Is high uric acid caused by diet? Many people have misunderstood! There may be problems in these areas...

Expert in this article: Li Tian, ​​chief physician of the Fifth Affiliated Hospital of Guangzhou Medical University. I believe everyone is already familiar with the hazards of the "three highs". If not properly controlled, it can easily cause coronary heart disease, myocardial infarction, cerebral infarction and other cardiovascular and cerebrovascular diseases.

However, in recent years, with the improvement of living standards and changes in dietary structure, another risk factor threatening health, the "fourth high" - high uric acid, has emerged and is showing a trend of becoming younger.

It is understood that there are about 177 million people with hyperuricemia in my country, which has exceeded the 114 million people with diabetes, and is closely following hypertension (200 million people) and hyperlipidemia (300 million people).

Therefore, it is urgent to lower uric acid levels. So how is high uric acid caused? Is it caused by eating? What are the dangers of high uric acid? Let's explain it all at once today.

How is uric acid produced?

Uric acid is the end product of purine metabolism in the human body. The synthesis of uric acid is jointly participated by amino acids, carbon dioxide, ribose phosphate and adenosine triphosphate (ATP) in the human body, and is formed into adenine through the action of certain enzymes in the human body, and then uric acid is generated under the action of xanthine oxidase or hypoxanthine convertase in the human body.

Is high uric acid caused by diet?

Hyperuricemia refers to fasting blood uric acid levels higher than 420 μmol/L for men and higher than 360 μmol/L for women on two different days under a normal purine diet. Clinically, hyperuricemia is divided into "symptomatic hyperuricemia" and "asymptomatic hyperuricemia."

The normal metabolism of purine in the human body (absorption, synthesis, decomposition, and excretion) plays a role in maintaining a dynamic balance of fluctuations in blood uric acid levels.

The factors that affect uric acid excretion are often related to these three factors: disease, medication, and personal constitution.

Two-thirds of uric acid produced is excreted through the kidneys. When kidney function is poor, the ability to excrete uric acid is weakened. One-third of uric acid produced is decomposed by bacteria in the intestines. When intestinal function is poor, the ability to decompose uric acid decreases. The use of diuretics, immunosuppressants (cyclosporine A) and other drugs will increase the reabsorption of uric acid in the proximal tubules, leading to an increase in blood uric acid levels.

These factors will affect the decomposition and excretion of uric acid, and only a small part of it can be excreted, while most of it remains in the blood, causing the blood uric acid level to increase, thus leading to hyperuricemia.

Many people believe that hyperuricemia is caused by bad eating habits. Although this is true to some extent, it is not entirely true.

Generally speaking, about 20% of the uric acid in human blood comes from the intake of exogenous purine foods, and the remaining nearly 80% of blood uric acid comes from the body's own metabolism. Exogenous purines taken from food are rarely used by the body to participate in the synthesis of nucleic acids in the human body, and most of them are broken down and converted into uric acid. Therefore, the intake of a large amount of high-purine diet in a short period of time can increase the level of blood uric acid. For friends with hyperuricemia, it is very easy to induce gout attacks and aggravation, but it is not the main factor.

If an average person eats normally, they can consume about 600~1000 mg of purine per day. If the intake of high-purine foods is strictly controlled, the blood uric acid level can only be reduced by about 60~120μmol/L.

Therefore, trying to reduce blood uric acid levels to normal by simply controlling diet is one-sided and not a long-term solution. Therefore, it is more important to pay attention to the excretion of uric acid.

What diseases can high uric acid cause?

Elevated uric acid levels in the blood may deposit in many tissues and organs, causing diseases:

Kidney disease

Increased blood uric acid will cause more uric acid crystals to deposit, directly causing renal vascular damage and chronic renal interstitial disease, leading to acute and chronic uric acid nephropathy, urinary stones, renal insufficiency and other diseases; conversely, renal insufficiency is also an important risk factor for hyperuricemia.

