Is there a difference between quick oats and old fashioned oats in terms of antioxidant content? The funny thing is that you often hear people say that the old fashion or rolled variety is healthier than instant oatmeal as well as other fast cooking versions. But if you compare them side by side, you will see their calories and other nutrition (fat, carbs, fiber, protein, etc.) is identical or very close to it.
So why then do people claim that certain versions are healthier? It's probably because the one thing that can differ dramatically between them is their Glycemic Index. Instant oatmeal, on average, has a GI of 83. All others (which consists of the slower cooking versions) have an average GI of 55. Clearly, if you have diabetes or just care about blood sugar spikes, it makes sense to skip the instant.
Though there is one nutrition category in which instant is the most healthy for... antioxidants, albeit only marginally higher. The ORAC of the instant is 2,308, the quick cook version is 2,169, and old-fashioned - as reflected above - is 1,708. It is an apples to apples comparison since all 3 tested them before cooking. Therefore, it appears there may be a correlation in terms of antioxidant preservation and how oats are prepared.
USDA Database for the Oxygen Radical Absorbance Capacity (ORAC) of Selected Foods, Release 2 - Prepared by Nutrient Data Laboratory, Beltsville Human Nutrition Research Center (BHNRC), Agricultural Research Service (ARS), U.S. Department of Agriculture (USDA) - May 2010