All right, there is a difference in taste, for sure. But what I'm really interested in is whether it's nutritionally any different. And the story gets a little fishy here. You know how nutritionists are always recommending fish? Well, that's because many fish are rich in heart-healthy omega-3 fatty acids.
And where do the fish get these omega-3s? They eat it. (Well, generally, the tiniest sea creatures eat algae, and it moves up the food chain to bigger fish.) With grass-fed cows, it's a similar story. Omega-3s are in their meat— because they're eating grasses and clover rich in these heart-healthy fatty acids.
A recent analysis from the Union of Concerned Scientists found that grass-fed steak has about twice as many omega-3s as a typical grain-fed steak. Another study published in March in Nutrition Journal backed up those numbers.
Still, with 35 milligrams of heart-healthy fats per serving, grass-fed steak can't compete with a salmon dinner, which has about 1,100 milligrams. But it's a significant difference in omega-3s between grass-fed and corn-fed beef. (You can calculate the fat/protein or micronutrients of any food in your diet with this USDA tool.)
And since grass-fed cattle are typically leaner, almost all cuts of grass-fed beef have less total fat than beef from corn-raised cattle. Of course, the breed of cattle leads to variation, too