Women who drink two or more sugary drinks a day, even if they are of normal weight, appear to be at higher risk of heart disease and diabetes, according to a new study presented over the weekend to the American Heart Association’s (AHA’s) Scientific Sessions 2011, which is running from 12-16 November, in Orlando, Florida. An abstract of the study is available to view online in the AHA journal Circulation.

Sugar-sweetened drinks includes beverages such as carbonated sodas or flavored waters with added sugar.

Previous studies have examined and found links between drinking sugar-sweetened beverages and obesity, high blood fats, high blood pressure, and type 2 diabetes. But studies following large, ethnically diverse populations looking at links with cardiovascular risk factors are sparse, said the researchers.

Lead author Dr Christina Shay, an assistant professor at the University of Oklahoma Health Sciences Center in Oklahoma City and colleagues, compared middle-aged and older women who consumed two or more sugar-sweetened drinks to women who drank one or less a day.

They found that women who drank two or more such drinks a day were significantly more likely to develop larger waists and have impaired fasting levels of glucose. They were also nearly four times as likely to develop high triglycerides, a type of blood fat linked to increased risk of heart disease.

They didn’t find any such links in men.

Shay said in a press statement:

“Women who drank more than two sugar-sweetened drinks a day had increasing waist sizes, but weren’t necessarily gaining weight. These women also developed high triglycerides, and women with normal blood glucose levels more frequently went from having a low risk to a high risk of developing diabetes over time.”

“Most people assume that individuals who consume a lot of sugar-sweetened drinks have an increase in obesity, which in turn, increases their risk for heart disease and diabetes. Although this does occur, this study showed that risk factors for heart disease and stroke developed even when the women didn’t gain weight,” she added.

For the study, Shay and colleagues examined data from 4,166 African-American, Caucasian, Chinese-Americans and Hispanic adults who took part in the the Multi-Ethnic Study of Atherosclerosis (MESA). The participants, aged from 45 to 84 years, had completed food-frequency questionnaires when the study started in 2000-2002.

During five years of follow-up, the participants underwent three exams from which the researchers were able to assess changes in body weight, waist size, levels of high density lipoproteins (HDL “good” cholesterol), levels of low density lipoproteins (LDL “bad” cholesterol), triglycerides, levels of fasting glucose, and presence of type 2 diabetes.

The study was conducted at Northwestern University’s Department of Preventive Medicine in Chicago, where Shay used to be based.

She and her colleagues noted that the metabolic influence of sugar-sweetened beverages is “complex and is not homogenous between men and women”.

They said we know that women need fewer calories than men, so it looks like when a higher proportion comes from drinking sugar-sweetened drinks, they therefore experience a higher cardiovascular risk.

But exactly how such drinks influence cardiovascular risk, what biological mechanisms might be involved, is still somewhat unclear and warrants further investigation, said the researchers, who are planning to do just that.

Funds from the National Heart, Lung, and Blood Institute helped pay for the study.

Written by Catharine Paddock PhD