Hypertension, cardiovascular and cerebrovascular diseases

Studies have shown that long-term accumulation and precipitation of uric acid on the blood vessel walls can damage the arterial intima, cause endothelial cell dysfunction, form blood clots, promote the process of atherosclerosis and platelet aggregation, and accelerate the deposition of lipids on the blood vessel walls.

For every 60 μmol/L increase in blood uric acid levels, the relative risk of hypertension increases by 13%, and the risk of death from coronary heart disease increases by 12%. The risk of stroke in patients with hyperuricemia increases by 47%, and the risk of death from stroke increases by 26%.

Gouty arthritis, tophi

A large amount of urate crystals deposited in the joint cavity can induce gouty arthritis, which manifests as sudden joint pain in the middle of the night, tearing and cutting pain, accompanied by joint redness and swelling, and increased local skin temperature. In severe cases, it affects walking.

If uric acid is not treated well, causing recurrent gout attacks, a large amount of urate crystals will be deposited under the skin and in the joint cavity, condense into clumps, and form tophi, causing joint bone destruction and deformity.

diabetes

Studies have shown that for every 60 μmol/L increase in blood uric acid levels, the risk of new-onset diabetes increases by 17%, and 20% to 50% of patients with hyperuricemia have diabetes. Conversely, long-term diabetes can also affect purine metabolism.

Obesity and hyperlipidemia

Studies have shown that the proportion of hyperuricemia patients with hyperlipidemia and obesity is as high as 68% in women and 71% in men. Moreover, obese people who do not pay attention to diet control are prone to high uric acid. Some patients have also improved their weight after regular and effective uric acid-lowering treatment. Similarly, standardized lipid-lowering treatment is also conducive to lowering blood uric acid.

Which groups of people need to be wary of high uric acid?

Lack of exercise, drinking and smoking, irregular life, high mental stress, staying up late and overwork, high-purine diet, high blood pressure, high blood lipids, cardiovascular and cerebrovascular diseases, diabetes, kidney disease, and postmenopausal women are closely related to hyperuricemia.

For example, estrogen in premenopausal women helps promote uric acid excretion and thus prevent urate deposition, but after menopause, the lack of estrogen protection can lead to an increased incidence of gout.

How to ensure that uric acid levels remain normal?

Establish a reasonable and nutritionally balanced diet plan

Develop a healthy lifestyle, avoid large intakes of high-purine foods (seafood, animal offal, thick gravy soup, etc.), and keep daily purine intake to less than 150 mg;

The preferred protein source is foods low in purine, such as milk, eggs, etc.; alcohol is prohibited (alcohol metabolism can increase the concentration of lactic acid in the blood, and lactic acid can inhibit the secretion of uric acid by the renal tubules, reducing the kidney's ability to excrete uric acid);

Eating less sweets and drinks containing fructose, drinking more water (more than 2000ml) and alkalizing urine (you can use pH test paper to test, if it is between 6 and 6.5, it has reached alkalinization) can promote uric acid excretion;

In addition, different food preparation and cooking methods (boiling or blanching can reduce the purine value of food) will also affect the purine level in food.

Exercise moderately and control your weight

Exercise more (but avoid strenuous exercise), aim to sweat slightly, and choose appropriate exercise methods, such as swimming, simple yoga, cycling, etc., to promote metabolic rate and improve mental well-being.

Adhere to scientific medication

Lowering uric acid requires long-term, systematic treatment. It is a gradual process. Under the standardized guidance of a doctor, an "individualized" uric acid lowering plan is tailored for the patient.

Use drugs with caution

Use with caution drugs that may affect uric acid excretion or increase uric acid levels: such as aspirin, hydrochlorothiazide, anti-tuberculosis drugs, etc.

Pay attention to regular physical examinations

This is even more important for patients with asymptomatic hyperuricemia. Ordinary routine blood draws can reflect whether the blood uric acid level exceeds the standard, so as to detect and treat it early and prevent it before it happens.

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