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While a healthy level (on the high side) of uric acid might correlate with intelligence, elevated uric acid levels can be harmful.

Read this post to learn if you should check your uric acid, testing options for it, why uric acid is good or bad, and what to do about it.

Contents

Uric Acid – Part 2 of a 3-Part Series

What Is Uric Acid?

Uric acid (urate) is an end-product of purine degradation in humans. Purines are generated as a final product in the digestion of certain proteins and DNA in the diet, but some are synthesized in the body (R).

Uric acid has antioxidant properties but can be pro-oxidant depending on its chemical environment (R).

In normal conditions, uric acid is eliminated via urine (R). However, many factors affect the ability of the kidneys to eliminate it efficiently. This results in abnormal blood uric acid levels (too high or too low)

High uric acid levels have been linked to (R):

  • Kidney stones
  • Gout
  • High blood pressure
  • Kidney disease
  • Obesity
  • Diabetes
  • Cognitive dysfunction

How Our Bodies Produce Uric Acid

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Source: (R)

Uric acid is the last step in the breakdown pathway of purines. Purines are converted to hypoxanthine, then to xanthine and finally, to uric acid.

For the last two steps in conversion, we need the enzyme xanthine oxidase (uricase). Humans have a mutation that prevents the production of the enzyme that destroys uric acid (uricase) (R).

Consequently, humans have higher urate levels (around 240–360 μM) compared to other mammals (around 30–50 μM in mice) (R).

How Uric Acid Is Eliminated from the Body

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Source: (R)

Uric acid is removed via the kidney and the gut: through urine (70%) and feces (30%) (R).

Uric Acid Tests

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Uric Acid Blood Test

A uric acid blood test is the most common test used to monitor people who have (R):

  • Gout
  • Likely problems with kidney functions, kidney disorders, or stones
  • Undergoing chemotherapy or radiation treatment

Reference values for blood uric acid levels generally fall between 2.6 – 5.7 mg/dl for women and 3.5 – 7 mg/dl for men, although this may vary between laboratories (R).

Uric Acid Urine Test

For the test, 24 hours of urine is collected to measure the amount of uric acid in the urine and evaluate how the body produces and eliminates uric acid. The test is also used used to detect gout or hyperuricemia (RR2).

Normal results for this test are (R):

  • Adults (normal diet): 250-800 mg/day
  • Adults (purine-free diet): <420 mg/day
  • Adults (low-purine diet) :
    • Males: <480 mg/day
    • Females: <400 mg/day
  • Adults (high-purine diet): <1000 mg/day

High Levels of Uric Acid and Diseases Associated with It

An excess of uric acid in the body is known as hyperuricemia.

Urates are found in urine, bloo,d and in tissue. Urate deposits can lead to oxidative stress , inflammation and cellular dysfunction (endothelial) (RR2).

People with high uric acid without symptoms typically don’t need any medical treatment, but it presents several health risks, so the high uric acid levels should be addressed.

1) High Levels of Uric Acid Lead to Gout 

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Gout is a form of inflammatory arthritis associated with hyperuricemia. It occurs when there are high levels of uric acid in the circulating blood, which causes urate crystals to settle in the tissues of the joints (R).

The symptoms appear suddenly, overnight. It comes with agonizing pain, redness, and swelling of the joint. The attack may be precipitated by too much food, alcohol, by starting a diuretic, or by dehydration (R).

Symptoms go away after 10 to 15 days, but may keep recurring. Eventually, stone-like deposits known as tophi may build up in joints, ligaments, and tendons, which lead to possible joint deformation (R).

2) High Uric Acid Increases the Risk of Kidney Stones

If your urine contains more calcium, oxalate, and uric acid, you are more likely to develop kidney stones (R).

The most common risk factor for uric acid stones is acidic urine (pH<5.5) because uric acid stones precipitate in acidic environments. Therefore, patients should increase their alkaline load by eating more fruits and vegetables (R).

3) High Uric Acid Levels Lead to Metabolic Syndrome

Blood uric acid is significantly correlated with metabolic syndrome and its components, particularly blood triglycerides and waist circumference (R).

This might have to do with high fructose consumption in soda and processed foods that raise uric acid levels, cause insulin resistance, and obesity (RR2).

