It's one of the best selling herbal supplements in America, but are there any antioxidants in ginkgo biloba? Even we were surprised to see these test results, given that the suggested benefits it has been marketed for are things like memory, cognition, and some symptoms of Alzheimer's and dementia. Those claims are not conclusively proven, but the research for them is fascinating nonetheless. One claim though you may not hear discussed is talk of the leaf's antioxidant activity.
Several years back, researchers at the University of Oslo in Norway conducted tests on a large number of supplements. They measured the ORAC value for them, which is a number reflecting the total in vitro antioxidant content of a substance. Measuring in vivo, meaning inside the human body, is not possible and therefore it's only theoretical as to what effects any detected antioxidants would have inside of a living human.
For the ginkgo biloba ORAC test, they used a common brand which was purchased in the United States. Each capsule was marketed as having 60 mg of ginkgo biloba in it. 100 grams of these capsules were used for measuring.
The results were impressive, as the above number is higher than one may expect. To give you an idea of how high it is, it's over 400% higher than blackberries and garlic powder. Compared to goji berries, it's 10x the value.
Now in all fairness, it's important to keep in mind that all of these numbers reference the measurements for 100 grams worth, which is about 3.5 ounces. Obviously taking a capsule or two of ginkgo would only weigh a tiny fraction of that, and hence, the ORAC per serving would also be that fractional amount. On the other hand, with superfoods like berries you do often consume a few ounces per serving.
Furthermore, since the ginkgo supplement is dried, its antioxidant content is more concentrated, since the water weight has been removed (compared to fresh fruits and vegetables, which contain a great deal of water). That is why dried spices are usually potent sources, many being even higher than this tree leaf. Regardless, how much antioxidants there are in ginkgo biloba is impressive, especially considering that it might be a "hidden" benefit which most people are not even aware of when they buy it.
Research Support, Non-U.S. Gov't: Carlsen MH, Halvorsen BL, Holte K, et al. Nutrition Journal NIH Jan 2010