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Can coffee cause cancer?

Whether earlier it was simply not advertised (or can really not know what they were dying from), or there were no such connections with a huge number of people, but a while ago almost nothing was heard about cancer. And now quite often on hearing – “yes, he died of cancer.”

The last quarter of a century, namely since 1991, one of the most popular drinks on the planet – coffee bears the label of “possibly causing cancer.” And more recently, on June 15, 2016, the International Agency for Research on Cancer (IARC), a division of the World Health Organization (WHO), which is involved in the assessment of evidence and research results related to cancer, has stated …

… that coffee does not cause cancer.

In the distant year of 1991, this same agency placed coffee in the category of carcinogens 2B, suspecting the guilt of this drink in bladder cancer. Twenty-five years later, another group of IARC scientists gathered to evaluate research and scientific publications on the relationship of coffee to bladder cancer and not only. This working group, which, in addition to seven IARC observers, included 23 experts from around the world, met from 24 to 31 May 2016 to assess the impact of “coffee, mate, and very hot beverages” on the likelihood of cancer in consumers.

This time, based on scientific research and medical statistics, the expert group came to the conclusion that the weight of accumulated evidence allows us to reduce the classification of the cancer’s cancer risk. Therefore, on June 15, 2016, coffee is classified in Group 3, or “not carcinogenic to humans.” For fans of coffee – this is encouraging news. 
How does IARC assess the carcinogenic risk?

IARC has a classification of carcinogens that assigns a category from 1 (carcinogens) to 4 (probably not carcinogens). Experts assess evidence of various types, including cancer research in humans, animal cancer research, sources and mechanisms of exposure (when it is known how a substance can cause cancer). 
Some of the substances that IARC refers to Group 1 (carcinogens) are not surprising, for example, this list includes: arsenic, formaldehyde, diesel engine emissions and tobacco.
However, when the substance enters Group 2, everything becomes less obvious. Both subgroups 2A and 2B, mean the existence of limited data on the dangers of cancer for humans. But the classification may change from Group 2B (“may cause cancer”) to Group 2A (“probably causing cancer”) when there is sufficient evidence that the relevant substance is a carcinogen for animals.

For such a reassessment, IARC experts examined more than 1,000 studies, but the combination of evidence did not allow raising the classification above “can cause cancer.” In its report of 2016, the IARC Working Group states that the previously stated relationship between coffee consumption and bladder cancer could be associated with an inadequate evaluation of the impact of tobacco smoking in previous studies.

Now that the international group of experts has weakened our concerns about the connection between coffee and cancer, can we consider ourselves safe? 
Maybe coffee is good for a person?

Coffee is consumed by more than half the adult population in the US, consuming an average of three cups a day. Europe and Russia are almost inferior in terms of the amount of coffee consumed. If you drink coffee, the good news for you is that you do not need to reduce its consumption. In addition, consumption of coffee in moderate quantities can bring health a number of benefits. Now you can breathe a sigh of relief.

Despite the fact that the definition of the term “moderate amount” varies among different studies, as a rule, this means 3-5 cups a day. And although the standard cup contains 8 ounces (227 g), do not forget that most coffee houses offer coffee in 12 ounce cups (340 grams). A standard cup of coffee contains, on average, 108 mg of caffeine. But this amount can vary, depending on the strength of the drink and the size of the portion. The Mayo Clinic states that for most healthy adults, a dose of 400 mg of caffeine (4 cups a day) is permissible. 
Many recent coffee studies were conducted at the Harvard School of Public Health, which reports on the connection of moderate coffee consumption with favorable health moments.
Perhaps the most pragmatic measure of the utility of something for health can be mortality. This is true if coffee is considered, or some other substance. To this extent, the meta-analysis of data (a large-scale statistical analysis of data presented to various studies), both for 2014 and for 2015, shows that moderate coffee consumption is associated with a reduction in the risk of death from all cancers. Other similar analyzes have shown a reduction in the risk of serious diseases, including strokes, heart attacks, type 2 diabetes, and Parkinson’s disease.

