NEW ORLEANS, March 21, 2018 -- Adults over the age of 45 who consume large amounts of sugary beverages including soft drinks, fruit drinks and fruit juices may have a higher risk of dying from heart disease or other causes, compared to those who drink fewer sugary drinks, according to preliminary research presented at the American Heart Association's Epidemiology and Prevention | Lifestyle and Cardiometabolic Health Scientific Sessions 2018, a premier global exchange of the latest advances in population based cardiovascular science for researchers and clinicians.
The researchers found a graded association between consuming more sugary beverages and an increased risk of death from heart disease or any cause. Study participants in the top 25 percent of consumers, those who tended to drink 24 ounces or more of sugary beverages each day, had twice the risk of death from coronary heart disease compared to those in the lowest 25 percent of people who drank less than 1 ounce. In addition, there was an increased risk of death from all causes, including other cardiovascular conditions. The study, however, found no link between the consumption of sugary foods and increased risk of death, a distinction the researchers said may be related to how sugary drinks and foods are processed by the body.
Several studies have shown an association between added sugar and obesity and various chronic diseases. However, few have been able to look at the association between increased sugar consumption and death. It is important to note that this study does not prove cause and effect, rather it identifies a trend.
"There were two parts of this question we wanted to understand," said Jean Welsh, Ph.D., M.P.H., study author, assistant professor at Emory University and a research director with Children's Healthcare of Atlanta. "Do added sugars increase risk of death from heart disease or other causes, and, if so, is there a difference in risk between sugar-sweetened beverages and sugary foods? We believe this study adds strong data to what already exists highlighting the importance of minimizing sugary beverages in our diet."
This study used data from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study, a U.S.-based longitudinal study of 30,183 black and white adults over age 45. The final study population was 17,930 after excluding those with a self-reported history of heart disease, as well as stroke and Type 2 diabetes. This type of study is designed to find an association or trend, not to prove cause and effect.
The researchers estimated sugary food and beverage consumption using a food frequency questionnaire. Sugar-sweetened beverages included those pre-sweetened, such as sodas and fruit drinks. Sugar-sweetened foods included desserts, candy and sweetened breakfast foods as well as foods to which calorie-containing sweeteners such as sugars or syrups had been added.
The participants were followed for an average of about 6 years, and researchers used death records to look at the cause of death, focusing on deaths from heart disease, such as heart attack, heart failure and deaths from all other causes.
The researchers observed this effect when they statistically made the participants equal with respect to income, race, education, smoking history and physical activity. When they controlled for known heart disease risk factors such as total calorie consumption, high blood pressure, abnormalities in blood lipids or body weight, the effect remained. Researchers did not see any increased risk with consumption of sugary foods.
The quantity and frequency of consumption of sugary beverages, coupled with the fact that they contain few, if any other nutrients, results in a flood of sugars that need to be metabolized, Welsh said. When people consume sugars in foods there are often other nutrients such as fats or proteins which slow down metabolism and may explain the different effect seen between the two.
The study's finding should encourage healthcare providers to ask patients about sugary beverage consumption during well visits to open the door to a conversation about a dietary change that could be made to reduce risk, Welsh said.
"We know that if healthcare providers don't ask patients about lifestyle practices linked to obesity and chronic disease, patients tend to think they're not important," Welsh said. "Simply asking patients about their sugary beverage consumption is valuable."