Creating Waves of Awareness
June 1, 2010 — Cutting back on consumption of beverages that contain added sugar can lower blood pressure, but not only because it may reduce body weight, according to a prospective cohort study that also found no influence on blood pressure (BP) from caffeine or consumption of diet soft drinks . The analysis also suggested that change in overall intake of sugar, whether added to or naturally occurring in food and drink, had an effect on BP.
The study found--in its population of >800 adults participating in a hypertension trial of dietary and behavioral interventions--that drinking one less sugar-sweetened beverage a day was independently associated with declines of about 1.2 mm Hg and 1.1 mm Hg in systolic and diastolic BP, respectively, over 18 months. The relationships remained significant after researchers further controlled for weight change.
"Our study is observational in nature, but our data show that if you reduce sugary drink consumption, you will reduce blood pressure," lead author Dr Liwei Chen (Louisiana State University Health Science Center, New Orleans) told heartwire . The analysis was published online May 24, 2010 in Circulation.
The findings, she said, are consistent with studies using different animal models that show increased sugar intake can induce hypertension, even after controlling for weight. They also complement other observational studies suggesting links between dietary added sugar, including in soft drinks, and hypertension, dyslipidemia, and the metabolic syndrome, as heartwire has reported, but conflict with some of their data suggesting that the link between soft drinks and blood pressure extends to artificially sweetened soft drinks.
In the current study, a third of participants cut their consumption by 1.3 servings per day over 18 months, and systolic BP dropped 1.5 mm Hg more than it did in participants who didn't change their intake of sugar-sweetened beverages, Chen et al write. So intake reduced to at least that degree "should be achievable and could be beneficial."
In the current analysis, which included 810 participants in the randomized, multicenter PREMIER trial with prehypertension or stage 1 hypertension, daily intake of calories, different nutrients, and beverages (derived from the average of two 24-hour dietary recalls) was determined at baseline, six months, and 18 months.
Sugar-sweetened beverages, defined as any drinks with added sucrose or high-fructose corn syrup, included "soft drinks, fruit drinks, lemonade, fruit punch, and other sweetened beverages but excluded diet drinks. Diet beverages were defined as carbonated or noncarbonated drinks that were sweetened with [noncaloric] artificial sweeteners."
After a variety of potential influences on blood pressure, including body-mass index but not body weight, were controlled for, changes in sweetened beverage intake over 18 months were significantly related to changes in systolic and diastolic BP (p<0.001 for both). Adding weight change to the covariates attenuated both the effect of such intake on BP and its significance, although p values remained <0.05, "suggesting that reducing sugar-sweetened beverage intake has a BP-lowering effect that is independent of weight loss."
Relationship Between Blood Pressure Changes and Changes in Intake of One Serving (12 Ounces) of Sugar-Sweetened Beverage After 18 Months in PREMIER
|Change in BP (mm Hg) per 1-serving difference||Model 1a||Model 2b|
|Systolic||1.76 (p<0.001)||0.70 (p=0.01)|
|Diastolic||1.08 (p<0.001)||0.38 (p=0.04)|
a. Adjusted for sex, race, family history of hypertension, PREMIER treatment group, PREMIER site, age, alcohol intake, body-mass index, baseline sugar-sweetened beverage intake, baseline fitness, change in fitness, baseline physical activity, change in physical activity, baseline urinary sodium excretion, change in urinary sodium excretion, and adherence to DASH diet
b. Further adjusted for change in body weight
In the non–weight-adjusted model, systolic and diastolic pressures, respectively, changed 0.30 mm Hg (p<0.001) and 0.24 mm Hg (p<0.001), for every 10-g/day difference in total consumption of sugars from all food and beverages. The BP changes over 18 months were still significant when weight change was added to the model, at 0.17 mm Hg (p=0.003) and 0.15 mm Hg (p<0.001). Intake of caffeine or artificially sweetened drinks showed no significant relationships with blood pressure in either model.
"Our study has important public-health implications," observe Chen et al. "For example, it has been estimated that a 3-mm-Hg reduction in systolic BP should reduce stroke mortality by 8% and coronary heart disease mortality by 5%. Such reductions in systolic BP would be anticipated by reducing sugar-sweetened beverage consumption by an average of two servings per day."
PREMIER was funded by the National, Heart, Lung, and Blood Institute; the current analysis was partially supported by grants from Louisiana State University and Johns Hopkins University (Baltimore, MD). None of the coauthors had disclosures.