Diet taboos for kidney stone patients

Long-term high-salt diet, daily water intake of less than 1500ml, frequent large intake of high-fructose foods and beverages, and other taboos vary from person to person. There is no need to blindly follow the trend and avoid certain foods.

I just treated a 28-year-old Internet programmer last week. He came to the emergency department curled up in pain and was found to have a 3mm calcium oxalate stone. He thought about it for a long time and thought it was because he always ate hot pot with friends. In fact, after asking, he found out that he relied on iced milk tea and iced coke to satisfy his thirst while working overtime. He could not drink half a cup of boiled water a day. The biggest trigger was actually lack of water and high fructose intake - fructose will promote the excretion of urinary calcium and uric acid. No matter what type of stone you have, drinking a lot of sweet drinks and eating processed desserts for a long time is equivalent to "fertilizing" the stone. There is also the issue of high salt which is easily overlooked. Many people are overweight and eat takeout with extra pickles and bibimbap. The sodium in the salt will greatly increase the excretion of calcium in the urine. The saltier the food is, the higher the concentration of calcium in the urine, which naturally makes it easier for crystals to form and form stones.

Speaking of this, someone must ask, is the "you can't eat spinach and tofu" that has been spread for many years reliable? This happens to be a controversial topic in the kidney stone diet field for many years. The old clinical point of view would suggest that patients with calcium oxalate stones should completely avoid high-oxalate foods. Spinach, amaranth, and nuts should all be blackened. Even tofu is included in the taboo list because of its high calcium content. However, follow-up data in recent years have actually overturned this one-size-fits-all conclusion: As long as you don’t show off half a pound of raw spinach every time, boiling it in boiling water for 1 minute before eating can remove more than 70% of the free oxalic acid, and you can eat it in moderation. ； As for tofu, most of the calcium in traditional brine and gypsum tofu is in a bound state. As long as you are not a patient with absorptive hypercalciuria, nor do you eat spinach and stewed tofu every day, eating it two or three times a week will not increase the risk of stones at all. I met an aunt in her 60s a few months ago. After she was diagnosed with a 5mm calcium oxalate stone, she immediately stopped all green leafy vegetables and soy products. She only ate white rice with winter melon and potatoes every day. When she came back three months ago, the stone was not smaller. Instead, she was deficient in vitamin K and suffered from habitual constipation. She went to an extreme.

Of course, this does not mean that there are no things that require targeted taboos. It depends on the type of stone you have.

For more than 70% of patients with calcium oxalate stones, in addition to controlling excessive oxalic acid intake, the most important thing to pay attention to is not to supplement calcium blindly. Many people take care of their health regardless of their situation. They take two tablets of calcium carbonate a day regardless of whether they are deficient in calcium. Some elderly people blindly take large doses of calcium carbonate to prevent osteoporosis. If they have metabolism problems, the calcium supplement is not absorbed by the bones and is excreted in the urine. On the contrary, it is easy to become the raw material for stones.

If you are found to be a patient with uric acid stones, you must control your intake of high-purine foods. Don’t eat animal offal, thick broth, and shelled seafood frequently, and drink as little beer as possible. However, there is also a common misunderstanding here. Many people think that soy products should not be eaten because of high uric acid. In fact, although soybeans are high in purine, most of the purines are lost after being soaked, ground, and squeezed into tofu and soy milk. As long as it is not an acute attack of gout, it is perfectly fine to eat it two or three times a week. There is no need to kill them all.

There are also relatively rare infectious stones, that is, magnesium ammonium phosphate stones. Instead, patients with this type should drink less soda and other drinks that alkalize urine. They can usually eat more foods that are metabolized to be acidic, such as grains and lean meat, which can slow down the growth of stones.

Oh, by the way, many people have asked me, if you have stones, do you need to drink pure water instead of mineral water? It’s really not a mistake. The calcium content in ordinary mineral water is only tens of milligrams per liter. If you drink 2 liters a day, you will only supplement less than 100 mg of calcium. It is not as much calcium as half a carton of pure milk. As long as you are not a patient with hypercalciuria, you can drink it normally. Spending a lot of money on purified water is a waste of money. There is also the amazing "drinking lemon water to eliminate stones" that is widely circulated on the Internet, but it is not useful for everyone. If you are a patient with uric acid stones, drinking some light lemon water can indeed help alkalize the urine and promote the dissolution of uric acid. However, if you are a patient with calcium oxalate stones, drinking strong lemon water every day will ingest too much oxalic acid, which will easily make the stones larger. It is not a general remedy at all.

In fact, if you have kidney stones, there is really no need to live in fear. If you have stones that you pass by yourself, it is best to go to the hospital for a component analysis. It costs a few dozen dollars and is more useful than looking up a hundred taboo lists online. After all, eating happily is also very important. As long as you don't step on the three common pitfalls of high salt, lack of water, and high fructose, and control the amount of other foods appropriately, you can eat most of them with confidence, and you won't lose your mouth for a small stone.