THE DETAILS: As reported in the journal Circulation, researchers uncovered the link between sugar and blood pressure when they analyzed 810 pre-hypertensive and hypertensive adults involved in the PREMIER study. The researchers measured blood pressure and dietary intake at baseline, then again at six and 18 months. Because this was a behavioral intervention study, the researchers were able to alter the participants’ diets in order to measure the effect of dietary change. After accounting for confounding factors like weight loss (which can have a positive effect on blood pressure), the researchers found that decreasing intake of sugar-sweetened beverages (SSBs) by one 12-ounce serving a day significantly lowered blood pressure among the study subjects. (Note: Average SSB intake among the study participants was about one serving at baseline; however, many averaged three servings or more.)
WHAT IT MEANS: Though the average blood pressure reduction among study subjects seems slight—1.8 mm Hg for systolic pressure and 1.1 mm Hg for diastolic—it is significant in terms of possible health benefits, believe the researchers. For example, from other studies it has been estimated that just a 3 mm Hg reduction in systolic blood pressure may reduce stroke mortality risk by 8 percent and heart disease mortality risk by 5 percent.
So why would sugary drinks raise blood pressure in the first place? The authors put forth two possible mechanisms for the sugar/blood pressure connection. “First, sugars may cause the blood vessels to constrict, which would raise blood pressure,” says study coauthor Lawrence Appel, MD, MPH, of the Johns Hopkins Medical Institutions in Baltimore. “And second, the increased sugar intake may lead to greater sodium retention, which, again, would tend to increase blood pressure.”
Today in the U.S., the average daily intake of SSBs is 2.3 servings (27.6 ounces) for adults, which translates to lots of calories and not much nutrition. To help you lower your intake, American Dietetic Association spokesperson and Boston University clinical associate professor Joan Salge Blake, MS, RD, LDN, recommends the following:
• Change your mindset. “Not long ago in this country, soft drinks and other SSBs were seen as something special,” says Blake. “Maybe you or your kids drank one once a week when you went out for a meal, or to get fast food. Now everyone has them in the fridge. So it’s important to try and get back to that earlier mindset. You should be drinking SSBs as an exception, not as a rule.” Just keeping them out of the house is a good first step.
• Reduce intake gradually. “If you average three SSBs a day—and this is pretty close to the average intake for Americans—go down to two, and replace that one with a diet drink or water,” she says. “Sparkling water is another good option, as it’ll give you the carbonation, which is what a lot of people get hooked on. Once you’re used to two sweet drinks a day, go down to one by replacing that second one with a nonsweet alternative. And so on.”
• Establish good habits early. “Even if you’re young and don’t have a weight or blood pressure problem, it’s a lot easier to establish good fluid-intake habits now than after years and years of habitual SSB drinking,” believes Blake. “Again, think of them as drinks you get on special occasions, not as an every day thing.”