Soda consumption linked with metabolic syndrome

July 24, 2007
By Leanne Sullivan

Drinking at least one soda per day is associated with a significantly higher risk of developing metabolic syndrome, compared with drinking less than one soft drink a day, according to an observational study of participants in the Framingham Heart Study.

After adjusting the data for other risk factors, the prevalence of metabolic syndrome in those who drank one or more 12-ounce soft drinks per day – regular or diet – was 48% higher than in those who drank fewer than one of these beverages daily, investigators reported in the July 31 issue of Circulation.

The prevalence rose with higher soda consumption, Dr. Ravi Dhingra of Harvard Medical School, Boston, and his colleagues reported

The soda drinkers had a 44% higher risk of developing new-onset metabolic syndrome after adjusting for intake of saturated and trans fats, dietary fiber, and total calories, as well as smoking and physical activity.

Metabolic syndrome was defined as the presence of three or more of the following factors: waist circumference of 35 inches or more for women and 40 inches or more for men; fasting blood sugar of 100 mg/dL or higher, or treatment with insulin; blood pressure of 135/75 mm/Hg or higher, or treatment for hypertension; serum triglyceride levels of 150 mg/dL or higher; and HDL cholesterol levels of less than 50 mg/dL in women and less than 40 mg/dL in men.

Consumption of soft drinks has increased over the past 3 decades, so the findings have far-reaching ramifications. The results are consistent with those of previous studies that reported an association between soft drink consumption and increased risk of metabolic syndrome, obesity, high blood pressure, and diabetes, the authors noted (Circulation 2007 July 31 [ePub DOI: 10.1161/CIRCULATION AHA.107.689935] ).

The study, which spanned the years 1987 through 2001, included 8,997 person-observations made via physical examinations, physician-administe red questionnaires, and a self-administered food frequency questionnaire. The study population was white Americans, aged 42-66 years. Roughly half were men.

When each individual marker of metabolic syndrome was analyzed separately using multivariate logistic regression, the researchers found that the frequent soda drinkers had a 25%-32% higher adjusted risk for each trait, with the exception of high blood pressure, which had an 18% higher risk that was of borderline significance.

Dietary behavior may be a factor in the higher risk, as individuals who drink more soda also tend to have a higher-calorie diet that includes more fat and less fiber than the diets of those who are not soda drinkers, and tend to be sedentary and have higher rates of smoking. Yet despite adjusting the data to account for these other risk factors, Dr. Dhingra and his colleagues still found a significant association between soda drinking and the risk of developing metabolic syndrome. The researchers acknowledged, however, that “there may be residual confounding caused by lifestyle factors not adjusted for in the present analysis.”

Both regular and diet soda consumption resulted in increased risk of metabolic syndrome and its individual traits, which suggests that factors other than calorie and sugar content contribute to the higher risk. The authors theorized that such factors may include a greater desire for sweet foods stimulated by the sweetness of soft drinks, and the caramel content of these beverages, which may be a source of glycation end products; these complexes of sugars may promote insulin resistance and inflammation.

Similar results also were seen for both caffeinated and uncaffeinated soft drinks.
Although the authors cautioned that, “given the observational nature of the present study, we cannot infer that the observed associations are causal,” the data also “raise the possibility that public health policy measures to limit the rising consumption of soft drinks in the community may be associated with a lower of the burden of metabolic risk factors in adults.”
The Original Article from MD Consult:
http://www.mdconsult.com/das/news/body/75245338-2/mnfp/0/187187/1.html?nid=187187&date=week&pos=&general=true&mine=true