1. People with high blood pressure and diabetes. The nephrotoxicity of carambola is undeniable. Patients with high blood pressure and diabetes must pay attention to their kidney function when eating carambola. The elderly, even if they do not have kidney disease, should not eat on an empty stomach or when they are dehydrated from strenuous exercise. Take your time when eating star fruit after a meal, no more than a small one at a time, that is, no more than two taels. People with kidney disease, or those who have had kidney disease in the past, should not eat star fruits. Patients who have received a kidney transplant, or are undergoing hemodialysis or peritoneal dialysis with renal failure, must not touch carambola, carambola juice, or canned carambola.

2. People suffering from renal insufficiency. Especially for patients undergoing peritoneal dialysis or hemodialysis, this toxin accumulates in the body and causes trouble. It will not only cause damage to the basement membrane of glomerular capillaries, damage to the foot processes of epithelial cells, lead to hematuria, but also cause a series of allergic reactions in the body. About half an hour or within 5 hours after eating carambola, about one-fifth of the patients will have epileptic symptoms, and the mortality rate of these patients is as high as 75%. In addition, Malayan carambola is much more toxic than Hainan carambola.

3. Children. Children may urinate blood after eating star fruit, but they usually get better without eating it. However, little babies will not try this. Healthy children can still eat it, just be careful not to go on an empty stomach.