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Native to South America, particularly the Amazon River and its tributaries and estuaries (J. Agric. Food Chem. 2006;54:8,598-603), the açaí palm (Euterpe oleracea Mart.) has become a subject of great interest in recent years, because its fruit is believed by many to boast significant antioxidant capacity.
The juice and pulp of açaí are popular beverage components in juice blends, smoothies, and other drinks in Central and South America. Mainstream attention, including features on popular U.S. television programs, “has increased interest in the United States in the potential and rumored health effects of açaí. This column will briefly review recent findings regarding this increasingly popular antioxidant-rich plant.
Juicy Benefits
In 2008, investigators studied the antioxidant and anti-inflammatory activities of a commercial juice blend (MonaVie Active) containing açaí as the main ingredient. Anthocyanins, the primary active phenolic components in açaí, were found to be the main antioxidants in the juice, particularly cyanidin 3-rutoside, cyanidin 3-diglycoside, and cyanidin 3-glucoside. In vitro, the antioxidants in the blend were shown to protect against oxidative damage. Polymorphonuclear cells exhibited decreased formation of free radicals and lower migration toward certain proinflammatory chemoattractants.
In vivo, a randomized, double-blind, placebo-controlled crossover trial with 12 healthy participants revealed within-subject increases in serum antioxidants 1 hour and 2 hours after consumption of MonaVie Active, and suppression of lipid peroxidation 2 hours after consumption (J. Agric. Food Chem. 2008;56:8,326-33).
In another study, a four-way crossover clinical trial compared açaí pulp and clarified açaí juice, with applesauce and a nonantioxidant drink as controls. Twelve healthy volunteers were dosed at 7 mL/kg of body weight following a washout phase and overnight fast. The investigators noted that plasma antioxidant capacity increased 2.3- and 3.0-fold for açaí juice and pulp, respectively, 2 hours after consumption of the beverage (J. Agric. Food Chem. 2008;56:7,796-802).
Additional recent research on antioxidant beverages has involved açaí. A study using four tests of antioxidant strength evaluated the relative antioxidant capacities of several polyphenol-rich beverages available on the U.S. market. These beverages included açaí juice, apple juice, black cherry juice, blueberry juice, Concord grape juice, cranberry juice, orange juice, pomegranate juice, red wines, and iced tea (black, green, and white). The in vitro antioxidant capacity of açaí juice was found to be in the middle of the pack, more potent than apple juice, cranberry juice, orange juice, and iced tea. The researchers cautioned, however, that in vitro antioxidant strength does not necessarily translate to in vivo biologic activity (J. Agric. Food Chem. 2008;56:1,415-22).
Anthocyanins
In 2004, investigators studied anthocyanins and other polyphenolic components of açaí in order to identify their contributions to the overall antioxidant profile of the fruit. They also sought to determine the color stability of anthocyanins against hydrogen peroxide at various termperatures. The researchers found that cyanidin 3-glucoside was the prevailing anthocyanin among 16 other polyphenolics in the tropical fruit, and the most influential in terms of its antioxidant capacity. In the presence of hydrogen peroxide, red grape anthocyanins were most stable, with açaí and pigments rich in acylated anthocyanins exhibiting lower color stability in a temperature-dependent fashion. In the presence of ascorbic acid, acylated anthocyanin sources displayed increased color stability. The authors concluded that açaí demonstrated functional characteristics that would be useful in food and nutraceutical products (J. Agric. Food Chem. 2004;52:1539-45).
Subsequently, some of the same researchers studied the effects of açaí polyphenolics on antiproliferation and induction of apoptosis in HL-60 human leukemia cells. They found that the açaí polyphenols indeed lowered leukemia cell proliferation in vitro, and concluded that açaí is a rich source of bioactive polyphenolic compounds (J. Agric. Food Chem. 2006;54:1,222-9).
