Excessive consumption of high oxalate foods such as spinach can easily lead to secondary oxalate deposition nephropathy, which can also be caused by metabolic abnormalities and intestinal diseases. To prevent this disease, it is necessary to do a good job in dietary adjustments. High risk populations should treat the underlying disease, control their diet, and undergo early screening. Spinach is highly favored by the public due to its rich content of vitamins and minerals. However, as the recognized "king of oxalic acid", improper or excessive consumption can easily lead to acute kidney damage. Recently, a news event about a man suffering from secondary oxalate deposition nephropathy due to consuming a large amount of spinach for several consecutive days has attracted the attention of netizens. Why does spinach cause damage to the kidneys? What is the pathogenesis of oxalate deposition nephropathy? How to prevent this disease? The reporter from Science and Technology Daily interviewed relevant medical experts on this matter. Chen Tianxin, Deputy Chief Physician of the Nephrology Department at the First Affiliated Hospital of Wenzhou Medical University, explained that oxalate deposition nephropathy refers to a type of disease in which oxalate crystals deposit in the renal tubules and interstitium, causing damage to the structure and function of the kidneys. According to different causes, oxalate deposition nephropathy can be divided into two categories: primary and secondary. Primary oxalate deposition nephropathy is caused by a rare genetic disorder in glyoxylate metabolism, leading to excessive oxalate synthesis in the human body and increased urine excretion, ultimately resulting in primary hyperoxaluria. This disease is often manifested as recurrent kidney stones and rapid decline in kidney function during childhood. The initial symptoms include renal colic, hematuria, and urinary tract infections, and in severe cases, acute kidney failure may occur. In comparison, secondary oxalate deposition nephropathy is more common and can occur at any age. ”Chen Tianxin told reporters that when there is excessive intake of oxalic acid, increased intestinal absorption, and decreased excretion ability, it is prone to secondary oxalate deposition nephropathy. Chen Tianxin reminded that in addition to spinach, purslane, beetroot leaves, nuts, soy products, chocolate, tea, and other high oxalate foods can also lead to secondary oxalate deposition nephropathy if consumed excessively. In addition, excessive intake of oxalic acid precursors such as ethylene glycol, food additives containing ethylene glycerol, and vitamin C can lead to the metabolism of large amounts of oxalic acid in the human body, thereby causing kidney damage and increasing the probability of disease onset. In addition, after high-temperature work or intense exercise, the human body will sweat a lot, reduce urine output, and also affect the metabolism and excretion of oxalic acid in the body; When the human body lacks the oxalate metabolism cofactor vitamin B6, it increases the risk of endogenous oxalate production, which in turn can lead to oxalate deposition nephropathy. Some intestinal diseases can also lead to secondary oxalate deposition nephropathy. ”Chen Tianxin said that patients with diseases such as Crohn's disease, ulcerative colitis, chronic pancreatitis, biliary tract diseases, and those who have undergone intestinal short-circuit surgery have high absorption of oxalic acid in their intestines, often accompanied by symptoms of poor digestion of intestinal fat, which can cause the binding of fat and calcium in the body, reduce the content of free calcium in the intestine, inhibit the binding and excretion of free calcium and free oxalic acid, and thus allow free oxalic acid to be absorbed into the bloodstream by the intestine, ultimately leading to the occurrence of the disease. How to check and prevent oxalate deposition nephropathy in daily life by doing a good job of dietary "addition and subtraction"? Chen Tianxin stated that the early stage of secondary oxalate deposition nephropathy is relatively mild and often asymptomatic. Patients can be diagnosed by testing the excretion of oxalate in their urine. If the excretion of oxalate in urine is greater than 45 milligrams within 24 hours, it indicates hyperoxaluria, which is an important condition for the occurrence of oxalate deposition nephropathy. When oxalate deposition nephropathy occurs in the acute phase, it can easily cause acute kidney injury, oliguria, or even anuria renal failure. Patients may experience symptoms such as poor appetite, fatigue, nausea, vomiting, chest tightness, and difficulty breathing. Renal biopsy is necessary for a clear diagnosis, and patients with severe symptoms need to undergo hemodialysis to avoid irreversible kidney function damage. ”Chen Tianxin said. The prevention of oxalate deposition nephropathy can be divided into two categories: basic prevention and key prevention for high-risk populations. Basic prevention mainly involves reducing and adding dietary intake. ”Chen Tianxin suggests that in terms of "subtraction", firstly, it is necessary to avoid consuming large amounts of high oxalate foods such as spinach in a short period of time, such as eating a lot of spinach for three meals a day while also consuming nuts or chocolate. When cooking vegetables with high oxalic acid content, it is best to blanch them first to reduce the oxalic acid content. The second is to avoid long-term oral or intravenous supplementation of large amounts of vitamin C, except for certain diseases that require it. "Addition" refers to reasonable calcium supplementation and hydration. Calcium can combine with oxalic acid in the intestine to form non absorbable calcium oxalate, which is excreted with feces, thereby reducing the body's absorption of oxalic acid. Timely supplementation of sufficient water can achieve the effect of diluting the concentration of oxalate in urine and preventing the formation of oxalate crystals. If there are symptoms such as heart failure and swelling, the human body can drink over 2000 milliliters of water per day, "said Chen Tianxin. Chen Tianxin suggests that patients with five key groups, including chronic kidney disease patients, those with weak gastrointestinal function, gout patients, kidney stone patients, and those taking special medications (such as anticoagulants), should actively treat the underlying disease, eat less foods with high oxalic acid content, follow medical advice, and have a reasonable diet. For patients with chronic intestinal diseases who are prone to absorbing oxalic acid in the intestine, a low-fat and low oxalic acid diet should be adopted, or calcium supplements should be reasonably supplemented under the guidance of a doctor to promote the excretion of oxalic acid; For patients with chronic kidney disease such as renal insufficiency, it is necessary to strictly control the intake of high oxalate foods and maintain sufficient urine output, while closely monitoring renal function and urine indicators. For patients with primary hyperoxaluria, timely genetic screening and counseling should be conducted to clarify the diagnosis and guide fertility. ”Chen Tianxin added. (New Society)