In general terms, I recommend a diet lower in carbohydrate than conventional guidelines say is healthy. At least part of my thinking is based on abundant evidence linking a relatively carbohydrate controlled diet with benefits in terms of body weight and disease markers for conditions such as heart disease and type 2 diabetes. However, I came across a recent paper which made me think more about the impact a low-carbohydrate might have on risk of another important condition – cancer [1].
You can read a summary of the paper here and download a provisional pdf of the full paper here.
The paper starts with reference to hunter-gatherer diets, and their relatively protein-rich, low-carb nature, and remarks that cancer has been found to be rare in societies eating such a diet. It then goes on to postulate several major mechanisms that may account for this association. These include:
1. Cancer cells feed preferentially on sugar (glucose)
Glucose (from sugary and starchy foods) provides the prime fuel for cancer cells, so a diet lower in carbohydrate may therefore reduce tumour development or progression.
2. Insulin and IGF-1 can stimulate tumour cell growth
High carbohydrate diets increase levels of insulin and what is known as insulin-like growth factor-1 (IGF-1) which stimulate tumour cell growth. A lower carbohydrate diet may reduce tumour proliferation as a result.
3. Ketones suppress cancer
Very low carbohydrate diets can lead to the production of ‘ketones’ (mainly produced from fat) that suppress tumours.
4. Low-carbohydrate and ‘ketogenic’ diets ‘starve’ cancer
Low-carbohydrate diets mimic caloric restriction and ketogenic diets mimic starvation – and caloric restriction/starvation is linked to reduce tumour development and progression.
5. Low carbohydrate diets can reduce inflammation
Inflammation is believed to be a risk factor in the development of cancer, and high-carb diets encourage inflammation. Low-carbohydrate diets have been found to be more effective than low-fat ones in terms of reducing markers of inflammation.
The paper also makes the case that such diets may help better meet the nutritional needs of those with cancer.
I’ve only plucked out some of the highlights of this paper, as you can read it in its entirety if you so wish. If you do, though, you may well find that the paper makes a pretty compelling case for the role of carbohydrate-restricted diets in the prevention and treatment of cancer.
References:
1. Klement RJ, et al. Is there a role for carbohydrate restriction in the treatment and prevention of cancer? Nutrition & Metabolism 2011, 8:75
