I love charts. I’m always starring articles that show up in my Google Reader with charts, graphs, and infographics. It’s perhaps the marketer inside. So, I was trying to find out the different of omega 6 fats in grain-fed versus grass-fed cows. And this looks most reliable. I know that Mark Sisson recently claimed that the omega 6 content was pretty much the same in grain and grass fed cows but, these charts would say otherwise.
So it looks like the omega 6 content is 2x higher in grain-fed cows and omega 3 is 4x lower. Grass-fed has a roughly 2:1 n6 to n3 ratio while grain-fed looks more like 10:1.
That is slightly alarming. The amount of n6 isn’t that alarming since it’s comparable to antelope, deer, and elk. Those animals seem like something we’d evolved to eat. But, their n3 is much higher and the ratio is never much more than 2.5:1.
Then there’s this chart:
Grain-fed cows just have a ton more fat.
So it looks like theres 25mg of n3 per 100g of meat. You would need about 125mg to match the 2:1 ratio in grass fed. Ideally, we’d want to reduce n6 instead of just eating loads of n6 and then balancing with n3 but, I still think that meat is a small fish to fry. It’s the processed foods and vegetable oils that really get us.
100g is about .22lbs—or 3.5oz—so a 12oz grain-fed steak would be about 340g and have 962mg of n6 and 87mg of n3. So a 12oz grain-fed steak would require 394mg of n3 to get the ratio to 2:1.
So generally speaking, grass-fed is best. If grain-fed is the best you can do then grain-fed + omega 3 supplementation might be perfectly fine and this gives us some idea of how much omega 3 we should be supplementing if our meal is a steak and vegetables.
And the data in the charts comes from: G.J. Miller, “Lipids in Wild Ruminant Animals and Steers.” J. of Food Quality, 9:331-343, 1986.