If you've watched television lately, you may have seen one of the many ads promoting various brands of açaí berry juice. While this “perfect potion” is new to the United States, it has been familiar in other parts of the world for hundreds of years.
Açaí (a-sigh-ee) palm trees are members of the genus Euterpe and grow mostly in Central and South American rain forests. The fruit is a dietary staple in the Amazon region, where various species are used in herbal remedies for diarrhea, jaundice, fever, skin ulcers, and tonics to enrich the blood. Euterpe oleracea is the variety that's causing all the buzz.1
Background
A classic palm, the açaí tree grows as tall as 80 feet. Its multiple long, thin trunks have branches near the top that support long, ribbonlike leaves. Dangling from the branches are clusters of three to eight deep-purple berries—so dark that they look almost black. Each berry is about the size of a blueberry and is composed of a small amount of pulp surrounding a large seed.1
Açaí berries debuted on the global market about seven years ago. Because they are very fragile, until recently most berries were used locally within a day or two of picking. But several local companies now process them for global distribution.2
Scientific evidence
One hundred grams (3.5 ounces) of the standard, freeze-dried powder made from açaí berry pulp and skin contains 533.9 calories, 52.2 g carbohydrate, 44.2 g dietary fiber, 8.1 g protein, and 32.5 g total fat.3 While few people consume a serving so large, it is easy to see how a small amount of this nutrient-dense fruit could be very beneficial.
Chemical analysis finds açaí juice to be an excellent source of essential fatty acids, fiber, and antioxidants. The National Institute on Aging has developed oxygen radical absorbance capacity (ORAC) values to measure the antioxidant capacity of various foods.4 With a rating of 161,400 units/100 g, açaí has the highest ORAC value of any food tested to date and is 10-30 times more powerful than red wine by volume.5
This rich antioxidant activity has spurred intense research into açaí's potential for preventing numerous diseases. A University of Florida study showed that açaí extract triggered a self-destruct response in up to 86% of leukemia cells in vitro.6 In a rat study at the University of Rio de Janeiro, açaí extract induced long-lasting endothelium-dependent vasodilatation, which is strongly linked to improved cardiovascular function.7
Meanwhile, in a randomized, placebo-controlled trial, 12 healthy volunteers ingested a standardized açaí extract. When serum antioxidant levels were sampled one and two hours later, the concentrations had definitely increased at each interval.8
Other touted and likely physiologic results from this berry are increased energy, improved mental clarity, improved GI function, better glycemic control for diabetic patients, improved cholesterol balance, and a slowing of cellular aging. All these benefits have yet to be proven, but other high-antioxidant products are credited with these effects.
Açaí may have another clinical benefit that's not directly related to nutrition. A study now under way is looking at açaí extract as a substitute for gadolinium contrast agents in MRI exams of the GI tract. In earlier research, açaí berry pulp was found to have a definite increased T1-weighted MRI signal in vivo, revealing a significant contrast on bowel walls and gastric tissue. Further analysis linked this to spectrophotometric detection of iron, magnesium, and copper ions.9
Safety, side effects
Few trials have studied açaí in human subjects, but the available nutrition data indicate that the risk of adverse effects is negligible. Aside from the potential for allergic response, there are no known side effects with this product and no particular cautions.
Still, some potent antioxidants can interact with medications, such as warfarin, due to competing metabolic pathways. Clinicians should ask patients who are on concomitant anticoagulant therapy whether they consume açaí regularly.
Dose
No one really knows what a recommended daily allowance (RDA) would be for açaí extract. Most literature recommends 500 mg a few times a week, preferably with breakfast.7 There are no known contraindications for pregnant or nursing women, but children should limit their intake.
How supplied and cost
While some commercial products are advertising açaí berry juice content, literature typically cites capsules filled with dried powder from the berry pulp and skin. A month's supply of these capsules ranges in price from $20 to $40, depending on the source. Bulk powder is available for smoothies and reconstituted juice.
Summary
It's not often that a health supplement tastes good, but this sounds like one of those rare substances. With no negative side effects to açaí products, the main decision is between capsules and beverages. While it's a little costly, açaí could easily eliminate the need for other antioxidants andmultivitamins, making it an excellent nutritional choice.
References
1. Açaí (Euterpe oleracea). Tropical plant database. Raintree Nutrition. Available at: www.rain-tree.com/acai.htm.
2. Brondízio ES, Safar CAM, Siqueira AD. The urban market of açaí fruit (Euterpe oleracea Mart.) and rural land use change: ethnographic insights into the role of price and land tenure constraining agricultural choices in the Amazon estuary. Urban Ecosystems. 2002;6:67-97.
3. Gross PM. Açaí —potent antioxidant superfruit. Natural and Nutritional Products Industry Center. January 8, 2007. Available at www.npicenter.com/anm/templates/newsATemp.aspx?articleid=17363.
4. Bhagwat S, Haytowitz DB, Holden JM. USDA database for the oxygen radical absorbance capacity (ORAC) of selected foods. 2007. American Institute for Cancer Research Launch Conference. Available at: www.ars.usda.gov/Services/docs.htm?docid=15866.
5. Pacheco-Palencia LA, Mertens-Talcott S, Talcott ST. Chemical composition, antioxidant properties, and thermal stability of a phytochemical enriched oil from Açaí (Euterpe oleracea Mart.). J Agric Food Chem. 2008;56:4631-4636.
6. Nordlie T. Brazilian berry destroys cancer cells in lab, UF study shows. University of Florida News. January 12, 2006. Available at: news.ufl.edu/2006/01/12/berries/.
7. Rocha AP, Carvalho LC, Sousa MA, et al. Endothelium-dependent vasodilator effect of Euterpe oleracea Mart.
(Açaí) extracts in mesenteric vascular bed of the rat. Vascul Pharmacol. 2007;46:97-104.
8. Jensen GS, Wu X, Patterson KM, et al. In vitro and in vivo antioxidant and anti-inflammatory capacities of an antioxidant-rich fruit and berry juice blend. Results of a pilot and randomized, double-blinded, placebo-controlled, crossover study. J Agric Food Chem. 2008;56:8326-8333.
9. Córdova-Fraga T, de Araujo DB, Sanchez TA, et al. Euterpe Olerácea (Açaí) as an alternative oral contrast agent in MRI of the gastrointestinal system: preliminary results. Magn Reson Imaging. 2004;22:389-393.
All electronic documents accessed December 11, 2008.