Low purine diets may be helpful in lowering levels of uric acid in the body, and may involve reducing or eliminating foods with high concentrations of purines. A purine is a compound that is mainly found in animal protein and is metabolized to uric acid in the body, comprising about 15% of the body's uric acid. This diet is usually given to individuals with gout and Lesch-Nyhan Syndrome (a rare genetic disorder that occurs in 1/100,000 people).
Uric acid is a substance resulting from the breakdown of purines, which are part of all human tissue and are found in many foods. Uric acid dissolves in the blood, passes through the kidneys, and is then eliminated in the urine. The buildup of this substance in the body may lead to problems, including kidney stones and gout.
Gout
(hyperuricemia) is a condition characterized by abnormally high blood levels of uric acid (urate). Urate crystals may form in joints, resulting in inflammation and pain. Urate crystals may also form in the kidney and urinary tract, resulting in kidney stones. This condition usually develops first in the joint of the big toe first. Common symptoms include inflammation, pain, redness, stiffness, swelling, and warm to the touch. Symptoms of gout may develop quickly and typically occur in only one joint at a time. Touching or moving the joint may be extremely painful.
Gout was once thought of as a "rich man's disease" because only the wealthy could afford to eat salted meats, rich breads, and malted liquors on a regular basis. The prevalence of gout has increased in the last 50 years due to the tendency of contemporary people to ignore foods high in purine levels in favor of convenience and cost.
Lesch-Nyhan syndrome (LNS) is a rare, inherited disorder that affects how the body builds and breaks down purines. It is caused by a deficiency of the enzyme called hypoxanthine-guanine phosphoribosyltransferase (HPRT). LNS is characterized by increased blood and uric acid levels which may lead to gout-like swelling in the joints or renal dysfunction.
Although a low purine diet is often adopted for the treatment of gout or Lesch-Nyhan syndrome, high-quality, long-term human trials dealing explicitly with the management of gout through a low purine diet alone are still lacking.
Low purine diets may be helpful in lowering levels of uric acid in the body, and may involve reducing or eliminating foods with high concentrations of purines. A purine is a compound that is mainly found in animal protein and is metabolized to uric acid in the body, comprising about 15% of the body's uric acid. This diet is usually given to individuals with gout and Lesch-Nyhan Syndrome (a rare genetic disorder that occurs in 1/100,000 people).
Uric acid is a substance resulting from the breakdown of purines, which are part of all human tissue and are found in many foods. Uric acid dissolves in the blood, passes through the kidneys, and is then eliminated in the urine. The buildup of this substance in the body may lead to problems, including kidney stones and gout.
Gout
(hyperuricemia) is a condition characterized by abnormally high blood levels of uric acid (urate). Urate crystals may form in joints, resulting in inflammation and pain. Urate crystals may also form in the kidney and urinary tract, resulting in kidney stones. This condition usually develops first in the joint of the big toe first. Common symptoms include inflammation, pain, redness, stiffness, swelling, and warm to the touch. Symptoms of gout may develop quickly and typically occur in only one joint at a time. Touching or moving the joint may be extremely painful.
Gout was once thought of as a "rich man's disease" because only the wealthy could afford to eat salted meats, rich breads, and malted liquors on a regular basis. The prevalence of gout has increased in the last 50 years due to the tendency of contemporary people to ignore foods high in purine levels in favor of convenience and cost.
Lesch-Nyhan syndrome (LNS) is a rare, inherited disorder that affects how the body builds and breaks down purines. It is caused by a deficiency of the enzyme called hypoxanthine-guanine phosphoribosyltransferase (HPRT). LNS is characterized by increased blood and uric acid levels which may lead to gout-like swelling in the joints or renal dysfunction.
Although a low purine diet is often adopted for the treatment of gout or Lesch-Nyhan syndrome, high-quality, long-term human trials dealing explicitly with the management of gout through a low purine diet alone are still lacking.
Diet Outline
The adoption of a low purine diet may help treat gout and avoid complications. For this reason, experts often suggest a low purine diet along with medications to reduce the uric acid concentrations. Some people may be able to lower their uric acid levels through diet alone. Most experts recommend consuming at least 50% of calories from carbohydrates, by eating six to ten servings of bread or starchy foods, and five fruits and vegetables each day.
Gout is often treated with medicines that help the body get rid of extra uric acid. But, eating the right foods may help limit the amount of purines in the body, thus decreasing the amount of uric acid in the body.
There is no cure for NLS. Treatment focuses on reducing the prevalence of symptoms. For this reason, a low purine diet may be attractive to the caretakers of individuals with NLS.
