Fructose: Should You Avoid It?


Fructose is the simple sugar in fruits and vegetables that makes them sweet. However, when added to food and beverages, fructose can be a problem. In fact, many health experts blame the substance for the growing epidemic of obesity and associated health problems such as insulin resistance, heart disease, diabetes and cancer.

Natural Fructose... the way to go

There is nothing wrong, of course, with the fructose you get from corn, carrots or apricots. It’s part of a high-fiber package that includes many beneficial vitamins and minerals. It would be virtually impossible to eat too much fructose from fruits and vegetables.

Added Fructose... not so much

When fructose–or any sweetener–is added to foods and beverages and consumed in large amounts, unnecessary calories are added to our diet. For your home baking, table sugar is the main sweetener; for soft drinks, packaged desserts and many processed foods, the sweetness comes from fructose that has been added–usually, either high fructose corn syrup (HFCS) or crystalline fructose.
Both HFCS and crystalline fructose are sweeter than table sugar; as a result, the desired level of sweetness can be attained with fewer calories.

Added Sugar, Added Calories

Added calories from any type of added sugar will cause weight gain and potential health problems unless there is a corresponding increase in physical activity. Sugary foods are high in empty calories.

High fructose corn syrup was introduced in the 1970s, and since that time, there has been a 25 percent increase in consumption of added sugars in the American diet. Fructose, used in excess, causes not only weight gain but also metabolic damage that can lead to diabetes and the early stages of heart disease.

Glucose vs. Fructose

Glucose is important; it’s the major source of energy. But the body is capable of making all of the glucose it needs from starchy carbohydrates such as potatoes, beans, cereal and bread in the diet. Whether from carbohydrates or added sugar, glucose goes directly to cells, and much of it is burned up immediately after you consume it.

Fructose, on the other hand, is not manufactured by the body, and it is processed differently. Rather than going to cells for energy, it is sent to the liver which processes it into either glucose or fat. When too much fructose is eaten, the liver gets overloaded and becomes more likely to turn the fructose into fat, setting the stage for fatty liver disease, increased abdominal fat, insulin resistance, the metabolic syndrome, diabetes and cardiovascular disease.

Moderation is key

With any sweetener, the problem is not use but excessive use. And use in this country has increased dramatically since the 1970s when high-fructose corn syrup started appearing in soft drinks and processed foods.

The World Health Organization and the U.S. Dietary Guidelines Advisory Committee recommend limiting intake of all added sugars to about 12 teaspoons (50 grams) a day–the amount in one 12-ounce serving of soda. You really should aim for about half that much, especially if you are overweight or at risk of heart disease or diabetes.

Amy J. Bidwell, “Physical activity offsets the negative effects of a high-fructose diet,” Medicine and Science in Sports and Exercise, 2014;46(11):2091-2098.
Will Boggs, M.D., “Excessive calories from snacking increase liver fat,” Reuters Health, May 16, 2014.
George A. Bray, “How bad is fructose?” American Journal of Clinical Nutrition, Vol. 86, No. 4, 895-896.
“Fructose,” Calorie Control Council.
Kris Gunnars, “Why is fructose bad for you? The bitter truth,”, January, 2013.
James Hamblin, “Being happy with sugar,” The Atlantic, June 5, 2014.
“Nutrition fact sheet,” Calorie Control Council.
Peter Stenvinkel, “Obesity–a disease with many aetiologies disguised in the same oversized phenotype,” Nephrology Dialysis Transplantation, 2015;30(10):1656-1664.
Luc Tappy, M.D., “How dangerous is fructose?” Medscape October 15, 2015.
Miriam E. Tucker, “Sugar-sweetened beverages linked to a variety of ills,” Medscape Medical News, October 1, 2015 (Journal of the American College of Cardiology, September 28, 2015).

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