No, Cutting Carbs Doesn't Prevent Cancer

“This link between sugar and cancer has sweeping consequences,”  wrote Johan Thevelein,  a Belgian biologist and co-author of a study published in the journal  Nature Communications. That study really made the media rounds this week and quickly anti-carb crusaders were allover the place claiming removing sugar and carbs from ones diet would prevent cancer.

Not so fast. The media is notoriously bad at presenting science, and this is no exception. The findings do not, in any way, prove that eating sugar has any effect on the development of cancer, nor does it prove that not-eating sugar will prevent cancer.

The research, done on yeast, found that high levels of glucose could overstimulate the production proteins found in tumor cells. And the expression of those proteins could cause cancer cells to grow and multiply at a faster rate. So, myth one already shattered, this study shows nothing about sugar causing cancer as the cells being exposed to glucose essentially already were cancer.  In essence, high sugar concentration worsened the growth of existing tumors.

Thevelein isn’t a clinician, he’s a research scientist working in the field of molecular biology. The study in question was an  attempt to understand the mechanisms behind the Warburg effect. Cancer cells lack the internal feedback loops designed to conserve resources in the absence of food. If there’s blood glucose around, cancer cells will consume it all and they do so by way of fermentation as opposed to respiration like healthy cells. All that fast energy drives cancer cells to grow bigger, faster and replicate. Thus tumors grow rapidly.

It’s interesting science, but isn’t medically relevant for making dietary recommendations in humans. If you won’t take my word on that, how about the researchers? On  Tuesday, Thevelein  told Newseek the following: “Some people are interpreting that we have found a mechanism for how sugar causes cancer, but that is certainly not the case.”

Overall, it’s a great reminder to scrutinize the media’s reporting of scientific research. You simply cannot take laboratory test-tube research of a metabolic pathway in yeast cells and translate that into dietary advice.

The true research here, however, is quite cool. There continues to be a debate over whether fermentation in cells is a cause or a symptom of cancer. And that is exactly what these Belgian scientists spent 9 years investigating. They discovered that at high concentration, glucose activates a gene called  Ras in cells which is a regulator of cell proliferation. Activation of  Ras causes the tumor cells to go into fermentation mode, sucking up all the glucose that’s available. So having a lot of sugar in a petri dish with cancer cells can speed up their growth.