Welcome to part two of our look into antioxidants where we look at how levels are actually measured! If you missed the first part (where we explored what they actually are) scroll down and you’ll see it right there in our related articles. Ok – let’s carry on!
The ORAC Score
The ORAC unit (Oxygen Radical Absorbance Capacity), ORAC value, or ORAC score is a method developed by scientists at the National Institute of Health and Aging (NIH) to measures the antioxidant capacity of different foods. Whilst the exact relationship between the ORAC value of a food and its health benefit has not been fully established, it is generally believed that foods with higher ORAC scores have greater antioxidant capacity, and more effectively neutralise harmful free radicals.
According to the free-radical theory of ageing and disease, a high antioxidant intake from foods, will slow the oxidative processes and free radical damage that contributes to age-related degeneration and disease.
Many many units do you need?
Scientists and researchers in the area of ORAC and antioxidants state that the body can effectively use 3000-5000 antioxidant or ORAC units per day. Any more than this (i.e. with mega-dosing in supplement form) seems to be of no added benefit and “excess” is most likely excreted by the kidneys. Dr Ronald Prior of the US Department of Agriculture Research Service at Tufts University, Boston, Massachusetts is quoted to have said,
“A significant increase in antioxidants of 15-20% is possible by increasing consumption of fruits and vegetables, particularly those high in ORAC value. However, in order to have a significant impact on plasma and tissue antioxidant capacity one can only meaningfully increase one’s daily intake by 3000-5000 ORAC units. Any greater amount is probably redundant. That is because the antioxidant capacity of the blood is tightly regulated. Thus there is an upper limit to the benefit that can be derived from antioxidants. Taking in 25000 ORAC units at one time (as reputedly occurs with mangosteen) would be no more beneficial than taking in a fifth of that amount: the excess is simply excreted by the kidneys”.
Whilst there is no “official” daily recommended intake of ORAC units, various researchers suggest an optimal intake to be 3000-5000 ORAC units per day, and the USDA have come up with a suggested intake of 5000 ORAC units per day. The UK FSA, and the FDA recommend “5 a day” of fruit and vegetable servings, which give an approximate ORAC score of 3500.
ORAC values of some common foods per 100g food
- Peppermint, fresh 13978
- Oregano, fresh 13970
- Nuts, walnuts, English 13541
- Nuts, hazelnuts 9645
- Cranberries, raw 9584
- Beans, kidney, red, mature seeds, raw 8459
- Beans, black, mature seeds, raw 8040
- Nuts, pistachio nuts, raw 7983
- Beans, pinto, mature seeds, raw 7779
- Lentils, raw 7282
- Raspberries, raw 4882
- Basil, fresh 4805
- Nuts, almonds 4454
- Apples, Red Delicious, raw with skin 4275
- Peaches, dried to 40% moisture (purchased in Italy) 4222
- Raisins, white, dried to 40% moisture (purchased in Italy) 4188
- Apples, Granny Smith, raw, with skin 3898
- Figs, raw 3383
- Cherries, sweet, raw 3365
- Gooseberries, raw 3277
- Apricots, dried to 40% moisture (purchased in Italy) 3234
- Peanuts, all types, raw 3166
- Cabbage, red, cooked, boiled, drained, without salt 3145
- Broccoli, raw 3083
- Apples, raw, with skin 3082
The World’s Top 10 High ORAC foods per 100g
Per 100g food…
- Spices, cloves, ground 314446
- Sumac, bran, raw 312400
- Spices, cinnamon, ground 267536
- Sorghum, bran, hi-tannin 240000
- Spices, oregano, dried 200129
- Spices, turmeric, ground 159277
- Acai berry, freeze-dried 102700
- Sorghum, bran, black 100800
- Sumac, grain, raw 86800
- Cocoa, dry powder, unsweetened 80933