1. Scientific research in recent years shows that bracken also has a certain cancer risk. In 1970s, the relationship between eating bracken and esophageal cancer was investigated in the mountains of central Japan. The results showed that eating bracken increased the incidence of esophageal cancer by 2. 1 fold in men and 3.7 times in women. In North Wales, the incidence of gastric cancer has always been high. 1990, a case-control study also showed that eating bracken in childhood would increase the risk of gastric cancer in the future.

2. Protopterin contained in bracken is a carcinogen, which will lead to a higher incidence of esophageal cancer and gastric cancer. Animal experiments have also confirmed that ferns can cause cancer in animals. Boiling and soaking in water can reduce the carcinogen content, but it will not be eliminated. It's best to eat less bracken. You only eat in Tomb-Sweeping Day a few times a year, but you don't eat in large quantities or every day. There should be no problem.