Fructose is both a natural fruit sugar and an artificially produced sweetener. When compared to other sugars, however, fructose produces strikingly different -- and potentially dangerous -- results. One of them is that it induces insulin resistance when consumed in high amounts. The American Heart Association states that for good health, you should consume no more than 100 calories per day from all sugars if you're a woman and 150 if you're a man.
Facts about Fructose
Fructose is a simple sugar found in honey and fruit. It's also an "added sugar," artificially produced and used in processed goods for its sweetening and preservative effects. It's one of the ingredients of "high-fructose corn syrup," the ubiquitous added sugar found in products from bread and snack foods to desserts and soft drinks. High-fructose corn syrup is one of the main ways Americans get fructose. Research in the "Journal of the American Society of Nephrology," or JASN, reported on average, Americans consume 74 g of fructose daily. Excessive fructose consumption is linked to obesity, hypertension, fatty liver disease, as well as insulin resistance.
Insulin Resistance
Your pancreas secretes the hormone insulin in response to eating. Insulin helps take blood sugar from the digested food to your cells. Blood sugar is fuel for the myriad biological functions needed to keep you alive. For many reasons, including genetics, poor diet and lack of physical activity, some people develop insulin resistance, which is when your pancreas produces insulin, but your body doesn't use it properly. More blood sugar builds up in the bloodstream instead of going into your cells. Your pancreas may produce more insulin to keep up with the rising levels of blood sugar. Insulin can also "tell" your liver to hold on to some glucose stores for later use, but eventually uncontrolled insulin resistance leads to diabetes.
Fructose Decreases Insulin Sensitivity
In the "Journal of Clinical Investigation," researchers from the University of California, Davis, reported that consuming fructose-sweetened beverages decreases insulin sensitivity. They compared fructose's effects with that of glucose, another sugar. In addition to gaining weight and padding their bellies with more fat, the fructose drinkers experienced a 17 percent decrease in insulin sensitivity over 10 weeks. The researchers suspect that fructose caused an increase in the amount of fats produced in the liver, which promoted insulin resistance. Research on mice appearing in "Cell Metabolism" confirmed that fructose more readily metabolizes to fat in the liver. The authors located a gene responsible for fat production in the liver and deactivated it. When that happened, fructose-induced insulin resistance cleared.
Fight Insulin Resistance
You need to consult with your doctor to know whether you have insulin resistance. Some high-risk symptoms include putting on weight and trouble losing it, having a waist measurement higher than 35 inches for women and 40 for men, high cholesterol and high blood sugar. To fight insulin resistance, you need to move more. Getting active helps make your body more sensitive to insulin. Moreover, you can build more muscle, which can absorb blood sugar without insulin. Losing weight also helps re-sensitize your body to insulin. If warranted, your doctor may prescribe diabetes medications.
References
- "Journal of the American Society of Nephrology"; The Effect of Fructose on Renal Biology and Disease; Richard J. Johnson et al.; December 2010
- "American Journal of Clinical Nutrition"; Potential Role of Sugar (Fructose) in the Epidemic of Hypertension, Obesity and the Metabolic Syndrome, Diabetes, Kidney Disease, and Cardiovascular Disease; Richard J. Johnson et al.; Oct. 2007
- National Diabetes Information Clearinghouse; Insulin Resistance and Pre-diabetes; Oct. 2008
- "Journal of Clinical Investigation"; Consuming Fructose-Sweetened, not Glucose-Sweetened, Beverages Increases Visceral Adiposity and Lipids and Decreases Insulin Sensitivity in Overweight/Obese Humans; Kimber L. Stanhope et al.; May 2009
- "Nutrition & Metabolism"; Fructose, Insulin Resistance, and Metabolic Dyslipidemia; Heather Basciano et al.; Feb. 2005
- "Cell Metabolism"; A Sweet Path to Insulin Resistance Through PGC-1b; Carlos Hernandez and Jiandie D. Lin; March 2009
