Gout is an arthritic condition afflicting as many as 5 million Americans, according to Johns Hopkins Medicine. Some evidence exists that it can worsen or improve, depending on your diet. Foods high in purine, an amino acid, may aggravate it, and avoiding these foods can potentially limit attacks. You should avoid or limit canned tuna, as it has a moderately high purine content.
Role of Purines
When you eat purine-rich foods, your body metabolizes the purine into uric acid. In healthy individuals, this process replaces damaged tissue. Your body naturally produces some purine for this reason. If you are prone to gout, you may have an intolerance for additional purine from your diet, which then produces more uric acid.
Role of Uric Acid
Once your body converts purine into uric acid, your kidneys usually dispose of any excess through your urine. If you have gout, your kidneys are unable to do this efficiently. It remains in your body, forming into crystals which can gather at your joints. Left untreated, these clusters, called tophi, will begin to appear under your skin.
There is no defined limit to how much purine you can consume daily if you suffer from gout. It's a matter of personal tolerance. You can figure out your own limits by keeping a food diary, noting what you ate just before experiencing an attack. However, a generally accepted rule is to avoid all foods that contain more than 400 mg of purine per 100 g, and to limit foods that fall in the 100 to 400 mg range. Canned tuna contains 290 mg. A report in "The New York Times" Health Guide implicates canned tuna as a food to avoid if you suffer from gout.
In addition to limiting your intake of canned tuna, avoid other seafood, such as sardines, anchovies and shellfish. If tuna is a favorite, you might be able to eat it on occasion if you take other steps to neutralize the purine content. Drinking plenty of water might help your kidneys dispose of additional levels of uric acid. "The New York Times" also indicates this might help flush excess uric acid crystals from your body. Avoid alcoholic beverages as a substitute for water. Alcohol can step up your body’s metabolism of purine.