The idea that sweeteners are bad for your health is not new. Studies have also established a link between their excessive consumption and pathologies such as obesitythe type 2 diabetes and cardiovascular disease. But the links to cancer remained more uncertain.
For example, it had been shown that an artificial sweetener, cyclamate (E952), increased the risk of bladder cancer and testicular atrophy in rats. However, since human physiology is different from that of rats, it was not possible subsequently to find an equivalent link between this sweetener and these risks in humans.
Despite this, the media continued to report a link between sweeteners and cancer.
But today a recent French study published in PLOS Medicineconducted on 102,865 adults (NutriNet-Santé cohort), brings new data (the participants were divided into three groups, non-consumers, low consumers and heavy consumers of sweeteners, this last group being itself subdivided into two according to gender, editor’s note). This important work of statistical analysis has shown that people who consume high levels of certain sweeteners actually have a slight increase in the risk of developing several types of cancer.
To assess their consumption of artificial sweeteners, the researchers asked the participants to keep a food diary (medical history, lifestyle, etc. were also filled in). About half of the participants were followed for more than eight years.
The study revealed that theaspartame (E951) and theacesulfame-K (E950), in particular, are associated with an increased risk in particular of breast cancer and cancers linked to obesity: colorectal, stomach and prostate cancers. This suggests that removing certain types of sweeteners from your diet may reduce cancer risk.
The cancer risk of sweeteners
Many common foods contain sweeteners. These additives mimic the effect of sugar on our taste receptors, providing an intense sweet taste with very little or no calories. Some sweeteners are of natural origin (such as stevia or yacon syrup). Others, like aspartame, come from an artificial synthesis.
Although they contain few or no calories, sweeteners are not without effect on our health. For example, aspartame turns into formaldehyde(a known carcinogen), when the body digests it. It can then accumulate in the cells and make them cancerous.
Our cells are organized to self-destruct when they become cancerous. But it has also been shown that aspartame ” off “ the genes that control this protective process. Other sweeteners, including sucralose and saccharin, have also been shown to damage DNA, which again can lead to cancer.
Sweeteners can also have a profound effect on bacteria that live in our gut – our intestinal microbiota. The modification of these microorganisms can weaken the immune systemagain with a deleterious effect on the identification and elimination of cancer cells.
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The difficulty of collecting data
But until now, these results had only been obtained in cells in culture (in vitro) and not in a living organism – or else in a model organism but not in humans. And these experiments on animals and cells do not yet make it possible to know precisely how sweeteners trigger or promote cancerous changes in cells.
Many of these experiments remain difficult to conduct in our species, as they require the sweeteners being tested to be administered in much higher doses than a human could ever (normally) consume.
Another limitation of previous research on this topic is that most have only observed the effect of sweetener consumption without making a comparison to a control group that did not consume any sweetener. A recent systematic review of nearly 600,000 attendees even concluded that there is limited evidence to suggest that high consumption of artificial sweeteners may increase the risk of certain cancers. A study published in the BMJ came to a similar conclusion.
A study that calls for others
Hence the interest of the results obtained this time for our species by this new study (which concludes that “artificial sweeteners (particularly aspartame and acesulfame-K), which are used in many brands of food and drink products worldwide, have been associated with an increased risk of cancer », Ed.). This certainly justifies additional research, requested by the authors.
It is therefore important to know the limits of this first milestone to go further. First, the food diaries kept by participants may not be completely reliable. On the one hand a some dishonesty is always possible as to what is eaten; on the other hand because they can forget, in all good faith, what they have consumed.
Although this study collected food diaries every six months, there remains a risk of error in accurately recording what is eaten and drunk. The research team was aware of this and worked to mitigate this risk by asking participants to also take pictures of the foods they ate. Despite this double security, it remains possible that not all the foods consumed were included.
Another point: weight gain, not insignificant when you know the impact of obesity on certain cancer risks. However, on the basis of current data, it is generally accepted that the use of artificial sweeteners is associated with increased body weight — although researchers aren’t entirely certain that sweeteners are the direct cause of this phenomenon. Although this research took into account the body mass index of the adults followed, it is possible that it is the changes in body fat observed that have contributed to the development of several of these types of cancer. And not the absorbed sweeteners.
Finally, the risk of developing cancer in people who consumed the highest amounts of artificial sweeteners compared to those who consumed the lowest amounts was modest – with “only” an additional 13% relative risk during the period. of study.
So, although people who consumed the highest amounts of sweeteners did indeed have an increased risk of cancer, this was still only slightly higher than those who consumed the lowest amounts.
Sweeteners are not without risk
While the link between the use of sweeteners and disease, including cancer, is still controversial, it cannot be ignored. Additionally, it is important to note that not all sweeteners are created equal.
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Aspartame, present in thousands of food products, and saccharin may be associated with health concerns, other sweeteners appear to be less harmful.
Stevia, produced from the plant Stevia rebaudianawould be useful to control the diabetes and body weight and reduce blood pressure. Xylitol, a natural sugar alcohol, may support the immune system and digestion. It would also seem that stevia and xylitol do not promote dental caries, possibly because they kill “bad” oral bacteria.
Beyond the amount of sweetener you consume, deciding which type you use, and how, is also important. (In France, health authorities recommend learning to eat less sugar. Assessing the benefits and risks of intense sweetenersANSES indeed indicates “that there is no conclusive evidence to encourage, within the framework of a public health policy, the substitution of sugars by intense sweeteners”editor’s note)