Cherries May Prevent Gout Flares

Janis C. Kelly

October 03, 2012

October 3, 2012 — Patients with gout were less likely to report acute attacks after 2 days of eating cherries or imbibing cherry extract than during periods after no cherry intake, according to data reported in Arthritis & Rheumatism by Yuqing Zhang, DSci, and colleagues from Boston University School of Medicine in Massachusetts.

Dr. Zhang, who is professor of medicine and epidemiology at Boston University School of Medicine, told Medscape Medical News that cherry intake during a 2-day period was associated with a 35% lower risk for gout attacks and that cherry extract intake was associated with a 45% lower risk.

Risk for gout attacks was reduced by 75% when cherry intake was combined with allopurinol use. Dr. Zhang said, "We found that if subjects took allopurinol alone, it reduced the risk of gout attack by 53%; if subjects took cherry alone, it reduced the risk by 32%; if they took both, the risk of gout attack was reduced by 75%."

These associations were discovered in a case-crossover study of 633 individuals with physician-diagnosed gout who were prospectively recruited and followed online for 1 year. When a participant reported a gout attack, the researchers asked about the onset date of the gout attack, symptoms and signs, medications, and potential risk factors (including daily intake of cherries and cherry extract) during the 2 days before the attack. Patients served as their own controls, so the same information was assessed for 2-day control periods not associated with gout attacks. A cherry serving was defined as one-half cup or 10 to 12 cherries.

Participants had a mean age of 54 years; 88% were white and 78% were male. Of patients with some form of cherry intake, 35% ate fresh cherries, 2% ingested cherry extract, and 5% consumed both fresh cherry fruit and cherry extract. Researchers documented 1247 gout attacks during the 1-year follow-up period, with 92% occurring in the joint at the base of the big toe.

Factors associated with increased serum uric acid levels, such as increased alcohol consumption and purine intake, or use of diuretics, were associated with increased risk for recurrent gout attacks.

"Our findings indicate that consuming cherries or cherry extract lowers the risk of gout attack," Dr. Zhang said in a press release. "The gout flare risk continued to decrease with increasing cherry consumption, up to three servings over two days." Further cherry intake was not associated with additional benefit.

"However, the protective effect of cherry intake persisted after taking into account patients' sex; body mass (obesity); purine intake; and use of alcohol, diuretics, and antigout medications," according to the release.

The authors speculate that cherries may decrease serum uric acid levels by increasing glomerular filtration or reducing tubular reabsorption. They also note that cherries and cherry extract contain high levels of anthocyanins, which possess anti-inflammatory properties.

Dr. Zhang told Medscape Medical News, "While our study findings are promising, randomized clinical trials should be conducted to confirm whether cherry products could provide a nonpharmacological preventive option against grout attacks. Until then we would not advocate on the basis of the current findings that individuals who suffer from gout abandon standard therapies and opt for cherry extract products as an alternative."

In an accompanying editorial, Allan Gelber, MD, from Johns Hopkins University School of Medicine in Baltimore, Maryland, and Daniel Solomon, MD, from Brigham and Women's Hospital and Harvard University Medical School in Boston, write that the findings are promising but reiterates the need for randomized clinical trials to confirm that consumption of cherry products could prevent gout attacks.

Dr. Gelber told Medscape Medical News, "For the patient who asks his/her doctor 'Doc, what can I do, myself, to decrease my chance of developing another gout attack, above and beyond the medications you have prescribed for me?' our response would include that one of the options is dietary modification. Previously, physician recommendations included advocating for moderation in alcohol consumption, weight reduction, and decreasing high-purine foods from the diet…but now there are new data supporting a beneficial role in eating cherries to reduce one's risk for recurrent gout attacks."

Dr. Gelber noted that the most definitive support for the recommendation to eat cherries as a strategy to reduce gout risk would come from a randomized clinical trial. "Just as with new medications that come down the pipeline, dietary interventions ought also be subject to the rigor of a clinical trial. Such a study could be undertaken. There is logistical challenge to undertaking such a trial since cherry fruit is broadly available. But, in a controlled setting, such a trial would be feasible," he said.

This research was funded by grants from the National Institute of Arthritis and Musculoskeletal and Skin Diseases, Arthritis Foundation, and American College of Rheumatology Research and Education Fund. Dr. Zhang, Dr. Gelber, and Dr. Solomon have disclosed no relevant financial relationships.

Arthritis Rheum. Published online September 28, 2012. Abstract Editorial