Nutrition – ketogenic diet

Tuesday 08 May 2018

This is a subject that I have wanted to look at for a while and what has spurred me on is that I saw a visitor at Maggie’s who was following this diet. I will write more about that later but for now let’s look at what the ketogenic diet is, the principles of how it is proposed to work, and looking at it in practice

Like all ‘diets’ or ‘eating plans’, it is designed to reap benefits if it is followed to the letter. The interest in this way of eating and cancer has certainly been researched with some interesting results.  But let's’ start at the beginning and see what exactly it is or means.

What is the ketogenic diet?
Basically it is a way of eating that drastically reduces glucose levels in the body. By doing this the cells in the body switch from using glucose as a source of energy to using ketones instead. Ketones are produced by the liver and are a bi-product of fat metabolism and are produced in the absence of glucose.

How does it work?
By eating to induce ketosis i.e. developing ketone bodies, it is proposed that this starves cancer cells. Basically, according to research, this is because cancer cells and normal cells can both use glucose for energy. The difference is that cancer cells can only use glucose and not ketones (like normal cells). So in theory no glucose, no cancer growth.

This should not be confused with ketoacidosis that is essentially ketosis run wild, when the concentration of ketones in the blood gets too high. This is quite different to a controlled ketogenic diet and normally has an underlying cause of diabetes or very heavy alcohol intake..

To produce these ketone bodies the diet has to be void of simple carbohydrate foods like sugars, corn syrups, processed foods, confectionary, processed baked goods etc. It must be high in fat and include modest amounts of protein.

This concept is not new and has existed in many forms over the years. I was first introduced to this when I was studying nutrition as a way of treating epilepsy and obesity but much wider applications have since developed, particularly surrounding cancer.

We could look at this another way. When we eat a lot of glucose our blood sugar levels rise and with this we produce insulin and another compound called insulin-like growth factor (IGF-1), which as the name implies encourages cell growth. 

Ketogenic diet and cancer
The bottom line then is that it is a high fat, modest protein, and low carbohydrate diet. Note: not No carbohydrate. As I mentioned there is a great deal of interest in this way of eating and cancer suppression. In 2012 Professor Dominic Agostino from the University in Florida carried out extensive research and the results he discovered made him convinced that a ketogenic diet was a very powerful tool in suppressing cancer growth. He even went as far as stating that it was more powerful and less harmful than chemotherapy.

In 2009 other research by the University of Ohio showed that in the absence of glucose a molecule called miR-451 shuts down, known as the ‘engine of the tumour’.

All quite impressive and I am personally not in a position to dispute any of this but coming from a nutritional background it does raise some questions I think.

Some questions surrounding the ketogenic diet

Firstly 75% of the diet should come from fat. This is because fats have no impact on blood sugar. It would be important to make sure that this is ‘Good’ fat from nuts, seeds and their cold pressed oils, coconut oil, olive oil, avocado and eggs, and to avoid the bad fats like hydrogenated fats, trans fats, (both found in commercially produced foods) and fats from animal foods high in saturated fats, which contain high levels of cholesterol.

Protein should make up 20% of the food intake in a day, coming from foods like chicken, fish, eggs and lentils, which seems appropriate.

Carbohydrates make up the last 5% of the diet using non starchy carbohydrates from plants. This basically means eating vegetables that grow above the ground and avoiding vegetables that grow below the ground which naturally store a lot of carbohydrate. Having said that, if the carbohydrate in the root vegetables was counted as part of the daily allowance it should be fine.

I do feel that the limitations of the diet makes me worry that it may lead to nutrient deficiency, particularly the phytonutrients that come from the coloured pigments in fruit and vegetables. These have been shown to have huge health protecting qualities. But advocates of the diet insist that we can get all the nutrients we need by eating this way.

With carbohydrates the diet expects you to calculate the NET carbohydrate. That is the available carbohydrate not the fibre. This is because the fibre passes through the body undigested. You can get charts of net carbohydrate values but basically it is the total carbohydrate value of the food minus the fibre count. A few examples; carrots have a net value of 8.66 per cup, spinach a net carbohydrate value of 0.39, onions a value of 11.98, and lettuce 0.54 g per cup.

Is it getting complicated?
Well, yes it does seem that way but going back to my visitor who was totally converted and appeared to be reaping the benefits. The story was that the diagnosis was not good with several tumour sites. No more treatment was available and the tumours were expected to grow. Well, after adopting the diet, two further scans three months apart showed the tumours had not developed at all and the medics were very surprised at the results. Another scan is due in two months, which will be interesting.

What can we read into this? Well I am not sure. You would think that the adoption of the ketogenic diet may be responsible but this is so difficult to measure. Such a positive outlook certainly will have a very stimulating effect on the immune system. All we can do, of course, is watch this space and wish this visitor continued positive reports.

Finding out more
If you want to learn more there are many many books dedicated to eating a ketogenic diet. I have added the titles of two I found useful  below.

There is plenty of info on the internet as well but do be wary of sensational stories attached to a specific diet or regime as these are generally not science based and are best ignored. 

Ketogenic diet crash course Robert Fleischer. It is what the title says but a very good introduction to the diet I think. 

The Cantin ketogenic diet  Elaine Cantin. Very American in its language but there is a section on ketogenic diet and cancer which is interesting. The rest of the book focuses on other health conditions that could possibly benefit from such an eating plan. Half of the book is recipes and menu planners which may be useful to someone wanting to have a go.

Blog originally written by Caroline December 2014 - links updates April 2020

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