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Sugar and cancer: is there a link?

Sugar and cancer

Information on the link between sugar and and cancer is often presented in a worrying light for consumers, leading to feelings of guilt. The Cancer likes sugar concept, developed in the 1920's, has returned to news reports, although in an indirect manner. The real relationship between sugar and cancer.

Excess weight and obesity are more often mentioned as risk factors in terms of digestive cancer than sugar-rich food or diets Although it is true that cancerous cells do not react in the same way as healthy cells to glucose, this is one of the effects of cancer, not its basic cause.


In terms of breast cancer, some studies show a link between the appearance of breast cancer and the over-consumption of sweetened foods. In fact, this type of cancer is based on a mechanism that associates the production of insulin with hormonal growth factors. However, there are other known risk factors associated with this type of cancer and studies need to be continued in this area.

Cancer and diet

The role of food is currently the object of numerous research studies. Scientists are studying both the causes of cancer and ways of preventing it in terms of the appearance of cancerous lesions. The number of dietary factors involved makes it difficult to draw any clear cut conclusions.


As a result, after studying the many publications available on this subject, and in the absence of intervention studies on the possible consequences of consuming carbohydrates, the AFSSA (The French Food Safety Agency) arrived at the conclusion, at the end of 2004, that “there are currently no convincing arguments to suggest that the consumption of carbohydrates plays a role in the development of cancer”, or to call into the question a type of carbohydrate, in particular simple carbohydrates or sugars (mono or disaccharides).

In 2007, among the recommendations made by the WCRF (World Cancer Research Fund) on the subject of cancer prevention, is the avoidance of weight gain, including a recommendation to limit the consumption of foods with a high-calorie content and sweetened drinks. Obesity is described as a factor independent of the risk of cancer.

The studies each use highly different data collection models, which makes it difficult to compare their results. Some consider the quantity of carbohydrates consumed, very often based on the average glycaemic index of the food, and others add the glycaemic load to introduce the notion of quantity. Moreover, dietary data is often collected at the beginning of the study, without establishing the diet of its subjects at the end of the study.

Sugar and digestive cancer:is there a link?

In 1997, a review of forty epidemiological studies focusing on the relationship between the consumption of sucrose and digestive cancers, concluded that there was insufficient proof of a link between the consumption of sucrose and digestive cancers.


In a 2007 report, experts from the WCRF confirmed this conclusion and did not put forward any particular recommendations with regards to sweetened foods. Excess weight and obesity are more often mentioned as risk factors in terms of digestive cancer thansugar-rich food or diets. Lastly, in terms of the risk of pancreatic cancer, numerous studies have been performed with contradictory results, depending on the population studied and the sweetened foods studied.

Sugar and extra-digestive cancers: is a conclusion possible?

For extra-digestive cancer pathologies, the data does not enable us to establish a clear link. For women, breast cancer trials are inadequate both in number and quality. The countries in which the deaths caused by breast cancer is highest, the consumption of simple carbohydrates is particularly high. However, here again, these same countries exhibit other known breast cancer risk factors, at a very high level: early puberty, high average height and environmental pollution.


The evidence linking breast cancer with sugar consumption often refer to insulin resistance, itself associated with excess weight. This is explained by the fact that insulin resistance leads to a higher level of insulin production, a hormone that regulates glucose levels in the blood. Insulin simulates the production of another hormone, IGF-1, which is know to favour cell multiplication.

Some studies focus on non-food factors. They distinguish between menopausal and non-menopausal women, with a higher risk for menopausal women. These results require more advanced research.