Summer K-foods that can harm kidney patients

During the summer, Korean people often seek out nourishing foods to replenish their energy depleted by the heat, often pairing them with seasonal fruits.

According to a 2023 survey conducted by a job platform targeting office workers ahead of the hottest day of the summer, the most preferred nourishing foods were samgyetang (ginseng and chicken soup), chueotang (loach soup), eel, and beef, accompanied by seasonal fruits.

Consuming summer tonic foods is generally safe for those with normal kidney function. However, individuals with kidney disease should exercise caution, as certain summer foods may be harmful.

The kidneys filter waste products and regulate the body's fluid and electrolyte balance. Acute kidney disease, which typically results from reduced kidney function due to medication, can be treated relatively easily with fluid therapy to restore kidney function. In contrast, chronic kidney disease is characterized by reduced kidney function for over three months or persistent hematuria and proteinuria, making it difficult to restore kidney function.

“Kidney function can decline by more than 70 percent without noticeable symptoms, making it difficult to detect, and once damaged, recovery is challenging,” said Dr. Lee Ji-eun, director of the Nephrology Department at Incheon Himchan General Hospital. “Consuming high-protein diets or summer fruits high in potassium without knowing about impaired kidney function can strain the kidneys.”

Avoid samgyetang as well as watermelon, oriental melon, and other seasonal fruits

During the hot and humid summer, the body maintains its temperature by releasing heat through perspiration, or sweat.

When moisture and minerals are excreted through sweat, fatigue can easily set in. Chicken, the main ingredient in samgyetang, is rich in protein, which helps boost immunity and energy, but high-protein foods can be a burden on the kidneys for those with kidney disease.

In healthy individuals, waste products generated during protein metabolism are excreted through the kidneys without problems. However, in cases of impaired kidney function, consuming high-protein foods can worsen kidney function during protein metabolism, potentially exacerbating the condition. Protein is broken down into urea during digestion, which is then excreted through the kidneys in the form of urine. Therefore, high-protein intake can place a burden on the kidneys.

The same applies to seasonal fruits, such as watermelon and oriental melon, which are commonly consumed in summer for hydration.

These fruits are high in potassium. In patients with impaired kidney function, excessive potassium intake can easily lead to hyperkalemia.

Hyperkalemia can cause numbness in the hands and feet, muscle weakness or paralysis, low blood pressure, and arrhythmias. In severe cases, it can lead to a heart attack. Therefore, it is best to avoid fruits high in potassium, including watermelon, oriental melon, melon, tomato, plum, and banana. Soaking fruits in water for more than two hours and peeling them before consumption can reduce their potassium content.

Kidney disease patients should also be cautious about excessive fluid intake

Once damaged, the kidneys are difficult to restore to a healthy state. As the disease progresses to its final stages, symptoms like shortness of breath, nausea, and vomiting worsen, making daily life difficult. Ultimately, patients may require lifelong dialysis or a transplant.

Regular check-ups are essential for detecting and treating kidney disease in its early stages. Older adults should be especially vigilant. In 2023, 81.5 percent of chronic kidney disease patients were aged 60 or older.

Kidney function typically begins to decline after the age of 40. If you have diabetes or high blood pressure after age 40, it is recommended to undergo urine tests and kidney function tests at least once a year. Smoking and alcohol consumption, which worsen kidney function and cause inflammation, must be avoided. As kidney function declines, it becomes increasingly difficult to excrete sodium; therefore, it is advisable to develop the habit of eating as lightly as possible.

Especially in the summer, it is recommended to drink at least two liters of water a day to prevent dehydration caused by sweating. However, patients with kidney disease should be cautious. Patients with impaired kidney function have reduced water metabolism, making it difficult for them to properly excrete water through urine, which causes it to accumulate in the body. This can lead to swelling around the eyes, face, feet, neck, and other parts of the body.

Excessive fluid accumulation in the lungs can cause pulmonary edema, leading to breathing difficulties. Drinking too much water can also result in hyponatremia, a condition where sodium levels in the blood drop too low. This can cause symptoms, such as headaches, muscle cramps, and vomiting, and in severe cases, may lead to loss of consciousness or seizures.

“Drinking excessive amounts of water forces the kidneys to work overtime to remove unnecessary fluids,” Dr. Lee emphasized, “Dietary management is crucial for kidney health, so it is important to consume the necessary nutrients, including food and water, in appropriate amounts.”