Grass-fed beef vs grain-fed beef.

I want to tackle some commonly held beliefs about beef. Many people, my clients and athletes alike, often consume beef as a staple protein source in their daily diets. Beef has quite the nutritional resume with its high protein content (25g in 3.5oz cooked serving), quality (92/100 on the Protein digestibility-corrected amino acid or PDCAA score), and mineral composition (10 essential nutrients).

Beef also has a wide range of culinary options, making it suitable for many palates and preferences. Fifty-eight percent of U.S. meat consumption comes from beef, so clearly, it’s a popular option among Americans. One common presumption about beef is that grass-fed beef is more nutritious than grain-fed.

nutrient differences chart

Food Myth #2: Grass-fed beef is healthier than grain-fed beef.

As an athlete who enjoys beef as part of a healthy diet, and as a fitness/nutrition professional, I wanted to know the true answer based on science, so I reached out to an expert.

Setting the discussion straight

Justin Sexten, Director of Supply Development at Angus Beef, explained the differences between grass and grain-fed cattle.

First, it’s important to understand that all cattle consume grass and forage-based diets for the first seven months of their life, up until they are finished weaning. How the cattle are finished after weaning is where the differences emerge. This is also the first fact of the myth.

Fact #1: Cows are finished not fed.

After weaning, grain-finished calves continue with a diet of forage and grass with the addition of supplemental nutrition for about 5 months. This is called the “background phase,” after which the cattle switch to an almost all corn and/or grain diet for the 5-6 months before processing. Typically, grain-finished cows are sent for processing at 16-18 months old.

Grass-finished calves consume pasture or stored forages such as grass, hay, or alfalfa their entire lives. Depending on the lower calorie grass for nutrition, it takes grass-finished cattle almost twice as long to reach the same weight as grain-finished cattle. Generally, grass-finished cows don’t head for processing until they are 25-30 months old.

So, which is more nutritious?

Fact #2:

Research shows the following major differences between finishing methods, per 100g of beef (Van Elswyk M., 2014, Duckett S.K., 2014,S.B., Smith 2013,Daly A., 2010). Keep in mind the breed of cattle, age of cattle, specific beef cut and species of grass fed all impact these findings as well.

  • Grass-finished cattle are typically older, leaner, and smaller than grain-finished cattle at processing
  • Grass-finished cattle have 1.4g less saturated fat than grain-fed
  • Omega 6:3 ratio in grain-finished is 9.5:1; in grass-finished it is 2.4:1
  • Both grain-finished and grass-finished beef can contribute to your omega 3 intake, averaging between 2–19 mg and 5–33 mg respectively, most as alpha-linolenic acid (ALA) (For reference, 1 Tbsp. of canola oil has 1400mg ALA)
  • Grain-finished beef has ~1.8g more monounsaturated fatty acids (MUFA), mostly the omega 9 oleic acid but grass-finished beef has ~75mg more polyunsaturated fatty acids (PUFA)
  • Both grass and grain-finished beef provide ~20mg of conjugated linoleic acid (CLA), well below the 5.8g per day shown to have some possible health benefits in randomized control trials
  • Beta carotene may be 1.5x higher, and one form of Vitamin E may be 3x higher in grass-finished beef
  • There is no statistical difference of trace materials in either grass or grain-finished
  • Grass-finished beef has 2mg more calcium and 12mg more Ka
  • There are no differences in zinc and iron
  • Sodium differences were strongly tied to the soil where the grass was grown for grass-finished cattle
  • Grass-finished may provide 2x riboflavin and 3x niacin

But the flavor!

Beyond nutrition, flavor, texture, and color often drive consumer preferences. Perceptions of beef based on these factors is complex and diverse. Flavor acceptability may be related to individual preference or cultural norms. U.S. consumers seem to prefer the flavor of grain-finished beef while consumers in other countries find the flavor of grass-finished animals preferable (T.G. O’Quinn, 2016, S.K. Duckett, 2013). Flavor also varies depending on the type and maturity of forage, cattle breed, fat content, and marbling score, so it is difficult to compare the subjective flavor appeal of beef from grass-finished and grain-finished cattle.

Are there any health considerations?

With Americans eating about 80g of red meat per person per day (R.D. Sayer, 2017), it’s clear that many people, athletes and general public alike, select beef as a popular protein food source. Red meat from either finishing method can be part of a healthy diet, as research shows (R.D. Sayer 2017, McNeil 2014). My recommendation for people who choose to consume beef regularly is to focus more on the cut of beef rather than the finishing method since so few meaningful nutritional differences exist.

The USDA defines “lean and extra lean” cuts of beef as those with 5g and 10g or less per 3.5oz serving cooked, respectively. (Mayo Clinic). The leanest cuts will almost always have the terms “round,” “sirloin,” or “loin” in its name. Ninety-three percent lean ground beef is also classified as a lean form of beef. Beef is graded by the USDA as Choice, Select, and Prime based on marbling (intramuscular fat), so opt for Choice and Select whenever possible for leaner beef selections.

Final thoughts to chew over

In the end, there are several factors to consider when choosing beef and you shouldn’t get caught up in the grass-grain debate. Cost may be a factor, as was found in an October 2015 Consumer Reports article showing that grass-finished beef can cost $2.50 more than grain-finished beef. Along with budget, consumers need to consider flavor preference and whether their overall diet structures dictate the adoption of meatless or restricted meat meals relative to their goals.

As personal trainers, sports RDs and nutrition professionals, it’s important to make sure we guide our clients and athletes toward the big-picture decisions that allow them to maintain a lifestyle suitable for their sport, health goals, and fitness outcomes while not getting distracted by fringe details unlikely to lead to any difference in outcomes. Trainers, coaches, sports RD’s and athletes alike need to focus on the big picture issues with beef which are:

  • Grass and grain fed beef at equal serving size are BOTH nutritious options with small difference in each pending the nutrient in hand
  • The nutrient differences in fat content (omegas, CLA, MUFA, PUFA) are so small it would not make a difference in overall diet quality
  • The calories and protein content in equal servings are the same in both types
  • The grade and beef cut selection make more impact on nutrition(leanness) in either type that feeding type
  • The total amount eaten per week has higher effect on health than does feeding type
  • Taste and cost are factors that need to be considered for both affordability and palatability of the individual

But which is more sustainable?

Right after the nutrition question about beef finishing methods, I am often asked about sustainability differences and animal welfare factors. As a born-and-raised, dairy-cow-loving cheesehead from Wisconsin, I also wanted to know. The answers go beyond the scope of this newsletter, so check out this extremely well-written article—with citations—from Jenny Splitter, a science, health, and food writer.

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