Children and adults are consuming more sugar-sweetened beverages than ever, while the portion sizes of many sugary drinks have grown. According to the National Cancer Institute, 50% of people in the United States consume sodas, sports drinks and fruit drinks on any given day, with 1 in 4 getting at least 200 calories from sugar-sweetened beverages.
The increased consumption, according to some researchers, can lead to major health risks, including type 2 diabetes, cardiovascular disease and obesity.
“In terms of the epidemiological studies, there’s more and more evidence building to suggest there’s a link between consuming sugar-sweetened beverages and the development of type 2 diabetes, of increased CV risk, and problems like tooth decay, as well as weight gain,” Christina A. Roberto, PhD, an adjunct assistant professor of social and behavioral sciences at the Harvard T.H. Chan School of Public Health, told Endocrine Today. “So there seems to be a link between these drinks and negative health outcomes.”
In a January 2013 study, Guy Fagherazzi, PhD, of the Integrated Research Cancer Institute in Villejuif, France, and colleagues analyzed a French cohort of 66,118 women for 14 years and found that, compared with nonconsumers, women in the highest quartiles for sugar-sweetened beverage consumption (> 359 mL per week) were at increased risk for type 2 diabetes (HR = 1.34; 95% CI, 1.05-1.71). The association was partly mediated by BMI, but a significant independent effect remained, according to researchers.
Speaking at the 51st European Association for the Study of Diabetes Annual Meeting in September, Louise Brunkwall, MPH, a PhD student at Lund University in Malmö, Sweden, said Fagherazzi’s study was one of several pointing to an association between sugary drinks and type 2 diabetes and other metabolic health risks.
Although some studies suggest that sugar-sweetened beverages take most of the blame, the real answer, Brunkwall said, may not be so clear.
“We know we do not consume single products, or single foods or single beverages,” Brunkwall said during her presentation. “We consume food and beverages in patterns and in combinations.”
The real risks of soda
In an analysis of five commonly consumed beverage types and their link to diet quality, Brunkwall and colleagues found that, among 25,112 healthy adults aged 45 to 74 years, adults consuming large amounts of sugary beverages were more likely to eat foods perceived as unhealthy, whereas adults consuming more juice and tea were more likely to choose foods perceived as healthy.
“Different beverages associate differently with the overall diet,” Brunkwall said. “These findings might show that the overall diet could confound beverage–disease association studies because the diet is associated both with the disease and the beverage of interest. This makes it hard to know the true effect of a beverage ... however, it is still interesting to know how beverages are consumed in the general population.”
Consumers of sugary drinks might be justifiably confused about the effect of these beverages on their health.
“Randomized controlled trials do show that if you drink sugar-sweetened beverages, your weight will go up,” Diana Thomas, PhD, professor at Montclair State University and director of the Center for Quantitative Obesity Research, told Endocrine Today. “The evidence the other way around — if I reduce the sugar-sweetened beverages, will weight go down — for adults, that data is actually inconclusive. There’s observational evidence that people who are overweight report drinking more sugar-sweetened beverages than people of [average] weight.”
A ‘cluster effect’
For many adults who consume sugary drinks, other bad habits follow, Thomas said.
“People who report drinking sugar-sweetened beverages are also more likely to report eating fried foods, and smoking too,” Thomas said. “They call this a core health cluster effect. [Poor health habits] all come together and it’s tough to isolate and say, ‘You’re the one culprit that contributed to my obesity.’”
In a position statement released by The Obesity Society in April 2014, researchers recommended reduced consumption of sugary drinks as part of a larger strategy to reduce daily caloric intake. The statement echoed similar recommendations from the AMA, American Academy of Pediatrics, CDC and Institute of Medicine, all of which call for either reducing or eliminating the consumption of sugary drinks.
“But, there is no guarantee from the evidence that, just because you reduce your sugar-sweetened beverages, you’re suddenly going to be a swimsuit model,” Thomas said. “We recommend that overweight and obese individuals decrease consumption of sugar-sweetened beverages as part of a more general effort to reduce calories.”
Soda vs. sports drinks
Sugar-sweetened beverages break down into several different types and, depending on the study, may be classified differently. The Obesity Society defines a sugar-sweetened beverage as any drink made up of primarily water and added sugar, which would include sodas, fruit drinks, energy drinks and sports drinks. Juice, coffee, tea and artificially sweetened beverages (including diet sodas) are classified differently. It remains unclear if different types of sugar-sweetened beverages — for example, soda vs. an energy drink — have different effects in terms of weight gain or metabolic health.
Thomas said the research can lead to confusion among consumers and even among other researchers.
“The kind of sugar-sweetened beverages that are used in the studies … there’s no consensus, they’re really all over the place for what they use in their studies,” Thomas said.
Some makers of sugar-sweetened beverages have made changes in recent years to help consumers make healthier choices, including smaller portion sizes among their offerings and easier-to-read nutrition labels, while also funding new research.
Coca-Cola, one of the largest producers of sugary drinks, received negative publicity after a report published in August detailing the company’s financial support of the Global Energy Balance Network, a nonprofit organization promoting the idea that physical activity can offset a poor diet, including a diet with sugar-sweetened beverages.
“This is a big debate — why are you singling out sugary drinks when consumers are eating all these other [unhealthy] foods too?” Roberto said. “There are a few reasons to think of sugary drinks as a special case, and a reason to focus on them from a policy perspective.”
Sugary drinks, Roberto said, offer only empty calories, with no nutritional value. In addition, evidence suggests that some people may not feel as sated when consuming the same number of calories in a sugary drink when compared with food, leading to an increased obesity risk with excessive consumption.
Clinicians, she said, need to work with patients to reduce consumption.
“It’s actually a nice, simple message to say, leave everything else the same for now, and just try this one strategy and try to drink fewer of these, and then we’ll check back in and we’ll see how that’s going,” Roberto said. “The message is simple, it’s the behavior change that’s hard.” – by Regina Schaffer
Brunkwall S, et al. Abstract 190. Presented at: 51st EASD Annual Meeting; Sept. 14-18, 2015; Stockholm.
Fagherazzi G, et al. Am J Clin Nutr. 2013;doi:10.3945/ajcn.112.050997.
For more information:
Louise Brunkwall, MPH, can be reached at firstname.lastname@example.org.
Christina A. Roberto, PhD, can be reached at email@example.com.
Diana Thomas, PhD, can be reached at firstname.lastname@example.org.
Disclosures: Brunkwall, Roberto and Thomas report no relevant financial disclosures.