April 22, 2003 -- When it comes to preventing type 2 diabetes, women don't need to shun sugar. In fact, total calories and a sedentary lifestyle play larger roles in putting women at risk.
That's the finding from an important study of middle-aged women -- one that clears up a long-held misconception.
"People have always assumed that sugar consumption causes higher blood sugar levels, that sugar is bad," says lead researcher Sok-Ja Janket, DMD, MPH, with Brigham and Women's Hospital and Harvard Medical School.
"Our study is the first one to directly investigate this relationship -- is sugar causing high blood sugar levels or type 2 diabetes?" Janket tells WebMD. "We found no evidence that moderate amounts of sugar cause diabetes."
The study appears in the April 2003 issue of Diabetes Care.
Ronald Goldberg, MD, associate director of the Diabetes Research Institute at the University of Miami Medical Center, agreed to comment on Janket's study.
He offers his own cautionary note. "By far the most important lifestyle factor leading to type 2 diabetes is obesity, and obesity develops when you have excess calories from any source -- whether it's carbohydrates, protein, or fat," Goldberg tells WebMD. "Too many calories, and you're going to put on weight, and if you have genes for diabetes, obesity will make it emerge."
Indeed, understanding diet's role in type 2 diabetes has evolved over the past two decades. In the past, people with diabetes have been advised to adhere to a low-sugar diet.
However, more recent studies have found that a moderate amount of sugar in a balanced diet does not have any harmful effects on blood sugar levels.
But what are the long-term effects of sugar intake on the risk of developing type 2 diabetes?
In this study, researchers analyzed data on nearly 39,000 middle-aged women, all of whom completed a 131-item food questionnaire. Six years later, there were 918 cases of type 2 diabetes among the women.
However, there was "no definitive influence of sugar intake on the risk of developing type 2 diabetes," write Janket and her colleagues.
Even after they adjusted for possible dietary changes made by women who were told they had high blood pressure and high cholesterol, they got the same result.
But don't switch to a jelly bean-and-chocolate diet, says Janket. "It doesn't mean can eat all the sugar you want. That's not true. You still have to keep track of calories."
Also, exercise is a big factor. "The women in our study were healthy and got regular exercise. The bottom line: If your intake of sugar is more than 60 grams a day -- and if you're not exercising -- you will gain weight, which increases risk of type 2 diabetes."