'Too soon to say' whether low carb diet can prevent cancer or slow tumour growth

In collaboration with Adfero

Cancer Research UK has responded to claims that eating a low-carbohydrate, high-protein diet could be beneficial to prevent cancer and slow its growth, by warning that the research is still at a preliminary stage.

The Canadian research, published in the journal Cancer Research, focused on the effects of different diets on a group of mice that had cancer.

The animals were given one of two diets - a typical Western diet (55 per cent carbohydrate, 23 per cent protein, 22 per cent fat), or a high-protein, low-carbohydrate diet (15 per cent carbohydrate, 58 per cent protein, 26 per cent fat).

Tumour growth was found to be slower in the mice on the high-protein, low-carbohydrate diet than in those on the Western diet.

The researchers then repeated the experiment using mice that were genetically prone to developing breast cancer.

They found that almost half of mice on the Western diet developed breast cancer within their first year of life and just one mouse reached a normal life span (about two years).

In contrast, none of the mice on the high-protein, low-carbohydrate diet developed the disease that quickly and more than half reached or exceeded their normal life span.

Jessica Harris, senior health information officer at Cancer Research UK, said: "This study was done in mice, so it doesn't tell us whether such a diet would have a similar effect in humans.

"There is a substantial amount of evidence that eating a healthy, balanced diet that's high in fibre, fruit and vegetables and low in red and processed meat, saturated fat and salt could reduce the risk of developing certain types of cancer, but it's far too soon to add this dietary pattern to the list."

To account for their observations, lead researcher Dr Gerald Krystal suggested that, since tumour cells need more glucose than healthy cells to grow and thrive, a low-carbohydrate diet may help to deprive tumour cells of both glucose and insulin, slowing their development.

He also speculated that a low-carbohydrate, high-protein diet may boost the immune system's ability to kill cancer cells.


  • Ho, VW et al (2011). A Low Carbohydrate, High Protein Diet Slows Tumor Growth and Prevents Cancer Initiation Cancer Research DOI: 10.1158/0008-5472.CAN-10-3973