Tuesday, March 22, 2011

Superfruits and ORAC value

A normal piece of fruit may have hundreds of ORAC units, a laboratory measure of antioxidant activity in a test tube. A “superfruit” may have tens of times higher antioxidant activity than our common fruits. Part of the reason for this is the environmental conditions of superfruits: some of them come from rainforests; others from more arid regions. It has been shown in studies that plants make antioxidants in response to environmental challenges such as droughts, variations in nutrient availability, competition with weeds, attacks by molds or bugs, lack of or excess sunlight, and other substandard conditions that are less common in modern chemical agricultural farming. This makes non-conventional crops more nutritious, especially in antioxidant nutrients like polyphenols that have only been compared to conventional crops for about a decade.

ORAC units, being a measure of test tube activity, may not be an ideal way to measure antioxidant potential in a food. However, it does give us a comparative measure of antioxidant compounds in various foods. The fact that these numbers may not accurately reflect their ability to act as antioxidants in the human body has become an issue, but until we get a better measure, or determine exactly which compounds measured by ORAC are used in what ways, this imperfect method still gives us a useful yardstick for nutritional density related to the foods’ antioxidant potential.

Naturally, numerous factors will affect the price and availability of superfruits including long supply chains, weather, transport costs, supply-and-demand, etc. Several superfruits are predicted to have an enduring market presence: Acai, Goji, Mangosteen, Noni, and Pomegranate. Maqui berries possess among the highest known ORAC value (Oxygen Radical Absorption Capacity) of any superfruit. Maqui berries are purple berries rich in anthocyanins.

It’s important to realize that rainforest fruits play a role in preserving tropical rain forests. If the indigenous people can make a living by harvesting wild fruit from mature trees, rather than finding it advantageous to clear cut to farm corn and soybeans, you can see that their vested interest would lie in protecting that forest from developers. Wildcrafted fruit would tend to be more nutritious in antioxidants than orchard-grown fruit, based on the results of comparative studies showing that environmental diversity protects and challenges the plants to produce protective phytochemicals that serve as human nutrients. Of course, these superfruits are not necessarily locally sourced, but they are extremely nutritious and do help to preserve the rainforests.

It’s important to note that the federal government refuses to recognize “structure-function” claims made on foods, which do not have DSHEA protections. You’ve probably heard that food companies touting the benefits of their own superfoods – cherries, fortified OJ, probiotics, pomegranate juice – have been targeted by federal agencies enforcing their rules that all food claims go through the tedious approval process of publishing in the Federal Register, etc. In this regard one can make more claims on a dietary supplement label – if properly documented – than on a food label.

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