Gout is a chronic inflammatory condition characterized by severe attacks of pain, redness and tenderness in the joints, especially the joint at the base of the big toe. At times, the joint can feel like it's on fire. Men are the most likely to suffer from gout, but women are also at high risk after menopause. Gout is caused by the excessive breakdown of purines from foods such as sardines.
Purines are a class of chemical molecules that play a critical role as the building blocks of genetic material like DNA and RNA. When the purines reach the end of their life cycle, the liver converts them into a waste product known as uric acid. Some uric acid dissolves in the blood and passes out as urine, but high levels can form needle-like crystals in the joints. This is the provenance of the pain and inflammation endemic to gout.
Small oily fish such as sardines, herring and anchovies contain particularly high concentrations of purines. These concentrations are only rivaled by yeast, liver and certain kinds of meat. However, the precise amount of purines is not fixed. It can change, depending upon how the manufacturer prepares the sardines. Between 100 and 1,000 mg of purine per 3 oz. serving is a typical amount in sardines. By comparison, a normal daily intake is 600 to 1,000 mg.
There is a general correlation between the amount of purines in the diet and the risk for gout, but the type of food also matters. In 2004, a group of researchers from Massachusetts General Hospital, publishing in "The New England Journal of Medicine," found that male subjects who ate seafood were at the highest risk for gout, whereas the moderate consumption of purine-rich vegetables did not increase risk and dairy products actually decreased it. The study should not be mistaken for medical or dietary advice, but vegetables and dairy are part of a healthy diet and may work to counteract the effects of gout.
If you are not getting enough omega-3 fatty acids in your diet, your doctor may advise you to take fish oil, a dietary supplement derived from oily fish such as sardines. Fish oil is distilled and highly purified and contains very little if any of the purines typically found in fish, so it should not affect your risk for gout. The opposite is also true. If you are at risk for gout, then you may want to take fish oil supplements as a way to achieve the daily recommended intake of omega-3 fatty acids without consuming fish.