Grass-Fed vs. Grain-Fed Beef: What's the Healthy Choice?

Next time you shop for groceries, you can find a wide variety of choices at the meat counter, including grass-fed beef, an alternative to conventionally farmed beef.

Grass-fed cattle spend their entire lives grazing from pastures. Here in Iowa and the Upper Midwest, grass-fed cattle are also fed hay in the winter, when the grass isn’t growing and pastures are covered in snow.

Both grass-fed and grain-fed cattle similarly spend the majority of their lives grazing in pastures, with the key difference in the finishing process. During the process, conventionally farmed cattle are fed a balanced diet of grains, local feed ingredients, and hay or forage in the feedyard.

Iowa - the nation’s top corn producing state - is recognized worldwide for its USDA Prime-grade, corn-fed beef.

Is grass-fed beef healthier?

Food marketers and health influencers often claim that grass-fed beef provides more omega-3 fatty acids than grain-fed beef. Omega-3 fatty acids are considered “good” fats for heart health.

Studies have shown that grass-fed beef has more omega-3s than conventional grain-fed beef.

However, that doesn’t mean grass-fed beef is a significantly better source of omega-3s than grain-fed beef, says Ruth Litchfield, an Iowa State University nutrition scientist.

A 3-ounce serving of grass-fed ground beef has about 0.015 grams of omega-3 fatty acids, according to the U.S. Department of Agriculture’s National Nutrient Database. “So 100ths of a gram of omega-3s,” Litchfield notes. (For a real-world visual, 1 gram is equal in size to one raisin.)

In comparison, a 3-ounce serving of conventional ground beef has about 0.003 grams of omega-3s, according to the National Nutrient Database.

Even though conventional beef has less omega-3s than grass-fed beef, it isn’t a clinically significant difference to human health, Litchfield says.

What is a good source of omega-3s?

Beef in general – whether grass-fed or conventional – isn’t considered a good source of omega-3s, Litchfield explains.

Seafood, in comparison, is an excellent source of omega-3 fatty acids. A 3-ounce serving of wild-caught Alaskan salmon has about 1.5 grams of omega-3 fatty acids, much greater than the 0.015 grams of omega-3s in grass-fed beef, according to the National Nutrient Database.

“You would have to consume 100 times the amount of (grass-fed) ground beef to get the same amount of omega-3s as the similar portion of salmon,” Litchfield says. “So in the scheme of things, you can’t eat enough (grass-fed beef) to make a significant impact on your (omega-3) intake.”

What are the nutritional benefits of beef?

However, all beef – grass-fed and grain-fed - is considered an excellent source of many other micronutrients, including B12, iron, zinc and high-quality protein, that are essential for human health, Litchfield says.

The USDA also recommends lean beef as part of a heart-healthy diet in its MyPlate dietary guidelines.

So whether it’s grass-fed or grain-fed beef, both are nutritious choices, Litchfield says.

Learn more about author Teresa Bjork here.