Comparing Fruit Juices:
Jacob Schor, ND, FABNO
March 27, 2010
A patient presented me with an advertisement for Acai berries yesterday afternoon and asked what I thought. As many of you know, although I’m a fan of fruit and vegetable juices, exotic sources for these juices make me suspect. In my opinion, which some say may be too easily and strongly expressed at times, the novelty of foreign fruits and berries often prompts them to be overly valued by consumers in comparison to many more common and more familiar foods. I expressed these thoughts. Were they correct though?
A paper published in the Journal of Agricultural and Food Chemistry about two years ago compared the antioxidant strength of a list of fruit juices. The authors, researchers from UCLA, are aware that terms like anti-oxidant are commonly used to promote juice products to consumers. They, like me, found some of the claims of ‘our product has the most antioxidants’ suspicious, so they tested them.
In this study they used a variety of different tests. Four different tests to measure antioxidant potency were performed:
- Trolox equivalent antioxidant capacity (TEAC),
- Total oxygen radical absorbance capacity (ORAC),
- free radical scavenging capacity by 2,2-diphenyl-1-picrylhydrazyl (DPPH),
- ferric reducing antioxidant power (FRAP)
The juices were also tested for antioxidant functionality by measuring how well they inhibited low-density lipoprotein (LDL) oxidation by peroxides and malondialdehyde. Recall that oxidation of these lipoproteins is the first step in forming atherosclerotic plaques and you understand the relevance of measuring this.
The total polyphenol content was also measured as gallic acid equivalents (GAEs).
Several different brands of each type of juice were purchased and tested. The juices included: (number of brands in parenthesis)
- apple juice (3)
- açaí juice (3)
- black cherry juice (3)
- blueberry juice (3)
- cranberry juice (3)
- Concord grape juice (3)
- orange juice (3)
- red wines (3)
- iced tea beverages (10) [black tea (3), green tea (4), white tea (3)]
- Pom Wonderful pomegranate juice. [note: UCLA has published several papers using this product in the past, receives research funding from the manufacturer, and thus obviously has some partiality toward this particular product.]
The test results were given equal weight and combined together to create an overall “antioxidant potency composite index.” Pomegranate juice had the greatest antioxidant score among the beverages tested. Its score was more than 20% higher than red wine which came in second place.
Here is the order from highest antioxidant score to least: (or Best to Worse)
- Pomegranate juice
- Red wine
- Concord grape juice
- Blueberry juice
- Black cherry juice
- Açaí juice
- Cranberry juice
- Orange juice
- Iced tea beverages
- Apple juice
Obviously these laboratory measures do not tell us which products will work best to prevent disease. They do give us some perspective though on the various label and advertising claims we are confronted with.
There’s a second paper of interest related to this, also from 2008. In this paper Chinese researchers gave 26 people a daily glass of either apple juice or pomegranate juice and tested the blood of the test subjects to compare effects of the two juices.
They measured changes in plasma antioxidant capacity, activity of antioxidant enzymes, contents of ascorbic acid, vitamin E, reduced glutathione, malondialdehyde, oxidized low-density lipoprotein and carbonyls, and the degree of DNA damage in mononuclear blood cells.
Those who drank the pomegranate juice had a significantly higher plasma antioxidant capacity. The apple juice also had benefit but much less. The blood levels of vitamins C and E and other chemical antioxidants were not particularly different between the two groups of test subject so the researchers concluded that it is the phenols in these juices, chemicals like quercetin, ellagic acid and gallic acid that are responsible for the effects.
This is not to show any disrespect to apple juice, a substance that continues to show benefit in a variety of conditions. A paper published a few days ago reported benefit in patients with Alzheimer’s disease who drank 8 ounces of apple juice a day.
This reminds me of a paper from several years ago that compared clarified apple juice versus un-clarified cider. Finding it may be a challenge as there are nearly a thousand articles in the medical literature that deal with apple juice. Back about three years ago Polish and German researchers both reported that cloudy apple juice, what we call cider, contains more antioxidants than clear apple juice. Oszmianski's Polish team found that procyanidins were between 2.6 and 5.3 times as abundant in cloudy juice as in clear, depending on the variety of apple used. Overall, the cloudy juice was 1.5 to 1.8 times as effective an antioxidant as the clear juice.
