Scientists conducted animal experiments with cows, rats, sheep and quails, all of which induced tumors, with an incidence rate as high as 79%. Later studies have shown that bracken can not only directly cause cancer, but also promote and coordinate the growth of cancer. Scientists tried to feed animals after treating them according to the method of human consumption, and the results still induced intestinal and bladder tumors. It's just a long incubation period and a low incidence.

Scientists have experimented with milk and found that there are carcinogens in the milk of cows that eat bracken. Therefore, small animals raised with milk can induce cancer in intestines, kidneys and bladders, and if humans drink this milk directly, there is also a risk of cancer. However, almost no one drinks raw milk, and the milk that humans drink is generally sterilized at high temperature, which will greatly reduce the risk of cancer.

So, what substance does bracken contain that is so carcinogenic?

After more than 20 years of unremitting efforts, in the early 1980s, Japanese scientists successfully isolated a substance called protopterin. Protopterin exists in the roots, stems and leaves of Polygonum cuspidatum, with the highest content in the shoots. Subsequently, people used "protofern glycoside" for animal experiments and found that it could really induce the symptoms and diseases mentioned above.

It has been proved by scientific research that bracken contains cancer-related substances, including phenyloxalic acid, fern lactam, flavanols, acoflavin and some substances similar to acoflavin, which are related to digestive tract cancer.

Of course, eating bracken once or twice will not cause cancer immediately, which is related to the amount of carcinogens ingested, but eating bracken for a long time will be harmful to health. Don't be alarmed if you used to eat it frequently, because in the process of processing bracken, we usually blanch it with water before eating it, which will greatly reduce the content of the original bracken. However, such treatment only reduces, not eliminates, and if it is eaten for a long time, the original glycoside will still accumulate in the body. Therefore, although bracken is beautiful, it is better to stay away from it.