Reducing carbohydrate consumption may help to prevent cancer

This paper was published in Nutrition and Metabolism 2011 Oct 26;8(1):75

Study title and authors:

Is there a role for carbohydrate restriction in the treatment and prevention of cancer?

Klement RJ, Kammerer U.

This paper can be accessed at: http://www.ncbi.nlm.nih.gov/pubmed/22029671

Dr. Rainer J Klement from the University Hospital of Wurzburg reviewed the evidence of 162 scientific papers regarding the subject of carbohydrate restriction and cancer.

Dr. Klement found:

• Cancer, which might be considered a disease of civilization, was very rare among uncivilized hunter-gatherer societies. Their diet was mainly meat and fat, whereas modern diets have quickly changed to easily digestible carbohydrates derived mainly from grains. Our genes have not had time to adapt to the new carbohydrate foods, and diseases of civilization have ensued.
• Reducing the amount of dietary carbohydrates could stop, or at least delay, the emergence of cancer, and that growth of already existing cancer could be slowed down.
• Most carbohydrates are converted into glucose by the body. Most cancer cells depend on glucose for growth as their ability to use fats or ketone bodies has been impaired.
• High carbohydrate diets cause a rise in insulin and insulin like growth factor levels which promote cancer growth.
• Ketone bodies that are elevated when insulin and blood glucose levels are low, have been found to stop cancer cells growing.

Dr. Klement concludes that the evidence presented in the review shows that reduction of the high carbohydrate intake in modern diets may play an important role in cancer prevention. 

Research by a Nobel prize winner shows that high carbohydrate diets cause cancer

This paper was published in Science 24 February 1956: Vol. 123 no. 3191 pp. 309-314

Study title and author:
On the origin of cancer cells
Warburg O

This paper can be accessed at: http://www.sciencemag.org/content/123/3191/309.extract

Otto Warburg won the Nobel prize for medicine in 1931 for discovering that cancer cells are fundamentally different compared to healthy cells.

He found that energy and growth in cancer cells is mainly generated by the fermentation of glucose, unlike normal cells which contain tiny organelles inside them called mitochondria which work away producing enegy to keep the cells healthy. The mitochohdrial activity in cancer cells is impaired and cancer cells can use glucose by up to 200 fold the rate of healthy cells.

How does this relate to cancer and diet?

To produce energy humans mainly use either:
(i) Fat and ketone bodies.
(ii) Glucose.

Fat may be provided by dietary fat, and ketone bodies are compounds that are produced when fats are broken down for energy by the liver and kidneys. Almost all carbohydrates are broken down by the body into glucose.

Fat and ketone bodies need mitochondria to provide energy, whilst glucose also has the ability to provide energy by fermentation. This means that fat, ketone bodies and glucose can be used for energy by healthy cells, but only glucose can be used by cancer cells.

The implication of this is if you follow a very low carbohydrate diet it is very difficult for cancerous cells to survive because they will have little or no energy to feed on.

Warburgs research shows that a high carbohydrate diet will encourage cancer growth, whereas a diet low in carbohydrate and high in fat discourages the growth of cancer.