How is uric acid stored in your body? And how long time does it take to get rid of it?
When you are hyperuricemic, which is a fancy word for having more uric acid in your body than you can ececrete at any one time, your body will store the uric acid which it can not expel through the urine in your body tissue.
Microscopic image of uric acid crystals.
The uric acid has an affinity for cartilage and connective tissue. This is why people get tophi, which are uric acid storage nodules, in their ears. There are no bones in the ear, only cartilage. It may sound strange that an acid should collect in cartilage, but this is not acetic acid or hydrocloric acid, which are relatively simple compounds. Uric acid is a complex organic compound and it is no stranger that it should accumulate in cartilage than minerals accumulate in your sweat glands when you are hot.
The uric acid is aggregated in the cartilage and connective tissue, but the crystals are not inserted directly in the cartilage like pins in a pincushion. That would destroy the tissue. Instead, they are enclosed in small balls of protein, coming from the white blood cells. Think about it like the white blood cells eating the uric acid crystals, and then dying whine leaving their shells to enclose the danger. It is still microscopic, and if your body is balanced, they can be reabsorbed into the bllod. But if you continuosly have so much uric acid in your body that there always are crystals forming, it builds up.
When the storage grows so large that there is a hard lump, it is known as a tophi. There are many types of tophi, I sometimes get small, itchy red spots on my fingers. They go away after a day; but they are physiologically the same as the hard lumps that people sometimes get: Uric acid enclosed by white blood cells that get sequestered in the fine capillaries in the limbs. Typically that is in the hands, legs, and ears.
The main storage is in connective tissue and cartilage, and since the crystals are stored in a thin shell of proteins, they can be released when something disrupts the shell. That can be a bump (trauma), dehydration (which increases the concentration of uric acid), stress (when the increased blood pressure might disrupt those fragile shells), or a sudden increase in uric acid concentration, changing the balance - like after a big meal full of purine-rich foods.
That release of the naked uric acid crystals in the fluid lubricating your joints is what causes a gout attack. Think of it like sand in the brake fluid of your car. There is no oil filter in your body, so the body brings the filter to the affected place by causing an inflammation.
The pain of a gout attack does not come from the crystals themselves - there are no nerves in the cartilage of your joints. Instead, the pain comes when the blood vessels which carry white blood cells to the location of the uric acid crystals expand to carry more blood, and put pressure on nerves in the limb. The more nerves, the more pain. Lots of cartilage and connective tissue, lots of nerves, narrow space for the blood vessels to expand - these are among the explanations for gout attacks happening in the feet.
The pain of a gout attack does not come from the crystals themselves - there are no nerves in the cartilage of your joints. Instead, the pain comes when the blood vessels which carry white blood cells to the location of the uric acid crystals expand to carry more blood, and put pressure on nerves in the limb. The more nerves, the more pain. Lots of cartilage and connective tissue, lots of nerves, narrow space for the blood vessels to expand - these are among the explanations for gout attacks happening in the feet.
A common misconception among gout sufferers is that the crystals form just before the gout attack, and melt away when the attack subsides. This is not quite how it works.
As I described above, the crystals form during a long time, if you are hyperuricemic. Uric acid is created by your liver as it breaks down complex sugars into glucose, which is fuel for the cells. But while the liver can use purines created from your own dead cells to create the enzymes it needs to break down sugars, the end result being uric acid, it will use any purines it can get to create enzymes.
As I described above, the crystals form during a long time, if you are hyperuricemic. Uric acid is created by your liver as it breaks down complex sugars into glucose, which is fuel for the cells. But while the liver can use purines created from your own dead cells to create the enzymes it needs to break down sugars, the end result being uric acid, it will use any purines it can get to create enzymes.
Uric acid is created in the liver and is transported through the blood to its destination. Normally this is the kidneys, where the uric acid is extracted from the blood together with other rest products and execreted through the urine. But the kidneys have a limited capacity to process uric acid, and when that is exhausted, the uric acid that remains in the blood continues to circulate. The blood goes everywhere in the body, taking the uric acid with it.
If the concentration of uric acid in the blood is higher than 6.8 mg/dL (actually a range from about 5 to 8 mg/dL) the uric acid will start to form crystals. The process is the same as when you make sugar glaze from powdered sugar - the sugar just dissolves in the water, and then at some point it starts to thicken and turn white. This is because the sugar becomes supersaturated.
