Ten dietary taboos after kidney transplantation

The 10 dietary minefields that need to be avoided after kidney transplantation are: 1. Various foods and health products that are clearly effective in improving immunity； 2. Incompletely cooked meat, eggs, aquatic products, and insufficiently sterilized raw and cold food ； 3. Ingesting a large amount of high-potassium foods at one time when kidney function is unstable ； 4. Long-term and frequent consumption of high-purine foods ； 5. Unrestrained consumption of processed foods high in sugar and oil ； 6. Grapefruit (Seville orange) and its processed products ； 7. Blindly supplement high-protein medicated diet and large tonic soups ； 8. Long-term consumption of strong tea and high-dose functional drinks ； 9. Eating high-salt pickled and smoked foods for a long time ； 10. Folk remedies and dietary supplements with unknown ingredients.

There must be some people who feel that they can’t eat this or that, and life is no longer fun? In fact, it is not true. Many taboos have preconditions. I have been working in the transplant follow-up position for almost 8 years. I have seen too many examples of pitfalls and encountered many different opinions on dietary requirements. I will break it down for everyone and it will be clear.

The first thing to mention is supplements to improve immunity, which are really the most pitfalls for post-operative patients. Many people feel weak just after the surgery, and their families are also anxious to take supplements. They stuff their mouths with Ganoderma spore powder, Cordyceps sinensis, royal jelly, and ginseng, completely forgetting that the core of the transplant is to rely on immunosuppressants to suppress immunity and prevent the new kidney from being rejected. There was a 28-year-old young man who felt that his recovery was slower than others half a year after the operation. He secretly ate a Cordyceps gift box from a friend for three months. His creatinine, which was originally stable at around 100, rose to 132, and his tacrolimus concentration also dropped a lot. Fortunately, he was discovered early and stopped taking supplements and slowly adjusted them back. Otherwise, he might have to be hospitalized for hormone therapy. Of course, there is also controversy here. Many transplant centers believe that mild Qi-enhancing ingredients such as astragalus will not have a significant impact on immune status if boiled and drank within 10g per day. Some centers also require the complete avoidance of all ingredients that may affect immunity. The safest way is always to ask your follow-up doctor before eating, and don’t make blind decisions on your own.

Another thing that everyone has heard of more or less, but some people can’t help but touch is grapefruit. The furanocoumarins in grapefruit directly inhibit the CYP3A4 enzyme in the liver that metabolizes immunosuppressants. This is equivalent to the medicine you originally took according to the dosage. If it cannot be metabolized, it will accumulate in the body, and the blood concentration of the medicine may suddenly double or triple. Don't believe it, last year there was a little girl who was greedy and drank half a cup of grapefruit sparkling water from a friend. The next day, her blood concentration jumped from the normal 5.8ng/ml to 13.7ng/ml. She felt dizzy and nauseated for several days, and also had diarrhea for two days. The stable concentration that had been adjusted for more than half a year was broken. Of course, not all citrus fruits are off-limits. The current consensus among most centers is that you should not eat more than one segment of ordinary honey pomelo and grapefruit at a time. Eating it once in a while is not a big problem. However, red grapefruit and Seville orange should be completely avoided. Don’t even touch jams, sparkling water, and pre-mixed cocktails with grapefruit ingredients.

In the summer, I especially want to mention the issue of raw and cold food. Think about it, we have been taking immunosuppressants for a long time, and our immunity is already lower than that of ordinary people. Normal people may be fine if they eat cold vegetables, uncooked pickled vegetables, soft-boiled eggs, and medium-rare steaks from roadside stalls, but we can easily get bacterial infections after eating them. Last summer, an old patient who had been with me for 5 years was really greedy for Chaoshan pickled raw food and secretly ate two shrimps. He contracted bacillary dysentery for three days and was hospitalized for a week. In order to prevent infection from affecting kidney function, he temporarily adjusted the amount of immunosuppressant. He suffered from old sin. Of course, there are also patients with good health who say that it is perfectly fine for them to occasionally eat cooked Japanese food and clean cold dishes after surgery. But to be honest, we really don’t need to bet on this probability. After all, the infection is serious and the new kidney that was damaged is the hard-earned new kidney.

Many people think that after the kidney function is normal after transplantation, they can eat fruits and vegetables as they like, but this is not the case. Especially for patients whose renal function has not been completely stabilized just 3 months after surgery, or whose creatinine has recently fluctuated, be sure not to eat a large amount of high-potassium foods at one time, such as half a bunch of bananas, a large plate of uncooked spinach, and several kilograms of lychees. Potassium cannot be excreted and accumulates in the body. In severe cases, it can induce arrhythmia, which is really dangerous. Of course, this does not mean that high-potassium foods must be completely avoided. If your kidney function is long-term and stable, and your blood potassium is within the normal range every time you check it, you can eat half a banana at a time and blanch spinach for 2 minutes in advance to remove most of the potassium. You can eat it normally without making yourself afraid to touch anything.

As for high purine, high sugar, and high salt, they are actually not much different from the healthy dietary requirements of ordinary people. We just need to pay more attention to them. After all, immunosuppressants themselves will affect the metabolism of blood sugar, uric acid, and blood pressure. If you eat animal offal, seafood, thick broth, milk tea, fried chicken, and pickled vegetables every day, even a normal person's kidney cannot handle it, let alone a kidney transplant. There was an uncle who felt that he had completely recovered 2 years after the operation. He went out to eat hot pot with friends every day and had goose intestines. After half a year, the uric acid soared to 620 μmol/L, and the creatinine also increased by more than 20%. Later, he controlled a low-purine diet for 3 months before it slowly came back down.

Oh, by the way, some people like to stew various tonic soups after surgery, such as ginseng, black-bone chicken soup, turtle soup, and deer antler soup. They think that protein supplementation will speed up recovery, but it is really unnecessary. The eggs, milk, lean pork, and fish we eat every day contain enough high-quality protein. Supplementing too much protein will increase the metabolic burden on the kidneys and cause good intentions to do bad things. It’s okay to drink light tea, but don’t drink strong tea or functional drinks every day. The caffeine and taurine content in them is too high, which not only affects sleep, but may also interact with medications.

The most important thing to remind everyone is not to believe in folk remedies that "specialize in treating post-transplant rejection" or "preserving and nourishing the kidneys." Many folk remedies contain Chinese herbal medicines whose ingredients are unknown. Many of them are nephrotoxic or may affect the metabolism of immunosuppressants. I have seen patients with acute kidney injury who take folk remedies before. It is a pity.

In fact, after so many years of experience, I have always told my patients that eating does not need to be as tiring as doing chemical experiments. Most home-cooked light meals can be eaten. Occasionally, a mouthful of milk tea or two pieces of fried chicken will not make the world collapse. The core is to remember not to touch the drug concentration, not to take random supplements to improve immunity, the ingredients are clean and hygienic, and the amount is controlled. That is enough. After all, eating well and being happy are the best medicine for recovery.