At the Burnsides Laboratory at the University of Illinois, Champaign-Urbana, we carried out an analysis of the fatty acids (fat molecules) in grain-fed and grass-fed beef tallow. The sample of grass-fed tallow came from a farm in western Maryland; the grain-fed tallow was purchased in a supermarket in southern Maryland. This research was funded by the Weston A. Price Foundation.
To explore the difference in the fatty acid profile between grass-fed and grain-fed beef tallow, we analyzed one sample of each type by gas chromatography, a method used to separate and quantify individual fatty acids. See the table below for the concentrations of specific fatty acids.
The largest differences between the two samples were the total concentrations of polyunsaturated fatty acids (PUFA), and the balance between the omega-3 and omega-6 forms of these fatty acids. Grass-fed tallow had 45 percent less total PUFA, 66 percent less omega-6 linoleic acid, and four times more omega-3 alpha-linolenic acid. The ratio of omega-6 to omega-3 fatty acids was over sixteen for the grain-fed tallow but only 1.4 for the grass-fed tallow. Whatever the ratios, beef tallow is not a rich source of polyunsaturated fatty acids, with only 3.45 percent in grain-fed and 1.9 percent of the total in grass-fed.
Thus, while even grain-fed beef tallow has a much lower content of polyunsaturated fatty acids than modern vegetable oils, the amount found in grass-fed tallow is much lower and similar to that found in the coconut products that dominate the traditional diets of Pacific Islanders, who have been extensively studied and shown to be free of heart disease. This would allow the use of tallow in the context of a mixed diet that includes other foods naturally rich in polyunsaturated fatty acids, such as fatty fish, while still keeping the overall intake of these fatty acids low and similar to that found in successful traditional diets.
Grass-fed beef is often promoted as healthy because of a lower saturated fatty acid content. But saturated stearic acid was 36 percent higher in grass-fed beef (17.45 percent versus 12.8 percent). Levels of sixteen-carbon palmitic acid, considered “atherogenic” because in some studies it raises cholesterol levels slightly, were virtually the same in both samples. Thus, in equally fatty cuts of beef, there would be a higher content of saturated fatty acids in the grass-fed beef. In many traditional diets where the fattiest cuts and the fat itself were sought out, intake of these saturates would likely be considerably higher.
|Fatty Acid||Fatty Acid||Grain-Fed||Grass-Fed|
|Numerical Designation||Common Name||Percent||of Total Fatty||Acids|
|16:1||Palmitoleate (may include sapienate)||3.4||2.5|
|Putative Conjugated Linoleic Acid (CLA )||0.25||0.3|
|20:4n-6 + 22:0 A||Arachidonate + Behenate||0.1||0.1|
Grass-fed tallow also had 65 percent less natural trans fatty acids, and 22 percent more of the monounsaturated oleic acid. Differences in other fatty acids were minor. We could not identify conjugated linoleic acid (CLA) conclusively with this method, but we identified a fatty acid that is likely CLA, and its concentrations were identical between the two samples.
In a future issue, we will report the concentration of fat-soluble vitamins in these samples.
Cod Liver Oil Survey – Preliminary Results
I n April of 2012, we received an anecdotal report from a midwife of several women experiencing severe postpartum hemorrhages while reportedly following the dietary recommendations of the Weston A. Price Foundation. Concerned that the large amount of omega-3 fatty acids found in cod liver oil could have contributed to the hemorrhages through their blood-thinning properties, especially if not balanced by adequate liver, egg yolks, and other sources of arachidonic acid, we conducted a survey to determine whether postpartum hemorrhage and vaginal bleeding during pregnancy were associated with the use of cod liver oil or the dietary recommendations of the foundation. To reduce the risk of bias and increase the amount of information that could be gained from the survey, we circulated the survey widely on the Internet and asked about a large number of foods, perinatal complications, and medications. Over 3,500 women following many different diets completed the survey.
There was no association between the type of diet the women reported following and any of the complications or medications. Women who reported taking cod liver oil were 30 percent more likely to experience postpartum hemorrhage, but the difference was not statistically significant (P=0.09), meaning there is a reasonable likelihood the association could be due to chance. Several observations suggest this is unlikely to be a true biological effect: there was no association with the dose of cod liver oil; omega-3 fatty acids are also found in fish oil, but there was no association with the use of fish oil; there was no association between cod liver oil and the risk of vaginal bleeding during pregnancy; and there was no association between cod liver oil and the use of medications used to control bleeding.
By contrast, cod liver oil was associated with a large (63 percent) and statistically significant (P<0.001) drop in the risk of preeclampsia, and the magnitude of the drop in risk correlated well with the dose of cod liver oil (P<0.001). Since this is an observational study, it cannot demonstrate cause-and-effect relationships, but this association could reflect a protective effect of the fat-soluble vitamins in cod liver oil.
The data gathered from this survey are voluminous and will be reported in much greater detail in the next issue of this journal.
This article appeared in Wise Traditions in Food, Farming and the Healing Arts, the quarterly journal of the Weston A. Price Foundation, Winter 2013.