Source:  Tom Johnston, MEATINGPLACE.COM, 5/31/10

Grass-fed beef may not be as healthful as some believe, according to a study conducted at Texas A&M University's AgriLife Research center.

Dr. Stephen Smith, one of the facility's meat scientists, and a team of researchers have discovered that ground beef from grass-fed cattle had no beneficial effects on plasma lipid.

However, high monounsaturated fat ground beef from grain-fed cattle increased HDL cholesterol, increased LDL particle diameters and decreased insulin, indicating that ground beef from grain-fed cattle is "a healthful, high-quality source of protein," he said.

"We wanted to see from this study if product from pasture-fed and corn-fed cattle had different effects on LDL or HDL cholesterol," Smith said. "We looked at the scientific literature and could not find any justifications for the statement that pasture-fed beef is better for you. All we found were rat studies in which they were fed omega-3 fatty acids, so we wanted to know if this applied to beef from grass-fed cattle."

In the study, funded by the National Cattlemen's Beef Association, one group of Angus cattle was fed a pasture diet with supplement hay until 20 months of age.

A second group of Angus steers was fed as the animals would be fed at a conventional feedlot and kept on a corn-based diet until 16 months of age, then reaching USDA Choice status.

A third group of Angus steers were fed the corn-based diet the longest, until reaching USDA Prime. The fat in cattle that are high in marbling is low in saturated and trans-fats, and higher in monounsaturated fats.

Beef cuts from the plate and flank from all three grades were processed into a ground beef product, which contained 24 percent fat.

Then a group of 27 men completed a three-way crossover study. Each group rotated, consuming five 114-gram ground beef patties per week for six weeks from each of the three sets of cattle used in the study.

"There really were no negative effects of feeding ground beef from the pasture-fed cattle," Smith said. "We did see many positive effects in men that consumed ground beef from corn-fed cattle. The ground beef from the USDA Prime cattle increased HDL cholesterol and LDL particle diameter. Both effects are protective against cardiovascular disease. The Prime ground beef also decreased insulin, so it may have some protective effect against type II diabetes."

Smith presented the findings to the National Cattlemen's Beef Association last year and is now sharing among consumers and producers.

The study team included Dr. Rosemary Walzem, AgriLife Research poultry scientist, and Dr. Stephen Crouse, researcher from Texas A&M University's health and kinesiology department.

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