Study links sugary drinks with higher blood pressure

Last year I wrote about a study which found that drinking sugary drinks was associated to increased blood pressure (a risk for heart disease and other health problems).  A newly published study (1) has backed up these findings showing that adults who drink sugar-sweetened drinks tend to have higher blood pressure levels.

The study (1) involved UK and US participants of the International Study of Macro/Micronutrients and Blood Pressure (known as INTERMAP).  Over 2500 individuals aged between 40 and 59 were included in the study and various data samples were collected including dietary data, urine and blood pressure readings.  Sugary drinks included those containing fructose, glucose and sucrose.

The researchers found that for every extra sugar-sweetened beverage drunk per day (1 serving = 355mL) participants on average had significantly higher systolic blood pressure by 1.6 millimeters of mercury (mm Hg) and diastolic blood pressure higher by 0.8 mm Hg. These figure remained statistically significant even after adjusting for differences in body mass (1).

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. 

The study found (1) that higher blood pressure levels were present in individuals who consumed more glucose and fructose, both sweeteners which are found in high-fructose corn syrup, the most common sugar sweetener used by the beverage industry.  It was also noted that blood pressure was higher in those individuals consuming high levels of both sugar and sodium (salt).

Sugar intake in the form of glucose, fructose and sucrose was found to be highest in those individuals who consumed more than one sugar-sweetened drink daily. It was also found that individuals consuming more than one serving per day of sugar-sweetened drinks consumed significantly more calories than those who didn’t, with average energy intake of more than 397 calories per day.  Those individuals who did not consume sugar-sweetened beverages had lower average body mass index (BMI) than those who consumed more than one of these drinks daily.

In a press release (2) the senior author, Paul Elliott said “This points to another possible intervention to lower blood pressure,” “These findings lend support for recommendations to reduce the intake of sugar-sweetened beverages, as well as added sugars and sodium in an effort to reduce blood pressure and improve cardiovascular health.

Ian Brown, a research associate at London’s Imperial College UK said (2)People who drink a lot of sugar-sweetened beverages appear to have less healthy diets,” “They are consuming empty calories without the nutritional benefits of real food. They consume less potassium, magnesium and calcium”.  Ian Brown went on to say why sugary drinks may be impacting blood pressure levels: “One possible mechanism for sugar-sweetened beverages and fructose increasing blood pressure levels is a resultant increase in the level of uric acid in the blood that may in turn lower the nitric oxide required to keep the blood vessels dilated. Sugar consumption also has been linked to enhanced sympathetic nervous system activity and sodium retention.”

The study is only an association study, it does not prove that sugary drinks cause higher blood pressure “This is a population study. It’s one piece of the evidence in a jigsaw puzzle that needs to be completed,” said Ian Brown (2)In the meantime, people who want to drink sugar-sweetened beverages should do so only in moderation.”

As Mr Brown mentions, sugar represents ‘empty calories’, it provides energy without any nutritional benefits.  A nutrient rich diet, packed with vitamins, minerals, fibre and flavonoids is one which contains an abundance of vegetables, fruits, beans/pulses, nuts/seeds, wholegrains and other unprocessed, unrefined foods.  Cutting back on added sugars is a great step toward better health

(1)Brown IJ et al.  Sugar-Sweetened Beverage, Sugar Intake of Individuals, and Their Blood Pressure: International Study of Macro/Micronutrients and Blood Pressure.  Hypertension.   Published online before print February 28, 2011, doi: 10.1161/HYPERTENSIONAHA.110.165456

(2)Press Release. American Heart Association (2011, March 1). Sugar-sweetened drinks associated with higher blood pressure. ScienceDaily. Retrieved March 2, 2011, from http://www.sciencedaily.com­ /releases/2011/02/110228163030.htm

 

Written by Ani Kowal

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