Huemmer’s German team compared anthocyanin content and found a similar higher content in cider compared to clear juice. I’ve mulled over this information for years every time I’ve purchased Martinelli’s Sparkling Cider.
I should stop here but there is one last consideration that we are obligated to include. Combining a number of fruit juices together may have a synergistic effect and provide more benefit than single juices. Thus the juice blends that one might initially discredit as attempts to lower the price by adding cheaper juice such as apple juice, may still outshine the more expensive versions.
For example, Rui Liu, one of my heroes at Cornell University, had an interesting paper published last September. Liu is famed for measuring the synergistic effect at inhibiting cancer growth when two or more phytochemicals are combined. In this paper he tells us that combining apple extracts with quercetin creates a 2- to 4-fold increase in effect on breast cancer cells.
Elderberry juice is one of our best sources of quercetin, as the berries contain about 42 mg/100 gram. [Note: capers are the best source of quercetin, 180 mg/100 gm, but eating a significant quantity would be difficult; consuming caper juice impossible]
The effect of quercetin also may be increased by combining it with the epigallocatechins from green tea. Hsieh reported in the October 2009 issue of Anticancer Research a synergistic effect against prostate cancer cells when EGCG was combined with quercetin and genestein. A similar synergy was reported a year earlier when combining resveratrol with green tea and vitamin E.
The UCLA fruit juice study that we started with, in which pomegranate juice was the clear winner, employed a range of tests for antioxidant action as if antioxidant action is all that matters. In reality it isn’t. It also doesn’t predict synergistic effects as Liu and Hsieh report. These fruit juice extracts that didn’t make the top of the list may still have benefits that we are not able to predict based on these tests. Still, until we have animal and better, human clinical trials, comparing the relative benefits, using these kinds of tests is the best choice we have, certainly better information to rely on than what the sellers and advertisers tell us.
So until we have information otherwise, plain old grape juice is probably better for you than Açaí juice.
I’ve written about Liu in the past. His work is behind my yearly postings of fruit cake recipes:
J Agric Food Chem. 2008 Feb 27;56(4):1415-22. Epub 2008 Jan 26.
Comparison of antioxidant potency of commonly consumed polyphenol-rich beverages in the United States.
Seeram NP, Aviram M, Zhang Y, Henning SM, Feng L, Dreher M, Heber D.
Center for Human Nutrition, David Geffen School of Medicine, University of California, Los Angeles, California 90095, USA.
A number of different beverage products claim to have antioxidant potency due to their perceived high content of polyphenols. Basic and applied research indicates that pomegranate juice (PJ), produced from the Wonderful variety of Punica granatum fruits, has strong antioxidant activity and related health benefits. Although consumers are familiar with the concept of free radicals and antioxidants, they are often misled by claims of superior antioxidant activity of different beverages, which are usually based only on testing of a limited spectrum of antioxidant activities. There is no available direct comparison of PJ's antioxidant activity to those of other widely available polyphenol-rich beverage products using a comprehensive variety of antioxidant tests. The present study applied (1) four tests of antioxidant potency [Trolox equivalent antioxidant capacity (TEAC), total oxygen radical absorbance capacity (ORAC), free radical scavenging capacity by 2,2-diphenyl-1-picrylhydrazyl (DPPH), and ferric reducing antioxidant power (FRAP)]; (2) a test of antioxidant functionality, that is, inhibition of low-density lipoprotein (LDL) oxidation by peroxides and malondialdehyde methods; and (3) evaluation of the total polyphenol content [by gallic acid equivalents (GAEs)] of polyphenol-rich beverages in the marketplace. The beverages included several different brands as follows: apple juice (3), açaí juice (3), black cherry juice (3), blueberry juice (3), cranberry juice (3), Concord grape juice (3), orange juice (3), red wines (3), iced tea beverages (10) [black tea (3), green tea (4), white tea (3)], and a major PJ available in the U.S. market. An overall antioxidant potency composite index was calculated by assigning each test equal weight. PJ had the greatest antioxidant potency composite index among the beverages tested and was at least 20% greater than any of the other beverages tested. Antioxidant potency, ability to inhibit LDL oxidation, and total polyphenol content were consistent in classifying the antioxidant capacity of the polyphenol-rich beverages in the following order: PJ>red wine>Concord grape juice>blueberry juice>black cherry juice, açaí juice, cranberry juice>orange juice, iced tea beverages, apple juice. Although in vitro antioxidant potency does not prove in vivo biological activity, there is also consistent clinical evidence of antioxidant potency for the most potent beverages including both PJ and red wine.
