Fat worth chewing: nutritional profiles of beef
—Review examines differences between grain-, grass-finished beef
It has been long asserted that grass-finished beef is healthier than grain-finished beef. The argument will likely continue on long into the future, but a recent scientific review offers a nuanced look at the issue for American consumers to chew on.
The review—full title, “Impact of grass/forage feeding versus grain finishing on beef nutrients and sensory quality: The U.S. experience”—found that the greater healthfulness of one type of beef or the other depends on how you slice it, metaphorically speaking. The differences come down to fat; what types, and how much, in a given serving of beef.
“The reasons that U.S. consumers state for purchasing beef from ‘grass fed’ cattle vary and are based on perceptions including promotion of animal health and well-being, environmental sustainability, and/or production of meat products with a modified nutritional profile, particularly with regard to a lower total fat content and more healthful fatty acid profile,” read the introduction of the review.
The review looked at quantitative analyses of the fat content of grass- and grain-finished beef conducted in the U.S. The authors pointed out that a good deal of the research in this area compares the fat and nutritional profile of U.S. grain-finished beef to the grass-finished beef of other countries. Considering differences in breeds, region, feeding regimens, and numerous other factors that are geographically tied, they asserted much of the existing research is not applicable to the U.S. market.
When cumulative findings were presented on a grams (g) of fat to 100g of beef scale, the answer to the question, “Which is healthier?” is hard to answer with regard to fat. Fats are complex things, and there are many types of fat and various nutrients that interact differently with the body.
For example, several studies covered in the review found that a larger percent of the fat in grass-finished beef is saturated fat, widely accepted as a “bad fat” which increases the risk of heart disease. However, the overall lower levels of fat in grass-finished beef make even that higher percentage of the saturated fat it does have less than the saturated fats in grain-finished beef. See image below for a visualization.
Another example highlighted the differences in the presence of monounsaturated fats, which are considered “good fats” and beneficial to heart health. The review found that grass-fed beef had both less fat overall in a 100g piece of beef, and less (30-70 percent) of the fat that was present was the “good” monounsaturated fats. On the other hand, in grain-fed beef—which has more fat in a 100g piece—there is more of the “good” monounsaturated fat.
The authors did note, however, that fat composition and location differs based on breed, age of the animal, and specific cut, as well as grass- versus grain-finishing feeding protocols. These facts make it all the more difficult to answer the question of health and generalize about the effects of feeding protocols alone. They stressed the need for more controlled examination of the issues.
The review was published in the January, 2014, issue of the academic journal Meat Science (vol. 96, issue 1) and is free to the public. It can be found online at http://www. sciencedirect.com/science/ar ticle/pii/S0309174013004944. — Kerry Halladay, WLJ Editor