A recent study in the British Journal of Nutrition demonstrated the benefits of grass-fed beef over grain-fed beef. Many of us have heard that grass-fed meats are superior to grain-fed meats for a variety of reasons, and demand for grass-fed beef is definitely increasing. Environmentalists tell us that mass-production of corn for the purpose of feeding animals in confined feeding operations (CAFOs) is bad for the topsoil. Moralists tell us that forcing cattle to live in these conditions is inhumane.
Nutritionists (well, nutrition scientists, there is a big difference there!) tell us that feeding cattle grain obliterates the fatty-acid composition of the meat such that instead of having an omega 6 / omega 3 ratio of 2 or 3 to 1 (as it would when pastured), the ratio skyrockets. Nutrition researchers report that grain-fed meat is fattier and less nutrient-dense than than grass-fed meat (see citations on the eatwild page for peer-reviewed research, and another study here). To be sure, the grain-fed cattle industry has not wanted this kind of research to come forth, and they’ve even gone so fat as to declare that grass-fed meats contain more trans-fatty acids than grain-fed meats. The grain-fed cattle industry, of course, neglects to mention, however, that conjugated linoleic acid (classified as a trans fat, but it is naturally occurring) is among the most promising anti-carcinogenic compounds that we know of.
Importantly, there is a growing consensus that it is the last weeks of a cow’s life that make the difference in this lipid profile. Specifically, if one feeds a cattle grass all of its life but grain for the last few weeks of its life, the beneficial lipid profile will deteriorate to that of a cattle who was grain fed for its entire life. The opposite also holds: If you feed a cattle grain all of its life and then grass for the last few weeks of its life, the beneficial lipid profile appears. Hence the term, “grass-finished.”
The study? Researchers wanted to know if eating grass-finished animals instead of grain-finished animals would provide a significant increase in omega 3 in the animal meat and if this increase would actually make a difference in blood counts of those consuming the meat. Two groups of Irish people (all with good cholesterol and blood pressure numbers and without any prescription medications) were given weekly portions of beef and lamb, either grass-finished or grain-finished. The animals were “finished” for a minimum of six weeks. Both groups were told to avoid fatty fish and oils rich in omega 3 for the duration of the study. Both groups of people ate roughly 469 grams of red meat a week for four weeks.
Data indicated that grass-finished meat experienced improved plasma and platelet fatty acid composition such that their blood contained less omega-6 and more omega-3. This increase in omega 3 is associated with a more balanced inflammatory response and subsequent better health.
Other important findings: Lipid profiles of the meat-eaters did not significantly differ (HDL, LDL, triglycerides). The serum and platelet fatty acid content was what changed. Those who consumed grass-finished meat experienced higher levels of EPA, DPA, DHA, stearic acid, long-chain omega 3 fatty acids, and total omega 3, along with a reduced omega 6 to omega 3 ratio. Importantly, the omega 6 to omega 3 ratios in our fat cells determine what kind of inflammatory cytokines our platelets will secrete in an inflammatory response, so having too much omega 6 in our platelets results in an unhealthy, overly-inflammatory response.