From Medscape Medical News
Emma Hitt, PhD
August 16, 2010 — Consumption of sugar-sweetened drinks, at least 1 drink per day, is significantly associated with the development of metabolic syndrome and type 2 diabetes mellitus vs consumption of less than 1 sugar-sweetened drink per month, and these effects do not appear to result entirely from an association with weight gain, new research findings suggest.
Vasanti S. Malik, ScD, with the Harvard School of Public Health, Boston, Massachusetts, and colleagues reported their findings in Diabetes Care, published online August 6, 2010.
Although consumption of sugar-sweetened drinks has been associated with weight gain, their role in the development of related chronic metabolic diseases, such as metabolic syndrome and type 2 diabetes, has not been quantitatively reviewed, Dr. Malik and colleagues note.
According to the researchers, the high content of rapidly absorbable carbohydrates in sugar-sweetened drinks and the large volumes consumed may "increase risk of metabolic syndrome and type 2 diabetes mellitus not only through obesity but also by increasing dietary glycemic load, leading to insulin resistance, beta-cell dysfunction, and inflammation."
To evaluate this association, the researchers conducted a MEDLINE database search, selecting 11 prospective cohort studies assessing sugar-sweetened drink intake and the risk for type 2 diabetes (8 studies) or the risk for metabolic syndrome (3 studies).
Sugar-sweetened beverages were defined as soft drinks, fruit drinks, sports drinks, energy and vitamin waters, sweetened iced tea, punch, cordial, squashes, and lemonade. Not included were 100% fruit juices without added sweeteners.
The 8 studies assessing type 2 diabetes included 310,819 participants and 15,043 case patients with diabetes. The highest quantile of consumption was most often 1 to 2 servings per day vs the lowest quantile (0 or < 1 serving per month).
The risk for type 2 diabetes in the highest quantile was increased by 26% (relative risk [RR], 1.26; 95% confidence interval [CI], 1.12 - 1.41). Likewise, among studies evaluating metabolic syndrome, including 19,431 participants and 5803 case patients, the risk was increased by 20% (RR, 1.20; 95% CI, 1.02 - 1.42).
The authors point out in their discussion that fructose, present in large quantities in sugar-sweetened drinks, may promote accumulation of visceral adiposity and ectopic fat deposition, both of which create a dysmetabolic state, increasing the risk for type 2 diabetes and cardiovascular disease.
"This meta-analysis has demonstrated that higher consumption of [sugar-sweetened drinks] is significantly associated with development of metabolic syndrome, and type 2 diabetes mellitus," the study authors conclude.
The study "provides further support to limit consumption of these beverages in place of healthy alternatives such as water, to reduce obesity-related chronic disease risk," they add.
The study was not commercially supported. The study authors have disclosed no relevant financial relationships.
Diabetes Care. Published online August 6, 2010.