Hypotheses to explain the increase in cancer cases

The publication of our file “Why so many cancers among people in their forties? » generated a voluminous letter. Several of our readers have put forward hypotheses to explain the increase in cancers among young adults. What does science say about it? We discussed it with Professor Borhane Annabi, professor of biochemistry at UQAM and holder of the Research Chair in Cancer Prevention and Treatment.

Several readers have submitted hypotheses to us and wonder if they could explain the increase in cancer cases among young adults. Among them, pesticides, GMOs, cellular waves, food additives, etc. Apart from the most often cited risk factors, such as smoking and obesity, is there research being done on these other potential causes?

“Of course there is research on these hypotheses,” says researcher Borhane Annabi. But so far, the evidence of the carcinogenic effect of the consumption of genetically modified foods, or of exposure to cellular waves, is not sufficient to draw a correlation with the increase in cancer cases. “It seems to be imprinted in people’s imagination…” notes the researcher, who is sad that recognized risk factors, such as excessive consumption of processed foods, lack of physical activity, or even lack of sleep, are not receiving greater attention to prevent cancer.

Take, for example, the increasing use of pesticides over the past 50 years – a hypothesis mentioned by many readers. Isn’t this a cause of cancer?

Science has demonstrated the danger that exposure to pesticides poses to farmers who handle them, says Annabi. But when it comes to eating foods grown with pesticides, the correlation with cancer is less clear. “Ultimately, once you receive these foods and wash them, the doses consumed are not enough to accumulate in the body before they are detoxified by the body,” says Borhane Annabi. On the other hand, what has been proven is that the consumption of plants “is always greater than the potential deleterious effect of pesticides”, recalls Mr. Annabi. A diet low in fiber and rich in red and processed meats (such as processed meats) is a risk factor for gastrointestinal cancers. “Personally, I am much more afraid of not consuming enough [d’aliments] plants than having consumed traces of pesticides in these plants. The beneficial effects are much higher than the harmful effects. »

What about food colors and other additives found in processed foods?

Studies are emerging from time to time concerning the toxicity of certain food additives. The way of interpreting the results is different from one country to another: for example, titanium dioxide (which is used as a dye) is prohibited in the European Union, but permitted in Canada. “Certain molecules in food additives are capable of translating carcinogenic mechanisms,” says Borhane Annabi. “But is it really the additive that causes cancer, or rather the excessive consumption, at a young age, of processed foods that contain these additives? For me, this is the reflection we must have. »

Another thing that has changed over the past three decades is the use of cell phones and wireless networks (Wi-Fi). Is there an avenue to explore?

Yes, but it is perhaps not the one proposed by the readers who raised this hypothesis. Several readers say they are concerned about exposure to the waves emitted by these devices – so far, the international scientific consensus is that there is not enough evidence to confirm the carcinogenic potential of this exposure. These “non-ionizing” waves are very different from the ionizing waves used during an x-ray, recalls Mr. Annabi. “Ionizing rays break DNA, which is why we must limit our exposure. Cellular waves have no ionizing impact. »

On the other hand, it is undeniable that the omnipresence of telephones, tablets and computers connected to the Internet has had an impact on the health of the population, says Borhane Annabi. “And it’s beyond ionizing or non-ionizing rays,” says the researcher. “It’s the quality of our sleep that is affected. » Sleep regenerates the immune system, allowing it to better identify and attack the broken cells that cause cancer. “And what has disrupted our sleep for 20 years is the emergence of technologies. I admit it myself, I take my emails before going to bed…”

Read our file “Why so many cancers among people in their forties? »