Increased Dietary Sugar Drives Global Rise in Diabetes

Marlene Busko

February 27, 2013

The increasing availability of sugary food and drink — independent of excess calories, excess weight, or a sedentary lifestyle — explains part of the rise in cases of type 2 diabetes worldwide, suggests a new study published online February 27 in PLoS ONE.

The authors, led by Sanjay Basu, MD, from the Department of Medicine, Stanford University, Palo Alto, California, examined a decade of cross-sectional data from 175 countries. They note that most of the worldwide rise in diabetes is thought to be type 2, linked to the metabolic syndrome, a cluster of factors including dyslipidemia, hypertension, and insulin resistance.

They report that for each added 150 calories of sugar available per person per day — equivalent to one 12-oz can of soda — the prevalence of type 2 diabetes increased by about 1% (P < .001), after they controlled for factors such as food types, total calories, overweight and obesity rates, aging, urbanization, income, and time.

Sugar Alone Explains 25% of Increase in Diabetes

It is important to identify risk factors for type 2 diabetes, since nearly 1 in 10 adults worldwide has the condition, and the rates are increasing. "If obesity is a primary driver of diabetes, then measures to reduce calorie consumption and increase physical activity should be prioritized," Basu and colleagues write. "However, if added sugar consumption is a primary driver, then public health policies to reduce sugar consumption warrant investigation as diabetes-prevention proposals — especially for developing countries, where diabetes rates are rising dramatically, irrespective of obesity."

They give examples of several countries with high diabetes prevalence rates but low obesity rates, including the Philippines, Romania, France, Bangladesh, and Georgia.

To determine whether sugar in a country's food supply predicts subsequent spikes in diabetes rates, the researchers used a regression model to correlate the prevalence of diabetes from 2000 to 2010 in adults aged 20 to 79 living in 175 countries with the availability of sugar in a country's food supply.

They found that during this decade, the prevalence of worldwide diabetes rose by about 27%, with one quarter of this increase explained by an increase in the availability of sugary foods. No other food category had any significant effect on diabetes prevalence.

Rates of diabetes increased in a dose-dependent manner the longer a population was exposed to excess sugar and the greater the amount of available sugar in the food supply. Each extra year of living where sugary foods were widely available was linked with an increase in diabetes prevalence of 0.053% (P < .05).

The reverse was also true. Following periods of scarce sugar (typically due to changes in trade agreements), the prevalence of diabetes decreased by 0.074% (P < .05), after correction for confounding variables.

Although their findings were robust, the study was not designed to establish a causal link between sugar intake and subsequent diabetes diagnosis, the authors admit. Prospective longitudinal cohort studies in international settings, which are now under way, should shed more light on this link.

The authors have disclosed no relevant financial relationships.

PLoS ONE. Published online February 27, 2013. Full article