Drinking sugar-sweetened sodas and fruit drinks appears to be associated with a greater risk for high blood pressure among adults, a new study suggests.
The research team says that both the glucose and fructose found in such drinks are implicated in the linkage.
The findings "suggest that individuals who consume more soda and other sugar-sweetened soft drinks may have higher blood pressure levels than those who consume less," said study author Ian J. Brown, a research associate in the department of epidemiology and biostatistics with the School of Public Health at Imperial College London. "And the problem may be exacerbated by higher salt intake, an important cause of high blood pressure in itself."
"We also found that men and women who consumed one or more sugar-sweetened beverages a day tended to be heavier, consume more calories, and have less healthy diets than those who consumed none," Brown added.
Brown and his colleagues report their findings in the Feb. 28 issue of Hypertension.
To explore the potential for a link between sugar-sweetened drinks and high blood pressure, the authors analyzed the consumption patterns of nearly 2,700 American and British men and women between the ages of 40 and 59.
Diet diaries covering food, sugars, sugar-sweetened drinks and diet drinks were completed over a four-day period for each study participants. Detailed questionnaires focusing on a range of lifestyle, medical and social factors were also completed. Urine samples and blood pressure readings were taken throughout the study period.
The team observed that those who drank more than one sugar-sweetened beverage a day had the highest sugar consumption (whether glucose, fructose or sucrose) and the highest calorie consumption, at an average of about 400 extra calories a day.
Those drinking more than one sugar-sweetened beverage a day also registered higher average body-mass indexes (BMI) compared with those who drank none, suggesting that those who consumed such drinks also consumed less healthy foods.
And as for blood pressure, for every serving (355-milliliters) of sugar-sweetened beverage consumed per day, there was a significant bump in both systolic and diastolic readings (+1.6 and +0.8, respectively), even after adjusting for BMI.
What's more, the association between drinking a sugar-sweetened drink and having higher blood pressure appeared to be even stronger among those who also had higher dietary sodium intake.
Drinking a diet beverage, however, was actually linked to a slight drop in blood pressure (although this finding did not meet "statistical significance"), while caffeine consumption appeared to have no impact on blood pressure.
"Sugar-sweetened beverage consumption has been linked to high blood pressure, obesity, type 2 diabetes and heart disease risk," said Brown. "So we suggest that if individuals want to drink these beverages, they do so only in moderation."
For those who wish to follow American Heart Association guidelines, Brown noted that a moderate amount would translate to roughly three 12-ounce cans per week for individuals who routinely consume about 2,000 calories a day.
"Better still," he advised, "choose heart-healthy alternatives such as water or unsweetened teas."
Dr. Sahil Parikh, a cardiologist at the Harrington-McLaughlin Heart and Vascular Institute at University Hospitals Case Medical Center in Cleveland, said the findings "fall along the lines of the kind of common sense your mother would offer."
"We have long known that sugary drinks are bad for you, because they are a lot of empty calories," he said. "But what makes this study important is that it suggests that beyond just making you fatter these drinks also prompt hypertension, which can increase the incidence of heart attack and stroke."
"Now we will need to have future studies to understand how this works," Parikh added, "because even though this data shows a pretty clear association between sugary drinks and high blood pressure, it doesn't definitively suggest a mechanistic link."
"Having said that, as a cardiologist my concern is how do we minimize our risk factors for cardiovascular events," he continued. "And we know the way to do that is to avoid tobacco use and avoid obesity. So to the extent that one can control calorie intake, there really isn't a downside to eliminating sugar drinks. They're empty calories of limited value. So why not do that?"
In response to the latest findings, the American Beverage Association issued a statement Monday saying that while high blood pressure is "a serious health concern," the current study "does not and cannot establish that drinking sugar-sweetened beverages in any way causes hypertension."