Introduction: Some people are bothered by Gout but does not know much about it. They may have heard it's due to high uric acid level in their blood or ate too much purine rich foods.  However, those are just part of the story. We are going to help debulk how to deal with gout in today's post.
What is gout?


Gout is a chronic disease characterized by recurrent episodes of severe pain and swelling of joints.  It is caused by uric acid forming monosodium urate crystals in joints and pain is triggered by flare ups. Uric acid is a chemical that is produced when the body breaks down certain foods, usually purine containing foods.


Our body constantly processes purines, breaking down it, recycling and removing the by-products. When the kidneys cannot effectively excrete uric acid or excessive uric acid build up in the body, it will cause the level of uric acid to increase, over time, may become crystalized and precipitate in the body tissue.


Gout tends to occur in the joints of the lower extremities. About half of gout attacks happens on the big toe, but it can happen somewhere else too, such as ankles, heel, knees, fingers etc. The formation of uric acid crystals can lead to joint deformation and severe disability. The pain usually begins at night and is severe enough to wake a person from sleep.


Usually, the progression of the disease happens in four stages: asymptomatic, gout flare, intercritical gout, and tophaceous gout.


Prevalence of gout


It is estimated, gout prevalence ranges from 0.1% to about 10% globally. 
• Men are almost three times more likely to be affected by gout than women
• The first onset of gout for men, often happens between the ages of 40 and 60.
• The first onset of gout for women, often happens between age of 50 and 70. The disease rarely occurs in premenopausal women (possibly associated with protective effect of estrogen)

Risk factors of gout


Most flare ups occur without obvious causes.


Factors that increase the risk of gout include:
• Obesity (However, rapid weight loss / hunger (e.g. fasting)/ dehydration also increases the risk of gout)
• Hypertension
• Diabetes
• Excessive Alcohol use (Not only increases the production of uric acid, but also reduces the excretion of uric acid.)
• Consuming large amounts of meat or seafood
• Certain medications Low-dose aspirin as well as several types of antihypertensive drugs are associated with drugs including diuretics, beta-receptor blockers and most renin-angiotensin system drugs.
• Family history of gout
• Decreased kidney function
• Intense exercise
• Dyslipidemia
• Genetic variation
• Early menopause


How does uric acid get crystalized?


Some people have high uric acid but never developed gout, while some people get frequent gout attack with slightly elevated uric acid level. In fact, less than 20% of people with hyperuricemia will develop gout. Uric acid needs to form crystal to cause problem.


So, what does it take for uric acid crystal?  
• Hyperuricemia (serum urate concentration > 6.8 mg/dL [408 mcmol/L])
• Temperature (lower the temperature, easier to form crystal)
• Blood pH level (Too high or too low pH level increase crystallization)
• Other factors (such as mechanical stress, cartilage components, and other synovial and serum factors)


Besides the uric acid level and dietary component, one should also pay attention to keeping warm, avoid excessive exercise (exercise increases lactic acid to reduce blood pH), keep hydrated, etc. to help reduce risk of gout flare up.


Treatment of gout


Acute attack
• Although acute attacks are usually self-limiting and subside spontaneously within 1 to 2 weeks, treatment can speed up the progress.
• For non-severe cases, doctor may suggest using pain medications to help with the pain and swelling. In severe cases, the doctor will treat it with a combination of anti-inflammatory medications.


Chronic attack
• In addition to the above treatments, doctors may recommend use of uric acid-lowering drugs, such as allopurinol to keep uric acid lower.


Prevention of gout


Prevention is always the primary treatment. Preventing gout attacks can be achieved by reducing risk factors blow.
• Lose weight but avoid losing weight too quickly. Aim for 1-2 lbs per week as a goal. It is not recommended that people with high uric acid lose weight by extreme diets that induce starvation, one should also avoid excessive animal protein intake due to high purine content.
• Maintaining normal blood pressure (follow DASH diet)   Controlling blood pressure helps protect kidney function.
• Adequate hydration Avoid dehydration as being dehydrated makes uric acid concentration increase further.
• Protect your kidney Your kidney plays an important role removing excessive uric acid.
• Avoid excessive consumption of high purine foods Such as certain seafood, organ meat and other high-purine foods. Avoid drinking alcohol, especially beer.
• Medication adjustment Follow the doctor's instructions regarding your medication regimen, timely adjustment of medication can achieve the best treatment results.
• Avoid alcohol Alcohol increases the production and reduces the excretion of uric acid.


Foods that affect uric acid


Foods that raise uric acid (eat less)
• Purine rich food
– Restrict: liver, dehydrated food (dried fish, dried meat, dried beans, dried mushroom, because the proportion of purine becomes higher after dehydration in these foods), red meat, seafood (shellfish and small fish). There is no strong evidence showing purine rich vegetables increase the risk of gout. 
– Daily intake recommendation of purine: <400mg/d    (From Japanese study)
• Fructose also increase uric acid, as purine is one of the by-products from fructose metabolism. Plenty of evidence showed fructose increases uric acid level.
• Tomatoes   are positively correlated with gout attacks on one New Zealand study.
• Other foods that raise uric acid: sorbitol, sucrose, lactate. 
Foods that reduce uric acid (eat more in moderation)
• Coffee   (but not caffeine, tea has no effect on uric acid reduction)
• Vitamin C   study found that people who consume 1000-1500 mg per day had a 45 percent lower risk than those who consume less than 250 mg a day.  Vitamin C decreases reabsorption of uric acid.
• Dairy products
• Folic acid
• Cherry


Bottom Line


• Hyperuricemia is the main risk factor for the development and recurrence of gout.
• High uric acid level is caused excessive uric acid production or a decline in excretion or both.
• Gout patients should seek weight loss if overweight but avoid losing weight too fast.
• Gout patients need to avoid alcohol, which increases uric acid production while reducing uric acid excretion
• Avoid foods high in purine and fructose can help reduce risk of gout attack.
• Maintain good blood pressure, kidney function, lipids and blood sugar control can also be helpful preventing gout.
• Follow doctor’s advice if needs medication to lower uric acid and adjust medication if taking medication that interferes uric acid balance.
• May consider increase consumption of vitamin C, dairy etc. to help reduce uric acid. 



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[14] Diet and gout – what is the role of purines? https://onlinelibrary.wiley.com/doi/abs/10.1111/nbu.12205

Copyright © | Bor S. Luh Food Safety Research Center  of Shanghai Jiao Tong University 2015