Aaah.... Found this about CLA supplements. CLA Supplements: Not The Same As Real Food It’s easy to get trapped in “nutritionism”: the idea that we can eat whatever junk we want, and take supplements to replace the nutrients we’re not getting from our food. This rarely works…and in the case of CLA supplements, we know why. Recall that “conjugated linoleic acid” can mean a whole host of different fats, depending on the positions of the double bonds. Most CLA supplements are derived from safflower oil— —and they contain equal parts rumenic acid (cis-9, trans-11 18:2) and an unnamed trans-10, cis-12 18:2 isomer. In other words, half of a CLA supplement is an entirely different chemical than what you’re getting from meat and butter. Unfortunately, trans-10, cis-12 doesn’t have all the same beneficial effects. While it still seems to have anti-cancer properties in mice, it doesn’t have the same effects on human metabolism as rumenic acid: Circulation. 2002; 106: 1925-1929 Supplementation With Conjugated Linoleic Acid Causes Isomer-Dependent Oxidative Stress and Elevated C-Reactive Protein: A Potential Link to Fatty Acid-Induced Insulin Resistance Ulf Risérus, MMed; Samar Basu, PhD; Stefan Jovinge, MD, PhD; Gunilla Nordin Fredrikson, PhD; Johan Ärnlöv, MD; Bengt Vessby, MD, PhD “The significant increase from baseline in 8-iso-PGF2a, 15-K-DH-PGF2a and CRP after t10c12 CLA was 1.04±0.7 (578%), 0.30±0.31 (77%), and 2.89±3.66 (110%), respectively. … This randomized, double-blind, placebo-controlled trial demonstrates that dietary supplementation with t10c12CLA causes isomer-specific oxidative stress that is related to induced insulin resistance.” Diabetes Care September 2002 vol. 25 no. 9 1516-1521 Treatment With Dietary trans10cis12 Conjugated Linoleic Acid Causes Isomer-Specific Insulin Resistance in Obese Men With the Metabolic Syndrome Ulf Risérus, MMED1, Peter Arner, MD, PHD2, Kerstin Brismar, MD, PHD3 and Bengt Vessby, MD, PHD1 “This randomized placebo-controlled trial has revealed unexpected metabolic actions by conjugated fatty acids in humans—actions that seem isomer-specific. The t10c12 CLA isomer, but not a CLA mixture, significantly increased insulin resistance, fasting glucose, and dyslipdemia in abdominally obese men.” [i can't resist an editorial comment at this point: [i]why did neither study test rumenic acid alone, the way it occurs in real food?[/i] Might it have actually reduced oxidative stress and decreased insulin resistance, when not forced to fight equal amounts of the imposter t10c12?] It’s important to note that many of the studies that claim benefits for t10c12 are on mice or rats. As Risérus et.al. note: “Conjugated linoleic acid (CLA) is a group of dietary fatty acids with antiobesity and antidiabetic effects in some animals. The trans10cis12 (t10c12) CLA isomer seems to cause these effects, including improved insulin sensitivity.” Unfortunately, as their experiment proved, the safflower-derived t10c12 doesn’t have the same benefits for humans as it does for rodents. And perhaps we shouldn’t be surprised that ingesting a chemically extracted fraction of a seed oil doesn’t produce the same benefit as eating real food. Conclusion: Keep Eating Like a Predator, Keep Eating Real Food Our conclusions should be obvious, but I’ll restate them: If we’ve eaten something for millions of years, the odds are very good that we’re adapted to eating it. Be skeptical of studies that feed fat to mice—herbivores that naturally subsist on plants and seeds. Whenever possible, eat real food, not supplements. You might not be getting the same benefits…or even the same nutrients. Most importantly: keep eating delicious fatty red meat and butter!
