Is there a significant difference in health benefits between portobello mushrooms vs. white mushrooms? The latter cost significantly less, while grocery stores (and restaurants) are known for charging higher prices on containing portobello. Taste preferences aside, are they worth paying more for?
Both are low calorie foods. One cup of diced white mushrooms is only 1 calories and portobellos are 22 calories. Both offer about 2 grams of protein and 1 gram of fiber. Neither have any significant vitamin of mineral content, which is typical for fungi. For example, portabella mushrooms have zero vitamin C and vitamin C. White have a little C but nothing noteworthy - merely 2% of your daily value.
But what about antioxidants? That is where they differ. The ORAC value of portabello mushrooms is 968 versus white mushrooms at 691. That may may seem like a dramatic difference but keep in mind that 968 is a fairly low bar to begin with. Therefore, it's not worth buying one type of mushroom over the other solely for antioxidant purposes. Really it comes down to taste and cost, base your decision on which of those two factors is most important to you.
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