Uric acid concentrations increase after fructose ingestion

Intakes of fructose, regardless of source, elevate uric acid levels in the circulation, reports a study.

The investigators randomized 73 participants to one of three groups to ingest small (205 g) and large (410 g) servings of apple segments, small (170 mL) and large (340 mL) servings of apple juice, or a glucose and a fructose control beverage to determine whether fructose present in fruit is of sufficient quantity or in a form that will increase uric acid concentration.

Participants within each group ingested both treatments in a crossover design. There was 26.7 g fructose in the fructose control and the large servings of apple and juice. Test foods were ingested within 10 min. The investigators took blood samples at baseline and at 30 and 60 min after intake.

Plasma uric acid concentrations escalated following intakes of all fructose-containing treatments and dropped after the glucose beverage. At 30 minutes, the mean uric acid increase was 15 µmol/L (95 percent CI, 10–21 µmol/L) for the fructose control, and 19 µmol/L (8–30 µmol/L) and 17 µmol/L (9–24 µmol/L) for the large servings of apple and apple juice, respectively.

No difference was seen in change in uric acid between baseline and 30 minutes when comparing the apple (3 µmol/L; −8 to 14 µmol/L) and apple juice (−7 µmol/L; −18 to 5 µmol/L) with the fructose control.

Any form of treatment had no effect on blood pressure taken 70 min after ingestion (p>0.05). There was no difference in change in satiety scores between the fructose and glucose control beverages (p>0.05). Participants who ingested whole apple felt more satiated after 30 min compared with apple juice intake.

Furthermore, the amount of glucose in each treatment was reflected by the glycaemic response.

“Longer-term studies are required to assess how small and transient increases in plasma uric acid contribute to health,” the investigators said.