Fruit Consumption
On the basis of discoveries that açaí fruit exhibits potent antioxidant capacity in vitro, particularly against superoxide and peroxyl radicals, Schauss et al. set out in 2006 to examine the potential health benefits that açaí fruit might impart. They investigated the antioxidant activity of a standardized freeze-dried açaí fruit pulp/skin powder (OptiAcai) in various assays using several sources of free radicals. The researchers found evidence in support of açaí’s antioxidant capacity against superoxide and peroxyl radicals, including strong scavenging of superoxide and the highest antioxidant activity of any food against the peroxyl radical. Mild activity was noted against the peroxynitrite and hydroxyl radicals.
The investigators also performed an assay to assess the inhibition of free radical development in freshly purified human neutrophils, which revealed that the antioxidants in açaí can, at very low doses, penetrate human cells and exhibit oxygen-quenching activity. Finally, the investigators studied the anti-inflammatory and immune bioactivities of açaí components, and observed that the fruit has the potential to inhibit cyclo-oxygenase (COX)-1 and COX-2 (J. Agric. Food Chem. 2006;54:8,604-10).
In a separate study, Schauss et al. analyzed OptiAcai and identified anthocyanins (chiefly cyanidin 3-glucoside and cyanidin 3-rutinoside), proanthocyanidins (mainly polymers), and other flavonoids (i.e., homoorientin, orientin, isovitexin, scoparin, and taxifolin deoxyhexose, along with several unknown ones) as the primary phytochemical constituents. They also found oleic and palmitic acids to be the prevailing fatty acid components. Resveratrol was identified at trace levels, and 19 amino acids were found, comprising 7.59% of the total weight (J. Agric. Food Chem. 2006;54:8,598-603).
Nutritional Components
In a far-ranging study of açaí pulp culled in the Venezuelan Amazon from two harvests of the year 2005, investigators used spectrophotometric methods to determine the content of polyphenols, tannins, and anthocynanins. The study sought to characterize the polyphenolic content and antioxidant capacity of the fruit, along with other qualities, such as fatty acid content. Antioxidant capacity was analyzed through the 2,2-diphenyl-1-picrylhydrazyl method.
The researchers found that açaí has a high content of lipids, particularly oleic acid, as well as large amounts of protein, ash, and total dietary fiber. The antioxidant capacity was 88%. The investigators concluded that açaí confers significant nutritional value and contains antioxidant constituents such as polyphenols, tannins, and anthocyanins that may render the fruit ripe for industrialization (Arch. Latinoam. Nutr. 2007;57:94-8).
Researchers studying the antioxidant capacities of 11 commercial and noncommercial varieties of açaí fruit pulp against three reactive oxygen species found that all purple açaí samples were potent scavengers of peroxyl radicals, good against peroxynitrite, and poor against hydroxyl radicals, compared with recently studied common European fruit and vegetable juices. One white açaí species displayed low antioxidant capacity against all three reactive oxygen species. Anthocyanins were found to account for only about 10% of the overall antioxidant capacities of the fruit. The investigators concluded that as-yet unidentified constituents of the açaí fruit pulp appeared to be responsible for most of its antioxidant activity (Int. J. Food Sci. Nutr. 2005;56:53-64).
Seed Extracts
The same researchers, along with others, later assessed the antioxidant capacity of methanol and ethanol seed extracts from açaí against peroxyl radicals, peroxynitrite, and hydroxyl radicals. They found that the antioxidant activity of the seed extracts was similar to that of the pulp against peroxyl radicals, and was greater against peroxynitrite and hydroxyl radicals. They also determined that procyanidins contribute significantly to the overall antioxidant capacity of açaí, but as-yet unidentified compounds account for the majority of such activity (J. Agric. Food Chem. 2006;54:4,162-7).
In a recent study, Pacheco-Palencia et al. examined the absorption and antiproliferative effects of açaí pulp extracts and a polyphenolic-enriched oil derived from the fruit pulp of the açaí berry. Investigators ascertained the chemical composition, antioxidant activity, and polyphenolic absorption of phytochemical fractions in a Caco-2 monolayer, in addition to their cytotoxicity in a human colon cancer cell line (HT-29 adenocarcinoma cells).
