Oliver Childs March 24, 2014
Another idea we see a lot is that sugar apparently ‘feeds cancer cells’, suggesting that it should be completely banished from a patient’s diet.
This is an unhelpful oversimplification of a highly complex area that we’re only just starting to understand.
‘Sugar’ is a catch-all term. It refers to a range of molecules including simple sugars found in plants, glucose and fructose. The white stuff in the bowl on your table is called sucrose and is made from glucose and fructose stuck together. All sugars are carbohydrates, commonly known as carbs – molecules made from carbon, hydrogen and oxygen.
Carbs – whether from cake or a carrot – get broken down in our digestive system to release glucose and fructose. These get absorbed into the bloodstream to provide energy for us to live.
All our cells, cancerous or not, use glucose for energy. Because cancer cells are usually growing very fast compared with healthy cells, they have a particularly high demand for this fuel. There’s also evidence that they use glucose and produce energy in a different way from healthy cells.
Researchers are working to understand the differences in energy usage in cancers compared with healthy cells, and trying to exploit them to develop better treatments (including the interesting but far from proven drug DCA).
But all this doesn’t mean that sugar from cakes, sweets and other sugary foods specifically feeds cancer cells, as opposed to any other type of carbohydrate. Our body doesn’t pick and choose which cells get what fuel. It converts pretty much all the carbs we eat to glucose, fructose and other simple sugars, and they get taken up by tissues when they need energy.
While it’s very sensible to limit sugary foods as part of an overall healthy diet and to avoid putting on weight, that’s a far cry from saying that sugary foods specifically feed cancer cells.
But dietary advice must be based on nutritional and scientific fact. When it comes to offering diet tips to reduce cancer risk, research shows that the same boring healthy eating advice still holds true. Fruit, vegetables, fibre, white meat and fish are good. Too much fat, salt, sugar, red or processed meat and alcohol are less so.
This post, from the Junkfood Science blog, explores the science behind sugar and cancer in more detail.