Apart from excessive sodium intake sugar may contribute to hypertension, the researchers say. The mechanism has not been fully understood. May be it has some interaction with sodium.
Sugar-Sweetened Drinks Linked to Elevations in Blood Pressure
February 28, 2011 (London, United Kingdom) — There is yet another reason to stay away from soft drinks, sweetened fruit juices, and sugar-loaded sports drinks: a new study has shown that there is a direct association between fructose and glucose intake and increases in blood pressure and that these sugar-sweetened beverages are associated with significant increases in systolic and diastolic blood pressures .
“Sugar-sweetened beverages have been linked to high blood pressure, obesity, type 2 diabetes, and heart-disease risk, and this is one more piece of evidence showing that if individuals want to drink these drinks, they should do so in moderation,” lead investigator Dr Ian Brown (Imperial College London, UK) told heartwire
. “Also, one of our interesting findings was that the association between sugar-sweetened beverage consumption and blood pressure was stronger in people who are consuming more sodium. We already know that salt is bad for blood pressure, but what we’re finding is that if you’re consuming more sodium, you appear to be, at least in this study, exacerbating the effects of these sugar-sweetened beverages.”
In a multiple linear regression analysis, there was a direct association with systolic and diastolic blood pressure. In a model that adjusted for energy intake, urinary sodium, potassium, dietary alcohol, cholesterol, and fatty-acid intake, consuming one sugar-sweetened beverage was associated with a systolic blood pressure increase of 1.6 mm Hg and a diastolic blood pressure increase of 0.8 mm Hg, adjusted down to 1.1/0.4 mm Hg when height and weight were included in the model. Diet beverage intake, on the other hand, was inversely associated with blood-pressure levels.
The American Heart Association (AHA) has published recommendations for maximum dietary intake of “added sugars,” such as those found in sodas and fruit drinks. These upper limits vary by sex, age, and activity level, but the AHA puts them at 140 kcal for most American men and 100 kcal for most American women. As Brown noted, however, those who drank the sugary drinks in INTERMAP consumed approximately 400 kcal more than those who did not, and these people also had a higher body-mass index (BMI).
Right now, investigators aren’t sure what underlying mechanism is causing the increase in blood pressure with sugar-sweetened beverages. They suspect, however, that the drinks increase serum uric-acid levels, and this in turn inhibits nitric oxide in the blood, thereby decreasing vasodilation. Although the mechanisms might not yet be clear, Brown said the data are more evidence clinicians can use in communicating to their patients the importance of following a healthy diet.
“As I look at it, this is an additional nutritional intervention that we have in our toolbox,” Brown told heartwire
. “The DASH trial showed that if you consume a high-vegetable, lean-meat, low-fat-dairy, no-sugar-added diet, and if you also reduce sodium, hypertensive individuals can lower their blood pressure by 8 to 10 mm Hg, which is as effective as multiple drug therapies. This is just another tool to help us reduce blood-pressure levels at the population level.”