In general, the study added to the relatively slim body of literature on the bioactive properties, chemical composition, and cellular absorption of açaí polyphenolics. The investigators found that polyphenolic mixtures from the açaí pulp and oil significantly inhibited cell proliferation, and that standardized extracts featured a preponderance of hydroxybenzoic acids, monomeric flavan-3-ols, and procyanidin dimers and trimers (J. Agric. Food Chem. 2008;56:3,593-600).
Phenolic Constituents
Later in 2008, Pacheco-Palencia and two of the same researchers identified for the first time the phenolic constituents in crude oil extracts of the açaí berry. Like the berry, the oil was found to contain high concentrations of phenolic acids (i.e., vanillic acid, syringic acid, p-hydroxybenzoic acid, protocatechuic acid, and ferulic acid), (+)-catechin, and several procyanidin oligomers. The researchers evaluated the thermal stability of the oil during short- and long-term storage for lipid oxidation and phenolic retention, in terms of the effects on antioxidant activity. They found that phenolic acids underwent a 16% loss at 20° or 30° C after 10 weeks of storage, and a 33% loss at 40° C. Procyanidin oligomers showed greater degradation: 23% at 20° C, 39% at 30° C, and 74% at 40° C, in both high- and low-phenolic açaí oils. Phenolic and antioxidant capacity decreased less than 10% during short-term (20 minutes) heating at 150° C and 170° C. The investigators concluded that the high phenolic composition of açaí oil renders it a potentially beneficial food and supplement option, as well as a promising cosmetic agent (J. Agric. Food Chem. 2008;56:4,631-6).
Conclusions
Açaí berry is a popular ingredient in beverages in Central and South America, and its popularity is steadily increasing in North America. It is highly touted for its antioxidant potency. The berry is available in oral supplement form and is advertised as a miraculous weight-loss elixir. It is not often found in topical preparations because of its blue color.
While some of the scant research on açaí is compelling and, indeed, suggests significant antioxidant capacity, there is no evidence to support the use of açaí for weight loss. It is important that practitioners deflate the hype surrounding this botanical and indicate to patients that much more research is necessary to determine whether the antioxidant properties of açaí can be appropriately harnessed in topical or oral skin products.
That said, while I strongly recommend disabusing patients of the notion that açaí will help them lose weight, adding a sizable portion or portions of anthocyanin-containing berries, including açaí, in one’s diet is a healthy choice. As always, it’s best to suggest whole foods – real fruit – as opposed to diluted but sugared fruit drinks.
Native to South America, particularly the Amazon River and its tributaries and estuaries (J. Agric. Food Chem. 2006;54:8,598-603), the açaí palm (Euterpe oleracea Mart.) has become a subject of great interest in recent years, because its fruit is believed by many to boast significant antioxidant capacity.
The juice and pulp of açaí are popular beverage components in juice blends, smoothies, and other drinks in Central and South America. Mainstream attention, including features on popular U.S. television programs, “has increased interest in the United States in the potential and rumored health effects of açaí. This column will briefly review recent findings regarding this increasingly popular antioxidant-rich plant.
Juicy Benefits
In 2008, investigators studied the antioxidant and anti-inflammatory activities of a commercial juice blend (MonaVie Active) containing açaí as the main ingredient. Anthocyanins, the primary active phenolic components in açaí, were found to be the main antioxidants in the juice, particularly cyanidin 3-rutoside, cyanidin 3-diglycoside, and cyanidin 3-glucoside. In vitro, the antioxidants in the blend were shown to protect against oxidative damage. Polymorphonuclear cells exhibited decreased formation of free radicals and lower migration toward certain proinflammatory chemoattractants.
In vivo, a randomized, double-blind, placebo-controlled crossover trial with 12 healthy participants revealed within-subject increases in serum antioxidants 1 hour and 2 hours after consumption of MonaVie Active, and suppression of lipid peroxidation 2 hours after consumption (J. Agric. Food Chem. 2008;56:8,326-33).
