The 2021 cancer barometer from the National Cancer Institute and Public Health France shows that certain received ideas about cancer persist. Overview of these erroneous beliefs.
The perception of certain lifestyles increasing the risk of cancer is improving, but certain misconceptions persist. the cancer barometer 2021 published this Monday by the National Cancer Institute (INCa) and Public Health France (SPF) shows this well. This study, carried out every five years since 2005, draws its lessons from a telephone survey of 4,938 people aged 15 to 85 over several months in 2021. It shows that certain beliefs about cancer are quite widespread in the population. despite the lack of scientific basis to support them. Here is a non-exhaustive overview.
• The risk of cancer exists from 9.2 cigarettes per day
Smokers questioned for the barometer estimate that the risk of tobacco-related cancer exists from 9.2 cigarettes per day on average. In detail, 30.2% of smokers identify a risk from one cigarette per day, 25.3% between 2 and 9 cigarettes per day and 18.9% between 10 and 19 cigarettes per day.
More than one in five smokers (21.2%) think that the dangerousness threshold is above 20 cigarettes per day. 4.4% don’t know.
“Smoking is dangerous from the first cigarette,” says the director of the National Cancer Institute (INCa), Thierry Breton. “You should not start smoking at all and stop as soon as possible”.
• The number of cigarettes per day is more dangerous than the duration of smoking
4 smokers out of 10 think that the duration of smoking has a greater influence on the appearance of cancer than the daily quantity of tobacco smoked, nearly 6 out of 10 smokers think that it is rather the number of cigarettes smoked per day. According to INCa and SPF, “prolonged exposure over time to carcinogenic substances in tobacco smoke is much more dangerous: when the duration of smoking doubles, the risk of cancer is multiplied by twenty”.
“Double the daily consumption doubles the risk of cancer,” adds the survey.
• Playing sports cleans the lungs
Asked about the statement “playing sports helps cleanse the lungs of tobacco”, 54.8% or more than half of the people questioned (smokers or not) say they totally agree or tend to agree” .
However, as Thierry Breton points out to BFMTV.com, this idea is not based on “any scientific basis”. “No mechanism, except stopping smoking, can compensate” smoking. “The earlier we stop, the more we can regain normal lung capacity,” he adds.
• The main dangers of alcohol are violence and road accidents
In terms of alcohol too, there are many misconceptions. The opinion “the main risk with alcohol is road accidents and violence” is the most shared among those questioned as part of the barometer: on average, more than 8 out of 10 people say they agree with this view.
For Thierry Breton, this figure shows that “the health risk of alcohol is less well identified”. Indeed, only 50.2% of 15-85 year olds believe that drinking one glass of alcohol a day increases the risk of developing cancer.
Nevertheless, a study published by Public Health France in 2015 estimated that 41,000 deaths were attributable to alcohol in metropolitan France this year, including 16,000 deaths from cancer (the others came in particular from cardiovascular diseases and digestive diseases). This study attributed 5,400 alcohol-related deaths to an “external cause (accident or suicide)”.
“We would therefore expect the health risk to be at the same level as the risk of violence and road accidents”, comments Thierry Breton.
• Strong alcohols contribute particularly to the risk of cancer
Another erroneous idea about alcohol: the fact that “it is especially strong alcohol that increases the risk of cancer”, an opinion shared by 38.6% of people questioned by INCa and SPF.
“It doesn’t matter the type of alcohol, it’s the dose of alcohol that counts”, explains Thierry Breton.
A standard drink contains approximately 10 grams of pure alcohol, regardless of the type of drink (wine, beer, or hard liquor). On the other hand, unlike cigarettes, alcohol consumption that remains below the benchmarks issued by the public authorities (no more than two glasses a day, not every day) presents no increased risk compared to someone who does not drink it at all.
• Drinking a little wine reduces the risk of cancer
More than one in five people (23.5%) believe that “overall, drinking a little wine reduces the risk of cancer rather than not drinking it at all”. If moderate consumption does not present an increased risk, nothing proves that alcohol has any protective power, according to the director of INCa. “Wine consumption, even small, does not protect against cancer,” says Thierry Breton.
“It is an old belief, in a country, France, where the culture of wine is very marked, he explains.
• Doing UV before the holidays prepares the skin for the sun
The 2021 cancer barometer is also interested in the perception of natural and artificial ultraviolet (UV) rays. 95.7% of those questioned identify that exposure to the sun poses a risk of cancer and 89.5% declare that using UV cabins is a cause of cancer. However, some erroneous beliefs persist. 23.9% of people questioned agree with the following statement: “doing UV before the holidays helps prepare your skin to protect yourself from the sun”.
“Whether in the cabin or in the sun, UV exposure is not protective”, contradicts Thierry Breton.
“Being tanned is not a protection”, adds the director of INCa, who notes a “lack of knowledge about the risks associated with UV and protective actions”.
In 2018, ANSES also warned of the risks associated with artificial UV rays. “Tanning booths emit high-intensity radiation, equivalent to exposure to a tropical sun” which “adds up to those received naturally”, explained on his site the national health security agency. These doses “cause DNA damage and increase the risk of skin cancer”, she added.
Tanning caused by exposure to artificial UV “follows a different mechanism from that of natural tanning and does not provide any protection against the deleterious effects of UV”, according to ANSES.
• Cancer is often hereditary
“In 2021, 67.7% of French people believe that cancer is hereditary compared to 61.8% in 2015 and 52.4% in 2010”, according to the INCa and SPF cancer barometer. This is a “confusion”, according to the two organizations, since it is not cancer that is hereditary, but certain genes that predispose it. “There may be a fragility in the genes, but it is not a transmission of cancer and it is not automatic”, explains to BFMTV.com Thierry Breton.
This belief does not help in prevention. “This induces a form of fatalism, we can say to ourselves ‘what’s the point of doing something if it’s hereditary’. This plays against the idea that we are actors in our health. However, 40% of cancers are preventable” , he pleads.
For the director of INCa, “we must fight all of these received ideas one by one”. He points in particular to the role of health professionals in this process: “doctors are effective when they explain the risk factors to patients, they are believed”.
