The mice were fed with bracken in the laboratory, and as a result, gastric cancer, intestinal cancer, breast cancer and bladder cancer occurred in the mice. The experimental data also revealed that the content of these carcinogens was the highest in the rhizome of Pteridium aquilinum, followed by in the leaves.

Protopterin is also a very unstable compound, which can be dissolved in hot water or hot ethanol, and can be transformed into pterin B with no carcinogenic activity under acidic conditions at room temperature, and may be transformed into nearly carcinogen/mutagen-an unstable diketene under alkaline conditions, which can make the DNA structure unstable and break, thus triggering a series of abnormal cell reactions, and finally leading to cell mutation.

2. Day lily

Fresh day lily contains toxic substance colchicine. After this substance enters the human body, it will make people dry throat, thirsty, burning sensation in the stomach, nausea, vomiting, abdominal pain and diarrhea.

3. Fresh lentils

Fresh lentils contain saponins and alkaloids, which are toxic, but will dissolve when heated. Blanch with boiling water or oil before eating, or dry until it becomes discolored before eating.

4. Immature tomatoes

Because immature tomatoes contain alkaloids, people can be poisoned after eating them. Therefore, you must eat red and ripe tomatoes. Especially if there are children at home, they may not notice and eat directly, but it is no problem not to eat in large quantities.

Extended data:

Doctors recommend vegetables:

1 cucumber

Cucumber contains vitamin C, vitamin B and many trace minerals. It is rich in nutrients and tastes crisp and refreshing when eaten raw. From the point of view of nutrition, cucumber skin is rich in nutrients and should be kept raw.

However, in order to prevent the harm of pesticide residues to human body, cucumber should be soaked in salt water for 15-20 minutes before being washed raw. When soaking cucumber in salt water, don't pinch your head and remove the roots. Keep the cucumber intact to avoid the loss of nutrients from the cut surface during soaking. In addition, cold salad should be cooked and eaten now, and it should not be placed for a long time after it is done, which will also lead to vitamin loss.

2, persimmon pepper or pepper

Pepper is the food with the richest vitamin C content in all vegetables. Vitamin C can improve human immunity and help resist various diseases. In summer, people are prone to catch a cold, and often go out. They have more contact with the external environment and more chances of being infected with the virus, so they need to improve their immunity.

Henan Health News Network-These three vegetables are never eaten by doctors. The more you eat, the happier the cancer cells are.

People's Daily Online-Six Vegetables Recommended by Doctors to Lose Weight Quickly