Yes there is some evidence for that. In particular grass fed beef vs grain fed beef: http://www.theglobeandmail.com/life/health-and-fitness/health/is-grass-fed

Yes there is some evidence for that. In particular grass fed beef vs grain fed beef: http://www.theglobeandmail.com/life/health-and-fitness/health/is-grass-fed-beef-more-nutritious-than-regular-beef/article28948990/ http://www.theglobeandmail.com/life/health-and-fitness/healt... Most claims, however, focus on omega-3 fats, in particular alpha linolenic acid (ALA). Higher intakes of this plant-based omega-3 fatty acid are associated with a lower risk of heart disease, stroke, Type 2 diabetes and depression. According to Dr. Richard Bazinet, a professor in the department of nutritional sciences at the University of Toronto who analyzes fatty acids in beef, grass-fed beef outranks grain-fed beef when it comes to ALA. Conventional beef has about 20 milligrams of ALA in three ounces, whereas the same amount of grass-fed beef has 50 to 100 mg. A big difference? Yes. Meaningful? That depends. Women need 1,100 mg of ALA each day; men require 1,600 mg. Eating a six-ounce grass-fed steak three times a week provides, at most, 5 per cent to 8 per cent of your daily ALA requirement. Keep in mind that during cooking, the ALA content of meat will decrease since ALA is found in fat. Making the switch to other grass-fed animal foods, such as pasture-raised poultry and eggs and grass-fed dairy, could conceivably make an appreciable difference towards your daily ALA needs.