Feb. 28, 2011 -- New research suggests that drinking sodas and other sugar-sweetened beverages every day may raise blood pressure, but a beverage industry trade group calls the study significantly flawed.
Sugar-sweetened beverages are the No. 1 source of added sugars in the American diet, and the research is among the first to link them to higher blood pressure.
The study found that the more sugary sodas and other sugar-sweetened beverages people drank, the higher their blood pressures tended to be.
Every extra sugar-sweetened beverage drank per day was associated with a 1.6 point rise in systolic blood pressure (the upper number) and a 1 point rise in diastolic pressure (the lower number).
The highest blood pressures were seen in study participants who drank the most sugar-sweetened beverages and also had the most added salt in their diets, study co-author Ian J. Brown, PhD, tells WebMD.
“We know that salt is a risk factor for high blood pressure,” Brown says. “But our findings suggest that sugar and salt together may be worse than salt alone.”
Sugary Sodas and Blood Pressure
Brown says this finding needs to be confirmed, adding that the research does not prove sugary sodas and other sources of added sugar in the diet have a direct impact on blood pressure.
That’s because the study was observational, meaning the participants were asked to recall what they drank instead of directly comparing participants given a specific amount of sugar-sweetened beverages to participants who were not given sugar-sweetened beverages.
People who reported drinking the most non-diet sodas or other sugar-sweetened drinks also had the highest overall intake of calories and salt and were the most likely to be obese.
Maureen Storey, PhD, of the soda industry group American Beverage Association, agrees the study does not prove a link between sugar-sweetened beverages and elevated blood pressure.
“Finding a very weak association between two things does not establish a cause and effect,” she says in a news release. “This study has significant flaws. In fact, the ... blood pressure changes noted by the authors are inconsequential and well within standard measurement error.”
In an interview with WebMD, Storey said there is little evidence that sugar-sweetened beverages are unique contributors to cardiovascular disease.
“A calorie is a calorie, and what the data clearly show is that we are eating too much and taking in too many calories, period,” she says, adding that Americans are consuming fewer sugar-sweetened beverages than they were a decade ago.
AHA: Limit Added Sugars
The research included close to 2,700 middle-aged people in the U.S. and U.K. who were enrolled in a larger health study.
The participants reported what they ate and drank for four days, during which time their blood pressures were taken eight times. They also completed a detailed questionnaire examining lifestyle, medical, and social issues.
People who reported drinking more than one serving per day of sugar-sweetened drinks took in an average of about 400 calories more each day than people who drank no sugar-sweetened beverages.
The American Heart Association recommends that women limit added sugars in their diets to no more than 100 calories a day and men limit added sugars to 150 calories.
A typical 12-ounce can of sugar-sweetened soda has about 140 calories, and just about all the calories come from added sweeteners.
“[Non-diet] sodas are basically sugar water with or without caffeine,” AHA spokesperson Rachel K. Johnson, PhD, tells WebMD. “They are the No. 1 source of added sugars in a population where the majority of people are overweight.”
She concedes that a direct link between soda consumption and obesity and cardiovascular disease would be difficult to prove, but adds that she does not think the science linking sugar-sweetened beverages to these health issues has been overplayed.
Johnson is a professor of nutrition at the University of Vermont.
“I don’t think anyone would say that limiting sugar-sweetened drinks is the only solution,” she says. “But to me, it is an important step in the right direction.”