There could be an easy way to ward off one of the most common and painful forms of arthritis. A study concludes that taking more vitamin C could lower the risk of gout.
An estimated six million people in the U.S. suffer from gout [updated 08/06/10], and more men are affected by it than women. The condition is caused by too much uric acid in the blood and results in often excruciating pain as well as swelling and stiffness in joints.
Previous studies have found that vitamin C can reduce uric acid levels, which can form crystal deposits that cause pain and inflammation. But Hyon K. Choi, MD, of the Boston University School of Medicine, says his new study, which was published in the March 9, 2009, issue of the Archives of Internal Medicine, took the research one step further by showing that the more vitamin C men took, the less likely they were to get gout. “This data shows what people suspected based on previous studies,” he says.
During the 20 years that researchers studied nearly 47,000 men, 1,317 of them developed gout. But the risk was not shared equally. For every 500-milligram increase in vitamin C intake, the risk for gout fell by 17 percent. The risk dropped by 45 percent when study participants took more than 1,500 mg of vitamin C a day.
Vitamin C is found in a number of fruits and vegetables. An orange, for example, has 50 to 100 mg of the vitamin. But some in the study were getting 10 times the recommended daily allowance of vitamin C. So Dr. Choi says simply enjoying a piece of fruit or having a glass of orange juice likely isn’t enough.
“If you have five to ten oranges, that would amount to 500 mg, which was a minimum effective dose,” he says. “So we are really talking about many oranges. Thirty oranges a day would be 1,500 mg. That is why they make supplements.“
The Food and Nutrition Board of the national Institute of Medicine says adults can tolerate up to 2,000 mg of vitamin C daily. But taking mega doses of vitamin C can put some at risk for developing kidney stones. So Dr. Choi says it’s important to talk with your doctor before taking any supplements.
Researchers believe vitamin C works by affecting the re-absorption of uric acid by the kidneys. It might also influence how fast the kidneys work or protect against inflammation.
Allan Gelber, MD, Associate Professor of Medicine at Johns Hopkins University School of Medicine in Baltimore, has been involved in studies looking at the effects of vitamin C on uric acid levels and he has written about the suspected benefits of vitamin C with gout. He says this latest study is helpful. But more is still needed.
“The ultimate proof, which still does not exist in 2009, is the proof of a randomized clinical trial,” he explains. “Short of that data, if you follow tens of thousands and look at exposure to outcomes, that’s a strong study. “
But he also points out that this study only involved men who were health professionals and were overwhelmingly white. He says going forward he would like to see research pools expanded beyond that.
“We look forward to other studies that would reproduce this study in other segments of the population like non-health professionals, women and under represented minorities,” he says.