But what about cancer? Here, the meta-analysis also showed that coffee consumption is associated with a reduction in the total number of cancer cases, and is particularly beneficial for reducing the risk of liver cancer (and treating liver diseases). In the IARC assessment of 2016, the working group stated that available evidence suggests that coffee has a carcinogenic effect on breast cancer, pancreatic cancer, and prostate cancer. They also noted that coffee has a beneficial effect on the mucous membrane of the uterus, and on liver cancer.
Although, at one time, coffee was strictly forbidden to pregnant women, midwives now talk about a safe dose of 200 mg of caffeine per day for pregnant women. This is equivalent to a large cup of coffee with a volume of 12 ounces (340 g). So, pregnant women do not need to switch to decaffeinated coffee, if they drink no more than a cup of coffee a day. Although the assumption that consuming more coffee can cause problems, is not backed up. Data on whether an increase in caffeine (more than 200 mg / day) increase the risk of miscarriage, to date do not agree with each other.

While it becomes clear that moderate consumption of coffee can be considered as beneficial to health, the reasons for its effect on health are not yet clear. A study at Harvard suggests that it’s not about caffeine, but rather about coffee components that have antioxidant and anti-inflammatory effects. 
What if the coffee is “very hot”?

There is an interesting nuance: MAIR states that you can drink coffee, but only if it is not too hot, that is, its temperature should not exceed 65 degrees Celsius. “Very hot drink” refers to their classification to group 2A, that is, “probably causes cancer.”

It is believed that this is due to the destruction of esophageal cells caused by a hot drink. In fact, it acts as a tumor activator. However, this research has revealed such connections in mate, which is traditionally used at a temperature close to boiling, using a metal straw. With coffee, the situation is somewhat different, the US this drink is served at a temperature of 60 degrees Celsius. So if coffee does not burn lips, then there is no need to chill it.


Of course, coffee is not suitable for everyone. Consumption of a large amount of caffeine (more than 500-600 mg per day) can cause such side effects as insomnia, increased nervousness, anxiety, irritability, upset stomach, heart palpitations and muscle tremor. Some people, in addition, are more sensitive to caffeine than others, and such symptoms can occur even with small doses of caffeine. Because of this, risk / benefit analysis may indicate a higher risk for people with such health problems, anxiety disorder syndrome, or taking certain medications.

But if you are a healthy person and like coffee, then the best advice seems to be to continue to satisfy your thirst – in moderation, of course – but at the same time reduce your coffee consumption if and when it starts to conflict with your health. Well, if you are concerned about health problems, then you should definitely talk with your doctor. 
American scientists and physicians believe that the main danger in this drink is the chemical compound acrylamide, which provokes oncological diseases. It is formed during heat treatment during the preparation of instant coffee.


Acrylamide is a dangerous carcinogen, capable of provoking vascular diseases and many others. Experiments have shown that in most cases rodents who used water with added substances developed oncological diseases.

US human rights activists intend to enforce the law on the labeling of dangerous products in coffee machines. In this case, in particular, owners of car washes and gas stations will be required to place warnings on automatic machines about the presence of chemical components that cause cancer in a soluble drink, ScienceAlert reports.


Meanwhile, natural coffee is recognized by experts as an effective tool for the prevention and control of a variety of diseases. People who eat three or more cups a day are less likely to die from heart disease. In addition, coffee lovers are less likely to suffer from depression and mental disorders.

The whole thing, of course, in carcinogens. The one in potatoes, coffee and cereals is called acrylamide. In large quantities, it can appear in foods cooked at 120 degrees or higher. Russian scientist, academician Valery Petrosyan took a long time to study colleagues. And in the end he refused himself and forbade his family to eat floury, fried potatoes and drink coffee. 
“There is a recovery of acid when interacting with sugars, acrylamide is formed, which is carcinogenic and causes cancerous tumors. If you want to live in longevity and health, you will refuse anything, “said Valery Petrosyan, vice-president of the Russian Academy of Natural Sciences and expert on chemical safety.


Chairman of the Council of Europe Donald Tusk is preparing a document where he urges to limit the consumption of these products or completely abandon them to citizens of the entire Old World. An alternative to a dangerous bread will be corn flour, and potatoes – rice. A new agreement with Japan on the multimillion-dollar supply of the latter for Europeans – as confirmation of the findings of scientists. 
“These are mainly oncological diseases associated with the intestinal system, cancer of the stomach, intestines, and liver. The more heat treatment, the more chemical additives, the worse, “said therapist Semyon Galperin.

