What are the dietary taboos for urinary stones?

There are no one-size-fits-all dietary taboos for urinary stones. The key is to first look at the composition of the stones in your body. There are several common high-risk foods that should be eaten as little as possible regardless of the type of stones. Adjusting your diet in a targeted manner is much more effective than blindly restricting foods. When I was following up patients in the urology department, I met a 27-year-old Internet operator who had two 120-degree injections in half a year because of stone obstruction. After the first stone fragmentation, he didn't take it seriously. He still drank three or four glasses of iced Americano with water every day, and ordered spinach and beef rice with daily nuts as a snack. The second time he came to take the stone for composition analysis, it was found to be very pure calcium oxalate monohydrate. The doctor said that his daily eating method was equivalent to feeding the body with synthetic raw materials for stone every day.

Maybe you have also heard a lot of so-called "list of stone taboos", which you can't eat and don't touch. In fact, many of them are outdated. Take calcium supplementation as an example. In the early years, academic circles did believe that patients with calcium-containing stones should limit their dietary calcium intake. Many people did not dare to drink milk and eat tofu. Two years ago, I met an aunt who had not touched dairy products for three years to prevent stones. In the end, she fell and fractured her bones. It was found that the osteoporosis was more serious than that of a 70-year-old man. But now the latest urinary stone guidelines have clearly mentioned that normal dietary calcium can combine with oxalic acid in the intestines, reducing the absorption of oxalic acid, and can reduce the risk of stone recurrence better than a low-calcium diet. Only patients diagnosed with idiopathic hypercalciuria need to control their calcium intake under the guidance of a doctor, and do not blindly abstain from calcium-containing foods.

Of course, that doesn’t mean that you don’t need to avoid anything. There are a few types of things that you need to control the amount of, no matter what type of stones you have. Foods with high oxalic acid, such as strong tea, spinach, amaranth, and unripe persimmons, especially should not be eaten on an empty stomach. I met an old tea drinker who brewed tea every day that was so strong that it was bitter. He drank the strong tea as water for more than ten years. During the physical examination, both kidneys were covered with small pustules. Stones, he also wondered why he still developed stones after drinking so much "water" every day. Little did he know that the oxalic acid content of strong tea is higher than that of many vegetables. When the oxalic acid that has not been metabolized after drinking combines with the calcium in the urine, it will easily precipitate into stones. You should also avoid high-sugar sweet drinks, milk tea, and carbonated drinks. Studies have shown that drinking 500ml of high-sugar milk tea can increase urinary calcium excretion by 30% compared to drinking plain water, which is equivalent to sending a wave of nutrients to stones.

If you are found to have uric acid stones, the food taboos are similar to those of gout patients. You should try to avoid high-purine animal offal, seafood, thick broth, and beer. I met an uncle with a history of gout before. He had been smoking skewers and drinking cold beer every night for a week. He woke up in the middle of the night and was taken to the emergency room. A test showed that his uric acid had spiked to 680 μmol/L and that he had an 8mm uric acid stone lodged in his ureter. He even laughed and said it was a problem caused by his food.

Another point that many people overlook is to eat less food that is too salty. If you take in too much sodium, the body will excrete calcium along with it. When the concentration of calcium in the urine is high, it is naturally easier to form stones. I have a friend who has a heavy mouth and has to eat salted food with every meal. Eat radish and pickled cabbage. Last year, he was diagnosed with ureteral stones during a physical examination. He broke out in a cold sweat when he was in pain. The first thing the doctor said was to give him up on pickling. He adjusted his diet and ate light food for half a year. This year, the small stones have disappeared and he no longer has any pain.

If you really want to know what foods you should avoid, the most reliable way is to wait for the stones to be passed or taken out, and send them for composition analysis, which is equivalent to doing an "identification" of the stones, and then adjust the diet accordingly. This is much more reliable than the general list found on the Internet. After all, you can't just eat everything delicious to prevent stones, right?