Summer delicacy top trend causes "Haff disease"? Crayfish says: I won't take the blame!

With the arrival of midsummer, crayfish has become the first choice for the nation's summertime midnight snack with its fresh and attractive taste. However, in recent days, disease control departments in Jiangsu and Jiangxi provinces have issued important reminders, reminding the general public that while enjoying the delicious crayfish, it is recommended to eat no more than 10 at a time to avoid excessive intake and the occurrence of Haff disease. Related topics quickly became hot searches, sparking heated discussions among netizens. Can crayfish still be eaten? How much to eat? How to eat? A food question has been turned into a scientific question.

Safety measures for eating crayfish in summer cannot be ignored

Haff disease: a rhabdomyolytic syndrome

First, we need to understand what Haff disease is.

Haff Disease, also known as rhabdomyolysis syndrome, is a clinical syndrome caused by damage to skeletal muscle cells due to various reasons, which in turn causes the leakage of intracellular substances into the extracellular and blood circulation. Patients usually develop symptoms within 24 hours after consuming aquatic products, with symptoms such as muscle pain, weakness, difficulty breathing, nausea and vomiting. In severe cases, signs such as muscle stiffness, tremor, tenderness, and sweating may also occur. Symptoms such as dark urine, general discomfort, numbness, stomach pain, and even life-threatening may also occur.

Haff disease was first recorded in 1924, when an outbreak of the disease characterized by "severe myalgia combined with soy sauce-colored urine" occurred in the Königsberg region on the Baltic Sea coast of Germany. Because it was considered to be related to eating fish in the lagoon, it was also called lagoon disease in some areas.

Subsequently, similar illnesses were reported in many parts of the world. The common feature was that the patients had eaten aquatic products, and the types of aquatic products involved were also quite a lot, including freshwater and seafood, such as salmon, buffalo, eel, pike, silver pomfret, crayfish, etc.

The first case of rhabdomyolysis in my country was reported in Nanjing, Jiangsu in 2010, after a diner ate 23 cases of crayfish. It was finally confirmed by experts from the Chinese Center for Disease Control and Prevention as Haff disease. In the following 10 years, similar cases have occurred in about 10 provinces, municipalities and autonomous regions across the country, including one death in Shanghai, which was also the first case of multiple organ failure caused by eating crayfish in my country.

Some experts have suggested that the cause of Haff disease may be due to the biological enrichment of fat-soluble, heat-stable freshwater or brackish water algae toxins produced under some unknown conditions in the aquatic food chain. Based on the above research, it is speculated that the pathogenic factor may be an unknown toxin that is not within the current toxin detection range, or a compound composed of several known toxins. During the growth process, crayfish may also accumulate unknown toxins in their bodies through feeding. Their bodies may contain certain biological or chemical substances that have not yet been fully identified. These substances may induce Haff disease when ingested in large quantities or when individuals are sensitive to certain substances.

Haff disease may cause muscle stiffness, tremors, tenderness, sweating, and dark urine.

Haff disease and crayfish: not necessarily related

Although every year there are people who are hospitalized for symptoms such as muscle aches, general fatigue, chest tightness, palpitations, and soy sauce-colored urine due to excessive consumption of crayfish, scientists say that this does not mean that eating crayfish will definitely lead to Haff disease. The onset of Haff disease is related to a variety of factors. The medical community generally believes that it may be related to individual differences, certain biological toxins or chemicals in food, and other factors. Therefore, we cannot simply attribute Haff disease to the consumption of crayfish.

The US FDA has tested suspected crayfish samples for heavy metals, pesticides, herbicides, freshwater and marine algae toxins, and the results were all negative. There were early rumors online that shrimp washing powder was the cause of the disease, but doctors said that although shrimp washing powder contains oxalic acid, the content is not enough to cause muscle dissolution in the human body.

The China Association for Science and Technology, Shanghai Disease Control Center, Shanghai Fifth Rehabilitation Hospital and other professional institutions have publicly stated that there is currently insufficient evidence to prove that "eating crayfish can induce rhabdomyolysis syndrome." In addition to eating aquatic products such as crayfish, factors that cause Haff disease include excessive exercise (such as running a marathon, improper use of a fascia gun), heat stroke, some drug-induced infections, and certain metabolic diseases or genetic diseases may also cause related symptoms.

Although authoritative statements from the scientific community have helped crayfish get rid of the label of being the culprit of Haff disease, safety measures for eating crayfish in the summer cannot be ignored.

Crayfish may indeed carry parasites, but this is not exclusive to them. Other aquatic organisms can also carry parasites, such as frogs, snails, shellfish, fish, water chestnuts, etc. The key to preventing parasitic diseases is to cook food thoroughly, especially not to eat raw or half-cooked crayfish. People in some places like to eat drunken shrimp, which is risky. Wine can kill bacteria but may not kill parasites. A safer way is to cook it at 100℃ for more than 10 minutes.

At the same time, experts recommend not to eat wild crayfish, and not to buy crayfish of unknown origin. Wild crayfish may absorb heavy metals, pesticides and other pollutants in the water during their growth, and these harmful substances may pose a potential threat to human health when eaten. At the same time, avoid eating shrimp heads, because shrimp heads are rich in these heavy metals and may host microorganisms and parasites.

Therefore, although Haff disease is related to the consumption of crayfish, it is not necessarily related. For food lovers, as long as they pay attention to eating in moderation, choose regular channels to buy, and ensure that they are cooked thoroughly, they can reduce the risk of Haff disease with a high probability. However, for people who are prone to allergies or have underlying diseases, they should still be cautious when eating crayfish to avoid inducing or aggravating their condition.

While pursuing delicious food, health is always an important factor that we cannot ignore. Let us treat the relationship between crayfish and Haff disease with a scientific attitude, so that we can enjoy the fun of delicious food while ensuring our health.