This may also be because the rise in uric acid after fructose intake induces insulin resistance (by lowering nitric oxide), a key factor involved in metabolic syndrome (R).

4) Hyperuricemia Is Linked to Type 2 Diabetes

FIG. 3.

Source: (R)

High blood uric acid is associated with higher risk of type 2 diabetes, independent of obesity, high cholesterol, and blood pressure (R). 

It is thought that hyperuricemia raises the risk for diabetes by increasing oxidative stress and inflammation (by increasing tumor necrosis factor-α), both of which are related to the development of diabetes (R).

5) High Uric Acid Is Associated with Hypertension and Chronic Kidney Diseases

Hyperuricemia is associated with hypertension (HTN) and chronic kidney disease (CKD) (R, R2).

Hyperuricemia may directly cause hypertension. In rats, hypertension associated with high uric acid was reversible with drugs that lower uric acid, including febuxostat and allopurinol (R).

Hypertension and chronic kidney disease are associated with higher risk of heart and other metabolic diseases (RR).

These include hardening of the arteries, heart failure, stroke, type 2 diabetes, metabolic syndrome, nonalcoholic fatty liver disease, and others (R).

Uric acid may harm blood vessels, increase oxidative stress, and cause the platelets and red blood cells to stick together. These increase the risks of negative heart events (R, R2, R3).

Chronic hyperuricemia in patients with gout increases uric acid crystal build-up in kidney tissues, resulting in tissue injury and inflammation (R).

6) Hyperuricemia Is Caused By Lesch-Nyhan Syndrome

Lesch-Nyhan syndrome, an extremely rare genetic disorder, is associated with very high blood uric acid levels (R).

In Lesch–Nyhan syndrome, hypoxanthine-guanine phosphoribosyltransferase (HPRT), an enzyme involved in the recycling of purine nucleotides, is mutated. This leads to increased uric acid production because purine nucleotides cannot be reused, so they are subsequently degraded (R).

Muscle tightness, involuntary movement, self-injury, cognitive retardation, and gout formation are exhibited in cases of this syndrome (R).

7) Uric Acid Levels Are Elevated in Down Syndrome

Patients with down syndrome consistently have higher blood uric acid levels (R).

8) High Uric Acid Levels May Increase Bone Fracture Risk

Increased blood urate levels are associated with an increased risk of hip fractures in men (R).

High uric acid levels induce inflammation in the bone, impair nitric oxide availability, and suppress vitamin D activation, all of which increase bone fragility and fracture risk (RR2R3).

9) Hyperuricemia Is Linked to Erectile Dysfunction

Erectile dysfunction is commonly observed in patients with gout. This is likely because high uric acid levels are strongly linked to poor blood vessel function, hypertension, and microvascular disease (disease of smaller blood vessels), all of which are risk factors for erectile dysfunction (R).

10) Psoriasis

Blood uric acid levels were significantly higher in patients with psoriasis compared with controls (R).

However, uric acid levels did not increase or decrease the inflammation seen in these patients.

Health Benefits of High Levels of Uric Acid

Read this post to learn about positive health benefits of having high uric acid.

Factors That Increase or Decrease Uric Acid Levels

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Source: (R)

Age: Uric acid levels start to rise after puberty. Men have slightly higher levels than women until female menopause (R).

These levels depend on the balance between purine production and the ingestion of dietary purines, as well as the elimination of urates by the kidney and intestine. Abnormal levels (too high or too low) are detrimental, and lead to a variety of health conditions (R).

Causes of High Uric Acid

1) Kidney Problems Increase Uric Acid Levels

Higher levels of uric acid occur when your kidneys don’t eliminate it efficiently. This could be due to kidney dysfunction and/or influence by certain metabolites and medications (R).

2) High Protein Diets Increase Uric Acid Levels

Studies have shown that each additional intake of meat portion per day increases the risk of gout by 21% (R).

In a crossover study design, the effect of ingesting some purine-rich foods like beef liver, haddock fillets, and soybean was investigated. Results showed that the ingestion of all the test meals caused an increase in blood uric acid levels (R).

3) Fructose Increases Uric Acid Levels

High dietary intake of fructose in foods and drinks increase the production of inosine and purines. Also, fructose competes with uric acid for secretion in the kidney (R).

