Grass Fed Beef: Weatherbury Farm, southwest of Pittsburgh. Beta Carotene

ß-carotene, a fat-soluble antioxidant, is derived from the Latin name for carrot, which belongs to a family of natural chemicals known as carotenes or carotenoids. Carotenes produce the yellow and orange color found in fruits and vegetables and is converted to vitamin A (retinol) by the body. While excessive amounts of vitamin A in supplement form can be toxic, the body will only convert as much vitamin A from beta-carotene as it needs, thus beta-carotene is a safe dietary source for vitamin A supplementation. (University of Maryland Medicine, 2002)

Vitamin A is a critical fat-soluble vitamin that is important for normal vision, bone growth, reproduction, cell division, and cell differentiation (Stephens et al., 1996). Specifically, it is responsible for maintaining the surface lining of the eyes and also the lining of the respiratory, urinary, and intestinal tracts. The overall integrity of skin and mucous membranes is maintained by vitamin A, creating a barrier to bacterial and viral infection (Semba, 1998; Harbige, 1996). In addition, vitamin A is involved in the regulation of immune function by supporting the production and function of white blood cells.(Ross, 1999; Gerster, 1997)

Descalzo et.al., 2005, found pasture-fed steers incorporated significantly higher amounts of ß-carotene into muscle tissues as compared to grain-fed animals. Concentrations ranged from 0.63 – 0.45 µg/g and 0.06 – 0.5 µg/g for meat from pasture and grain-fed cattle respectively, a 10 fold increase in ß-carotene levels for grass-fed beef.

Similar data is reported by Simonne, et.al., 1996; Yang et.al., 2002; and Wood and Enser, 1997, presumably due to the high ß-carotene content of fresh forage as compared to cereal grains (Simonne et al., 1996-- see below).

References: C.A. Daley, A.Abbott, P. Doyle, G. Nader, and S. Larson. College of Agriculture, California State University, Chico.
University of California Cooperative Extension Service
© csuchico.edu

Japanese importers place a premium on beef with ultra-white fat, which is difficult for New Zealand ranchers to achieve because they fatten their cattle on pasture. (Grass is rich in the antioxidant vitamin beta-carotene, which lends a healthy, creamy color to meat fat.) In a recent experiment, New Zealand researchers experimented with taking cattle off pasture and fattening them American-style on grain. Because grain is more expensive in New Zealand than it is in the States, grain-feeding was limited to less than 2 months. The experiment failed. The fat color did not change appreciably, even though serum levels of beta-carotene dropped 97 percent. What's more, 1) the animals weighed less than animals that were allowed to stay on pasture, 2) their meat was tougher, and 3) the meat lost more moisture when cooked.

Data from: "Short-term Grain Feeding and its Effect on Carcass and Meat Quality." Proceedings of the New Zealand Grasslands Association 1997. 57:275-277.

Beef fed through conventional feedlots contains approximately 41 μg of beta-carotene/100 grams (g) of ground beef and approximately 36 μg in a typical ribeye steak. Cattle fattened predominately on ryegrass effectively doubles the beta-carotene content in both steak (64 μg) and groundbeef (87 μg). ⁽¹⁾

Although beef is not a major source of beta-carotene, grass-fed beef supplies two times the beta-carotene of conventional beef. A typical 3 ounce (oz.) serving would provide 10% of the recommended dietary allowance (RDA) for beta-carotene for women as compared to 5 % supplied by conventional beef.⁽²⁾

References
1. Simonne AH, Green NR, Bransby JI. Consumer acceptability and beta-carotene content of beef as related to cattle finishing diets. J Food Sci 1996:61:1254-1256.
2. National Institute of Health Clinical Center, 2002: Facts about dietary supplements).
© csuchico.edu

Revised: January 19, 2010
grassfed.weatherburyfarm.com has been on-line since June 27,2007

Health Benefits: Rich in Beta Carotene