Interesting article in Slate by James McWilliams on the supposed health benefits of grass-fed beef. Yes, says McWilliams, grass-fed beef has higher levels of omega 3s and lower levels of saturated fat. But, no, says McWilliams, there is no evidence that grass-fed beef is free from the E. coli bacteria that has been causing recalls recently of ground beef (O157:H7 variety).
McWilliams traces the widespread belief that grass-fed beef is free from O157:H7 to an op-ed piece in the New York Times by food activist Nina Planck. Planck wrote that O157:H7 was 'not found in the intestinal tracts of cattle raised on their natural diet of grass, hay, and other fibrous forage." This assertion was apparently based on a 1998 report in Science that McWilliams says is now out of date. After that initial report, subsequent studies have found that O157:H7 is found in grass-fed cattle.
"The point in dredging up these studies—ones the media never covered—is not to play gotcha with advocates of grass-fed beef," McWilliams writes. "(As mentioned above, grass-fed beef may be healthier than conventional beef over all, and kinder to the animals.) Instead, it's a warning that advocacy for a trendy food choice might result in a public health hazard." McWilliams is the author of Just Food: Where Locavores Get It Wrong and How We can Truly Eat Responsibly.