In another study, a four-way crossover clinical trial compared açaí pulp and clarified açaí juice, with applesauce and a nonantioxidant drink as controls. Twelve healthy volunteers were dosed at 7 mL/kg of body weight following a washout phase and overnight fast. The investigators noted that plasma antioxidant capacity increased 2.3- and 3.0-fold for açaí juice and pulp, respectively, 2 hours after consumption of the beverage (J. Agric. Food Chem. 2008;56:7,796-802).
Additional recent research on antioxidant beverages has involved açaí. A study using four tests of antioxidant strength evaluated the relative antioxidant capacities of several polyphenol-rich beverages available on the U.S. market. These beverages included açaí juice, apple juice, black cherry juice, blueberry juice, Concord grape juice, cranberry juice, orange juice, pomegranate juice, red wines, and iced tea (black, green, and white). The in vitro antioxidant capacity of açaí juice was found to be in the middle of the pack, more potent than apple juice, cranberry juice, orange juice, and iced tea. The researchers cautioned, however, that in vitro antioxidant strength does not necessarily translate to in vivo biologic activity (J. Agric. Food Chem. 2008;56:1,415-22).
Anthocyanins
In 2004, investigators studied anthocyanins and other polyphenolic components of açaí in order to identify their contributions to the overall antioxidant profile of the fruit. They also sought to determine the color stability of anthocyanins against hydrogen peroxide at various termperatures. The researchers found that cyanidin 3-glucoside was the prevailing anthocyanin among 16 other polyphenolics in the tropical fruit, and the most influential in terms of its antioxidant capacity. In the presence of hydrogen peroxide, red grape anthocyanins were most stable, with açaí and pigments rich in acylated anthocyanins exhibiting lower color stability in a temperature-dependent fashion. In the presence of ascorbic acid, acylated anthocyanin sources displayed increased color stability. The authors concluded that açaí demonstrated functional characteristics that would be useful in food and nutraceutical products (J. Agric. Food Chem. 2004;52:1539-45).
Subsequently, some of the same researchers studied the effects of açaí polyphenolics on antiproliferation and induction of apoptosis in HL-60 human leukemia cells. They found that the açaí polyphenols indeed lowered leukemia cell proliferation in vitro, and concluded that açaí is a rich source of bioactive polyphenolic compounds (J. Agric. Food Chem. 2006;54:1,222-9).
Fruit Consumption
On the basis of discoveries that açaí fruit exhibits potent antioxidant capacity in vitro, particularly against superoxide and peroxyl radicals, Schauss et al. set out in 2006 to examine the potential health benefits that açaí fruit might impart. They investigated the antioxidant activity of a standardized freeze-dried açaí fruit pulp/skin powder (OptiAcai) in various assays using several sources of free radicals. The researchers found evidence in support of açaí’s antioxidant capacity against superoxide and peroxyl radicals, including strong scavenging of superoxide and the highest antioxidant activity of any food against the peroxyl radical. Mild activity was noted against the peroxynitrite and hydroxyl radicals.
The investigators also performed an assay to assess the inhibition of free radical development in freshly purified human neutrophils, which revealed that the antioxidants in açaí can, at very low doses, penetrate human cells and exhibit oxygen-quenching activity. Finally, the investigators studied the anti-inflammatory and immune bioactivities of açaí components, and observed that the fruit has the potential to inhibit cyclo-oxygenase (COX)-1 and COX-2 (J. Agric. Food Chem. 2006;54:8,604-10).
In a separate study, Schauss et al. analyzed OptiAcai and identified anthocyanins (chiefly cyanidin 3-glucoside and cyanidin 3-rutinoside), proanthocyanidins (mainly polymers), and other flavonoids (i.e., homoorientin, orientin, isovitexin, scoparin, and taxifolin deoxyhexose, along with several unknown ones) as the primary phytochemical constituents. They also found oleic and palmitic acids to be the prevailing fatty acid components. Resveratrol was identified at trace levels, and 19 amino acids were found, comprising 7.59% of the total weight (J. Agric. Food Chem. 2006;54:8,598-603).