Nutr Res. 2008 Feb;28(2):72-7.
Pomegranate juice is potentially better than apple juice in improving antioxidant function in elderly subjects.
Guo C, Wei J, Yang J, Xu J, Pang W, Jiang Y.
Department of Nutrition, Institute of Hygiene and Environmental Medicine, Tianjin, 300050, PR China. firstname.lastname@example.org
In the present study, 26 elderly subjects were recruited and randomly divided into 2 groups, that is, apple (low in antioxidant capacity) and pomegranate (high in antioxidant capacity) groups, and 250 mL of juice was consumed daily for 4 weeks. Changes in plasma antioxidant capacity, activity of antioxidant enzymes, contents of ascorbic acid, vitamin E, reduced glutathione, malondialdehyde, oxidized low-density lipoprotein and carbonyls, and the degree of DNA damage in mononuclear blood cells were measured. Urine samples were collected for determination of 8-hydroxy-2'-deoxyguanosine content. Increased plasma antioxidant capacity and decreased plasma carbonyl content were demonstrated after daily consumption of pomegranate juice. In comparison, apple juice consumption presented a less significant effect on antioxidant function in elderly subjects. It is concluded that daily consumption of pomegranate juices is potentially better than apple juice in improving antioxidant function in the elderly. Because the plasma ascorbic acid, vitamin E, and reduced glutathione contents did not differ significantly between the 2 groups in this study, the phenolics may be the functional components contained in pomegranate juice that accounted for the observations.
Am J Alzheimers Dis Other Demen. 2010 Mar 25. [Epub ahead of print]
Apple Juice Improved Behavioral But Not Cognitive Symptoms in Moderate-to-Late Stage Alzheimer's Disease in an Open-Label Pilot Study.
Remington R, Chan A, Lepore A, Kotyla E, Shea TB.
Preclinical studies demonstrate that apple juice exerts multiple beneficial effects including reduction of central nervous system oxidative damage, suppression of Alzheimer's disease (AD) hallmarks, improved cognitive performance, and organized synaptic signaling. Herein, we initiated an open-label clinical trial in which 21 institutionalized individuals with moderate-to-severe AD consumed 2 4-oz glasses of apple juice daily for 1 month. Participants demonstrated no change in the Dementia Rating Scale, and institutional caregivers reported no change in Alzheimer's Disease Cooperative Study (ADCS)-Activities of Daily Living (ADL) in this brief study. However, caregivers reported an approximate 27% (P < .01) improvement in behavioral and psychotic symptoms associated with dementia as quantified by the Neuropsychiatric Inventory, with the largest changes in anxiety, agitation, and delusion. This pilot study suggests that apple juice may be a useful supplement, perhaps to augment pharmacological approaches, for attenuating the decline in mood that accompanies progression of AD, which may also reduce caregiver burden.
PMID: 20338990 [PubMed - as supplied by publisher]
J Agric Food Chem. 2008 Aug 13;56(15):6520-30. Epub 2008 Jul 9.
Polyphenolic compounds and antioxidant activity of new and old apple varieties.
Wojdy?o A, Oszmia?ski J, Laskowski P.
