health markers arising from açai consumption in humans is limited.

    OBJECTIVE: The objective of the present study was to investigate the effect of açai consumption on acute changes in vascular function and on other disease risk markers, including postprandial plasma insulin, glucose, and oxidative stress.

    DESIGN: Twenty-three healthy male volunteers, aged 30-65 y and with a body mass index (in kg/m2) of 25-30, completed a randomized, controlled, high-fat challenge, double-blind, crossover, acute dietary intervention trial. The volunteers consumed either an açai-based smoothie (AS) or a macronutrient-matched control smoothie (PS) together with a high-fat breakfast meal challenge. The primary endpoint was the assessment of endothelial function in the brachial artery by flow-mediated dilatation (FMD).

    RESULTS: The acute consumption of an AS containing 694 mg total phenolics improved vascular function, with postprandial increases in FMD from baseline of 1.4% at 2 h compared with 0.4% after consumption of the PS (P = 0.001) and increases at 6 h of 0.8% for the AS compared with -0.3% for the PS (P < 0.001). There was also a significantly lower incremental area under the curve (iAUC) for total peroxide oxidative status after açai consumption relative to the control. No significant changes were observed in blood pressure, heart rate, or postprandial glucose response. However, the first postprandial insulin peak (after breakfast) and the iAUC for insulin were elevated for the AS relative to the PS. CONCLUSIONS: In this acute study in overweight men, açai consumption was associated with improvements in vascular function, which may lower the risk of a cardiovascular event. Future intervention studies, perhaps with a chronic design, in wider populations and with other biomarkers of disease risk are needed to fully elucidate the benefits of açai to health. Be well! JP

  7. JP Says:

    Updated 02/14/17:

    Clinical Nutrition – Published Online Feb 02, 2017

    Açai (Euterpe oleracea Mart.) dietary intake affects plasma lipids, apolipoproteins, cholesteryl ester transfer to high-density lipoprotein and redox metabolism: A prospective study in women

    The açai fruit (Euterpe oleracea Martius), which is native to the Brazilian Amazon region, was shown to have high polyphenols and MUFA contents. In this study, we aimed to assess the effects of açai consumption on plasma lipids, apolipoproteins, the transfer of lipids to HDL (which is a relevant HDL function), and some biomarkers of redox metabolism. Forty healthy volunteer women aged 24 ± 3 years consumed 200 g of açai pulp/day for 4 weeks; their clinical variables and blood sample were obtained before and after this period. Açai pulp consumption did not alter anthropometric parameters, systemic arterial pressure, glucose, insulin and total, LDL and HDL cholesterol, triglycerides and apolipoprotein (apo) B, but it did increase the concentration of apo A-I. Açai consumption decreased the ROS, ox-LDL and malondialdehyde while increasing the activity of antioxidative paraoxonase 1. Overall, the total antioxidant capacity (TAC) was increased. Regarding the transfer of plasma lipids to HDL, açai consumption increased the transfer of cholesteryl esters (p = 0.0043) to HDL. Unesterified cholesterol, phospholipids and triglyceride transfers were unaffected. The increase in apo A-I and the cholesteryl ester transfer to HDL after the açai intake period suggests that an improvement in the metabolism of this lipoprotein occurred, and it is well known that HDL is protective against atherosclerosis. Another important finding was the general improvement of the anti-oxidant defences elicited by açai consumption. Our data indicate that açai has favourable actions on plasma HDL metabolism and anti-oxidant defence; therefore açai could have a beneficial overall role against atherosclerosis, and it is a consistently good candidate to consider as a functional food.

    Be well!


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