A colleague recently sent me an e-mail asking, "Is it true cherries are good for gout?"
It was a question I hadn't heard before. I was ready to dismiss it as yet another medical myth. But, I figured I'd look into it first. Sometimes, what seems like folklore, rumor or myth, turns out to be an effective remedy.
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What Is Gout?
Gout occurs when uric acid, a normal byproduct of the body's metabolism, forms crystals in a joint. This causes intense inflammation. Pain can be so severe that it hurts to have a sheet placed over the affected joint. The first toe, foot and ankle are common places for gout. But just about any joint can be involved. Similar crystals can form in the kidney causing painful kidney stones.
Gout is a common condition. It affects up to 3 million people in the United States. While it's more common among older adults, it tends to affect postmenopausal women and men at any age. Risk factors include kidney disease, diuretic use (water pills) and obesity.
The joint inflammation caused by gout usually lasts a few days. Then, for rather mysterious reasons, it quiets down on its own. However, a number of medications, including non-steroidal anti-inflammatory drugs (NSAIDs) — ibuprofen or naproxen — and corticosteroids, can dramatically speed recovery. After many years of living with the disease, attacks may last longer and be more difficult to treat. Fortunately, we have other medicines (especially allopurinol) that can lower uric acid and effectively prevent attacks of gout.
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What's the Evidence That Cherries Help Gout?
One thing was clear as I researched cherries and gout: Many patients swear by the fruit. As I asked around, it became clear that my colleague's patient was not the only one. But is that enough to say they work?
Anecdotes and untested information passed down through families, friends or health-care providers are generally not enough to convince skeptical doctors. After all, we live in an era of "evidence-based medicine." So, you might wonder, what's the evidence that cherries are useful for gout?
Actually, there are at least two studies suggesting that cherries could be helpful for gout:
- A study published in 2003 in the Journal of Nutrition found that among 10 healthy women eating two servings of Bing cherries, uric acid fell by 15%. The authors concluded that the findings "support the reputed anti-gout efficacy of cherries."
- A Journal of Nutrition study from 2006 found that 18 healthy adults who ate 280 grams of Bing cherries each day for a month had a significant reduction in blood levels of substances associated with inflammation and immune cell activity. The authors concluded that the cherries' "anti-inflammatory effects may be beneficial for the management and prevention of inflammatory diseases."
- A 2012 study in the medical journal Arthritis and Rheumatism found that people who had recently eaten cherries or cherry extract reported fewer gout attacks.
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The Lure of Cherries
Studies to date offer several enticing explanations for why eating cherries might be useful for people with gout:
- Eating cherries was associated with a 60% increase in the amount of uric acid eliminated in the 2003 study mentioned above. This may lower blood levels of uric acid enough to reduce the likelihood of gout developing or, once it appears, of troublesome symptoms.
- Cherries contain vitamin C. A 2005 study found that taking vitamin C supplements lowered uric acid modestly. More recent studies linked vitamin C intake with lower blood levels of uric acid and a lower incidence of gout. In addition, vitamin C has anti-inflammatory and anti-oxidant effects. So, the vitamin C content of cherries could have a beneficial effect on the prevention or treatment of gout. Then again, there are a number of foods with much higher vitamin C content than cherries (including oranges, strawberries and broccoli). So if vitamin C is the mechanism, other foods may be even better for gout.
- Cherries are a good source of anthocyanins, plant-based members of the flavonoid family that have antioxidant and anti-inflammatory effects. Anthocyanins may help reduce the risk for gout.
- Cherries may have effects on the immune system. In the 2006 Journal of Nutrition study, blood levels of two measures of inflammation, nitric oxide and C-reactive protein, and T-cell activity (a measure of immune function) were reduced in healthy people eating cherries. These effects on the immune system might lower the risk of gout attacks.
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Why We Need More Data
The studies above suggest that cherries may potentially help to prevent or treat gout. However, it's hard to know whether this approach will work because we lack high-quality studies designed to measure their ability to treat or prevent the condition. It's one thing to document changes in uric acid or markers of inflammation after eating cherries, or to ask gout sufferers to keep food diaries to link attacks to their diets. But it's quite another to show conclusively that cherries improve gout. And it's even more difficult to show they prevent it.
Still, we need the right types of studies to know whether cherry consumption can help gout. But don't hold your breath. Large, expensive clinical studies are usually sponsored by drug companies or the government — neither is likely to fund a study proving the benefits of cherries for gout.
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It May Not Matter
Even if cherries are helpful for gout, it's not clear whether eating them would matter much.
If attacks are rare and readily controlled with non-steroidal anti-inflammatory drugs (as is true for many people with gout), it's unlikely that eating more cherries would provide much additional benefit.
It's unlikely that cherries would take the place of drugs that are used now to treat gout.
Then there are the "risks" of cherries to consider:
- Eating two servings of cherries every day (the dose used in the 2006 study) provides an extra 180 calories. If your diet is otherwise the same, this could contribute to weight gain of 1.5 pounds a month.
- If the immune effects of cherries are enough to block inflammation, they could actually increase the chance of infection (although this is unproven).
- Cherries are not cheap, especially when they're out of season.
- Eating cherries during an attack could make things worse. That's because any change in uric acid during an attack can make it worse or last longer.
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The Bottom Line
Eating cherries to prevent gout is probably harmless. And it could complement more traditional therapies. Given the evidence today, I'm not ready to call the cherry remedy for gout a myth. But I'd also say there's too little evidence to recommend them.
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Robert H. Shmerling, M.D. is associate physician at Beth Israel Deaconess Medical Center and associate professor at Harvard Medical School. He has been a practicing rheumatologist for over 20 years at Beth Israel Deaconess Medical Center. He is an active teacher in the Internal Medicine Residency Program, serving as the Robinson Firm Chief. He is also a teacher in the Rheumatology Fellowship Program.