According to CCTV's "*** with concern" report, whether it is experimental animals or livestock, consumption of ferns may cause poisoning, including liver damage, carcinogenic, and this carcinogenic substance is extracted from the fern fern glycosides in the 80s of the last century. By sending the ferns for inspection, it was measured that the content of proanthocyanidins in ferns was from high to low in leaves, stems and roots, and the content in leaves was 10 times of that in roots. In the official website of the International Agency for Research on Cancer (IARC), fernin is classified as a group II carcinogen.

The experimental data also revealed that these carcinogens were highest in the fern's roots and stems, followed by the leaves. Among them, Eurycarpin exceeded the safety limit by up to 37 times, and benzoic acid exceeded the limit by 22 times. Laboratory animal feeding tests on fern carcinogenesis showed that fern can induce stomach cancer, intestinal cancer, breast cancer, bladder cancer and leukemia in rats. Researchers have also conducted carcinogenicity tests on cooked and processed fiddleheads showing that even processed fiddleheads can induce cancer.

The fern is a representative of traditional wild vegetables, is the "king of mountain vegetables", many people think it is green, pollution-free, nutritious, and even anti-cancer, known as the "longevity dish". According to relevant information, fern leaves contain carotene, vitamins, protein, fat, sugar, crude fiber, potassium, calcium, magnesium and other nutrients and minerals. It also contains 18 kinds of amino acids and so on.

However, as early as in the Tang Dynasty, Sun Simiao, a great medical doctor, pharmacist, and "King of Medicine", put forward the idea of "long-time eating into the mass" on fern, which means that eating fern for a long time will bring negative effects to the body. Later, many countries in the world to carry out fern cancer test shows that fern contains cancer-related substances are phenyl oxalic acid, fern lactam, xanthohumol compounds, aconitin and aconitin similar to some of the substances.

But there are also relevant people pointed out that really like to eat fern, to control the amount of fern to eat, occasionally eat less, and do not need to be too panicked, but do not long-term consumption. Long-term, large quantities of fern consumption will indeed increase the rate of carcinogenicity, this is because "although the fresh fern in the consumption of sun-dried, boiled and other processing, can reduce the content of the original fern glycosides, but will not be completely eliminated".