FRIDAY, September 28, 2012 (MedPage Today) — Patients with gout sharply decreased their risk for painful disease attacks by including cherries in their diet, a large observational study found.
Among 633 patients who had at least one gout attack within the previous year, 2 days of cherry consumption was associated with a 35 percent reduction in risk for a recurrent attack, according to Yuqing Zhang, ScD, of Boston University, and colleagues.
Moreover, for patients who ate cherries and used the urate-lowering medication allopurinol, the risk was 75 percent lower than for those using neither, the researchers reported online in Arthritis & Rheumatism.
"Should our findings be confirmed by randomized clinical trials, cherry products could provide a novel nonpharmacologic preventive option against gout attacks," they wrote.
More than 60 years ago, cherries were first reported to have beneficial effects in gout, and small studies in animals and humans have shown uric acid reductions when cherries are consumed.
But carefully designed studies have not assessed the effects of cherry intake in gout, and the FDA has cautioned manufacturers of cherry products about claiming benefits against disease.
To provide initial data addressing this gap, Zhang's group prospectively recruited adults with physician-diagnosed gout from around the country, collecting sociodemographic information and data on gout attacks and other medical history and medication use.
When they experienced an acute attack, participants were asked about potential risk and protective factors during the 2-day period preceding the attack, such as alcohol use, consumption of purine-rich foods, physical activity, infections, anti-gout treatments, and alternative remedies.
They also specified how many servings of cherries they ate during the 2-day period, with a serving being one-half cup, or about 10 to 12 cherries.
Data also were collected on risk factors and cherry consumption at four 2-day control periods during the same year when no symptoms of gout were present, so patients served as their own controls.
Patients' mean age was 54, and most were white men.
During 12 months of follow-up, there were 1,247 gout attacks, most of which involved a lower extremity.
A variety of medications were used during the attack, including colchicine, nonsteroidal anti-inflammatory drugs, and corticosteroids.
A total of 35 percent of patients reported eating cherries, 2 percent used cherry extracts, and 5 percent consumed both.
For those who used cherry extract, the risk reduction was 45 percent.
Risk of a gout attack diminished with increased numbers of servings of cherries during the 2-day hazard period. No further benefit was seen, however, for four or more servings.
Among the possible mechanisms by which cherries might influence gout were by increasing the glomerular filtration rate and reducing the production of uric acid through inhibition of xanthine dehydrogenase and xanthine oxidase in the liver, the researchers explained.
In addition, anti-inflammatory effects of anthocyanins may ameliorate the inflammation caused by crystal deposition in the joint.
Zhang and colleagues noted that a nonpharmacologic approach to gout prevention would be welcome, because urate-reducing medications today are generally reserved for patients with severe or tophaceous gout.
In an editorial accompanying the study, Allan C. Gelber, MD, of Johns Hopkins University, and Daniel H. Solomon, MD, of Harvard Medical School in Boston, cautioned that patients should not be advised to avoid conventional medications.
"We would not advocate on the basis of the current findings that those who suffer from gout attacks abandon standard therapies and opt for cherry extract products as an alternative. Ultimately, and as the authors themselves promoted, both cherry fruit and cherry extract ought to be subjected to the rigors of randomized controlled clinical trials to fortify the evidence supporting their efficacy and potential widespread dissemination," they stated.
Aside from its observational design, other limitations of the study included the possible influence of unmeasured factors, a lack of data on uric acid levels, and the unknown long-term effects of routine consumption of cherries.
Last Updated: 9/28/2012