High fructose diet raises blood pressure

The researchers also found that the drug allopurinol may help lower the resulting high blood pressure.

Dr. Richard Johnson of the University of Colorado, Denver who studied the link between excessive consumption of fructose and blood pressure in men stated, “This is the first evidence of a role of fructose in raising blood pressure and a role for lowering uric acid to protect against that blood pressure increase in people.”

The researchers studied 74 middle-aged men with an average age of 51 years at the Mateo Orfila Hospital in Spain. All men were administered 200 grams of fructose daily in addition to their regular diet. Half of the men also took the drug allopurinol.

Outcome of the fructose study
After two weeks, the researchers noted that the men on fructose showed an increase of 6 mm Hg in their systolic blood pressure (the top blood pressure number) and a 3-mm Hg increase in their diastolic blood pressure (bottom blood pressure number).

The men assigned high-fructose diet along with allopurinol showed a decline in the uric acid level but no significant increase in their blood pressures. Another aspect observed was that the blood pressure level came back to normal within two months of the men reverting back to their normal diet.

The study also found that the metabolic syndrome, associated with cardiovascular disease and diabetes, increased among men consuming lots of fructose without allopurinol. By the end of the study, the incidence rose to 44 percent from 19 percent at baseline.

"These results support the idea that fructose, such as present in table sugar and high-fructose corn syrup, could have a role in the epidemic of obesity and metabolic syndrome," Johnson said. "Further, they suggest that [the two sweeteners] could have a role in high blood pressure, and that this might be mediated by uric acid."

American Heart Association spokeswoman Rhian M. Touyz, MD, PhD, of the University of Ottawa declared, "It is clear that we need larger studies to confirm this association. We know that eating lots of sugar contributes to obesity, but we can't say with certainty that it has a direct impact on blood pressure."

Recommendations by experts
The American Heart Association recommends that consumption of additional sugar should be limited to around 37.5 grams, equivalent to nine teaspoons.

Also, foods with added sugars, which lack nutritional value but are laden with calories, should not be substituted with those containing health nutrients.

The study was presented at the American Heart Association’s 63rd High Blood Pressure Research Conference.