Sugary Drinks Could Drive Up Blood Pressure

Feb. 28, 2011— -- People with high blood pressure may have to start watching their sugar as well as their salt, new research suggests.

In a new study, those who consumed the most sugar-sweetened beverages like soda and fruit juices had higher blood pressure readings, Dr. Ian J. Brown of Imperial College London, and colleagues reported in the journal Hypertension.

The data "suggest that individuals who consume more soda and other sugar-sweetened soft drinks may have higher blood pressure levels than those who consume less, and the problem may be exacerbated by higher salt intake," Brown said in an email to MedPage Today and ABC News.

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Previous research has shown that fructose -- one of the main components in sweetened beverages -- has been linked to high blood pressure. To further investigate this link, Brown and colleagues assessed data from the INTERMAP study, which included 4,680 patients from Japan, China, the U.K., and the U.S.

They focused their study on the 2,696 patients from the U.S. and U.K., gathering information from urine collections and blood pressure readings. Patients also reported on their regular diet over a period of four days.

The researchers found that people who drank the most sugary beverages consistently had higher blood pressure.

In fact, the researchers found that every extra soda or fruit drink per day increased a patient's mean systolic blood pressure -- that's the top number -- by about 1.6 millimeters of mercury, the unit in which blood pressure is measured.

There were similar associations for diastolic blood pressure, the researchers said.

Also, the link between sugary drink intake and blood pressure was even stronger among people who were found to have higher salt intake -- an important cause of high blood pressure in itself, Brown said.

And contrary to recent results that found diet soda to be culprit in an increased risk of stroke and heart attack, in this study the beverage had no link with blood pressure.

Could Empty Calories Displace Healthy Ones?

Yet there were direct associations between blood pressure and both fructose and glucose, the researchers noted.

Specifically, increases in fructose consumption were tied to increases in systolic blood pressure, even after controlling for weight, height, and other factors.

The association may work through the uric acid pathway -- fructose consumption leads to increased serum uric acid, which may influence blood pressure by reducing levels of nitric oxide, a "potent vasodilator," the researchers said.

They also found that people who had more sugar-sweetened beverages each day tended to have less healthy diets overall than those who didn't partake.

"It appears that empty calories from these drinks displace calories from other foods that have beneficial nutrients such as minerals and vitamins," Brown said.

The researchers said the findings are similar to those from other large cohort analyses, including the National Health and Nutrition Examination Survey (NHANES) and the Nurses Health Study, but they cautioned that it had a number of limitations including self-reported data and its lack of ability to determine causality.