Report by Dr Catherine Zollman, GP and Clinical Lead at Penny Brohn Cancer Care, Bristol
A mixed and lively audience of complementary therapists, cancer survivors, doctors and nurses, packed into a seminar room at the Holiday Inn, Bloomsbury to hear Damien Downing, Co-Chair of the BSIO’s Best Practice Committee and President of the British Society for Ecological Medicine (BSEM) describe his understanding of the potential ketogenic (Very Low Carbohydrate or VLCD) diets in people with cancer.
By revising some basic biochemistry, Dr Downing reminded us that whereas all human cells can produce energy from fats, via oxidative phosphorylation in the mitochondria, the use of glucose as a fuel is restricted to a very few cell types and is totally dependent on the presence of pancreatic hormones. His postulate was therefore that “we are designed to be mainly oil-fuelled, rather than mainly sugar-fuelled”. A review of man’s dietary intake over the last few centuries confirms that, since the invention of sugar refining and industrial food processing in the mid 20th century, a relatively tiny period in our evolution, our exposure to sugar has risen exponentially. Carbohydrate metabolism is designed to be our “emergency generator”, to be switched on in times of plenty so that we can rapidly store energy in the body, but it suppresses our ability to burn fat, so with a typical Western diet we end up running on the less efficient “emergency generator” all the time.
Our ability to cope with very little sugar or refined carbohydrates depends on our ability to produce ketone bodies as we breakdown fats. The brain can get 70-90% of its energy requirements in this way. On a very low carbohydrate diet (VLCD) our ability to tolerate low blood sugar levels increases and there is good evidence that this produces helpful, risk-reducing shifts in the body’s biochemical profile in Cardiovascular Disease, Epilepsy, Obesity and Diabetes. The clinical evidence for the benefits in Alzheimers, other neurological conditions and Cancer is not as strong, but the basic science mechanisms are highly plausible and animal and early human studies are progressing. In Cancer, the fact that many cancer cells become highly dependent on glucose metabolism as part of their disrupted cellular biology (a phenomenon known as the Warburg effect), whereas normal cells continue to be able to function in low glucose environments, provides a particularly intriguing argument for further clinical research in this area.
Dr Downing went on to describe some of the pre-clinical (test-tube and animal studies) and limited clinical (human studies) research that has been done, highlighting the potential role of a ketogenic diet in increasing the efficacy of cancer treatments such as radiotherapy and chemotherapy, for example in mice receiving radiotherapy for malignant glioma (1). The only human study mentioned was a small pilot feasibility and safety study (n=10), in self-selected patients (it must be almost impossible to randomise someone to having a VLCD!!) with rapidly-progressive advanced cancer (2). Half the patients achieved Stable Disease or Partial Remission on PET scan after 4 weeks of a Ketogenic Diet, and the degree of response seemed to correlate with the degree of ketosis achieved. Side effects of the diet were mild weight loss (mean drop in weight was 4% – not deemed clinically significant -, despite encouraging subjects to keep caloric intake up), and mild and transient constipation, fatigue and muscle cramps. The authors concluded that this was a safe and feasible intervention in selected patients, but that the small numbers meant the research needed to be interpreted with caution and repeated on a larger scale.
Dr Downing then went on to describe 3 practical tools which he finds helpful in supporting people wishing to embark on a Ketogenic Diet.
- a spiralizer which can make “pasta”-type food (noodle or spaghetti shaped) from low carbohydrate vegetables such as courgettes – I love the term “courgetti” and will definitely be trying this on my kids!
- a self-testing glucometer (finger prick blood test monitor for blood sugar levels) which also has the capacity to measure ketone levels
- a protein powder supplement called Master Amino Acid Pattern (MAP) which helps keep caloric intake up when on strict Ketogenic Diet
An audience member who is using a ketogenic diet as part of his strategy for managing advanced cancer, then spoke of his experiences and volunteered to have his blood ketones measured despite warning us that they might not be as good as he usually kept them because he had eaten some brown rice with cream on his journey to London! He was very clear that keeping to a largely Ketogenic Diet was part of what he believed was helping him stay well (he is also in the middle of chemotherapy, has hyperbaric oxygen sessions 3 times weekly, is under the care of a naturopath with a very positive outlook, drinks filtered water from glass, and eats organic foods where possible). He did admit that the diet was highly restrictive and not easy to follow without being very motivated, but said that, having adapted to it, he was now able to enjoy an active, social and full life.
The floor was then opened to questions and a lively debate ensued. One Palliative Care consultant questioned the suitability for this approach in advanced cancer patients where weight loss and cachexia were an issue (Dr Downing felt that amino acid supplementation would be particularly helpful in this group and various audience members offered information about cheaper alternatives to Dr Reinwald’s MAP). It was agreed that careful clinical monitoring of this group of patients would be essential. The competing strategies of Ketogenic Diet (low in sugar) vs Rainbow Diet (high in colourful vegetables and fruit containing a lot of anti-oxidants) were raised and the heterogeneity of cancers was given as a reason why for some cancers, it might be more beneficial to increase blood flow and oxygenation to try to reduce cancer growth, while other cancers might respond better to glucose deprivation. Some interesting work is being done in Germany to look at markers which might be able to help predict tumour sensitivity to a ketogenic diet. The potential role of metformin and other non-insulin, blood sugar lowering agents was raised. Some clinical research in this area is being conducted by the Care Oncology Clinic in London.
The evening concluded but many interesting conversations continued as people left and made their way to the tube. I personally felt that an interesting topic had been aired in an atmosphere that allowed for both scepticism and open-mindedness to be honoured and respected.
Download the presentation here – Ketogenic Diet for BSIO
- Abdelwahab MG, Fenton KE, Preul MC, et al. The Ketogenic Diet Is an Effective Adjuvant to Radiation Therapy for the Treatment of Malignant Glioma. Canoll P, ed. PLoS ONE. 2012;7(5):e36197. doi:10.1371/journal.pone.0036197.
- Fine EJ, Segal-Isaacson C, Herzkopf S, et al. A pilot safety-feasibility dietary trial targeting insulin inhibition in ten patients with advanced cancer. BMC Proceedings. 2012;6(Suppl 3):P60. doi:10.1186/1753-6561-6-S3-P60.
A number of books, websites and resources to support people wanting to learn more or undertake a Ketogenic Diet were shared by the audience. (Dr Downing and BSIO can take no responsibility for the content or quality of these resources) These include:
The Cantin Ketogenic Diet – by Elaine Cantin
Practical Keto Meal Plans for Cancer – by Patricia Daly http://patriciadaly.com.ebook
The Art of Eating Well by Jasmine and Melissa Hemsley
New Atkins New You by Eric Westman and Jeff Volek