The name 'purine' (purum uricum) was coined by the German chemist Emil Fischer in 1884. He synthesized it for the first time in 1899. The starting material for the reaction sequence was uric acid, which had been isolated from kidney stones by Scheele in 1776.

Purines are natural substances found in all of the body's cells, and in virtually all foods. The reason for their widespread occurrence is simple: purines provide part of the chemical structure of our genes and the genes of plants and animals. A relatively small number of foods, however, contain concentrated amounts of purines. For the most part, these high-purine foods are also high-protein foods, and they include organ meats like kidney, fish like mackerel, herring, sardines and mussels, and also yeast.

When cells die and get recycled, the purines in their genetic material also get broken down. Uric acid is the chemical formed when purines have been broken down completely. It's normal and healthy for uric acid to be formed in the body from breakdown of purines. In our blood, for example, uric acid serves as an antioxidant and helps prevent damage to our blood vessel linings, so a continual supply of uric acid is important for protecting our blood vessels.

Uric acid levels in the blood and other parts of the body can become too high, however, under a variety of circumstances. Since our kidneys are responsible for helping keep blood levels of uric acid balanced, kidney problems can lead to excessive accumulation of uric acid in various parts of the body. Excessive breakdown of cells can also cause uric acid build-up. When uric acid accumulates, uric acid crystals (called monosodium urate crystals) can become deposited in our tendons, joints, kidneys, and other organs. This accumulation of uric acid crystals is called gouty arthritis, or simply "gout."

Because uric acid is formed from the breakdown of purines, low-purine diets are often used to help treat conditions like gout in which excessive uric acid is deposited in the tissues of the body. The average daily diet for an adult in the U.S. contains approximately 600-1,000 milligrams of purines. Purines are found in high concentration in meat and meat products, especially internal organs such as liver and kidney. Plant based diets are generally low in purines. A moderate amount of purine is also contained in beef, pork, poultry, fish and seafood, asparagus, cauliflower, spinach, mushrooms, green peas, lentils, dried peas, beans, oatmeal, wheat bran, wheat germ, and hawthorn. Higher levels of meat and seafood consumption are associated with an increased risk of gout, whereas a higher level of consumption of dairy products is associated with a decreased risk. Moderate intake of purine-rich vegetables or protein is not associated with an increased risk of gout.

Recent research by Choi and others has shown that the impact of plant purines on gout risk is very different from the impact of animal purines, and that within the animal food family, purines from meat and fish act very differently than purines from dairy. Choi's work has demonstrated that purines from meat and fish clearly increase our risk of gout, while purines from vegetables fail to change our risk. Dairy foods (which can contain purines) actually appear to lower our risk of gout. In summary, this epidemiological research (on tens of thousands of men and women) makes it clear that all purine-containing foods are not the same, and that plant purines are far safer than meat and fish purines in terms of gout risk.

In a case of severe or advanced gout, dietitians will often ask individuals to decrease their total daily purine intake to 100-150 milligrams. A 3.5 ounce serving of some foods, all by itself, can contain up to 1,000 milligrams of purines. These foods include anchovies, herring, kidney, liver, mackerel, meat extracts, mincemeat, mussels, sardines, and yeast. You'll notice that only of these foods - liver - is included amongst the World's Healthiest Foods. The table below lists other foods that contain higher-than-usual amounts of purines, though not nearly as much as the foods described above.

In general, we want purines in our diet. As mentioned previously, our bodies can break purines down into uric acid, a substance that can help protect our blood vessels from damage and that is a common recycled product when our cells die. There are rare conditions, however, in which metabolism of purines in the body gets disrupted. While research in this area is not conclusive, many health care practitioners suggest screening for purine metabolism problems whenever confronted with other problems, particularly in children and infants, which cannot readily be explained. These problems include anemia, failure to thrive, autism, cerebral palsy, deafness, epilepsy, susceptibility to recurrent infection, and the inability to walk or talk.