“Eat your fruits and vegetables.”
If you think it’s just good ol’ Mom pushing that mantra, you are a step behind the times.
In June, the USDA revised its famous food pyramid, and the new graphic—a plate instead of a triangle—calls for nearly 50 percent of a person’s daily diet to be fruits and vegetables.
The national debt may be $14.6 trillion, but the government can afford an entire website to push this point, at aptly named www.fruitsandveggiesmatter.gov. Here, you can learn exactly how many fruits and veggies you need, based on your age and activity level. The adult average clocks in at 4.5 cups per day.
Nutritional insiders know that fruits and vegetables bring an array of benefits: vitamins, minerals and fiber. But the big buzzword then and now is antioxidants—those magical little compounds found in brightly colored plants that seem to be Mother Nature’s gift to the planet.
“In the plant kingdom, there are some 20,000 antioxidant compounds we know of that protect their own cells from heat, air, moisture and time,” explains Chris Kilham, an ethnobotanist and founder of Medicine Hunter Inc. “They fall into different categories like flavanoids, phenols, anthocyanins and carotenoids. Many of them are biologically active in the human body as well—often in remarkably small amounts.”
The food industry’s benchmark of a substance’s antioxidant properties has been the oxygen radical absorption capacity (ORAC) test, a method of measuring antioxidant capacities in vitro. But comparing ORAC values can be tricky: Some tests compare ORAC units per gram of dry weight, while others might test wet weight or by serving. Then there are other challenges.
The problem with ORAC
“Are you testing the actual fruit, that would be ideal, but maybe you only have access to a juice concentrate or a freeze-dried powder,” said David Bell, founder of Bell Advisory Services, and an adviser to Brunswick Labs. “Then, once you get to freeze-drying, you need the caveat of how it was freeze dried, what percent moisture it contains, etc.”
The other criticism of ORAC testing has been that it tests activity in a test tube, not a biological being.
“ORAC describes the ability of a substance to quench peroxyl radical in vitro—in a test tube—and there is certainly no unanimous agreement on what that means on health outcomes,” Bell said. “But I happen to think, and most consumers believe, that antioxidant benefits are real in human physiology. If you’re giving some suggestion of that benefit, that’s a good thing.”
The USDA agrees.
Summarizing the state of research, the USDA states on its webpage: “Early evidence indicates that antioxidant activity translates to animals, protecting cells and their components from oxidative damage.
“Getting plenty of the foods with a high ORAC activity, such as spinach, strawberries, and blueberries, has raised the antioxidant power of human blood, prevented some loss of long-term memory and learning ability in middle-aged rats, maintained the ability of brain cells in middle-aged rats to respond to a chemical stimulus, and protected rats’ tiny blood vessels—capillaries—against oxygen damage.”
ORAC: The Next Generation
Today, testing for a compound’s ORAC value is commonplace. Brunswick Labs of Massachusetts has been offering its patented ORAC assay for more than a decade. For the simple $275 test, companies have literally put their products on the map.
“People have built entire branding campaigns with ORAC,” Bell said. “This kind of messaging has been worth millions of dollars a year.
Now the question in 2011 is: What comes next? While scientists have garnered strong suggestive evidence of antioxidants’ ability to quench one specific free-radical source (peroxyl), ORAC testing does not measure the other sources of free radicals in the body.
Brunswick Labs’ answer to this question came out earlier this year when it extended its ORAC patent to include a new array of testing it calls ORAC5.0. This “total ORAC suite” tests five primary reactive oxygen species: peroxyl, hydroxyl, peroxynitrite, superoxide anion and singlet oxygen.
Such testing, Bell concedes, is subject to the same limitations of the traditional ORAC test—it is an analytical test conducted in a test tube. But the test essentially gives evidence of a substance’s antioxidant potential against five primary radicals, rather than just one.
This opens up powerful messaging opportunities for antioxidant sources that have been slighted in the conventional one-radical test.
“Take the example of oranges,” Bell says. “The traditional ORAC test shortchanges all fruits and vegetables rich in carotenoids, because they don’t perform particularly well against peroxyl. But they perform really well against a radical called singlet oxygen. This is like measuring an athlete against strength but not on agility.”
In ORAC5.0 lab results provided by Brunswick Labs, looking at how a fruit or vegetable scores in all five categories changes the antioxidant profile of the food—again, at least in the test tube. As an example, the fruit with the highest value in the five tested categories is blackberry, which has an aggregate ORAC5.0 value of 490 per gram. But if you look only at its simple ORAC value of 51 per gram, blackberry ranks well below blueberry (at 68) and plum (at 76).
“The values across different radicals are not proportional,” Bell explains. “A ‘10’ in the peroxyl (ORAC test) is not the same as a ‘10’ in the hydroxyl (HORAC) test. But where things get interesting is in the variation around an average for a given radical test. For a given product, you can see how the contribution to total varies. For example, for oranges, the contribution from SOAC (singlet oxygen) is 67 percent compared to 23 percent average for all fruits and vegetables. On the other hand, blueberries demonstrate strong balance across the radical spectrum.”
Medicine Hunter Chris Kilham agrees that tests like ORAC5.0 are helpful, in that they add to the knowledge of the whole nutritional field. “If we can say we have two, three, four different measures of how a compound might be working, that’s cool!” he said. It is also important, however, not to rush to too many conclusions.
“ORAC measures have value overall, of how anti-oxidant something is, but as far as I have been able to determine, the antioxidant activity of these compounds is not the big ‘wow.’ It’s not where our attention should necessarily be.
“Lycopene is just an okay antioxidant but it is really good for the prostate. Lutein is just an okay antioxidant, but it’s great for the eyes. It may help prevent macular degeneration. The flavanols in cocoa are better than statin drugs for lowering cholesterol. There are many other biological markers beyond antioxidant capacity that really matter in the long run.”