Does sugar have a direct effect on the risk of diabetes?
By Sophie Ramsey
Sugar may play a more direct role in increasing the risk of diabetes than previously thought, with research linking the availability of sugar in a country's food supply to the rise in diabetes.
The number of people with diabetes has increased dramatically in the past 30 years, with the disease now affecting nearly 1 in every 10 people worldwide.
One reason for this increase is the rising number of people who are very overweight (obese), as obesity is the main risk factor for the disease. But this doesn’t tell the whole story. In some countries, for example, the number of people with diabetes has increased while rates of obesity have actually gone down.
In the new study, researchers explored whether higher levels of sugar in the food readily available to people living in the country (the food supply) might be partially responsible. People worldwide have begun eating more sugary foods and drinks in recent decades. It’s well known that eating lots of sugary foods can lead to weight gain, as these foods are high in calories. But some studies have suggested that eating more sugar may also increase the risk of diabetes separate from its effect on people’s weight.
To test this, researchers looked at rates of diabetes in 175 countries over the last 10 years. They compared this with the amount of sugar in each country’s food supply, measured both as the total amount of sugar available and as the proportion of total calorie value of the food available per person which consisted of sugar. To see whether the diabetes and sugar supply were directly linked, they factored in several things that can affect the risk of diabetes, including obesity, levels of physical activity, and consumption of other foods.
The researchers found that the rate of diabetes increased by 1 percent for every additional 150 calories of sugar available per person per day in the food supply (150 calories is about the amount in a can of soft drink). In contrast, an additional 150 calories from any source increased the rate of diabetes by only one-tenth of a percent (0.1 percent).
The researchers also found that diabetes rates dropped over time when the availability of sugar dropped.
The researchers took into account many things that might have affected the rate of diabetes, most notably how many people were obese. This strengthens their finding of a direct link between higher levels of sugar and diabetes. However, the researchers can’t rule out the chance that they missed some other factor that played a role.
The figures all looked at how much sugar was available to buy, because there is no reliable international data about how much sugar people actually consume. So we can't be sure that higher availability of sugar in a country actually means that people in the country are consuming more sugar.
Also, compiling data from so many countries leaves considerable room for error. For example, countries may have different systems for recording how many people have diabetes, and some of this data may be more accurate than others.
These are interesting findings, but we need more research to confirm them. It’s also hard to know what they mean for individuals, since the researchers looked at the link between sugar and diabetes on a very large scale.
Still, we do know that eating a lot of sugar can play a role in diabetes by leading to weight gain. These findings suggest cutting back on sugar may lower the risk of diabetes in more ways than one.
Basu S, Yoffe P, Hills N, et al. The relationship of sugar to population-level diabetes prevalence: an econometric analysis of repeated cross-sectional data. PLoS ONE. Published online 27 February 2013.