Are cooked beans less nutritious than raw? This is a stark example of that being true, unfortunately. Raw pinto beans have an ORAC value which is almost 900% higher than the cooked version.
Unlike most veggies which are edible in both raw and cooked forms, with most legumes we have no choice but to cook them, so we just have to accept that antioxidants will be lost in the process. Beans can be difficult to digest for humans even when cooked, because we are lacking certain enzymes which are better suited for breaking them down. So if gas and bloating is a side effect of cooked, we don't even want to fathom what would occur if one ate raw pinto or black beans!
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