Whether you're already a fan of grass-fed beef or just considering plunking down the extra dollars to buy it, here's what you need to consider when choosing between grass-fed and conventional grain-fed beef.

Whether you're already a fan of grass-fed beef or just considering plunking down the extra dollars to buy it, here's what you need to consider when choosing between grass-fed and conventional grain-fed beef. Watch: What Organic Labels on Meat MeanHealthy Advantage
A number of studies show that grass-fed beef has less fat-no surprise because the cattle are leaner. It also has more vitamin E and beta carotene than conventional beef because of the cattle's diverse diet of grasses.

A 2010 Nutrition Journal study found that grass-fed beef had more heart-healthy omega-3 fatty acids and a lower ratio of omega-6 to omega-3 fatty acids, a profile which is believed to help prevent chronic diseases including heart disease and some cancers.

Still, it's important to note that while grass-fed beef may have more omega-3s than conventional, the total amount is tiny when compared with fatty fish. Grass-fed beef has only 20 to 30 milligrams of omega-3s per 100 grams; you get about 50 times more from the same amount of wild salmon.

Safer Steaks
Raising cattle on pasture may reduce the risk of bacterial contamination. Some studies found that grass-fed beef carries less E. coli than meat from grain-fed, confined animals and is therefore less likely to cause foodborne illness. Other studies have found no significant difference.

A More Humane Option
Pasture-raised cattle typically spend their days in the fields, where they can move freely, rather than in an enclosed pen. Whether the animals are humanely slaughtered depends on the farm.

Ideally, the animals do not have to travel long distances, which can be stressful, and systems are designed to minimize pain. Cows are ruminants, which means they have four stomachs that were designed to process grass.

While the animals like corn, it's like giving a human a big bowl of candy, said Will Harris, a Georgia rancher at White Oak Pastures, which produces grass-fed meats. The low-fiber diet makes them sick, he said.

Preserving Antibiotics
Because cattle get sick eating corn, conventional producers often give their animals antibiotics to keep infections at bay. The antibiotics also help the animals grow faster.

Unfortunately this type of overuse of antibiotics in food animals contributes to the creation of "superbugs," bacteria that have mutated so that they do not respond to antibiotics.

Buying meat raised without antibiotics helps to limit the use of these essential drugs, so that they are effective when humans need them for medical use. Many grass-fed producers don't use antibiotics, but note that the term "grass-fed" on a label does not necessarily mean "raised without antibiotics."

Impact on the Environment
There is little data that proves that grass-fed cattle operations use fewer resources, such as water and fertilizer. But this is because grass-fed operations are so different from one another that it is hard to generalize and compare them to more industrial farms.

In theory, though, the practice of regularly moving animals to fresh pasture and keeping them away from streambeds helps to spread manure more evenly and improve the quality and quantity of pasture grasses. This can help to conserve soil and reduce erosion and water pollution.

Beef production, no matter what kind, takes its toll on the environment. When cattle burp-and they burp a lot-they release methane, a potent greenhouse gas.

There are few definitive studies, however, on the net amount of methane emissions from grass-fed versus grain-fed cattle.

Defenders of conventional beef argue that since pasture-raised cattle gain weight more slowly than grain-fed animals, those animals take longer to reach slaughter weight and therefore have more months to emit more gases. (Plus since grass-fed cows don't grow as big, farmers need to raise more animals to produce the same amount of meat.)

But these methane emissions may be offset by another benefit, carbon sequestration: carbon that gets stored in the soil when using well-managed rotational grazing systems. The roots of healthier grasses grow larger, keeping more carbon in the soil and out of the air.

March/April 2014