Nutritional Components
In a far-ranging study of açaí pulp culled in the Venezuelan Amazon from two harvests of the year 2005, investigators used spectrophotometric methods to determine the content of polyphenols, tannins, and anthocynanins. The study sought to characterize the polyphenolic content and antioxidant capacity of the fruit, along with other qualities, such as fatty acid content. Antioxidant capacity was analyzed through the 2,2-diphenyl-1-picrylhydrazyl method.
The researchers found that açaí has a high content of lipids, particularly oleic acid, as well as large amounts of protein, ash, and total dietary fiber. The antioxidant capacity was 88%. The investigators concluded that açaí confers significant nutritional value and contains antioxidant constituents such as polyphenols, tannins, and anthocyanins that may render the fruit ripe for industrialization (Arch. Latinoam. Nutr. 2007;57:94-8).
Researchers studying the antioxidant capacities of 11 commercial and noncommercial varieties of açaí fruit pulp against three reactive oxygen species found that all purple açaí samples were potent scavengers of peroxyl radicals, good against peroxynitrite, and poor against hydroxyl radicals, compared with recently studied common European fruit and vegetable juices. One white açaí species displayed low antioxidant capacity against all three reactive oxygen species. Anthocyanins were found to account for only about 10% of the overall antioxidant capacities of the fruit. The investigators concluded that as-yet unidentified constituents of the açaí fruit pulp appeared to be responsible for most of its antioxidant activity (Int. J. Food Sci. Nutr. 2005;56:53-64).
Seed Extracts
The same researchers, along with others, later assessed the antioxidant capacity of methanol and ethanol seed extracts from açaí against peroxyl radicals, peroxynitrite, and hydroxyl radicals. They found that the antioxidant activity of the seed extracts was similar to that of the pulp against peroxyl radicals, and was greater against peroxynitrite and hydroxyl radicals. They also determined that procyanidins contribute significantly to the overall antioxidant capacity of açaí, but as-yet unidentified compounds account for the majority of such activity (J. Agric. Food Chem. 2006;54:4,162-7).
In a recent study, Pacheco-Palencia et al. examined the absorption and antiproliferative effects of açaí pulp extracts and a polyphenolic-enriched oil derived from the fruit pulp of the açaí berry. Investigators ascertained the chemical composition, antioxidant activity, and polyphenolic absorption of phytochemical fractions in a Caco-2 monolayer, in addition to their cytotoxicity in a human colon cancer cell line (HT-29 adenocarcinoma cells).
In general, the study added to the relatively slim body of literature on the bioactive properties, chemical composition, and cellular absorption of açaí polyphenolics. The investigators found that polyphenolic mixtures from the açaí pulp and oil significantly inhibited cell proliferation, and that standardized extracts featured a preponderance of hydroxybenzoic acids, monomeric flavan-3-ols, and procyanidin dimers and trimers (J. Agric. Food Chem. 2008;56:3,593-600).
Phenolic Constituents
Later in 2008, Pacheco-Palencia and two of the same researchers identified for the first time the phenolic constituents in crude oil extracts of the açaí berry. Like the berry, the oil was found to contain high concentrations of phenolic acids (i.e., vanillic acid, syringic acid, p-hydroxybenzoic acid, protocatechuic acid, and ferulic acid), (+)-catechin, and several procyanidin oligomers. The researchers evaluated the thermal stability of the oil during short- and long-term storage for lipid oxidation and phenolic retention, in terms of the effects on antioxidant activity. They found that phenolic acids underwent a 16% loss at 20° or 30° C after 10 weeks of storage, and a 33% loss at 40° C. Procyanidin oligomers showed greater degradation: 23% at 20° C, 39% at 30° C, and 74% at 40° C, in both high- and low-phenolic açaí oils. Phenolic and antioxidant capacity decreased less than 10% during short-term (20 minutes) heating at 150° C and 170° C. The investigators concluded that the high phenolic composition of açaí oil renders it a potentially beneficial food and supplement option, as well as a promising cosmetic agent (J. Agric. Food Chem. 2008;56:4,631-6).
