People who regularly consume sugary drinks have a significantly greater risk of developing diabetes types 2 or metabolic syndrome, researchers from the Harvard School of Public Health report in an article published in the medical journal Diabetes Care. The authors add that the association is clear and consistent. Metabolic syndrome is a collection of medical disorders which raise the risk of developing diabetes and cardiovascular disease. According to the American Heart Association, the definition includes an elevated waist circumference, high triglyceride blood levels, low HDL (good) cholesterol, elevated blood pressure, and elevated fasting glucose blood levels.

Lead author, Vasanti Malik said:

Many previous studies have examined the relationship between sugar-sweetened beverages and risk of diabetes, and most have found positive associations but our study, which is a pooled analysis of the available studies, provides an overall picture of the magnitude of risk and the consistency of the evidence.

Americans and most people around the world have been consuming sweetened drinks, especially sodas (UK: fizzy drinks) increasingly over the last few decades. Several studies have shown a link between the consumption of sugary drinks and a considerably higher risk of obesity or gaining weight, the authors write as background information.

This study differs from previous ones in that it is “the first meta-analysis to quantitatively review the evidence linking sugar-sweetened beverages with type 2 diabetes and metabolic syndrome.” A “meta-analysis” is a (quantitative) method of combining the findings of several independent studies and synthesizing summaries and conclusions.

Vasanti Malik, Frank Hu and team collected and analyzed data from 11 independent studies that sought to find a link between sugary drinks and metabolic syndrome and/or diabetes type 2. There were more than 300,000 participants, as well as 19,431 metabolic syndrome and 15,043 diabetes type 2 cases.

The combined findings demonstrated a 26% higher risk of developing diabetes type 2 and a 20% higher risk of developing metabolic syndrome among people who consumed 1 to 2 sugary drinks per day, compared to individuals whose monthly maximum was just one such drink. Even daily consumption of just one 12-ounce sugary drink raised diabetes type 2 risk by approximately 15%.

Hu said:

The association that we observed between soda consumption and risk of diabetes is likely a cause-and-effect relationship because other studies have documented that sugary beverages cause weight gain, and weight gain is closely linked to the development of type 2 diabetes.

The authors stress that consuming sugary drinks is just one of several factors that encourage the development of diabetes and metabolic syndrome. However, sugary drinks represent on risk factor we can easily modify – a modifiable risk factor.
Malik said:

People should limit how much sugar-sweetened beverages they drink and replace them with healthy alternatives, such as water, to reduce risk of diabetes as well as obesity, gout, tooth decay, and cardiovascular disease.

“Sugar-Sweetened Beverages and Risk of Metabolic Syndrome and Type 2 Diabetes”
Vasanti S. Malik, Barry M. Popkin, George A. Bray, Jean-Pierre Despres, Walter C. Willett, Frank B. Hu

Written by Christian Nordqvist