Sugary drinks and high blood pressure: Study establishes a link

By Dr. Ananya Mandal, MDFeb 28 2011

A new study has found that drinking sugar-sweetened beverages such as soda pop and fruit drinks may increase blood pressure in adults. The results of the study came in Tuesday’s online issue of Hypertension, Journal of the American Heart Association.

The team of researchers notes that higher blood pressure levels are common in people who consumed more glucose and fructose or sweeteners found in high-fructose corn syrup. This elevated blood pressure, in the long-term, is known to increase people’s risk for heart disease and stroke.

The researchers 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.

Results showed that 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). 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. Apart from this, those who consumed more than one sugary drink a day also took in an average 400 empty calorie writes study author Ian Brown of Imperial College London.

Brown said, “Maybe they should consider heart-healthy alternatives including water and unsweetened teas…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.”

The study also showed that those who drank 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.

According to the American Heart Association, people should consume no more than half of the discretionary calorie allowance from added sugars. However this study did not find a 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.

It is not uncommon for a person’s blood pressure to fluctuate by 1 or 2 points within a single day, says John Bisognano, the director of outpatient cardiology and hypertension at the University of Rochester Medical Center in New York, who was not involved in the new research. However, Bisognano adds, blood-pressure increases that might seem negligible in an individual could add up to substantial public health risks when multiplied across entire populations. “From a public health standpoint, if you could lower blood pressure 1 to 2 points in individuals over a community, it's a big deal…It could translate...into fewer strokes and maybe fewer heart attacks,” he explained.

Maureen Storey, the senior VP of science policy at the American Beverage Association, a trade group that represents the manufacturers of soda and other sweetened drinks, said in a statement that the average blood-pressure increases seen in the study are “inconsequential” and within the standard margin of error. Storey said, because the study looked only at a large cross section of people and did not follow individuals over time, it “does not and cannot establish that drinking sugar-sweetened beverages in any way causes hypertension…Finding a very weak association between two things does not establish a cause and effect relationship.”

“Moderation in everything is the bottom line here,” says Bisognano. “There’s a whole list of choices to make that could all make small differences, but an answer to high blood pressure or to cardiovascular risk isn’t going to be one specific thing.”