Fructose intake may increase blood pressure risk

CHICAGO (Reuters) - Eating a lot of foods and drinks sweetened with fructose significantly raises a person's risk of having high blood pressure, U.S. researchers said on Thursday.

The study is the latest to link a sugar-laden diet with higher blood pressure, but it also clearly fingers fructose as a major contributor.

"The data is very consistent with what has been in other papers," said Michael Chonchol of the University of Colorado Health Sciences Center in Denver, whose study appears in the Journal of the American Society of Nephrology.

He said cutting back on sugary foods and drinks should help to lower blood pressure, which can lead to heart and kidney disease.

Too much sugar of any kind not only makes people fatter, but is also a key culprit in diabetes, heart disease and stroke, according to the American Heart Association.

Several states, including New York and California, have weighed a tax on sweetened soft drinks to defray the cost of treating obesity-related diseases. President Barack Obama's administration has recommended that policy makers "analyze the effect of state and local sales taxes on less healthy, energy-dense foods" to fight childhood obesity.

Fructose, such as the sweet syrups made from corn used to sweeten beverages, baked goods and other processed foods, can raise levels of a compound called uric acid.

This, in turn, can trigger angiotensin II, a hormone that makes blood vessels contract, increasing blood pressure.

That is not the case with other sugars such as sucrose, made from sugar cane or beets and found in table sugar, Chonchol said.

INCREASED RISK

For the study, Chonchol's team studied diet surveys of 4,528 U.S. adults over 18 who had no history of high blood pressure or hypertension.

They analyzed what people ate to look specifically for the fructose content, and correlated that with blood pressure readings in three important ranges, pre-hypertension or those with a reading of 135/85; hypertension or a readings of 140/90 and extreme hypertension, or a reading of 160/100 or higher.

People who took in 74 grams (2.6 ounces) of fructose a day or more -- about 2.5 sugary drinks -- had a 28 percent increased risk of blood pressure of 135/85 or higher. They had a 77 percent higher risk of extreme high blood pressure of 160/100 or more, Chonchol said.

But the Corn Refiners Association objected to the study, saying the researchers overestimated the amount of fructose in drinks, although Chonchol denied this and defended his measurements.

The American Beverage Association also objected.

"This study, which looks at fructose intake, furthers the confusion and misunderstandings about high fructose corn syrup and sugar-sweetened beverages," Dr. Maureen Storey of ABA said in a statement.

She said the design of the study means it cannot establish a cause and effect relationship, something Chonchol agrees with. He said that would take a randomized clinical trial comparing the effects of other kinds of sugars.

Several studies have suggested that cutting back on sugary soft drinks, a major contributor of sugar in the American diet, could significantly reduce blood pressure risks.

A study last month in Circulation found drinking one less sugary drink a day significantly helped lower blood pressure.

(Editing by Maggie Fox and Sandra Maler)