Nutrition

Fructose and 'Natural' Is Not Always Good For You!

By: Lucho Crisalle, R.D.

08.31.2006

A favorite saying of mine is "just because its "natural" doesn't mean that it's good for you.  Actually tobacco is "natural," yet Not Good!  Arsenic is also natural, and definitely Not Good!"  It is obvious that these things are not good for us (yet some people still choose to smoke).  What may not be as obvious is that fructose, a "natural" sugar found in fruit can be just as harmful when not used correctly: too much at once, with sugar added, any and all fruit juices, late at night before bed, and even throughout the day unless paired with a substantial amount of protein. 

The latest research on fructose titled "Fructose, weight gain, and the insulin resistance syndrome," written by Sharon S. Elliott, Nancy L. Keim, Judith S. Stern, Karen Teff, and Peter J. Havel suggests that in this case, "natural" isn't always the best choice.  Thanks to the Atkins diet and many other low or no carbohydrate advocates, more manufacturers are making low carb bars and products because they want to prevent our body from secreting too much insulin.  Please note that insulin can be a good thing when manipulated correctly as it will cause muscle growth and definition.

One of the many things that makes fructose (fruit sugar) very different than table sugar as well as all others forms of sugars is that fructose DOES NOT cause insulin secretions.  This means that when fruit sugar enters the bloodstream, the pancreas is not prompted to secrete insulin. Insulin is in charge of storing sugar in our muscle and other body cells and then into fat cells as the other cells become full.  Because fructose does not cause an insulin reaction or secretion, this means that the sugar from fruit tends to hang around in our bloodstream as it is not stored because there is no insulin to cause its storage.  What happens to that sugar, you may ask? Well, it ends up binding to or sticking to our red blood cells or hemoglobin and creating a compound called glycosylated hemoglobin or hemoglobin A1c, one of the markers doctors and dietitians look for to be elevated in diabetes patients.

Another negative factor about fructose is that it skips one of the steps of sugar metabolism in the liver.  This step is a regulating mechanism responsible for sending a message of satiety via the central nervous system.  The same study cited above goes on to show that the use of high fructose corn syrup (HFCS) may be the main reason for obesity in children as well as one of the main causes for type II diabetes in children.  The study states that the fat cells in these children with type II diabetes were saturated with fat to the point where no more fat was being "accepted" by these cells.  This causes fat to circulate in the blood and end up in the pancreas, clogging and destroying beta cells responsible for insulin production.

Those of you that know me, and/or who have been on my customized nutrition program, know that I never recommend fruit juice in any program.  Whole fruit in its original form is the best source of the healthy vitamins and minerals obtained from fruit.   It takes three (3) oranges to make 4 oz. of orange juice.  You are better off eating one (1) orange as it provides the pulp, fiber and an array of vitamins and minerals that juice alone does not. 

 In closing, for best results and a healthier life, combine protein, fat, and carbohydrates in every meal, stay away from all sources of fructose other than fresh fruit (one serving consisting of 15 grams of carbohydrates or one exchange), and when choosing carbohydrates choose those where sugar is less than twenty percent of the total carbohydrate content of that product.  It may seem harsh to compare fructose to tobacco and arsenic, however the main difference between these is that excessive consumption of fructose will take a lot longer to kill you than tobacco and arsenic.

- 2006 Lucho Crisalle, R.D., Exercise & Nutrition Works, Inc. Lucho Crisalle, R.D. is a noted international expert in the field of nutrition and supplements, and the author of the Gold's Gym International Certified Fitness Nutrition Specialist (CFNS) program.  To learn more about Lucho Crisalle, R.D., visit www.ExerciseAndNutritionWorks.com.