Department of Fruit and Vegetable Technology, Wroc?aw Environmental and Life Science University, 25 Norwida Street, 50-375 Wroc?aw, Poland. email@example.com
There is considerable evidence to show that a greater intake of apple contributes to improved health by reducing the risk of diseases, such as cardiovascular disease and some forms of cancer. Apple fruit is a major source of phenol compounds, because its consumption is widespread in many countries and it is available on the market for the whole year. The phenolic composition of 67 varieties of apple cultivars (new and old varieties) was examined for the concentration of some important phytochemicals and antioxidant activity. For the first time, we have looked at the correlation and compared polyphenolic coumpounds in Golden Delicious variety and new varieties grown from it. Up to 18 compounds, including catechin, procyanidin, hydroxycinnamates, flavonols, anthocyanins, and dihydrochalcones, were analyzed by high-performance liquid chromatography with diode array detection analysis of crude extracts and after thiolysis and LC-MS. The mean content of total polyphenols lay between 523.02 and 2723.96 mg/100 g dw and depending upon the apples variety. Flavanols (catechin and oligomeric procyanidins) are the major class of apple polyphenols, representing more than 80%, followed by hydroxycinnamic acids (1-31%), flavonols (2-10%), dihydrochalcones (0.5-5%), and in red apples, anthocyanins (1%). In this study, the best correlation was found for the total polyphenols and ABTS method, with a lower correlation for FRAP and DPPH methods ( r = 0.871, 0.839, and 0.804, respectively). The presented data clearly demonstrated that new varieties, i.e., Ozark Gold, Julyred, and Jester, of apple had the same or higher value of bioactive compounds in comparison to the old varieties, i.e., Golden Delicious, Idared, and Jonagold.
Biotechnol J. 2008 Feb;3(2):234-43.
Content and mean polymerization degree of procyanidins in extracts obtained from clear and cloudy apple juices.
Huemmer W, Dietrich H, Will F, Schreier P, Richling E.
Chair of Food Chemistry, University of Würzburg, Würzburg, Germany.
The polyphenol profile of apples and that of technologically differently treated apple juices has already been studied thoroughly; nevertheless, the content of polymeric procyanidins has not received much attention up to date. Therefore, procyanidins in extracts made from six blended apple juices and two authentic clear as well as cloudy apple juices (Malus domestica cv. Bohnapfel and Bittenfelder) were investigated. Our determinations revealed significant differences in the total procyanidin content between apple juice extracts obtained from clear and the corresponding cloudy juices under study. Depending on the apple cultivars used average amounts of total procyanidin content determined in the extracts made from clear and cloudy juices ranged from 28.4 +/- 4.4% to 49.0 +/- 5.7% and from 48.3 +/- 0.3% to 60.6 +/- 0.3%, respectively. As the mean degree of polymerization (DPm) is supposed to have an influence on bioavailability and toxicity on different cells lines used in in vitro systems, the average degree of polymerization of the juices under examination were determined. Depending on the cultivar used and the technology of juice processing the DPm ranged between 3.0 and 13.4.
J Agric Food Chem. 2009 Sep 23;57(18):8581-6.
Synergistic effect of apple extracts and quercetin 3-beta-d-glucoside combination on antiproliferative activity in MCF-7 human breast cancer cells in vitro.
Yang J, Liu RH.
Department of Food Science, Cornell University, Ithaca, NY 14853-7201, USA.
Breast cancer is the most frequently diagnosed cancer in women. An alternative strategy to reduce the risk of cancer is through dietary modification. Although phytochemicals naturally occur as complex mixtures, little information is available regarding possible additive, synergistic, or antagonistic interactions among compounds. The antiproliferative activity of apple extracts and quercetin 3-beta-d-glucoside (Q3G) was assessed by measurement of the inhibition of MCF-7 human breast cancer cell proliferation. Cell cytotoxicity was determined by the methylene blue assay. The two-way combination of apple plus Q3G was conducted. In this two-way combination, the EC(50) values of apple extracts and Q3G were 2- and 4-fold lower, respectively, than those of apple extracts and Q3G alone. The combination index (CI) values at 50 and 95% inhibition rates were 0.76 +/- 0.16 and 0.42 +/- 0.10, respectively. The dose-reduction index (DRI) values of the apple extracts and Q3G to achieve a 50% inhibition effect were reduced by 2.03 +/- 0.55 and 4.28 +/- 0.39-fold, respectively. The results suggest that the apple extracts plus Q3G combination possesses a synergistic effect in MCF-7 cell proliferation.
Anticancer Res. 2009 Oct;29(10):4025-32.