Fructose rapidly raises uric acid levels because it activates enzymes that breaks down ATP into AMP (fructokinase and adenosine deaminase), which leads to the increased production of inosines (R).

In addition, fructose stimulates uric acid synthesis from amino acid precursors, such as glycine (R).

4) Diuretics Increase Uric Acid Levels

Diuretics are one of the most important causes of secondary hyperuricemia. Drugs increase blood uric acid levels by an increase of uric acid reabsorption and/or a decrease of uric acid secretion (R).

5) Alcohol Increases Uric Acid Levels

According to a population-based cohort study, alcohol-related diseases were significantly associated with gout risk. Also, severe alcohol-dependent patients were associated with an increased risk of gout (R).

Alcohol may stimulate uric acid production by increasing lactic acid, which then reduces the excretion of uric acid in the kidneys (R).

Also, alcohol accelerates the breakdown of purines, thereby increasing the production of uric acid (RR2).

6) Hypothyroidism Raises Uric Acid Levels

Hyperuricemia and gout are frequently found in patients with hypothyroidism (R).

Thyroid hormones (T4 and T3) stimulate energy production processes, and heir deficiency affects purine metabolism, resulting in increases in uric acid levels and hyperuricemia (R).

Also, hypothyroidism may lead to a reduction in kidney blood flow and filtration rate, which elevates uric acid levels in the blood (R).

7) Obesity Increases Uric Acid Levels

According to a population-based epidemiological study, obesity resulted in an increased risk of developing hyperuricemia. If you are overweight, your body produces more uric acid. As a result, the kidney has a more difficult time eliminating uric acid (R).

Blood uric acid levels correlate with leptin levels. Since obese individuals have higher leptin levels (due to leptin resistance), high leptin may be linked to the development of hyperuricemia in obesity (R).

8) Genes That Increase Uric Acid Levels

The gene UCP2 influences blood urate concentration and the risk of hyperuricemia. The degree of association varies with gender and BMI levels (R).

Also, mutations in the secretory urate transporter genes, SLC2A9ABCG2, SLC17A1 or SLC17A3, may cause hyperuricemia (R).

9) Male Gender and Sex Hormones

Men have higher blood uric acid levels than women and are more at risk for developing gout (R).

Estrogen is required for the normal elimination of urate through the kidneys. During the post-menopausal period, women have the same content of uric acid as men of similar age, suggesting that low estrogen may have a role in hyperuricemia development (R).

10) Older Age

Blood uric acid content increases with age (R).

Also, the prevalence of gout increases approximately four-fold to 4.1% by the age of 75 years (R).

11) Nutrient Deficiencies

Vitamin D deficiency is significantly correlated with hyperuricemia in post-menopausal women (R).

12) Ketogenic Diet and High Sodium Intake

A ketogenic diet reduces the ability of the kidney to excrete uric acid because of competition for transport between uric acid and ketones (R).

Higher intakes of sodium are associated with increased blood uric acid levels (R).

13) Parathyroid Hormones

Elevated blood parathyroid hormone levels are associated with higher blood uric acid levels in the general population. Although exact mechanisms are unclear, it is thought that parathyroid hormone increases blood uric acid by reducing kidney urate excretion (RR2).

14) Cancer Treatment and Tumor Lysis Syndrome Elevates Uric Acid Levels

Tumor lysis syndrome (TLS) is a group of metabolic abnormalities that occur during cancer treatment. When large amounts of tumor cells are killed at the same time, they release their cellular contents into the bloodstream. When nucleic acids from the DNA and RNA of these cells are released into the bloodstream, it generates high concentrations of uric acid (R).

15) Chronic Lead Poisoning Leads to Hyperuricemia

Lead exposure is associated with impaired kidney function and increased blood uric acid levels (R).

High levels of lead damage the kidneys, causing inflammation and inhibiting urate excretion, which results in urate build-up and eventually, saturnine gout (i.e., lead gout) (R).

16) Others

  • Niacin (R)
  • Immune-suppressing drugs (R)

How to Lower Uric Acid Naturally

1) Weight Loss 

Weight loss may help reduce high uric acid levels in overweight and obese people (R).

2) Purine-Restricted Diet

Avoid alcohol, red meat, seafood, and sugary beverages. Avoid/ limit refined carbs if you have high uric acid levels. The foods lowest in purine content include eggs, fruit, cheese, nuts, and vegetables other than legumes (R).

