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You hear a lot of hype in nutritional news these days about ORAC values of different fruits and vegetables, as well as nutritional supplements. What are ORAC values exactly?
ORAC Values are a measure of the antioxidant capacity of fruits and vegetables. ORAC stands for Oxygen Radical Absorbency Capacity. This standard was developed by Brunswick Labs and adopted by the U.S. Department of Agriculture.
ORAC values indicate antioxidant capacity of a food by measuring how long it takes an antioxidant to react to free radicals, as well as the amount of antioxidants within the specific food. It combines these elements into one measurement that is commonly expressed in terms of a 100-gram serving.
Foods with a higher ORAC value have a greater antioxidant potential than those with low values. The foods that tend to rank the highest in ORAC values are fruits with bright colors, such as berries, red grapes, cherries.
Why ORAC Values May Not Be So Important.
Some question remains about whether or not ORAC values are actually the best way to determine the most beneficial antioxidant foods. For example, the methods used to obtain values listed in the ORAC tables only apply to water-soluble antioxidants, not fat-soluble ones, like the carotenoids. So, you won't find some carotene-rich foods high on the list, even though they may be more beneficial. Other labs have also designed their own standards for measuring antioxidant capacity, using different criteria. This raises another question about which method is more accurate and useful.
Some antioxidants can't be measured. You also have to keep in mind that there are thousands of phytonutrients (plant nutrients) that scientists have not yet been able to identify or isolate, and can't be measured by any standard. This means that there is no way to completely assess the full nutritional and antioxidant benefit of any given fruit or vegetable using the ORAC table. In general, though, theres no reason to doubt that foods high on the ORAC list should be considered a valuable source of antioxidants.
ORAC Numbers can be manipulated. Another problem with the ORAC table is that the numbers can be manipulated to make one nutritional product look more powerful than any other. Companies will use different sets of measurements either dry weight, liquid measures, or typical serving sizes; they also will not include other foods that might compete with their numbers and make them look less impressive. This is common practice among the producers of various antioxidant juices on the market, such as acai and goji berries.
Using different types of measurements, different foods can appear to have higher ORAC scores than others. For example, prunes have an ORAC value of 5570, considerably higher than plums, which measure out at 949. The truth is that theyre the same fruit, and a prune has no more antioxidant potential than the plum from which it was dried. Its just missing the water content, which makes up most of the weight. So do yourself a favor and don't worry about the numbers too much, just eat whichever fruits on the list you like.
ORAC Values don't account for the many different types of antioxidants. Most people dont realize how many different antioxidants there are. Some foods, such as onions, have dozens of known phytonutrients and an unknown number that have never been isolated and studied. Antioxidants found in carrots arent the same as those found in tomatoes, or leafy greens, or broccoli.
Even among similar antioxidant fruits, the specific types of antioxidants differ. The antioxidants found in acai berries are different from those in mangosteen or goji berries. Ideally, you want many different types of antioxidants as much as you want a huge quantity of any particular one. Your body wants all of the different types, because antioxidants work together as a team, producing more effective results together than they can by themselves.
When it comes to antioxidant nutrition, variety counts as much as quantity. It's important to eat a variety of healthy foods, not only for their antioxidant levels, but for their other nutritional properties as well. So don't get hooked into the ORAC table numbers. Just eat a wide variety of fruits and vegetables to get most of what you need, and use supplements as extra insurance. Food especially rich in antioxidants include any type of berry, dried fruits such as prunes or raisins, dark-green leafy vegetables, and beans. There are numerous supplemental products that incorporate antioxidant-rich fruits such as acai and goji berries, or green powders such as chlorella and spirulina.