But in Russia, replacing carcinogenic products – especially legislatively – no one is going. According to Rosstat, potatoes and bread are the main products on the table of 80 percent of Russians. In addition, they are the most affordable. So, the risk of getting sick, if you follow the scientific reasoning, our citizens – the highest. 
“To say that this research can fundamentally change the consumers’ preferences of Russians is unlikely. Moreover, there is nothing to replace them with, “- explained the economist Dmitry Nesvetov.


Care for their health both in Russia and abroad is left to the fear and risk of everyone. Food prohibitions are useless. Especially where these products are part of the gastronomic culture. No matter how many arguments scientists give, complete refusal of aromatic espresso or fried potatoes requires concrete and even frightening examples. But so far it has not been possible to link science directly to the same bread and death from cancers.

The beverage can begin to label as a dangerous product

The court of the American state of California is currently considering an unusual case. If the lawsuit of the Council for Education and Research on Toxics is satisfied, cafes and gas stations selling coffee will be required to post signs warning that coffee can cause cancer. Violators will have to pay a fine, notes Science Alert.

A group of researchers who filed a lawsuit believe that coffee contains acrylamide, a substance that is considered carcinogenic.

In this case, the fact of the danger of acrylamide is not clinically proven. It is known that in large doses this chemical compound actually causes cancer in some experimental animals. However, as experts emphasize, laboratory mice received doses of acrylamide, hundreds of thousands of times higher than those that people get with food. It should be noted that acrylamide is formed when frying almost any plant food – vegetables and cereals, and not just coffee. The reverse is also true – it is impossible to roast coffee beans and not to get acrylamide compounds. 
In general, experts say, the risk of getting cancer is reduced by 18% in coffee mates compared to other drink lovers. Finally, coffee fans are less likely to face future Alzheimer’s disease or senile dementia.

In spite of the fact that in the mentioned claim the focus is on coffee, acrylamide is present in several types of finished products, as well as in cigarette smoke. So even passive smokers, and with them people who fall under the puffs of smoke on the street, not wanting to do so, are somehow affected by the carcinogen. Live Science explains that in the list of products containing acrylamide, along with coffee beans, there are starchy foods such as French fries and potato chips, cereals, hot toasts, and canned olives, which look a bit strange here, but nonetheless.


Acrylamide is also used in some industries for the production of polyacrylamide and acrylamide copolymers – substances necessary for the manufacture of paper, dyes and plastics. In addition, acrylamide substances, according to the National Cancer Institute (US National Cancer Institute), are often used to purify drinking water and wastewater. 
In NCI, it is added that, despite the industrial use of acrylamide, basically the substance affects the body through smoke and food. If we believe the studies published in 2004 and 2008, we can reduce the amount of acrylamide in the diet by abandoning the starchy products or at least reducing their number in the menu.

If you have long wanted to quit smoking, then the story with acrylamide can be another reason why you need to do this. A review on a topic published in 2009 in the journal Nutrition and Cancer shows that smokers of markers of acrylamide exposure in the blood are usually 3-5 times greater than those of non-smokers.

What happens with acrylamide in the body?

Once acrylamide enters the body, it turns into glycidamide, a compound that can cause mutations and damage to DNA. But despite the fact that all this is true for laboratory mice, the effect of acrylamide on the human body is less obvious, so scientists prefer not to make expository conclusions yet.

Some studies do say that acrylamide can increase the risk of developing cancer in humans. However, other studies conducted almost at the same time, believe that there is no similar effect for the compound and can not be. There is a possibility that the reason for the mixed results is the difficulty in determining more or less accurately the amount of acrylamide with which each participant of the study deals. Plus, it’s important to consider that mice and humans metabolize acrylamide at different rates, so projecting the results of rodents into humans would be wrong.


At the same time, however, acrylamide still found a place in the list of possible carcinogens, prepared by the International Agency for Research on Cancer (the International Agency for Research on Cancer), part of the World Health Organization. And some companies, CNN reports, have already expressed their readiness to declare potential risks on the packaging of their products. Anyway, if we talk about coffee, at the moment it is not included in the number of carcinogens, according to IARC. Moreover, WHO experts agree that in moderate amounts, coffee can even reduce the risk of certain cancers, including liver cancer, colon cancer and one type of melanoma.

Sources: -rak

Coffee does not cause cancer, but reduces the risk of oncology, the IARC statement

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