As summer arrives, delicious crayfish become a star on dining tables, but overconsumption can pose food safety risks. A 19-year-old man in mainland China developed rhabdomyolysis after binge-eating crayfish. Doctors warn that 2 parts of the crayfish are the most toxic and dirty and should be avoided. How should you eat and prepare crayfish to effectively reduce food safety risks?
According to mainland Chinese media Guangming Daily, a 19-year-old man in Zhejiang Province ate crayfish for several consecutive days. He then suddenly experienced severe headaches and difficulty walking. Rushed to the hospital, he was diagnosed with rhabdomyolysis. The incident has instilled fear in many seafood lovers.
Dr. Zuo Li, Chief Physician and Director of the Nephrology Department at Peking University People's Hospital, points out that the public need not overly panic. Crayfish themselves do not directly cause rhabdomyolysis. The online claim that "crayfish are poisonous" is one-sided and inaccurate. He explains that the body's limbs and trunk are covered in striated (skeletal) muscle. When muscle cells are damaged and rupture, myoglobin is released into the blood, circulating throughout the body, causing symptoms like difficulty breathing, muscle aches, and dizziness/weakness. If myoglobin enters the urine, it can block kidney tubules and severely damage the kidneys, causing urine to turn the color of soy sauce or even black – this is rhabdomyolysis.
Zuo states that the medical community currently recognizes that rhabdomyolysis associated with eating crayfish is mainly related to three factors: potential Haff disease factors within the crayfish, improper cooking, and individual tolerance. It is not directly related to the crayfish itself being poisonous or having heavy metal residues. Most cases occur in summer and are almost always related to eating undercooked shrimp, shrimp of unknown origin, or eating too many at once.
Doctor Reveals 3 Crayfish Eating Habits That Easily Trigger Discomfort – Avoid Eating 2 Parts
Dr. Guo Wei, Associate Chief Physician and Deputy Director of the Emergency Internal Medicine Department at Peking University People's Hospital, further emphasizes that the following 3 eating habits easily trigger discomfort and require increased vigilance:
- Overeating: Crayfish have very high protein content and are not easily digested. Binge eating several jin (a jin is approximately 500g) at once not only aggravates the digestive burden, leading to indigestion, but the metabolism of large amounts of protein can also trigger muscle stress reactions, causing physical discomfort.
- Undercooked: Many people like tender shrimp, unaware that thoroughly undercooked crayfish are highly likely to retain bacteria, parasites, and the Haff disease factors that have not been destroyed by high heat. This is a key trigger for rhabdomyolysis. Do not eat undercooked or half-cooked shrimp for the sake of texture.
- Eating the Wrong Parts: Many people love to eat the shrimp head and "shrimp paste" (the yellow/orange stuff in the head), finding them fragrant and flavorful. However, these two parts are safety hazard zones. The shrimp head contains the gills, hepatopancreas, and other internal organs, serving as a concentration site for heavy metals and various impurities. The "shrimp paste" is essentially the crayfish's liver and pancreas, which is not only very high in fat but also accumulates toxins. Long-term large consumption will increase the metabolic burden on the liver and kidneys. Therefore, it is strongly recommended to eat only the tail meat and absolutely avoid eating the head and the paste.
4-Point Crayfish Safety Guide: 3-Step Cleaning Method
The report also synthesizes the advice of the two doctors. When eating crayfish, follow these 4 safety guidelines to reduce health risks:
- Selection: Follow the "two choices, one avoid" rule:
- Prioritize selecting lively, energetic crayfish.
- Observe whether the back is bright red, the abdominal bristles are white, and the gills are clean and white – indicating a better growth environment.
- Avoid buying crayfish with dark red shells, black abdomens, and no energy, as these typically grow in poor-quality water and likely have off-odors and impurities.
- Preparation: Clean crayfish using this 3-step method for cleanliness and safety:
- Soak in salt water or white vinegar for 1-2 hours to allow the shrimp to expel sand and impurities.
- Wear gloves and use a brush to thoroughly scrub the abdomen, which most easily hides dirt.
- Cut off the head, remove the gills, and remove the digestive tract (the black line on the back) – reducing harmful substances at the source.
- It is best to wear gloves during handling to prevent injury from claws and maintain hand hygiene to avoid infection.
- Cooking: Must be thoroughly cooked. It is recommended to apply high heat continuously for at least 10 minutes to completely kill bacteria, parasites, and destroy potential pathogenic factors. Do not eat undercooked or half-cooked shrimp for the sake of tenderness.
- Eating Method: Do not exceed 500g per serving. Pair with vegetables and staple foods, avoiding eating on an empty stomach. Since crayfish have medium purine content and are high in protein, individuals with allergies and gout patients (especially during acute attacks) should try to eat less or not at all.
Seek Immediate Medical Attention If 3 Symptoms Appear After Eating Crayfish
Doctors also remind that if the following 3 symptoms appear within 24 hours after eating crayfish, rhabdomyolysis should be highly suspected, and immediate medical attention is necessary. Timely treatment allows for rapid recovery; delay may cause kidney damage:
- Severe muscle pain and weakness, especially in the limbs, worsened by movement.
- Urine color significantly darkens, appearing dark tea-colored or soy sauce-colored – a critical danger signal.
- Accompanied by nausea, vomiting, fever, etc.
Source: Guangming Daily (光明日報)
