Fructose: Sweeter But Not Healthier
Fructose, which is used primarily in beverages and baked goods, seems to reduce satiety. At the same time it adds significant calories to your diet. So you are eating more calories, but you do not feel like you are eating more calories!
Of all the naturally occurring sugars, fructose is the sweetest. For many years it was hoped that replacing less-sweet sugars like corn syrup (glucose) in the diet with fructose-rich sweeteners might be beneficial to those with type 2 diabetes mellitis (DM). Also because fructose is sweeter than other sugars, it was believed by some that increasing the amount of fructose in the diet at the expense of other sugars might aid weight loss by reducing calorie intake. Unfortunately, Americans have been getting fatter as the amount of dietary fructose has increased due in part to the growing use of high-fructose corn syrup.
Fructose does not stimulate the release of insulin the way glucose from corn syrup, starch or even sucrose do. Unfortunately, elevated blood glucose and insulin levels after meals appear to play a role in satiety so replacing glucose (or starch) in the diet with fructose or high-fructose corn syrup appears to reduce satiety after eating resulting in a modest increase in calorie intake. A recent study reported at the American Diabetes Association 67th Annual meeting in Chicago that overweight subjects who consume 3 drinks daily sweetened either with glucose or fructose only gained weight on the fructose-containing drinks. In addition their LDL-cholesterol levels increased and they became less sensitive to insulin.
Diets with more than 15% fructose increase serum triglyceride levels after meals (postprandial) and in the fasting state in both normal subjects1 and in those with insulin resistance.2 Elevated fasting and postprandial triglyceride levels are associated with more atherosclerosis and cardiovascular disease (CVD) and are part of the Metabolic Syndrome. Since people with type 2 DM are insulin resistant and have a much higher risk of CVD, it is important to know whether or not the mechanism by which dietary fructose elevates triglyceride levels is similar to that seen in patients with the Metabolic Syndrome. If so, this apparently adverse impact of diets high in fructose would be a particular concern for those with the Metabolic Syndrome and type 2 DM.
A recent study examined the mechanism whereby dietary fructose promotes elevated serum levels of triglyceride (hypertriglyceridemia). What they observed was that fructose appears to raise serum triglyceride levels primarily by increasing delaying the clearance of fat rich lipoprotein particle from the blood. The authors stated that ?The similarity of fructose-induced hypertriglceridemia to certain forms of endogenous hypertriglyceridemia is also suggestive of potential cardiovascular risk.?3
In large amounts (10-15% of calories or more) fructose promotes weight gain and increase insulin resistance. There are other reasons to suspect diets high in fructose may be dangerous for people with the metabolic syndrome and type 2 DM. Diets higher in fructose adversely impact blood lipids and promote CVD and can lead to insulin resistance and type 2 DM in genetically predisposed people.
By James J. Kenney, PhD, RD, FACN
1. Am J Clin Nutr 2000;72:1128-34
2. Am J Clin Nutr 1983;37:740-8
3. Am J Clin Nutr 2007;85:1511-20
Foods That Often Contain High-Fructose Corn Syrup:
Below are foods that often contain high-fructose corn syrup.? Read the ingredient list of foods you are buying. Bold foods below usually contain a substantial amount.
Fruit drinks and juices
Ice cream, sherbet and sorbet
Instant breakfast drinks
Jams, jellies and preserves
Pickles and relish
Salad dressing and mayonnaise
Sauces and condiments
Soft drinks and sweetened beverages
Tomato sauce, tomato paste, pasta sauce
Judy’s passion for cooking began with helping her grandmother make raisin oatmeal for breakfast. From there she earned her first food service job at 15, was accepted to the world famous Culinary Institute of America at 18 (where she graduated second in her class), and went on to the Fachschule Richemont in Switzerland where she focused on pastry arts and baking. But after learning that the quality of a croissant directly varies with how much butter it has, Judy sought to challenge herself by coming up with recipes that were as healthy as they were tasty.
Judy received The Culinary Institute of America’s Pro Chef II certification, the American Culinary Federation Bronze Medal, Gold Medal, and ACF Chef of the Year. Her enthusiasm for eating nutritiously and deliciously leads her to constantly innovate and use the latest in nutritional science to guide her creativity, from putting new twists on fajitas to adapting Italian brownies to include ingredients like toasted nuts and cooked honey. Judy’s publishing company, Food and Health Communications, is dedicated to her vision that everyone can make food that tastes as good as it is for you.