If the concentration of uric acid in the blood is higher than 6.8 mg/dL (actually a range from about 5 to 8 mg/dL) the uric acid will start to form crystals. The process is the same as when you make sugar glaze from powdered sugar - the sugar just dissolves in the water, and then at some point it starts to thicken and turn white. This is because the sugar becomes supersaturated.
Just like sugar, uric acid starts forming crystals when the concentration is high enough. But different from sugar, which starts precipitating when the solution has become supersaturated, uric acid forms salts, in particular monosodium urate. Those salts are what form crystals.
Since the concentration depends on the volume of the fluid in which the uric acid is dissolved - in this case the blood - the volume of the blood matters. The more blood, the lower concentration. Dehydration can trigger a gout attack.
Temperature also plays a role. Monosodium urate forms crystals at a temperature slightly lower than body temperature (which is why they often form in the feet). But that does not mean you can affect the crystals by heat. Heating up your foot may help decrease crystal creation while it is heated, but as soon as it cools down the conditions become crystal formation friendly. And crystals do not disappear because you raise the temperature; the melting point of uric acid is much higher than body temperature, so the reason crystals disappear is not that they melt, but that they dissolve.
Since the concentration depends on the volume of the fluid in which the uric acid is dissolved - in this case the blood - the volume of the blood matters. The more blood, the lower concentration. Dehydration can trigger a gout attack.
Temperature also plays a role. Monosodium urate forms crystals at a temperature slightly lower than body temperature (which is why they often form in the feet). But that does not mean you can affect the crystals by heat. Heating up your foot may help decrease crystal creation while it is heated, but as soon as it cools down the conditions become crystal formation friendly. And crystals do not disappear because you raise the temperature; the melting point of uric acid is much higher than body temperature, so the reason crystals disappear is not that they melt, but that they dissolve.
Since the uric acid which gets stored in your ligaments, cartilage, and connective tissue, there would be nothing to store if your body could execrete all the uric acid in the blood through the kidneys. So there are two ways to prevent uric acid crystals from forming: Flushing out the uric acid through the kidneys, or decreasing the production so the amount becomes low enough for the kidneys to execrete it, and any stored uric acid to dissolve and be execreted.
Some supplements, like orotic acid, helps increase execretion. And allopurinol decreases production so the stored uric acid can dissolve. This is why people taking allopurinol experience gout attacks.
Some supplements, like orotic acid, helps increase execretion. And allopurinol decreases production so the stored uric acid can dissolve. This is why people taking allopurinol experience gout attacks.
The real problem, however, is overproduction of uric acid. Your body turns purines from dead cells into the enzymes that make glucose out of sugar and ends up as uric acid. But that is not the only source, and it is relatively constant (unless you are losing weight quickly).
The more purines you add to your diet by eating meat or seafood, the more uric acid your body produces. This is because in cases where the hyperuricemia underlying gout is triggered by metabolic syndrome, the regular mechanisms which swich off glucose production when the blood is full of sugar do not work (other possibilities that trigger gout are liver or kidney issues and medication).
The more purines you add to your diet by eating meat or seafood, the more uric acid your body produces. This is because in cases where the hyperuricemia underlying gout is triggered by metabolic syndrome, the regular mechanisms which swich off glucose production when the blood is full of sugar do not work (other possibilities that trigger gout are liver or kidney issues and medication).
The liver keeps producing glucose - and uric acid, by using up all available purines to produce enzymes which are used in glucose production. The end product is uric acid, and since the production does not stop, this will be turning you hyperuricemic.
This also answers the question why weight loss cures hyperuricemia: The less stress on the liver, the more efficient the mechanism that controls the production of glucose - and hence uric acid.
This also answers the question why weight loss cures hyperuricemia: The less stress on the liver, the more efficient the mechanism that controls the production of glucose - and hence uric acid.
Answering the second question, how long time it takes to get rid of the stored uric acid, it is impossible to give a straight answer.
Assuming that you go on a zero-purine diet, stay on it every day without fault, and lose enough weight that you do not overproduce glucose any more, it depends on how much uric acid is stored in your body. And there is no way of measuring that. It takes a shorter time than it took to get you there, but it may be several years.
Assuming that you go on a zero-purine diet, stay on it every day without fault, and lose enough weight that you do not overproduce glucose any more, it depends on how much uric acid is stored in your body. And there is no way of measuring that. It takes a shorter time than it took to get you there, but it may be several years.