Targeting CWR22Rv1 prostate cancer cell proliferation and gene expression by combinations of the phytochemicals EGCG, genistein and quercetin.
Hsieh TC, Wu JM.
Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY 10595, USA.
Prostate cancer (CaP) is a significant cause of death in American men. While men residing in Asia show a lower incidence of hormone-refractory prostate cancer (HRPC) compared to Caucasian males, Asian men who move to and live in the United States and adopt a western lifestyle have HRPC rates indistinguishable from Caucasian males. These findings suggest that Asian diets contain ingredients that might protect against the development of HRPC. The identity and mechanisms of such HRPC protective agents remain to be elucidated. An Asian diet may confer protection against HRPC owing to functional synergy between bioactive dietary agents, thus broadening the chemopreventive index, with increased distinct anticancer properties and decreased untoward effects. Here, whether or not a combination of epigallocatechin gallate (EGCG), genistein and quercetin, phytochemicals present in a traditional Asian diet, might exert synergy in controlling proliferation and gene expression was investigated in CWR22Rv1 CaP cells, an in vitro model mimicking CaP transition from AD (androgen dependence) to HRPC. Cell proliferation was inhibited approximately 40%, approximately 15% and approximately 20%, respectively by 2.5 microM EGCG, genistein and quercetin used alone. The co-administration of 2.5 microM of these phytochemicals suppressed proliferation synergistically in the CWR22Rv1 cells maintained in RPMI-1640 supplemented with 10% fetal bovine serum, but not in the cells maintained as serum-free cultures. Synergy in the expression of androgen receptor, tumor suppressor p53 and detoxification enzyme quinone reductase type 1, denoted NQO1, was also observed for the combined phytochemicals. These results demonstrate the feasibility of developing a diet-based combinatorial approach for CaP prevention and treatment and raise the possibility that serum added to culture medium might affect uptake, bioavailability and biological efficacy of dietary phytochemicals.
Int J Oncol. 2008 Oct;33(4):851-9.
Suppression of cell proliferation and gene expression by combinatorial synergy of EGCG, resveratrol and gamma-tocotrienol in estrogen receptor-positive MCF-7 breast cancer cells.
Hsieh TC, Wu JM.
Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY 10595, USA.
Numerous dietary phytochemicals have shown anti-breast carcinogenic activities when tested in vitro; however, in most cases, the demonstrated efficacy of individual phytochemicals requires doses not readily achievable in vivo. Therefore, whether diets might exert translational promises and benefits in clinical settings and prevention of breast cancer remain unclear. Since cancer cells are endowed with complex, redundant, converging and diverging pathways spanning both the genetic and metabolic networks that are not merely replicates of those in normal cells, it is of interest to test whether a multicomponent approach involving lower, physiologically relevant doses of natural dietary agents may be developed as a chemopreventive strategy for breast cancer. Herein, we investigated, using the estrogen receptor-positive MCF-7 breast cancer cells as a model, whether the combination of epigallocatechin gallate (EGCG), resveratrol and gamma-tocotrienol at suboptimal doses elicits synergism in suppressing cell proliferation, modulating gene expression, and increasing antioxidant activity, as compared to each of the three phytochemicals added alone. The results showed that there was a approximately 33, 50 and 58% inhibition of cell proliferation by > or =50 microM EGCG, > or =25 microM resveratrol and > or =10 microM gamma-tocotrienol, respectively, added as a single agent. When a suboptimal dose (10 microM) of each phytochemical was used, a significant additive effect in suppression of cell proliferation was observed with the combination of resveratrol and gamma-tocotrienol whereas the three phytochemicals added together did not produce more pronounced inhibition of cell proliferation. A significant additive effect in reducing cyclin D1 and bcl-2 expression was found when gamma-tocotrienol was added with either EGCG or resveratrol. Functional synergism among the three phytochemicals was only observed in the induction of quinone reductase NQO1. These results suggest that diet-based protection against breast cancer may partly derive from synergy amongst dietary phytochemicals directed against specific molecular targets in responsive breast cancer cells, and provide support for the feasibility of the development of a diet-based combinatorial approach in the prevention and treatment of breast cancer.