Grass-Fed Meat vs Grain-Fed Meat: Part 1

Grass-Fed Meat vs Grain-Fed Meat: Part 1

To say one food is better than another, you have to prove it contains more nutrients and less toxins.  This is the underlying principle of the Bulletproof Diet.  The goal is to provide maximum nutrition with minimal damage.

Grass-fed meat fits this criteria perfectly.  It contains more antioxidants, omega-3’s, CLA, TVA, trace minerals, and vitamins than any other food, including conventional meat.

As you’re about to learn, consuming grass-fed meat is one of the best ways to prevent disease, improve brain function, lose weight, and become Bulletproof.

Let’s begin.

The first study we’ll look at was published in 2006.  It measured the fatty acid composition of grass-fed versus grain-fed meat.  Before we dive into the research, here’s what you need to know.

1. Omega-3 fatty acids are an essential component of nerve tissue.  They modify how the body responds to stress and control numerous other metabolic processes.  Most people eat too many omega-6 fats and not enough omega-3.

2. CLA is a type of naturally occurring trans-fatty acid that improves brain function, causes weight loss, and reduces your risk of cancer.

What a steer eats dictates how much of these compounds are in the meat.   This study compared how grain feeding effects this process.


Study #1: 2006

Effect of feeding systems on omega-3 fatty acids, conjugated linoleic acid and trans fatty acids in Australian beef cuts: potential impact on human health.

Researchers compared the fatty acid compositions of three kinds of feeding.  Each group contained 18 Australian cattle.  The first group was fed grains 80 days before slaughter, the second group was fed “by-product feedstuff” for 200 days, and the third group was grass-finished and grass-fed.

Group #1: Short Term Grain Feeding (80 days)

Group #2: Long Term Feedlot Rations* (150-200 days)

Group#3: Grass Feeding (Life time)

*Feedlot rations for australian beef are made of 50 percent barley and/or sorghum (a type of wheat) and some form of cottonseed/protein mix:  A mixture of grains.



The grass-fed cows had more omega-3’s and conjugated linoleic acid (CLA).  Just 80 days of grain feeding was enough to destroy the omega-3 content of the beef.  CLA content plummeted in the same amount of time.  The longer the animals were fed grains, the lower the quality of the meat.

“There was a significantly higher level of total omega-3 (n-3) and long chain n-3 FA in grass-fed beef than the grain-fed groups regardless of cut types.”

The omega-3 quantity in grain-fed meat was so low, it didn’t qualify as a meaningful dietary source.  Grass-fed meat has enough omega-3 to be considered a good source of n-3 fats.  As Chris Masterjohn has shown us, the total amount of omega-3 we need is small if you have a good omega-6 to omega-3 ratio.  Therefore, eating grass-fed meat along with some fatty fish may be enough to cover your omega-3 needs.

“Only grass-fed beef reached the target of more than 30mg of long chain n-3 FA/100 g muscle as recommended by Food Standard Australia and New Zealand for a food to be considered a source of omega-3 fatty acids.”

Grain feeding significantly reduces the omega-3 and CLA content of meat.  The feedlot cattle had the lowest levels, the grain-fed cattle were in the middle, and the grass-fed cattle had the most.  The longer an animal is fed grains, the lower the nutrient content of the meat.



  • Grain-fed beef is much lower in omega-3’s and CLA
  • The longer steers are fed grains, the lower the omega-3 and CLA content.
  • Feedlot cattle have the lowest amount of omega-3‘s.  Regular grain-fed cattle are slightly better.
  • The last part of a cow’s life is the most critical in terms of fat quality.

Meat can be a good source of omega-3’s, if it’s grass-fed.  Grain-fed meat has lower levels, so you’ll need to eat a lot of cold water ocean fish or take fish oil supplements to reach your daily omega-3 requirements.  Grass-fed meat has more healthy fats than grain-fed meat.

This study only covered a few types of fats.  The next study in this series shows how grass-fed beef has a broad spectrum of beneficial fats and other nutrients that are missing from grain-fed meat. Check it out here.


Some background research for this post may have been conducted by Bulletproof staff researchers.