ACCORDING TO WHO, CANCER DISEASES (in particular, cancer of the lung, trachea and bronchi) occupy the fifth place in the list of leading causes of death in the world. At the same time, they are much more afraid of them than coronary heart disease or stroke, which are in the first two positions. Fear has given rise to panic: carcinogens are now looking for – and finding – in everything from cigarette smoke and exhaust fumes to non-stick pans and coffee . Let’s figure out which of them you can really hide from and whether it should be done.
What it is
The name speaks for itself: a carcinogen is a substance or effect that affects the integrity of DNA and promotes carcinogenesis, that is, the formation and reproduction of malignant cells. The fact that there are chemicals with such effects became known about a hundred years ago, and in 1916, Japanese scientists were first able to cause cancer in a rabbit during an experiment: the animal was coated with coal tar every day. Of course, there was no question of the ethics of research then – but a revolution took place in medicine, because for the first time it was possible to see how a malignant tumor occurs in an absolutely healthy individual under the influence of chemicals.
Since the resin was a complex mixture of chemicals, scientists (not only in Japan) went in search of other substances that could cause cancer. Despite the fact that carcinogens are indeed more common in synthetic substances, studies have shown that plant compounds can also have carcinogenic properties. However, this does not make either one or the other undoubtedly dangerous.
What are carcinogens
Scientists have not fully decided how best to classify the effects that can cause cancer: they are divided either into radioactive (all types of hazardous radiation fall into this group) and non-radioactive, then into genetic and associated with environmental influences . The latter include lifestyle factors – smoking, alcoholism, unhealthy diet, low physical activity – and exposure to sunlight or viruses, and work in hazardous industries, and the use of certain drugs such as chemotherapy drugs. By and large, it is not important how to classify carcinogens – it is important what this can give in practice. After all, if it is sometimes impossible to refuse from a certain therapy, even carrying a risk of carcinogenesis, then the impact of other factors can be minimized (for example, by protecting the skin from the sun or quitting smoking).
Carcinogens affect DNA , causing dangerous changes – but the latter do not necessarily lead to the formation of a tumor, they only increase the likelihood that the proliferation of abnormal cells reaches a level at which the immune system cannot cope. A recent study found that two-thirds of the genetic mutations that lead to cancer are errors that occur spontaneously when copying DNA, and only the remaining third is caused by environmental carcinogens.
Are they so scary
The WHO list of carcinogens is constantly growing; for a layman who sees a document for the first time, it can cause horror – it seems that all the products and substances mentioned in it are terribly dangerous. In fact , this is not so – and all carcinogens on the list are assigned a special code: 1 (carcinogenic to humans), 2a and 2b (potentially carcinogenic to humans, and for “a” the probability is higher than for “b”), 3 (not classified as carcinogenic to humans), 4 (possibly not carcinogenic to humans).
The first, most dangerous group includes not so many agents – scientists are still not sure about the carcinogenicity of chlorinated water, caffeine even in large quantities, hair dyes, dental materials, sulfites, which are often used in cosmetics, or tea (all these substances are labeled with code 3), as well as those classified as categories 2a and 2b red meat, aloe vera leaf extract , or shift work that disrupts circadian rhythms. This is a random sample of familiar foods from the “carcinogenic list” and shows why you shouldn’t believe the loud headlines about “new research that will shock you.”
Many substances on the list of carcinogens are not as dangerous as they seem: we are not under the influence of them enough or we do not consume them in the quantities necessary to cause real harm. Trying to eliminate all carcinogenic substances from life can affect mental health, rewarding you with anxiety or orthorexia . But still it is worth paying attention to those carcinogens that are recognized as truly dangerous and at the same time amenable to control.
Should you be afraid of fried food?
Research is increasingly hinting that burnt food should be wary of. According to scientists, acrylamide is to blame – a compound that is formed during the heat treatment of certain foods, especially those rich in carbohydrates. This substance is also used in the textile, plastic and paper industries, in the synthesis of dyes and for wastewater treatment. However, there is still no convincing evidence of its harm to humans, although there is data on the ability of acrylamide to interact with DNA and lead to certain mutations – and its place in the list with code 2a is explained by studies in which mice and rats were given doses of dozens thousands of times greater than what you can get.
In general, the carcinogenicity of fried potatoes for humans has not been proven. Experts believe that the consumption of fried carbohydrates should really be reduced because they are full of unnecessary calories – and obesity is one of the main triggers of cancer worldwide.
Will switching to electronic cigarettes save
Of course, smoking is a personal choice of everyone, but you can’t argue with statistics: it is this that is the main cause of lung cancer. It is very important to try to protect yourself from secondhand smoke: according to research , such components of cigarette smoke as benzene, polonium-210, benzopyrene and nitrosamines, not only provoke DNA damage, but also affect the genes encoding the body’s ability to defend against cancer by working thus in two directions at once. Once in the bloodstream, chemicals from cigarette smoke are carried throughout the body, which endangers not only the lungs, but also the kidneys, liver, digestive system, bladder, ovaries and other organs.
At the same time, vapes, invented just in order to reduce the risks associated with smoking (an electronic cigarette in the form as we know it, patented in 2003, and in 2004 was released on the market by the Chinese Hon Lik , whose father shortly before died of lung cancer), in fact, turn out to be almost worse. Their main problem is understudied. But even a negligible amount of research, in comparison with cigarettes, allows us to say that a cocktail of chemicals contained in smoking fluids gradually causes irreparable harm to the body.
Alcohol is also a carcinogen
Alcohol is considered a common cause of breast, larynx, liver, esophagus, oral cavity cancers, and a likely cause of pancreatic cancer. When alcohol enters the body, it breaks down first to acetaldehyde and then to acetic acid. Acetaldehyde causes liver cells to renew faster than normal, and this acceleration increases the likelihood of gene copying errors. It is important that this applies to alcohol in any beverage: aged wine, premium vodka, or the cheapest beer. While we regularly learn new things about the benefits of craft beer or red wine , a dose of healthy skepticism doesn’t hurt as the risks outweigh any benefits so far, and even the authors of alcohol-justifying studies agree.
All this – perhaps, together with attempts to fit alcohol into a healthy lifestyle and find a new business niche – leads to the fact that alcohol enthusiasts are trying to bring new types of intoxicating drinks to the market. For example, alcosynth , which does not lead to the formation of acetaldehyde, or California non-alcoholic wine based on marijuana – the latter can reduce the risks, since marijuana, even when smoked, is less carcinogenic than tobacco.
What about meat and sausage
In 2015, meat was listed as a potential carcinogen. Its problem, scientists say, is in heterocyclic amines (HA) and polycyclic aromatic hydrocarbons (PAHs) – chemicals that are released during heat treatment of meat, especially when frying or grilling. The longer the beef is cooked, the higher the level of potential carcinogens becomes.
Let’s be fair: the connection between GA and PAH and the increased risk of cancer has not yet been established. But a number of epidemiological studies show that addiction to processed red meat increases the risk of colorectal, pancreatic and prostate cancers. WHO advises to consume no more than 70 grams of red and processed meat per day.