2011-03-01 06:25:20
By Michelle Roberts Health reporter, BBC News
soft drink People are advised to avoid drinking too many sugar-laden beverages
Drinking too many sugary beverages appears to raise the risk of high blood pressure, experts are warning.
Findings suggest blood pressure goes up incrementally for every extra can of sugary drink consumed per day.
Drinking more than 355ml a day of sugar-sweetened fruit juice or carbonated drink can be enough to upset the balance, data on over 2,500 people reveals.
The study by UK and US researchers appears in the journal Hypertension.
The precise mechanism behind the link is unclear, but scientists believe too much sugar in the blood disrupts blood vessel tone and salt levels in the body. Non-sugar sweetened diet drinks did not carry the same risk.
Start Quote
This is another nail in the coffin for soft drinks
End Quote Professor Graham MacGregor Chairman of the Blood Pressure Association
On four separate occasions the participants aged 40-59 from the UK and the US were asked to record what they had eaten in the preceding 24 hours and give a urine sample as well as have their blood pressure measured.
The researchers found that sugar intake was highest in those consuming more than one sugar-sweetened beverage daily.
They also found that individuals consuming more than one serving per day of sugar-sweetened beverages consumed more calories than those who didn't consume sugary drinks - around 397 extra calories a day.
For every extra can of sugary drink consumed per day, participants on average had a higher systolic blood pressure by 1.6mmHg and a higher diastolic blood pressure by 0.8mmHg.
Overall, the people who consumed a lot of sugar-sweetened beverages appeared to also have less healthy diets and were more likely to be overweight.
But regardless of this, the link with blood pressure was still significant even after adjusting for factors such as weight and height.
Stroke risk
Professor Paul Elliott, senior author of the study, from the School of Public Health at Imperial College London, said: "It's widely known that if you have too much salt in your diet, you're more likely to develop high blood pressure.
"The results of this study suggest that people should be careful about how much sugar they consume as well."
High blood pressure is a major risk factor for cardiovascular disease.
Someone with a blood pressure level of 135mmHg over 85mmHg is twice as likely to have a heart attack or stroke as someone with a reading of 115mmHg over 75mmHg.
In the study, the link between sugary drinks and higher blood pressure was especially strong in people who consumed a lot of salt as well as sugar. Excess salt in the diet is already a known to contribute to high blood pressure.
The British Heart Foundation said more research was now needed to better understand the relationship between sugar and blood pressure.
Victoria Taylor, Senior Dietician at the BHF, said it was best to avoid too many sugary drinks because they add extra calories to our diets that can lead to obesity, a major risk factor for heart disease.
The American Heart Association says people should drink no more than three 355ml cans of soda a week.
Professor Graham MacGregor, chairman of the Blood Pressure Association said: "This is another nail in the coffin for soft drinks.
"Not only do they make you obese but they may also put up your blood pressure. Drinking sweet soft drinks is not good news."