Recently, I introduced some of the benefits of eating shrimp to you, and it is estimated that many friends will eat shrimp as the main food, which makes me very worried. Because shrimp may produce a lot of toxins in the process of breeding, processing, storage and transportation, and even add a lot of harmful chemicals, which has a great impact on our health. So hurry up to do an issue of content and remind everyone, I am nutritionist Wang Yan, health is our greatest wealth, let us manage him well. 
I have a friend who works on Wall Street, and he's a very busy young man who works overtime a lot and has a lot of pressure. So there are many opportunities to eat out, and he especially likes to eat seafood, especially shrimp. One day, he suddenly felt unwell, nauseated, vomited, and dizzy after dinner. When he went to the hospital, the doctor suspected that he might have been poisoned. After the examination, I didn't find the reason, so I suspected that it might have something to do with what he ate, and after doing some tests, it was found that there were a lot of heavy metals in his body. These heavy metals mainly include mercury, lead, etc., and some other chemical residues. Of course, it wasn't necessarily whether these substances were the direct cause of his symptoms, but it was clear that the other ingredients in the shrimp could be the cause of his discomfort, and there were also some hazards that he didn't know about.
So what kind of harmful substances are often found in shrimp? The first is antibiotics, in the process of shrimp farming, excessive or improper use of antibiotics will lead to people eating this shrimp for a long time, antibiotic resistance. Of course, it is not certain whether antibiotics can cause these symptoms, but if you eat shrimp that contain antibiotics for a long time, it may not be effective if you take antibiotics when you are infected. In addition, pesticides, fungicides and other chemical residues, some of which are exposed to these chemicals for a short period of time but in high concentrations, can cause acute symptoms such as nausea, vomiting, and abdominal pain. I guess that's the case with this friend. Long-term exposure to low concentrations of harmful substances may unknowingly produce some chronic diseases, such as neurological problems, hormonal imbalances, and even the risk of cancer.
The third is that heavy metals, such as mercury, lead, manganese, arsenic, etc., will accumulate in shrimp. As we said on our last show, eating shrimp and vitamin C cannot be used at the same time because it contains arsenic. However, those are organic arsenic and are not necessarily harmful. However, if the amount is very large, other heavy metals, especially mercury, cadmium, lead, etc., can cause adverse effects on our nervous system, brain, and kidneys, especially for pregnant women, infants, and children, who are more susceptible to heavy metal infections.
Therefore, in clinical practice, we must pay attention to heavy metal detection, which can be checked by detecting hair and urine. In addition, there are many environmental pollutants in shrimp, such as polychlorinated biphenyls (PCBs) and persistent organic pollutants (POPs). These can affect our health, and the harm to the body is manifold, including disrupting the endocrine system, reducing immune function, affecting adolescent development, and increasing the risk of cancer.
Some people say that I will buy wild shrimp, the environment is good. But there's also the question of how they store and handle these shrimp. Sometimes the cheaper it is, the more chemically treated it is. For example, sodium bisulfite, which is used to prevent shrimp from developing dark spots when exposed to oxygen after harvesting. Everyone thinks that dark spots are not good, but in fact, there is nothing wrong with black spots, just like apples, the meat will turn brown in the air after being cut, but it does not affect nutrition at all.
The addition of this sodium bisulfite, which does not stop the deterioration of the shrimp, or has any other effect, is purely for the sake of aesthetics. So everyone loves that the shrimp meat is perfectly pink and there are no shades. In fact, having a little bit of dark spots is not necessarily a bad thing, which means that the shrimp has not undergone such chemical treatment, on the contrary, it means that the shrimp has not been affected by the chemicals.
Another option is the addition of phosphates, which work to increase the absorption of moisture by adding 7 to 10 percent of the seafood's weight. It's not very conscientious to say, mainly to make these seafood heavier, increase moisture, and look fresher. But when you fry it, you will find that it will fry a lot of water, and it looks very elastic and gelatinous. After cooking, the shrimp is also strangely translucent, because the shrimp are not opaque when they are properly fried.
But if you want to avoid this, try to buy shrimp with shells, so that you can buy shrimp that have not been treated with phosphate. The U.S. Food and Drug Administration considers small doses of phosphate and sodium bisulfite to be safe. But in the United States, at least 1% of the population is allergic to sulfites.
So how do we choose shrimp that are less poisonous or non-toxic? First of all, look carefully at the label, some labels will indicate what kind of chemical is contained or what chemical has been treated. Usually, such non-poisonous or less poisonous shrimp are certified by some important institutions and comparatively speaking, the toxin level is low.
Secondly, of course, try to choose wild-caught shrimp. Wild-caught shrimp may not have as many added hormones, antibiotics or other substances, and the environment may be cleaner and contain fewer heavy metals. But as I said earlier, if they use phosphate and sodium bisulfite to deal with it, then it is also problematic. 
Third, choose relatively small shrimp. The smaller the shrimp, the less toxin accumulates, and the less time it takes to accumulate toxins. In general, the most important thing is to look at the manufacturer of shrimp and the country. Because different countries have different regulations on seafood, some countries are stricter, some countries are more relaxed, and heavy metal testing may not be carried out frequently. Some seafood certification bodies, such as the Marine Stewardship Council and the Aquaculture Stewardship Council, often certify these products, particularly by testing for heavy metals as part of the standard. 
The other thing is to look at the freshness and smell. On the one hand, it should be fresh, this freshness is natural, it should have some marine smell, the texture should be firm and translucent. Avoid buying shrimp that have a strong odor, are curved or soft, or are discolored, as these can be signs of poor quality. This friend of mine now regrets that he used to only enjoy shrimp as a delicacy, but did not care about the pollution and health problems behind this delicacy. All in all, shrimp is very nutritious, but everyone must be careful about the pollution and toxins caused by its breeding, processing, ** and storage environment. 
Thank you for tuning in to my show. If you like, please**, like and subscribe, and share your experiences and questions in the comments section. I'm nutritionist Wang Yan, guarding health, we'll see you next time.