Conclusions
Açaí berry is a popular ingredient in beverages in Central and South America, and its popularity is steadily increasing in North America. It is highly touted for its antioxidant potency. The berry is available in oral supplement form and is advertised as a miraculous weight-loss elixir. It is not often found in topical preparations because of its blue color.
While some of the scant research on açaí is compelling and, indeed, suggests significant antioxidant capacity, there is no evidence to support the use of açaí for weight loss. It is important that practitioners deflate the hype surrounding this botanical and indicate to patients that much more research is necessary to determine whether the antioxidant properties of açaí can be appropriately harnessed in topical or oral skin products.
That said, while I strongly recommend disabusing patients of the notion that açaí will help them lose weight, adding a sizable portion or portions of anthocyanin-containing berries, including açaí, in one’s diet is a healthy choice. As always, it’s best to suggest whole foods – real fruit – as opposed to diluted but sugared fruit drinks.
Native to South America, particularly the Amazon River and its tributaries and estuaries (J. Agric. Food Chem. 2006;54:8,598-603), the açaí palm (Euterpe oleracea Mart.) has become a subject of great interest in recent years, because its fruit is believed by many to boast significant antioxidant capacity.
The juice and pulp of açaí are popular beverage components in juice blends, smoothies, and other drinks in Central and South America. Mainstream attention, including features on popular U.S. television programs, “has increased interest in the United States in the potential and rumored health effects of açaí. This column will briefly review recent findings regarding this increasingly popular antioxidant-rich plant.
Juicy Benefits
In 2008, investigators studied the antioxidant and anti-inflammatory activities of a commercial juice blend (MonaVie Active) containing açaí as the main ingredient. Anthocyanins, the primary active phenolic components in açaí, were found to be the main antioxidants in the juice, particularly cyanidin 3-rutoside, cyanidin 3-diglycoside, and cyanidin 3-glucoside. In vitro, the antioxidants in the blend were shown to protect against oxidative damage. Polymorphonuclear cells exhibited decreased formation of free radicals and lower migration toward certain proinflammatory chemoattractants.
In vivo, a randomized, double-blind, placebo-controlled crossover trial with 12 healthy participants revealed within-subject increases in serum antioxidants 1 hour and 2 hours after consumption of MonaVie Active, and suppression of lipid peroxidation 2 hours after consumption (J. Agric. Food Chem. 2008;56:8,326-33).
In another study, a four-way crossover clinical trial compared açaí pulp and clarified açaí juice, with applesauce and a nonantioxidant drink as controls. Twelve healthy volunteers were dosed at 7 mL/kg of body weight following a washout phase and overnight fast. The investigators noted that plasma antioxidant capacity increased 2.3- and 3.0-fold for açaí juice and pulp, respectively, 2 hours after consumption of the beverage (J. Agric. Food Chem. 2008;56:7,796-802).
Additional recent research on antioxidant beverages has involved açaí. A study using four tests of antioxidant strength evaluated the relative antioxidant capacities of several polyphenol-rich beverages available on the U.S. market. These beverages included açaí juice, apple juice, black cherry juice, blueberry juice, Concord grape juice, cranberry juice, orange juice, pomegranate juice, red wines, and iced tea (black, green, and white). The in vitro antioxidant capacity of açaí juice was found to be in the middle of the pack, more potent than apple juice, cranberry juice, orange juice, and iced tea. The researchers cautioned, however, that in vitro antioxidant strength does not necessarily translate to in vivo biologic activity (J. Agric. Food Chem. 2008;56:1,415-22).