3) Water

Dehydration leads to elevated uric acid levels (R).

4) Vitamin C 

Vitamin C increases the excretion of uric acid in the urine, and thereby lowers blood uric acid levels (R).

5) Coffee

Caffeine is a methylxanthine and may be a competitive inhibitor of xanthine oxidase (R). 

However, one study comparing the effects of coffee, tea, and caffeine intake on uric acid levels found that coffee consumption was associated with lower uric acid levels due to components in coffee other than caffeine, suggesting that coffee itself (regular or decaf), not caffeine, is responsible for the inverse association (R).

6) Dairy Products

Milk proteins (i.e., casein and lactalbumin) promote the excretion of uric acid in the urine (R).

7) Cherry Juice

Cherries lower blood uric acid levels by increasing kidney filtration rate and decreasing reabsorption of uric acid. Cherries are also natural xanthine oxidase inhibitors (R,R2).

Medical Treatments to Lower Uric Acid

1) Non-Steroidal Anti-Inflammatory Drugs

Most non-steroidal anti-inflammatory drugs increase urinary uric acid excretion and are recommended for the treatment of gout (R, R2).

2) Uricosuric Drugs

These drugs increase the secretion of uric acid in urine: probenecid, sulfinpyrazone, and benzbromarone (R).

Uricosuric drugs generally prevent the kidney from absorbing uric acid back into the blood (by blocking the function of URAT1) (R).

3) Xanthine Oxidase Inhibitors

Allopurinol is recommended because it prevents gout, but it also taken when patients have a certain form of leukemia or lymphoma, to prevent a complication of chemotherapy or tumor lysis syndrome.

Also, due to its adverse effect, allopurinol is currently not indicated in asymptomatic hyperuricemia and its related heart disease, or in the diseases other than gout (R).

4) Febuxostat

Febuxostat is a selective xanthine oxidase/xanthine dehydrogenase inhibitor (R).

It has several advantages over allopurinol including tolerability in allopurinol-hypersensitive patients, more effectiveness in kidney failure, and faster dissolution of tophi (R).

Febuxostat works quickly and treatment usually begins with doses of 40 mg/day. If blood uric acid level is not reduced to 6.0 mg/dL by two weeks, the dose can be increased to 80 mg/day. The average reduction in blood uric acid level is 40% and 56% at 40 mg/day and 80 mg/day respectively, and is similar in individuals with and without kidney failure, in contrast to allopurinol (R).

Technical

  • Uric acid is almost completely filtered out by the glomeruli (filtering units) of the kidneys. This means that 98 – 100% of the uric acid is then reabsorbed in the proximal tubule and 50% is secreted by the distal tubule of the kidneys (R)

Uric Acid – Part 2 of a 3-Part Series

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2 COMMENTS

  • NORMAN KURATA

    Glad to hear your success with using alternative means. Alas, for me (without the use of prescribed or otc drugs) the same was not in my experience. However, what worked for me was taking 2 tablespoons of apple cider vinegar mixed with water, 2X/day. I quit doing this after symptoms of gout were alleviated and to my horror my gout reappeared (although with less inflammation) again within a week. Going back on my program, my gout subsided. Now I take between 1 and 1-1/2 tablespoons of the acv daily to stay healthy with no re-occurrence in 2 years. FYI, I had multiple inflammation points in both feet/ankles with uric acid blood readings greater than 14 one week prior to the attack. Really extreme so your method(s) may provide benefit in lesser situations.

  • Scott

    I used to have a big problem with high levels of uric acid. I first noticed this when I got gout. I went to the doctor and they suggested similar things to avoid, like you mention in your article. No meat, beer, etc.. I tried that and it works temporarily, but the gout returned a few times – very painful!

    After researching further, I found that counteracting uric acid with alkaline is a much better solution than simply trying to reduce things that cause uric acid. Concentrated cherry juice is good for gout attacks. However, I find that celery and celery seed especially are best to raise the alkaline levels in my body. I take celery seeds daily, and have not had gout attacks in YEARS! With a daily dose of celery seed, I can now eat beef and drink beer with no problems.

    Please add celery seed to your list, it’s has been the cheapest and most effective solution (for me), above all.

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