Calorie Restriction & Cancer Treatment

For the first time ever, a randomized controlled trial that uses calorie restriction as a treatment for cancer — and measures a cancer-related outcome — was approved by the institutional review board at Duke University in Durham, North Carolina, and is on its way to the clinic.

"During the past 10 years or so, interest in the metabolism of cancer cells has seen a dramatic increase, which is surely why interest in dietary interventions...has increased," said Rainer Klement, MD, a radiation oncologist at the University Hospital of Würzburg in Germany.

The hypothesis that suppressing carbohydrates could suppress or slow cancer growth is supported by a lot of laboratory science. The pair explain that complex carbohydrates are ultimately digested as glucose, which can cause tumor cells to proliferate.

The Duke study will involve calorie restriction in men with prostate cancer — specifically, cutting down on carbohydrates. The participants will have "failed" primary therapy for prostate cancer, as evidenced by a rising prostate-specific antigen (PSA) score after surgery, and will have experienced disease progression.

A projected 60 men will be randomized to either a low-carbohydrate diet (<20 g/day) or usual care. The outcome measure is PSA doubling time or change in PSA over the 6-month study period. The value of PSA in diagnosing prostate cancer is dubious, but in the treatment of men with diagnosed disease it is a well-established measure of disease progression and stabilization.

The relation between insulin metabolism, obesity, exercise, and cancer has led to a recent surge of interest in dietary intervention during cancer treatment. This is exemplified with newer trials, such as the National Cancer Institute of Canada MA.32 trial, which is treating early-stage breast cancer patients with standard therapy and randomizes them to placebo or metformin, which affects several metabolic pathways,

Ref: Nick Mulcahy, Medscape Medical News, 02/2013