What are the dietary taboos for renal cysts?

The first thing I want to say is that the vast majority of benign simple renal cysts do not have strict dietary taboos at all. Most of the statements on the Internet that this cannot be touched and that cannot be eaten are exaggerations.

Two weeks ago, I met a 38-year-old patient in the outpatient clinic. His physical examination revealed a small 1.2cm cyst in his left kidney. I searched around on the Internet and was so scared that he gave up all soy products, seafood, and spicy food. He even dared not touch the soy milk he usually drank. He lost almost ten pounds in three months. When he came for a follow-up examination, the cyst had not grown by half a millimeter. His kidney function was all normal. He was simply asking for trouble.

Of course, this does not mean that all kidney cysts do not require attention to diet. The specific judgment must be based on the type and size of the cyst, whether it affects kidney function, or is combined with other problems. If you are diagnosed with hereditary polycystic kidney disease, you really need to pay more attention. This type of cysts will gradually increase in size with age, slowly squeezing the normal renal parenchyma. You should avoid high-sugar carbonated drinks. Existing research has confirmed that these drinks will accelerate the growth of cysts. In addition, do not buy high-protein supplements and change your eating habits of eating fish and meat. Otherwise, excessive metabolic waste will increase the burden on the kidneys and accelerate the decline of kidney function.

If it is a simple cyst but has grown to more than 4cm, and the reexamination has shown compression of the renal parenchyma and elevated creatinine, then the diet must be adjusted according to the requirements of chronic renal insufficiency. The daily salt intake is best controlled within 5g. High-salt foods such as pickles, sauced meats, and processed cooked foods should be avoided as much as possible. For protein, the priority is to choose high-quality protein that is easy to absorb, such as eggs, milk, and lean meat. Roughly processed soy products can be appropriately reduced to reduce the metabolic pressure on the kidneys. There are also people whose cysts are combined with kidney stones and urinary tract infections. The cysts themselves may affect the normal excretion of urine, and are more likely to induce stones or worsen infections. In this case, drink less strong tea, and do not eat high-oxalate foods such as spinach and asparagus all the time. Avoid high-purine foods such as animal offal and beer as much as possible. Otherwise, the stones will not only hurt when they grow, but also further damage the kidneys.

Nowadays, there are many opinions on the Internet that fermented foods and animal offal should be completely banned for kidney cysts. In fact, for patients with simple cysts smaller than 2cm, with no change in annual reexamination, and completely normal kidney function, there is no need to be so harsh. As long as they follow a normal healthy diet, occasionally eating spicy food and drinking a cup of soy milk, it will not stimulate the growth of the cyst at all, and there is no need to fight against everything. What I usually tell my patients the most is that instead of worrying about what not to eat every day, it is better to stay up less late at night and don’t randomly try the “cyst elimination” folk remedies mentioned on the Internet. The unknown ingredients in many folk prescriptions can actually damage the kidneys, which is much more harmful than eating a few so-called “taboo foods”.