Does bracken cause cancer? What is the truth?

Some people say that eating bracken will definitely cause cancer. This statement is incorrect. Bracken will not directly cause cancer. In fact, the onset of cancer is caused by multiple factors. In addition to frequent contact with carcinogens, it is also caused by living environment, living habits, genetic material and other factors. Bracken is a Class 2B carcinogen. If consumed for a long time, there is a risk of cancer, but eating it occasionally will not have a similar effect on the body.

1Carcinogenic mechanism of bracken

When talking about the carcinogenicity of ferns, we have to talk about pteridinic acid. Prototaxol is a "genotoxic carcinogen", which means that it will change genetic material such as DNA and cause cancer.

One of the important differences between genotoxic carcinogens and general carcinogens (such as arsenic) is that there is no "threshold of action". In other words, there is no so-called safe dose - no matter how small the dose is, it can theoretically cause cancer.

2 Is bracken 100% carcinogenic?

This is a typical logical error - there is no absolutely safe intake dose and any dose will definitely cause cancer. These are two completely different things.

Otherwise, the white rice we eat every day will inevitably contain trace amounts of another well-known genotoxic carcinogen - aflatoxin B1, the most potent known carcinogen. Does this mean that we Chinese should never touch rice again? In other words, every Chinese who eats rice as their staple food will get cancer?

In fact, whether cancer actually occurs is often the result of the combined effect of multiple factors over the years: in addition to the dose and frequency of exposure to carcinogens, many other details such as the individual's health status, genetic factors, living habits, living environment, etc. play an important role in the formation of cancer. Otherwise, it is difficult to explain why this person who does not smoke too much dies of lung cancer early while that person who is a heavy smoker is still alive and well in his seventies.

Therefore, whenever you see a headline like “100% carcinogenic,” you can almost 100% determine that it is pseudoscience.

3 Carcinogenicity rating of bracken

Rating of bracken by the International Agency for Research on Cancer (IARC). Bracken is classified here as [Grade 2B], which means it may be carcinogenic to humans.

Please note that the rating object here is bracken, not pteridinol. The carcinogenicity rating of pteridinol alone is actually lower, only level 3, that is: there is insufficient evidence to show whether the substance is carcinogenic to humans and animals; or although the substance is carcinogenic to animals, there is sufficient evidence to prove that it will not have similar effects on humans.

4. It is better to eat bracken in moderation

Seeing this, some people may feel relieved and laugh, and then plan to rush to a restaurant to eat fern root powder for 10 years in a row. Wait a minute! Don't forget that the carcinogenicity of a carcinogen depends on the dose ingested. Even if bracken is only a Class 2B carcinogen, consuming it in large quantities for a long time may still increase the risk of cancer. On the contrary, even if you occasionally eat a small amount of Class 1 carcinogens, such as aflatoxin contained in large quantities in moldy rice and peanuts, there is no need to worry about getting cancer to the point of losing your appetite.