Anthocyanins
In 2004, investigators studied anthocyanins and other polyphenolic components of açaí in order to identify their contributions to the overall antioxidant profile of the fruit. They also sought to determine the color stability of anthocyanins against hydrogen peroxide at various termperatures. The researchers found that cyanidin 3-glucoside was the prevailing anthocyanin among 16 other polyphenolics in the tropical fruit, and the most influential in terms of its antioxidant capacity. In the presence of hydrogen peroxide, red grape anthocyanins were most stable, with açaí and pigments rich in acylated anthocyanins exhibiting lower color stability in a temperature-dependent fashion. In the presence of ascorbic acid, acylated anthocyanin sources displayed increased color stability. The authors concluded that açaí demonstrated functional characteristics that would be useful in food and nutraceutical products (J. Agric. Food Chem. 2004;52:1539-45).
Subsequently, some of the same researchers studied the effects of açaí polyphenolics on antiproliferation and induction of apoptosis in HL-60 human leukemia cells. They found that the açaí polyphenols indeed lowered leukemia cell proliferation in vitro, and concluded that açaí is a rich source of bioactive polyphenolic compounds (J. Agric. Food Chem. 2006;54:1,222-9).
Fruit Consumption
On the basis of discoveries that açaí fruit exhibits potent antioxidant capacity in vitro, particularly against superoxide and peroxyl radicals, Schauss et al. set out in 2006 to examine the potential health benefits that açaí fruit might impart. They investigated the antioxidant activity of a standardized freeze-dried açaí fruit pulp/skin powder (OptiAcai) in various assays using several sources of free radicals. The researchers found evidence in support of açaí’s antioxidant capacity against superoxide and peroxyl radicals, including strong scavenging of superoxide and the highest antioxidant activity of any food against the peroxyl radical. Mild activity was noted against the peroxynitrite and hydroxyl radicals.
The investigators also performed an assay to assess the inhibition of free radical development in freshly purified human neutrophils, which revealed that the antioxidants in açaí can, at very low doses, penetrate human cells and exhibit oxygen-quenching activity. Finally, the investigators studied the anti-inflammatory and immune bioactivities of açaí components, and observed that the fruit has the potential to inhibit cyclo-oxygenase (COX)-1 and COX-2 (J. Agric. Food Chem. 2006;54:8,604-10).
In a separate study, Schauss et al. analyzed OptiAcai and identified anthocyanins (chiefly cyanidin 3-glucoside and cyanidin 3-rutinoside), proanthocyanidins (mainly polymers), and other flavonoids (i.e., homoorientin, orientin, isovitexin, scoparin, and taxifolin deoxyhexose, along with several unknown ones) as the primary phytochemical constituents. They also found oleic and palmitic acids to be the prevailing fatty acid components. Resveratrol was identified at trace levels, and 19 amino acids were found, comprising 7.59% of the total weight (J. Agric. Food Chem. 2006;54:8,598-603).
Nutritional Components
In a far-ranging study of açaí pulp culled in the Venezuelan Amazon from two harvests of the year 2005, investigators used spectrophotometric methods to determine the content of polyphenols, tannins, and anthocynanins. The study sought to characterize the polyphenolic content and antioxidant capacity of the fruit, along with other qualities, such as fatty acid content. Antioxidant capacity was analyzed through the 2,2-diphenyl-1-picrylhydrazyl method.
The researchers found that açaí has a high content of lipids, particularly oleic acid, as well as large amounts of protein, ash, and total dietary fiber. The antioxidant capacity was 88%. The investigators concluded that açaí confers significant nutritional value and contains antioxidant constituents such as polyphenols, tannins, and anthocyanins that may render the fruit ripe for industrialization (Arch. Latinoam. Nutr. 2007;57:94-8).