Low purine food and drink
Breads and cereals: low fiber, white flour, or refined grain types
Coffee and tea
Cream-style soups made with low-fat milk
Eggs (limit to 3 to 4 per week)
Fruits and juices
Gelatin
Fats and oils in small amounts
Low-fat and fat-free cheeses
Milk: skim or 1% (limit to 24 ounces per day)
Nuts and peanut butter: limit if trying to lose weight
Organ meats: brains, heart, kidney, liver, sweetbreads
Sardines
Scallops and mussels
According to the American Dietician Association (ADA), foods that contain 150mg or more purines per 100g serving should be avoided. In addition to limiting purine-containing foods, the diet also includes modification of these dietary factors:
Protein intake limited to 10-15% of total calories or 0.8g per kg body weight for well-nourished individuals. Persons who are poorly nourished or in the inflammatory phase of the disease should consume 1.5-2.0g per kg body weight per day.
Carbohydrate intake should be 50-55% of total calories.
Limit fat intake to 30% of total calories.
Cholesterol intake should be less than 300mg per day.
Maintain or achieve a healthy body weight. If weight loss is indicated, it should be gradual. Rapid weight loss through fasting or use of low-carbohydrate diets can cause the body to produce ketones, which may increase hyperuricemia.
Alcohol, especially beer, should be avoided because it increases purine production, leading to higher uric acid levels in the blood and urine.
Adequate fluid intake helps dilute urinary uric acid, which helps prevent formation of renal calculi. It is advised to drink 2 to 3L or 8 to 12 cups of fluid daily.
Lifestyle changes along with medication are often needed to control hyperuricemia. Diet is generally considered an adjunct therapy to medication, but may be used as an alternative treatment if medications are not tolerated.
Do not follow a high-protein diet as it can worsen gout conditions.
Theory/evidence
Uric acid is the waste product left over from the metabolism of chemical compounds called purines. The increased uric acid levels found in gout may be caused by increased ingestion of purines. Sodium urates then collect in the joints and tissue, creating inflammation and inducing pain.
Gout is caused by deposition of urate crystals in the joints. Purines are the source of urates and originate from body synthesis and diet. Uric acid levels are elevated and the kidneys may not be able to eliminate the excess effectively, causing crystals to form. Therefore, a condition known as hyperuricaemia is either due to overproduction or renal underexcretion of urate, or a combination of the two.
Uric crystals form and accumulate in body areas where blood flow is too slow to remove them. The knuckles, elbows, knees, and toes are common places of accumulation. If found between the joints, the surrounding tissue becomes inflamed. Then a nerve ending may become irritated, and extreme pain may result. If the crystals remain in the kidneys, partial or complete kidney damage may occur.
Lesch-Nyhan syndrome (LNS) is caused by a lack of the enzyme HPRT, which causes a buildup of uric acid in all body fluids leading to symptoms such as severe gout, poor muscle control, and moderate retardation, which appear in the first year of life. A prominent feature of LNS is characterized by lip and finger biting that begin in the second year of life. Abnormally high uric acid levels may cause sodium urate crystals to form in the joints, kidneys, central nervous system, and other tissues of the body. Neurological symptoms include facial grimacing, involuntary writhing, and repetitive movements of the arms and legs.
Pexioto et al. evaluated the effects of diet and medication on serum levels of uric acid in patients with hyperuricemia in hypertensive patients. Patients were divided into three groups, low purine diet, low purine diet plus allopurinol, and allopurinol only. Patients were evaluated with regards to their lifestyles (diet, smoking, physical, activity, alcohol consumption), uric acid, blood pressure, use of medication, body mass index, cholesterol, and triglyceride. The authors concluded that the low purine diet should be the first option for controlling hyperuricemia in patients with similar characteristics to the ones presented in this study because of the cost-benefit relationship.
High-quality, long-term human studies are still lacking. Many available reports describe the difficulty of committing to such a restrictive eating plan.
Safety
A low purine diet should not be used instead of medical therapy for gout or Lesch-Nyhan syndrome unless under the supervision of a qualified medical professional.
Gout may be a symptom of a more serious underlying disorder (e.g. Lesch-Nyhan syndrome). Consult a qualified healthcare provider before making any decisions about therapies and/or health conditions.
Peixoto MR et al. Diet and medication in the treatment of hyperuricemia in hypertensive patients. Arq Bras Cardiol 2001 Jun;76(6):463-72.
Remember, keep this and all other medicines out of the reach of children,
never share your medicines with others, and use this medication only for the indication prescribed.
