The Omnivore's Dilemma: A Natural History of Four Meals

by Michael Pollan

the problem with eating red meat—long associated with cardiovascular disease—may owe less to the animal in question than to that animal’s diet. (This might explain why there are hunter-gatherer populations today who eat far more red meat than we do without suffering the cardiovascular consequences.) These days farmed salmon are being fed like feedlot cattle, on grain, with the predictable result that their omega-3 levels fall well below those of wild fish. (Wild fish have especially high levels of omega-3 because the fat concentrates as it moves up the food chain from the algae and phytoplankton that create it.) Conventional nutritional wisdom holds that salmon is automatically better for us than beef, but that judgment assumes the beef has been grain fed and the salmon krill fed; if the steer is fattened on grass and the salmon on grain, we might actually be better off eating the beef. (Grass-finished beef has a two-to-one ratio of omega-6 to -3 compared to more than ten to one in corn-fed beef.) The species of animal you eat may matter less than what the animal you’re eating has itself eaten.