The British research showed that healthy volunteers who ate grass-fed meat increased their blood levels of omega-3 fatty acids and decreased their level of pro-inflammatory omega-6 fatty acids. These changes are linked with a lower risk of a host of disorders, including cancer, cardiovascular disease, depression, and inflammatory disease.
Interestingly, volunteers who consumed conventional, grain-fed meat ended up with lower levels of omega-3s and higher levels of omega-6s than they had at the beginning of the study, suggesting that eating conventional meat had been detrimental to their health.
British Journal of Nutrition (2011) Red meat from animals offered a grass diet increases plasma and platelet N-3 PUFA in healthy consumers. Volume 105, pages 80-89.