Grass Fed Meat Contains More Omega 3

Grass Fed Meat: Grass is high in Omega 3 (n-3) PUFAs. There is a direct relationship between the PUFA content of an animal's diet and the PUFA content of the eventual food products. Therefore, if we eat grass fed meat instead of grain fed meat, we will improve our n-3 to n-6 intake ratio.

How does livestock diet affect the PUFA content of the meat?

The PUFA content of meat, and especially the n-3 to n-6 ratio, varies greatly according to the livestock's diet. A number of independent research studies have shown a clear correlation between the proportion of grass in the animal's diet and the levels of n-3 and n-6 present in the meat. As the proportion of grass from pasturing increases in the diet, the level of n-3 present in the meat increases and the level of n-6 decreases, resulting in a much healthier n-3 to n-6 ratio.

Grass fed beef compared with grain fed beef

The data used to compile this table are from research by Leheska et al (2008). The study was conducted in order to provide data on grass fed beef to the USDA. However the USDA data appears to be slightly inconsistent with Leheska's published document.

Type of Beef ALA per 100g of Fatty Acid EPA per 100g of Fatty Acid DHA per 100g of Fatty Acid Total n-3 per 100g of Fatty Acid Total n-6 per 100g of Fatty Acid n-3 to n-6 ratio
Grass Fed Ground Beef (raw) No data given No data given No data given 0.88g 1.85g 0.48 to 1
Cereal Fed Ground Beef (raw) No data given No data given No data given 0.24g 2.20g 0.11 to 1
Grass Fed Strip Steaks (raw) No data given No data given No data given 1.07g 2.30g 0.46 to 1
Cereal Fed Strip Steaks (raw) No data given No data given No data given 0.19g 2.58g 0.07 to 1
Leheska et al: Effects of conventional and grass-feeding systems on the nutrient composition of beef. The Journal of Animal Science 2008, 86:3575-3585.

Learn more about why grass fed meat is better for you

How do other meats compare with beef?

The PUFA content of meat from ruminant animals such as cows and sheep differs greatly from that of non-ruminants such as pigs and chickens.

The PUFA consumed by ruminants is modified by biohydrogenation whereas for non-ruminants their dietary PUFA are incorporated into tissues without such modification (Chow p89).

While cows and sheep show roughly comparable PUFA composition, pigs differ greatly from these two ruminants. Here is a table based on the retail study conducted by Enser et al in 1996.

Meat ALA to LA Ratio n-3 to n-6 ratio
Beef - muscle 0.29 0.47
Beef - adipose tissue 0.43 0.43
Lamb - muscle 0.52 0.76
Lamb - adipose tissue 0.73 0.73
Pork - muscle 0.07 0.14
Pork - adipose tissue 0.10 0.13
Note: In order to be consistent with other tables provided by this website the ratios shown are the inverse of those published in the study.
Enser et al: Fatty acid content and composition of English beef, lamb and pork at retail. Meat Science 1996, 42:443-456. The data were taken from Chow p93, which cited this study.

The ratios for lamb are even better than beef in this study, while both are much better than pork. The same study covers the impact of different diets on the PUFA content of meat. Here is a summary for 4 lamb breeds and two diets:

Breed of Lamb and Diet ALA per 100g of Meat EPA per 100g of Meat DHA per 100g of Meat Total n-3 per 100g of Meat Total n-6 per 100g of Meat n-3 to n-6 ratio
Spanish Merino - Concentrates 13.4mg 8.4mg 6.5mg 43.7mg 269.6mg 0.16 to 1
Rosa Aragonesa - Concentrates 20.7mg 14.6mg 9.8mg 64.3mg 243.1mg 0.26 to 1
Welsh Mountain - Grass 67.1mg 26.9mg 9.0mg 129.8mg 124.4mg 1.04 to 1
Early Lamb - Grass 50.2mg 21.4mg 9.7mg 104.1mg 137.6mg 0.76 to 1
Enser et al: Muscle lipids and meat quality.
Note 1: Meat quantities were measured in the m.longissimus muscle.
Note 2: Other n-3 PUFAs were present so that Total n-3 exceeds the sum of ALA, EPA and DHA.
Note 3: The published study has LA incorrectly labelled 18:2 n-3 instead of 18:2 n-6 in table 2.

The lambs fed on a grass diet produced meat with much higher levels of n-3 and a significantly better n-3 to n-6 ratio.

Discover why the balance of omega 3 to omega 6 in your diet is important