Uric acid is a natural waste product that results from the breakdown of compounds called purines. Purines are found in body cells and in many foods, playing a role in DNA creation and energy production. Once purines are metabolized, uric acid is formed and dissolves in the blood to be removed. When the body produces too much uric acid or fails to remove enough of it, levels become elevated, leading to various health issues.
How Uric Acid is Produced and Eliminated
The metabolic process that creates uric acid primarily takes place in the liver and the small intestine. During this process, purines are broken down into uric acid through enzymatic reactions. Approximately two-thirds of the uric acid produced is generated internally from cell turnover, while the remaining third comes from dietary purines.
The body’s disposal system relies heavily on the kidneys, which filter and excrete about 70% through urine. The remaining portion is eliminated through the intestines, where it is broken down by intestinal flora. This balance between production and excretion determines the concentration of uric acid circulating in the blood.
Uric acid also serves a beneficial function in its normal circulating state, acting as a powerful antioxidant in the bloodstream. It is a strong scavenger of free radicals and contributes significantly to the overall antioxidant capacity of blood plasma.
Health Consequences of High Uric Acid Levels
When the concentration of uric acid in the blood becomes too high, a condition known as hyperuricemia occurs. Hyperuricemia is defined as a serum urate level exceeding 7.0 mg/dL in men and 6.0 mg/dL in women. This state is a necessary precondition for, but does not guarantee, the development of gout.
The main consequence of persistent hyperuricemia is the crystallization of uric acid into needle-shaped monosodium urate (MSU) crystals. These crystals can deposit in joints, tendons, and surrounding tissues, triggering an intensely painful inflammatory response known as gout. The onset of a gout attack, or flare, is often rapid, with pain peaking within a few hours.
Gout most frequently affects the joint at the base of the big toe, but it can also impact ankles, wrists, and fingers. Long-term, untreated hyperuricemia can also lead to the formation of tophi, which are hard, painless deposits of MSU crystals beneath the skin. The excess uric acid can precipitate in the urinary tract, contributing to the formation of painful kidney stones and potentially leading to kidney damage.
Managing Uric Acid Through Diet and Lifestyle
Managing elevated uric acid levels requires adjustments to diet and lifestyle. Maintaining a healthy body weight is helpful, as being overweight can increase the risk of gout, and losing weight can lower serum uric acid levels. Hydration is also important, as drinking adequate water helps the kidneys flush out excess uric acid, which reduces the risk of crystal buildup.
Dietary changes focus on limiting the intake of purine-rich foods that contribute to uric acid production. Foods to limit or avoid include red meat, organ meats like liver and kidney, and certain types of seafood such as anchovies, sardines, and scallops. Alcohol, especially beer and distilled spirits, and beverages sweetened with high-fructose corn syrup should also be limited or avoided, as they can raise uric acid levels.
The diet should emphasize complex carbohydrates from whole grains, vegetables, and fruits. Low-fat dairy products, such as skim milk and yogurt, reduce uric acid levels and speed up excretion. Specific foods like cherries and berries contain compounds with anti-inflammatory and antioxidant properties that may help lower uric acid levels and reduce the risk of gout flares.