Tart cherries, also known as sour cherries, are the main type of cherry used to make commercial cherry pie filling and cherry-based desserts. But scientific research indicates that tart cherry juice may be an effective way to treat certain medical problems, including gout. Gout is caused by a buildup of uric acid crystals in the joints and tissues. Tart cherry juice is not only low in the compounds that can elevate uric acid levels, but it may directly work to lower uric acid.

You may be placed on a low-purine diet if you have gout. Your body metabolizes purine compounds into uric acid. A diet too high in purines raises your uric acid level and increases the chance of severe gout symptoms. You'll need to avoid foods rich in purines such as organ meats, seafood like mackerel or mussels, gravy and meat extracts and limit your intake of foods with a moderate purine content, including poultry, lean meat and beans. Fruits and fruit juices like tart cherry juice are low in purines and are allowed on a gout diet.

A study conducted by researchers at Arizona State University and published in 2011 in the "Journal of the Federation of American Societies for Experimental Biology" demonstrated that 70 percent of adult subjects who consumed one 8-ounce serving of 100 percent tart cherry juice each day for four weeks significantly lowered the amount of uric acid in their blood. The study did not explore if there is a link between drinking tart cherry juice regularly and a decreased risk of developing gout. It also included only 10 participants. Further research on tart cherry juice as a treatment or preventative measure for gout is needed.

The University of Pittsburgh Medical Center recommends that people on a low-purine diet for gout consume between two and four servings of fruit or fruit juice each day. For tart cherry juice, 3/4 cup would count as a single serving. Because juice has more calories, a higher sugar content and less fiber per serving than whole fruit, limit yourself to a single serving of 100 percent fruit juice each day, advises the Harvard School of Public Health, filling the rest of your fruit requirement with fresh fruit.

When it comes to directly treating gout, the consumption of whole tart cherries has been studied more extensively than tart cherry juice. In an "Arthritis and Rheumatism" article published in 2012, researchers from Boston University showed that eating cherries daily could lower the number of flareups gout sufferers experienced by 35 percent. Subjects who ate cherries each day and who were also on allopurinol, a xanthine oxidase inhibitor commonly prescribed for treating gout, experienced a 75 percent decrease in their risk of a gout attack.