The study potentially has important public health implications, because even small reductions in blood pressure are projected to have substantial health benefits on a population level, according to the authors. The researchers also say further study – particularly randomized controlled trials to establish any cause and effect relationship – is warranted.
"Our findings suggest that reducing sugar-sweetened beverages and sugar consumption may be an important dietary strategy to lower blood pressure and further reduce other blood pressure-related diseases," said lead author Liwei Chen, M.D., Ph.D., assistant professor at Louisiana State University Health Science Center School of Public Health in New Orleans, La..
"It has been estimated that a 3-millimeters of mercury (mm Hg) reduction in systolic blood pressure should reduce stroke mortality by 8 percent and coronary heart disease mortality by 5 percent. Such reductions in systolic blood pressure would be anticipated by reducing sugar-sweetened beverages consumption by an average of 2 servings per day."
Researchers used data on 810 adults, ages 25 to 79, with prehypertension (between 120/80 and 139/89 mm Hg) and stage I hypertension (between 140/90 and 159/99 mm Hg ) who participated in the PREMIER study, an 18-month behavioral intervention study with a focus on weight loss, exercise, and a healthy diet as a means to prevent and control high blood pressure.
At the start of the study, the participants drank an average 10.5 fluid ounces of SSB/day, equivalent to just under one serving. At the study's conclusion, average consumption had fallen by half a serving/day and both systolic blood pressure (the pressure when the heart beats), and diastolic blood pressure, (the pressure between beats), had declined significantly.
After controlling for known risk factors of blood pressure, the analysis found that a reduction of one serving/day of SSB was associated with a 1.8 millimeters of mercury (mm Hg) drop in systolic pressure and a 1.1 mm Hg decline in diastolic pressure over 18 months. Researchers noted that this association was partially because of weight loss, but even after controlling for weight loss, the change in blood pressure was statistically significant.
Chen noted that American adults consume an average of 2.3 servings (28 ounces) of sugar-sweetened beverages per day. In this study, sugar-sweetened beverages were defined as drinks sweetened with sugar or high-fructose corn syrup including regular soft drinks, fruit drinks, lemonade and fruit punch. Diet drinks were excluded.
"Although this study was conducted among mostly overweight adults and many with hypertension, we believe that others will benefit by reducing the consumption of sugar-sweetened beverages," she said. "However, such evidence from humans is lacking, and we plan to conduct such research among non-hypertensive individuals."