The poppy seed antioxidant content should be taken with a grain of salt. Why? Because it's extremely unlikely one would consume 3.5 ounces (100 grams) of the seed, which is the amount measured in this ORAC value. You're more likely to be eating half of a teaspoon (if that), sprinkled on your bagel or lemon poppyseed muffin.
There are more reasons too for not getting excited about the nutritional value of poppy. Sure if you ate them in abundance they would be an excellent source of protein - 18 grams of protein per 100 grams of seed (that's 18% protein). But that would also entail 525 calories. Even if you're not on a diet or don't care about your weight, eating that much would potentially intoxicate you with a minute amount of opiates. Yes that's right, opium and prescription drugs made from it like morphine and codeine are derived from the poppy seed. Not enough to get you high but enough to be detectable in your urine.
They do thoroughly wash the seeds before selling them which removes almost all of the opium alkaloids, but there are still tiny quantities often detected. That's why, as crazy as it may sound, you can actually test positive for a drug test within the first 48 after eating pastries containing them such as bagels, cakes, and muffins (1). It's not a myth, though it would likely take more than just one item of food to test positive. It's largely dependent on where the seeds come from and how thoroughly the residue was washed off of them.
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