Is it true that bracken causes cancer? Scientific proof
There is a plant in the mountains of my hometown that people call "foot-based moss". Many people relied on it to get through the difficult times when my mother often said that there was not enough food to eat. But by the time I was born, no one ate it anymore. By the time I was in high school, this plant had become popular again, and gradually its price surpassed that of most "domestic" vegetables. It was even specially processed in a factory, packed in beautiful boxes, and sold to other places. This is how I learned the scientific name of this wild vegetable: bracken. According to legend, it is not only "safe" and "pollution-free", but also rich in nutrients and even has "anti-cancer" effects.
So I listened and believed it. When I went home during the holidays, I went to buy some to eat. When I went back to the city again, I also brought some to give to friends, which was always welcomed. One day when I checked other information, I accidentally found that this "pure natural" wild vegetable has a clear carcinogenic ability!
Fern is one of the most widely distributed plants in the world, found on several continents. In many places, its shoots are used as vegetables and starch is also extracted from the roots. More than a hundred years ago, people noticed that this plant can cause poisoning in cattle. Cows that eat bracken shoots in large quantities will die after a few weeks at the fastest. Those who eat less, the bone marrow function is gradually lost, resulting in a lack of white blood cells, thrombocytopenia, and acute hemorrhage and other symptoms. Sheep that eat ferns will gradually lose their sight. In the 1960s, more studies found that ferns can also cause cancer. This discovery aroused great interest among scientists. Many studies using ferns to toss various animals such as mice confirmed that ferns can indeed cause cancer in animals.
If a synthetic substance or processed food has such a "bad record" - especially carcinogenic ability, it will definitely be criticized and "pulled out and shot for five minutes". However, bracken is an "ancient" "pure natural" "green food", so people can tolerate it to the point of "indulgence". Even with the above "criminal evidence", people have only a small "verbal warning" for it. Bracken is still being chased by people.
"All-natural" wild vegetables can actually cause cancer? This is too challenging for people's psychological limits. And fern, again, was the first, perhaps the only food plant discovered so far that can cause cancer. So scientists worked tirelessly to figure out what was in it that caused cancer. For nearly two decades, many attempts have failed. It seems that this carcinogen is very unstable and difficult to isolate, and the carcinogenic effect is not so easy to confirm. In the early 1980s, a Japanese scientist succeeded in isolating something called ptaquiloside. The Chinese translation seems to be more reasonable. Since then, many people have tested this thing and found that feeding it to animals can produce the aforementioned symptoms. Biochemical experiments have found that it can also react with amino acids and can also damage genetic material DNA. That is to say, it is more toxic than thought. Worst of all, it can be transferred from cow food to milk, and it can also be dispersed into water and soil. If cows eat ferns, calves can develop symptoms of fern poisoning even if they only eat milk. This may explain why people in areas where ferns are thriving have a much higher risk of esophageal cancer and other cancers, even if they don't eat ferns.
However, people's coddling of "wild vegetables" and "natural foods" has led to the capture of protofernin, which has not kept people away from bracken. After all, sometimes the results of animal experiments do not appear in humans, and the incidence of cancer itself is not so high - doubled or tripled, and people may not be able to intuitively understand it. Even if someone has cancer, it is difficult to doubt that it is bracken, which has been eaten since the age when humans did not know what cancer was. On the other hand, the bracken people eat is only a young bud - is it also "old spicy" like ginger? Or, when people eat bracken, they have to process and cook it, will it destroy the toxin?
Because protokeratin was isolated, the above two problems were easy to verify. Scientific experiments have found that protokeratin is found in all parts of ferns, and the ferns that people eat - the young parts of ferns have a higher content! However, what makes people feel a little relieved is that fresh ferns are bitter and astringent. Except for some people who pursue "original flavor" and "pure natural", people generally treat fresh ferns with grass ash or alkaline water. And this treatment will greatly reduce the content of protokeratin. And milk, which is generally sterilized by high temperature, will also greatly reduce the toxicity of protofern.
However, such treatment only reduces, not eliminates. For humans, eating some treated bracken will generally not damage the bone marrow like cattle, or go blind like sheep. But will chronic toxins, such as carcinogenesis, emerge?
In the 1970s, the relationship between eating bracken and esophageal cancer was investigated in mountainous central Japan. It was found that among residents there, eating bracken increased the incidence of esophageal cancer in men by 2-1 times, and in women by 3-7 times. In North Wales, England, the incidence of stomach cancer has been high. A "case-control" study conducted in 1990 also showed that eating bracken in childhood increased the risk of later stomach cancer. Similar studies have been done in other parts of the world, and the results are generally consistent.
For most people, these research results only appear in academic journals. And some people who promote "wild vegetables" are eager to cite "scientific research findings" to support the "nutrition" and safety of "pure natural", but turn a blind eye to these studies. What's more - including some encyclopedic entries, they also claim that "scientific studies in recent years have shown that bracken also has certain anti-cancer effects." And one of the studies that support this claim is that protofernin has shown a certain inhibitory effect on the growth of certain cancer cells - scientifically, such results are far from saying that "bracken can fight cancer". Another investigation that supports this function is that eating a small amount of bracken (once a month or more) has some anti-cancer effect. Academic colleagues rated the results of this study as "surprising" - although it was statistically significant, due to the small sample size, this weak "anti-cancer effect" may well be a "digital illusion".
In general, the conclusion that "bracken causes cancer" is supported by fairly solid scientific evidence. And the claim that "bracken fights cancer" is like a vicious gangster who gives a few change to a beggar for no reason and is summarized as "this gangster is quite kind".
