High blood pressure is associated with an increased risk of heart disease and other health problems. Eating a healthy diet rich in fruit and vegetables and oily fish, which are rich in omega 3 fatty acids, and low in salt is associated with a reduced blood pressure. A recently published study (1) has found that drinking fewer sugar-sweetened drinks may lower blood pressure.
The authors of the study note (1) that an increased consumption of sugar-sweetened drinks is associated with an increased risk of obesity, metabolic syndrome (a risk for heart disease and diabetes) and type 2 diabetes. The researchers wanted to study the relationship between sugar-sweetened drinks and blood pressure. The study involved over 800 adults who were participating in an 18 month behavioural intervention trial. Blood pressure and dietary intake were measured at the start of the study and then again at 6 months and 18 months. Specialised models were used to estimate the changes in blood pressure and the relationship between sugar-sweetened drink consumption.
The researchers found (1) that a reduction of one serving per day of sugar-sweetened drink was associated with a 1.8mmHg reduction in systolic blood pressure over 18 months and a 1.1 mm Hg decline in diastolic pressure over 18 months. After additional adjustment for weight change over the same period, a reduction in sugar-sweetened drink intake was still significantly associated with reductions in systolic and diastolic blood pressures. Reduced intake of sugars was also significantly associated with reduced blood pressure. No association was found for diet beverage consumption or caffeine intake and blood pressure. The researchers conclude that “Reduced consumption of SSB [sugar-sweetened beverages] and sugars was significantly associated with reduced BP [blood pressure]. Reducing SSB and sugar consumption may be an important dietary strategy to lower BP”
In a press release the lead study author said “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,” “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.”
Systolic blood pressure, represented by the top number in a blood pressure reading, is the measure of the phase of the heartbeat when the heart contracts and pumps blood into the arteries. Diastolic blood pressure, represented by the bottom number in a blood pressure reading, is the measure of the phase of the heartbeat when the heart muscle relaxes and allows the chambers to fill with blood.
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. According to the study authors (2) the research results potentially have important public health implications, because even small reductions in blood pressure are projected to have substantial health benefits on a population level. The lead study author also said “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,” “However, such evidence from humans is lacking, and we plan to conduct such research among non-hypertensive individuals.” The study only shows an association between sugary drinks and blood pressure and is not conclusive. The researchers say that further controlled trials are needed to establish whether there is a cause and effect relationship between drinking sugar-sweetened drinks and blood pressure changes.
For more information about blood pressure please read this previous post. The British Heart Foundation(1) have a booklet on blood pressure with more detailed information on why blood pressure maintenance is important, the causes of high blood pressure and detailed advice on how to reduce it. The booklet can be downloaded from their website.
(1)Chen L et al. Reducing consumption of sugar-sweetened beverages is associated with reduced blood pressure: a prospective study among United States adults. Circulation. 121(22):2398-406.
(2) Press release. American Heart Association (2010, May 24). Drinking fewer sugar-sweetened beverages may lower blood pressure. ScienceDaily. Retrieved May 25, 2010, from http://www.sciencedaily.com /releases/2010/05/100524161244.htm
Written by Ani Kowal