Researchers studying the antioxidant capacities of 11 commercial and noncommercial varieties of açaí fruit pulp against three reactive oxygen species found that all purple açaí samples were potent scavengers of peroxyl radicals, good against peroxynitrite, and poor against hydroxyl radicals, compared with recently studied common European fruit and vegetable juices. One white açaí species displayed low antioxidant capacity against all three reactive oxygen species. Anthocyanins were found to account for only about 10% of the overall antioxidant capacities of the fruit. The investigators concluded that as-yet unidentified constituents of the açaí fruit pulp appeared to be responsible for most of its antioxidant activity (Int. J. Food Sci. Nutr. 2005;56:53-64).
Seed Extracts
The same researchers, along with others, later assessed the antioxidant capacity of methanol and ethanol seed extracts from açaí against peroxyl radicals, peroxynitrite, and hydroxyl radicals. They found that the antioxidant activity of the seed extracts was similar to that of the pulp against peroxyl radicals, and was greater against peroxynitrite and hydroxyl radicals. They also determined that procyanidins contribute significantly to the overall antioxidant capacity of açaí, but as-yet unidentified compounds account for the majority of such activity (J. Agric. Food Chem. 2006;54:4,162-7).
In a recent study, Pacheco-Palencia et al. examined the absorption and antiproliferative effects of açaí pulp extracts and a polyphenolic-enriched oil derived from the fruit pulp of the açaí berry. Investigators ascertained the chemical composition, antioxidant activity, and polyphenolic absorption of phytochemical fractions in a Caco-2 monolayer, in addition to their cytotoxicity in a human colon cancer cell line (HT-29 adenocarcinoma cells).
In general, the study added to the relatively slim body of literature on the bioactive properties, chemical composition, and cellular absorption of açaí polyphenolics. The investigators found that polyphenolic mixtures from the açaí pulp and oil significantly inhibited cell proliferation, and that standardized extracts featured a preponderance of hydroxybenzoic acids, monomeric flavan-3-ols, and procyanidin dimers and trimers (J. Agric. Food Chem. 2008;56:3,593-600).
Phenolic Constituents
Later in 2008, Pacheco-Palencia and two of the same researchers identified for the first time the phenolic constituents in crude oil extracts of the açaí berry. Like the berry, the oil was found to contain high concentrations of phenolic acids (i.e., vanillic acid, syringic acid, p-hydroxybenzoic acid, protocatechuic acid, and ferulic acid), (+)-catechin, and several procyanidin oligomers. The researchers evaluated the thermal stability of the oil during short- and long-term storage for lipid oxidation and phenolic retention, in terms of the effects on antioxidant activity. They found that phenolic acids underwent a 16% loss at 20° or 30° C after 10 weeks of storage, and a 33% loss at 40° C. Procyanidin oligomers showed greater degradation: 23% at 20° C, 39% at 30° C, and 74% at 40° C, in both high- and low-phenolic açaí oils. Phenolic and antioxidant capacity decreased less than 10% during short-term (20 minutes) heating at 150° C and 170° C. The investigators concluded that the high phenolic composition of açaí oil renders it a potentially beneficial food and supplement option, as well as a promising cosmetic agent (J. Agric. Food Chem. 2008;56:4,631-6).
Conclusions
Açaí berry is a popular ingredient in beverages in Central and South America, and its popularity is steadily increasing in North America. It is highly touted for its antioxidant potency. The berry is available in oral supplement form and is advertised as a miraculous weight-loss elixir. It is not often found in topical preparations because of its blue color.
While some of the scant research on açaí is compelling and, indeed, suggests significant antioxidant capacity, there is no evidence to support the use of açaí for weight loss. It is important that practitioners deflate the hype surrounding this botanical and indicate to patients that much more research is necessary to determine whether the antioxidant properties of açaí can be appropriately harnessed in topical or oral skin products.
That said, while I strongly recommend disabusing patients of the notion that açaí will help them lose weight, adding a sizable portion or portions of anthocyanin-containing berries, including açaí, in one’s diet is a healthy choice. As always, it’s best to suggest whole foods – real fruit – as opposed to diluted but sugared fruit drinks.