March 10, 2004 -- Ever since Ye Olden Days, gout was known as the "disease of kings" for a good reason: Besides such notable nobleman as Henry VIII, Sir Isaac Newton, and Benjamin Franklin, this type of inflammatory arthritis -- the most common in men -- usually afflicted only those who ate like royalty.
Their diet was much like today's typical American diet, centered around hefty portions of fatty red meats and seafood, as well as vegetables such as peas, beans, mushrooms, and cauliflower.
All of these foods are rich in purines, a chemical that breaks down into uric acid, the waste product that crystallizes and causes inflammation in joints, causing gout. As a result, those prone to or already with gout were long advised to avoid purine-rich foods.
But a new study clarifies exactly which purine foods may cause harm while exonerating others. And for the first time, researchers find that low-fat dairy products can actually prevent gout from occurring.
"Having more than two glasses of milk a day is associated with a 50% risk reduction," says lead investigator Hyon Choi, MD, DrPH, of Harvard Medical School and Massachusetts General Hospital. "We think it's because dairy products are low in purines, but also relatively high in protein. And protein most likely helps to reduce uric acid levels."
But protein-rich meats and fish are especially high in purines and have long been linked to contributing to gout. And in Choi's 12-year study involving 47,150 men, gout risk increased 21% with each serving of beef, lamb, or pork per day, and 7% with each serving of seafood per week. Chicken and other "white" meats do not increase risk, he says.
Yet purine-rich vegetables and grains such as oatmeal were not found to increase risk at all. His research, published in this week's New England Journal of Medicine, analyzed how eating habits affected gout occurrence in the men studied.
Red Meat High in Purines
Purines are found in many animal products with the exception of low-fat dairy foods and eggs. Organ meats (liver, heart, kidneys), herring, mackerel, anchovies, and trout are particularly rich sources. Beans and peas contain a moderate amount of purine.
"We don't clearly understand the 'whys,' and there several possible explanations," Choi tells WebMD. "It might be there's a different type of purines in meats and seafood than in vegetables, or different foods have different levels of purines. Or maybe the body absorbs purines differently, depending on the food type."
The role of food -- and in particular, purines -- has long been suspected in gout but never proven. And that's what makes Choi's study important, say experts.
"Gout is no longer a disease of the wealthy; rather, its appearance reflects an increase in access to fatty meats and a decrease in the intake of dairy products worldwide associated with Westernization," write Richard J. Johnson, MD, and Bruce A. Rideout, DVM, PhD, in an accompanying editorial.
"Gout should thus be considered part of the current global epidemic of obesity, hypertension, and diabetes. Diets that are rich in fruits, vegetables, and low-fat dairy products, such as the Dietary Approaches to Stop Hypertension (DASH), may reduce not only blood pressure, but also the frequency of gout."
In addition to diet, obesity and frequent alcohol consumption are also associated with gout, which is five times more common in men than women and affects some 5 million Americans. Alcohol contains purines and also interferes with the body's excretion of uric acid.
"This study confirms some of our suspicions and exonerates others," Choi says. "Even if you don't have gout, reducing intake of red meat is generally recommended because it's associated with other major health problems."
But what about fish, advised for good nutrition and known to help protect against heart disease and other problems? In Choi's study, all types of seafood -- including tuna, shellfish, and "heart-healthy" fish like salmon -- increased risk, most noticeably in men who were not overweight.
"You want to get the protective components like omega fatty acids that are in fish," he says. "So if you have gout, maybe the way to go is with fish oil capsules, rather than eating a lot of seafood."