Metabolic Syndrome VI: Fructose and AGEs

February 06, 2008

Metabolic Syndrome # 6:  AGEs and Fructose Link 

 Competency # 20 lifestyles of the Long-lived Reference: Miller Curr Opin Gastroenterol 2008 Mar;24(2):2004-9 Dietary fructose and the metabolic syndrome; Jandeleit-Dahm Clin Exp Pharmacol Physiol 2008 Mar: 35(3):329-3Date:  2/08 

 AGEs and AGEs ago we wrote an article with that “pun” about AGEs.  Advanced Glycation Endproducts are an important concept to revisit.  The reason is that they may be the “Holy Grail” of what sets off metabolic syndrome.  Our last article, last year, was how cooking foods over high heat make more AGEs.  I got much negative feedback from many backyard barbeque gurus who can stand the thought of eating nothing but minimally boiled meat. 

 Last week, we accused white carbohydrates of being part of the problem with setting off metabolic syndrome.  But the picture is a bit more complex and I’ll try and share that complexity. AGEs are what happens to your blood when you have high glucose levels for a long time.  Glucose molecules get spastically attached to protein molecules, without the benefit of an enzyme attaching them in a precise place.  That protein then functions poorly because it’s got an interfering glucose molecule hanging out in the wrong place.  

The best-known AGE is hemoglobin A1c. We can measure it in diabetics as an indication that their diabetes is in good control, or out of control. Someone with high glucose, for a long time, in other words, poorly controlled diabetes and really bad insulin resistance (in adult-onset diabetes) will have higher and higher Hemoglobin A1c.  (A level of 6.4 is the definition of diabetes.  But <5.7 is the Institute of Medicine's advice for longevity. Hence, a continuum of rising risk). But that’s not the only AGE out there.  High glucose results in many glucose molecules getting stuck out there all over the place.  That may happen for several reasons.  

Free oxygen radicals (what anti-oxidants gobble up) might be what fires up the glucose to make it more chemically reactive, and then it sticks to just about anything. The review articles I site above are all about AGEs and the receptor they interact with.  When you block AGE accumulation you reduce vascular disease.  

The second article refers to how fructose, by itself, may be the missing link in setting off metabolic syndrome, in which insulin resistance gets started. Here’s the proposed sequence of ideas that set off metabolic syndrome.  (1.) You eat too much fructose in either table sugar or fully sugared sodas and fruit juices. (2.) That starts you down the road of insulin resistance.  (3.) Once you start insulin resistance, white carbs make your blood glucose build up, (4) AGEs start to accumulate,  (5) proteins get injured with glucoses attached to them, (6) blood vessels get stiffer, (7) blood fats get inflamed and (8)stick to the injured blood vessel, and  (9) we get vascular disease.  For the science works out there, these two articles that explain that sequence caught my eye. 

 WWW: What will work for me?  The big picture continues to implicate fructose and white carbs, in combination and in excess.  Metabolic syndrome is the disease of the day.  60% of us have it for 20 years before we get a diagnosis of high blood pressure, diabetes, or heart attack.  If we want to catch it early and change our risk by our own lifestyle changes, the time is now.  We can reverse it, in its early stages.  So, I put the “Tres Leche” cake leftovers back in the fridge and brought an extra pear to work today instead.  What a good food choice, the natural sugar of a sweet pear instead of unbelievably delicious table sugar.  This is self-righteousness in its purest form. AKA: STOP the SUGAR in any form.  It's got fructose in it.

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