The Internet is awash in websites that proclaim the nutritional benefits of ground beef from grass-fed cattle. However, researchers in Texas A&M University’s Department of Animal Science have published the only two research studies that actually compared the effects of ground beef from grass-fed cattle and traditional, grain-fed cattle on risk factors for cardiovascular disease (CVD) and type II diabetes in men. Was ground beef from grass-fed beef actually more healthful? No, the study found.
Americans consume about 40% of their total beef intake as ground beef, which is much higher in total fat than most intact cuts of beef. In fact, ground beef is one of the most important sources of the healthful monounsaturated fatty acid – oleic acid – in the diet. Ground beef from grass-fed cattle naturally contains more omega-3 fatty acids than from grain-fed cattle (three times as much), but is higher in saturated and transfat.
At the other end of the spectrum is premium ground beef, such as from conventionally produced Certified Angus Beef or cattle with Japanese genetics (available as Wagyu or Akaushi ground beef). Ground beef from these cattle is very high in oleic acid, and also much lower in saturated and transfat, than ground beef from grass-fed cattle.
The information below is based on TAMU research that compared the fatty acid composition of ground beef from grass-fed and grain-fed cattle. Ground beef from grass-fed and grain-fed cattle that contains 10%-15% total fat (85%-90% lean) is available in retail stores, so the values listed below are for a 4-oz. ground beef patty (quarter-pound) that contains 85% lean (15% fat).
The most abundant omega-3 fatty acid in our foods is α-linolenic acid (ALA), one of the two essential fatty acids that must be obtained from the diet; tthe other is linoleic acid, which is an omega-6 fatty acid. ALA is found in flax seed and walnuts, but Americans obtain most of their ALA from canola oil.
Although the scientific studies aren’t conclusive, ALA may slow the growth rate of cancer cells and reduce risk factors for CVD. The Daily Reference Intake (DRI) of ALA is 1.1 grams (g)/day for women and 1.6g/day for men. So, a quarter-pound ground beef patty from grass-fed cattle contains 0.055 of the 1.1g ALA required by women, and 0.055 of the 1.6g ALA required by men.
Oleic acid in beef
In other words, that ground beef patty from cattle fed native Texas pastures contains only 5% of the DRI for ALA for women, and just over 3% of the DRI for ALA for men. Yes, grass-fed ground beef contributes to the omega-3 fatty acids in our diets, but can it be considered a significant source of ALA?
For comparison, a tablespoon of canola oil (about 14g) contains 1.4g of ALA. This is more than the DRI for women and almost as much as the DRI for men.
That same tablespoon of canola oil also contains 8.4g of oleic acid, which is similar to the amount of oleic acid in olive oil. Researchers have known for decades that oleic acid has positive health benefits, such as reducing LDL-cholesterol (the bad cholesterol) and perhaps increasing HDL-cholesterol (the good cholesterol). The World Health Organization has recommended that intake of oleic acid should be 15%-30% of daily energy intake.
For women, that would be equal to 25-50g/day of oleic; whereas for men, that would be equal to 40-80g/day of oleic. TAMU research shows that men consume about 20g/day of oleic acid, and women consume about 12g/day, but this can be nearly doubled by consuming ground beef high in oleic acid, such as ground beef from grain-fed cattle or cattle with Japanese genetics.
Grass feeding definitely does not increase the amount of oleic acid in beef. The quarter-pound ground beef patty from grain-fed cattle contains over 2g more oleic acid than ground beef from grass-fed cattle. In fact, the grain-fed ground beef patty contains nearly the same amount of oleic acid as the tablespoon of canola oil. Also, ground beef from grass-fed cattle has 2g more saturated fat plus trans-fat than the patty from grain-fed cattle.
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So, which is better, more omega-3 fatty acids (grass-fed) or more oleic acid with less saturated/trans-fats (grain-fed)?
TAMU studies demonstrate the effects of ground beef from grass-fed and grain-fed cattle. Men consumed both types of ground beef for five weeks in randomized crossover trials. In older, mildly hypercholesterolemic men, ground beef from grass-fed cattle decreased HDL-cholesterol. In men with normal cholesterol levels, only ground beef from grain-fed cattle increased HDL-cholesterol.
Neither ground beef type increased LDL-cholesterol in men. TAMU research similarly demonstrated that consuming ground beef does not affect LDL-cholesterol in postmenopausal women.
In men, plasma insulin was decreased by ground beef from both grass-fed and grain-fed cattle, indicating that ground beef in general reduces this important risk factor for type II diabetes. Thus, neither type of ground beef had negative effects on risk factors for CVD or type II diabetes, but the ground beef from the grain-fed cattle provided more positive health benefits by increasing HDL-cholesterol.
What about the cholesterol content of ground beef? Many websites claim beef from grass-fed cattle is lower in cholesterol than beef from conventionally raised cattle. A Texas Tech University study found no difference in cholesterol in ground beef from grass-fed and grain-fed cattle if the fat content is similar.
Early TAMU research demonstrated that the cholesterol in beef and beef products is stored in both the lean and the fat within the meat. If you trim all fat from beef (including the marbling), there will be about 45 milligrams (mg) of cholesterol in a 4-oz. serving of beef. For every 1% increase in total fat content, there is a 1-mg increase in cholesterol. So, ground beef that is 95% lean (5% fat) contains about 50mg of cholesterol, and ground beef that is 85% lean (15% fat) contains 60mg of cholesterol. This is as true for beef from both grass-fed and grain-fed cattle.
At this point, there is no scientific evidence to support the claim that ground beef from grass-fed cattle is a healthier alternative to ground beef from conventionally raised, grain-fed cattle.
Stephen B. Smith is a Regents Professor and Texas A&M AgriLife Research meat scientist in the Department of Animal Science at Texas A&M University.
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