A Little Sugar Goes a Long Way

Insulin sensitivity may be affected by eating nearly normal amounts of certain sugars

/ Author:  / Reviewed by: Robert Carlson, M.D

(RxWiki News) Eating too much sugar can change how your body responds to insulin - a hormone that is heavily involved in diabetes. Does eating normal amounts of sugar also have an effect?

Eating even normal amounts of certain sugars may increase cholesterol levels and change how your body responds to insulin.

"Try to limit the sugar you eat."

According to Kaspar Berneis, MD, of University Hospital Zurich in Switzerland, and colleagues, studies have repeatedly shown that diets high in calories and fructose (a type of sugar) can affect insulin sensitivity and cholesterol levels.

Insulin is a hormone that manages levels of sugar in the blood. One main role of insulin is to keep the liver from making too much glucose (a type of sugar).

If someone has low insulin sensitivity or insulin resistance, the liver may keep making too much sugar. If blood sugar levels rise too high, a person may be at risk of diabetes.

From their study, Dr. Berneis and colleagues found that people who drank high amounts of fructose had lower insulin sensitivity than those who drank high amounts of glucose.

In other words, the livers of people on a high-fructose diet produced more sugar than the livers of people on a high-glucose diet.

People who drank moderate to high amounts of fructose or sucrose (another type of sugar) had higher levels of LDL cholesterol (the "bad cholesterol) and total cholesterol, compared to those who drank high amounts of glucose.

These findings suggest that moderate amounts of fructose and sucrose can change insulin sensitivity and the body's ability to burn fats compared to similar amounts of glucose, the authors concluded.

"My interpretation of the study is that sugary drinks specifially are going to affect lipid metabolism," said Eve Pearson, MBA, RD, CSSD, LD, a registered dietitian who owns Nutriworks Comprehensive Nutrition Consulting.

"If someone ate foods, like fruit, with fructose in them as part of an otherwise balanced diet, this study would find different results. The American Heart Association recommends no more than 25 grams and 35 grams of added sugar each day for women and men, respectively. Americans consume way more than this number. Cereals contain 11-23 grams of added sugar. Breads range from 2-4 grams of added sugar. In reading a label on a frozen dinner, one will see four different added sugars for a total of 12 grams of added sugar," said Pearson, who was not involved in the study.

"It's clear that Americans consume too much sugar no matter the source. In general, it's difficult to single out any one source of sugar as being worse than the others," she said.

The size of this study was small, with only nine normal-weight men between 21 and 25 years of age.

Because of this limitation, more research is needed to see if different amounts of sugars have similar effects on other populations, including women and older adults.

The research was published August 28 in Diabetes Care, a journal of the American Diabetes Association.

Reviewed by: 
Review Date: 
August 28, 2012
Last Updated:
October 5, 2012