Health

Sugary drinks boost blood pressure risk to heart

Drinking sugar-sweetened beverages such as pop and fruit drinks may increase blood pressure in adults, researchers have found.
People who consumed more than one sugary drink a day took in on average 400 empty calories. ((Alejandro Rustom/Reuters))

Drinking sugar-sweetened beverages such as pop and fruit drinks may increase blood pressure in adults, researchers have found.

Tuesday's online issue of Hypertension: Journal of the American Heart Association found higher blood pressure levels in people who consumed more glucose and fructose —  sweeteners found in high-fructose corn syrup that's commonly used by the beverage industry.

In the long-term, elevated blood pressure is known to increase people's risk for heart disease and stroke.

The study looked at the diet of 2,696 Americans and Britons aged 40 to 59 who reported in in-depth interviews what they ate and drank. Researchers tested their urine tested and blood pressure over four visits. Participants also answered a detailed questionnaire about their lifestyle.

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For every extra sugar-sweetened beverage drunk per day participants on average had higher systolic blood pressure by 1.6 millimeters of mercury (mm Hg), researchers found. The systolic blood pressure in a reading of 120/80 for example is the top 120 number, which measures maximum pressure when the heart beats.

What's more, those who consumed more than one sugary drink a day also took in an average 400 empty calories, calories with no nutritional benefit that can lead to extra weight and complications, said study author Ian Brown of Imperial College London.

"Maybe they should consider heart-healthy alternatives including water and unsweetened teas," Brown suggested. "By doing so they're not just making improvements to their blood pressure, which is suggested by the research that we've done, but also this may have other benefits for their heart health, including improvements in weight and reduced risk of diabetes."

Sugary drinkers' poorer quality diet

Those drinking sweetened beverages also appeared to have less healthy diets overall, consuming fewer minerals and vitamins such as magnesium, potassium and calcium that may have beneficial effects on blood pressure and cardiovascular health, Brown noted.

The American Heart Association recommends people consume no more than half of the discretionary calorie allowance from added sugars.

In Canada, the beverage industry is promoting its move to put calorie information more prominently on the front of cans and bottles.

The Canadian and American Beverage Associations said the study does not, and cannot, establish that drinking sugar-sweetened beverages in any way causes hypertension.

"The level of blood pressure changes noted by the authors are inconsequential and well within standard measurement error. Regrettably, this study does nothing more than distract the public from widely accepted and clinically proven approaches to lowering the risks for hypertension and heart disease," the beverage groups said in a statement in response to the study.

In the latest study, Brown's team found no consistent link between diet soda and blood pressure levels. But those who drank diet pop tended to have higher body mass index and lower levels of physical activity than those who did not.

The researchers acknowledged limitations of their study, including how people reported their own consumption and that it did not follow them over an extended period of time.

The study was funded by the U.S. National Heart, Lung, and Blood Institute, the Chicago Health Research Foundation and national agencies in China, Japan and the UK.

With files from CBC's Derek Stoffel