NEW YORK (Reuters Health) – Excessive intake of fructose can increase blood pressure and induce other features of the metabolic syndrome, according to study findings presented Wednesday at the American Heart Association’s 63rd High Blood Pressure Research Conference.

The results also indicate that treatment with the anti-gout agent allopurinol can help reduce the rise in blood pressure.

“This is the first study to show that fructose can raise blood pressure in humans,” senior author Dr. Richard Johnson, from the University of Colorado, Aurora, told Reuters Health. “These data suggest that increased fructose intake could be a risk factor for hypertension.”

Dr. Johnson said that it was “remarkable” how quickly subjects with high fructose intake developed increased blood pressure and other features of the metabolic syndrome, including elevated triglycerides, reduced HDL cholesterol, and worsening insulin resistance. “The good news is that we were able to reverse this with dietary counseling and implementation of a low fructose diet after the study.”

The study featured 74 men who received 200 g fructose daily for 2 weeks, with or without allopurinol, in addition to their usual diet. Prior research has shown that uric acid levels are often increased in patients with high blood pressure, diabetes, and renal disease, but whether lowering the levels with allopurinol would have any benefit was unclear.

After just 2 weeks on the high fructose diet, systolic and diastolic blood pressures had increased by 6 and 3 mmHg, on average, respectively (p < 0.004 and p< 0.007). Mean fasting triglyceride levels increased by 55 mg/dL, while HDL cholesterol levels dropped by 2.5 mg/dL. Plasma glucose levels held steady, while fasting insulin levels and insulin resistance increased significantly. Depending on the criteria used, the prevalence of metabolic syndrome rose by 25% to 33%. Treatment with allopurinol reduced uric acid levels (p < 0.0001), prevented the increase in systolic blood pressure (p < 0.03), and attenuated the rise in diastolic pressure as well (p = NS). The drug had no effect on insulin resistance or on triglyceride levels, but it was linked to reductions in LDL cholesterol and to a drop in newly diagnosed cases of metabolic syndrome. “We recommend additional studies to determine if fructose may have a role in hypertension and metabolic syndrome,” Dr. Johnson concluded. “In particular, we would like to determine the benefits of a low fructose diet in subjects who are overweight and have features of metabolic syndrome.”