Interesterified Fats: A New Form of Fat Poison

September 10, 2007

Interesterified Fats: A New Form of Fat Poison 

 Competency # 13 Fats                           Reference: Sundram et al, Nutrition & Metabolism 2007, 4:16 (12 July 2007) (Web site for monkey research on trans fats) 

 Interesterified?  That should be something to do with ”interested” and “terrified”.  We should be some of both.  Instead of just being “partially” hydrogenated, the chemical reaction in this fat is to add a saturated fat into the polyunsaturated position of the chemical backbone (  Lo and behold, you don’t have to call it a “trans fat”.  

Yippee.  You can dodge the FDA's requirement to label your food with the dreaded trans fat label.  And you can come up with another fat family that is nice and creamy, makes your French fries crispy, and allows you to put banner headlines out there: “NO TRANS FATS”. Trans fats are known dietary poisons.  I use the word poison with intent, as they have the opposite effect of medicines. As Americans, we take statin drugs by the truckload to make our blood cholesterols better.  Then, we find that trans fats make our blood cholesterol go backwards and get worse, sort of a break-even deal.  Trans fats make your LDLs higher and your HDLs lower.  So, we are focused on getting rid of trans fats.  

Unfortunately, we haven’t focused on the choice of eating “better fat” foods.   The food industry has responded with a secret chemistry lesson, and added an “inter” group instead of adding hydrogen to the formally “unsaturated” double bond in the fatty acid.  You end up with an “interesterified” fat, a new form of “Fat Poison”?  Only this time, you are the lab rat. And we should be terrified.  This new fat, creamy and delicious, was fed to volunteers in a rotating diet that had trans fats and regular fats in it.  The study showed that, sure enough, trans fats do lousy things for your HDLs and LDLs.  What they didn’t expect to find was the glucose effect of the interesterifed fats.  Their effect on LDLs and HDLs was not as great as trans fats.  That makes them a little better than trans fats for HDLs and LDLs. But, surprisingly, the interesterified fats knocked insulin levels down and boosted up blood glucose levels by 20%.  Within days!   

Oh dear, just as we find a substitute for the wicked trans fat, our substitute is equally troubling with an added twist, it knocks your glucose metabolism off the couch. A further study: released this last spring shows that monkeys, fed a diet with about 8% of calories from trans fats gained weight compared to monkeys fed the precise same diet and amount of calories.   The control monkeys only gained 1.8% weight.  Trans fats make monkeys gain weight on equivalent calories.  And they gained it right around their middles, just like us humans.  Can you imagine an apple-shaped chimpanzee or bonobo?  The visual!  Now we know how to make one.  This wasn’t a human study but it adds weight gain to the long list of problems with trans fats.  It suggests that we humans get fatter by eating trans fats rather than ordinary fats. 

 WWW:  What Will Work for Me?  I just have to read the label.  I’m learning to pay attention.  Look at your label.  If it says, “partially hydrogenated”, that’s code for trans fat.  If it says, “fully hydrogenated”, that’s code for interesterified.  Don't buy it.  We don’t have certain proof, but I would get worried.  It’ll take 10 years to get certain proof.  I’m working with less time than that.  My personal metabolic syndrome is tip-toeing on the edge of getting better or worse.  Making these changes might tip me in the right way.  It appears that the three key ingredients of French cooking are what we should be using:  butter, butter, and more butter.  Or ghee, or lard, or olive, or sesame, or peanut.  Natural fats.  They haven’t been chemically changed.  Mother Nature may just be right.   Now, a splash of natural wine?

The column is written by Dr. John E. Whitcomb, MD, Brookfield Longevity, Brookfield, WI (262-784-5300)