Nutrition: ​Calorie restriction and cancer treatment part 1

Friday 04 May 2018

For some time now I have been wanting to write about the exciting new research that is emerging about calorie restriction before and/or after cancer treatment.

Calorie restriction is defined as a reduction in energy intake i.e. eating less food, without malnutrition. It is by no means a recommended practice yet, but evidence is beginning to paint a very positive picture.

Some of you may have already heard about this or even tried it. From what I have read there are some oncologists who even advocate it for their patients. In fact professor Seyfried of Boston University is already a firm advocate of it. It has taken me some time to read all the evidence so I will now attempt to explain the theory behind it and write about the results of some trials. I think that it appears on the surface to be something for the future. Between 2008 and 2013 research from major centres and experts such as Doctor Valter Longo of the University of California, professor Thomas Seyfreid of Boston and the Marx Plank institute all appear very much in favour.

Fasting is not new it has been recorded since Hippocrates time as a method of treatment for illness and disease.

As we know from some of my previous blogs that I have written on book reviews, calorie restriction is already very popular with people who want to lose weight or improve their longevity which can apparently be achieved by eating less. You may recall a book by Michael Mosely (see link) another by Professor Howel (see link) and also a very recent one by Patrick Holford called, ‘Burn Fat Fast’. All 3 have slightly different approaches but the end goal seems to be the same. So it is very interesting to see how calorie restriction is used prior to cancer treatment.

Calorie restriction and cancer

The research suggests that the benefits for people with cancer range from, halting cancer progression, improving survival, reducing side effects of drugs and radiotherapy and even causing tumours to disappear. These seem to be all very noble claims so it would be good to look at the background behind them.

It is interesting to note here that during the 2nd world war it was observed that populations such as the Belgians and Norwegians became healthier, with less cancer and heart disease when they had calorie restricted diets simply due to the lack of food available.

The main evidence so far has shown that when the body is put in a state of calorie restriction by eating 10 to 15% below ideal levels it stimulates the production of Sirtuins. These are hormones that protect us in times of stress such as calorie restriction might produce.

In 2007 one report showed that alternate fasting days where every other day there was a fast consisting of only 400 calories for women and 600 calories for men, was associated with reduced blood levels of insulin growth factor IGF-1. I have written a blog on this and also a reduction in bad fats.Now in 2013 the Oncology Magazine showed that people having radiotherapy and a restricted diet produced better results. It suggested that the same may be true of chemotherapy and as I write more trials are being planned.

There are many factors that go on when the body is put under a calorie restriction including less aggressive hormone production, less circulating ‘bad’ cholesterol, glucose deprivation and sirtuin stimulation. One of the main fears is that with calorie restriction comes weight loss which should not be confused with cachexia. In some cases weight loss would be positive because a leaner body has less fat and therefore less circulating hormones and toxins. According to The American Cancer Society there is overwhelming evidence that diet, exercise and weight control could improve survival times and even prevent cancer returning.

I do know that from my reading that some doctors (one in India) already puts their patients on calorie restrictions claiming that the results of treatment are more impressive.

The National Cancer Institute of America has noted that the foods that you eat can affect the way that the body absorbs and uses the drugs.

I suppose the strongest evidence to date is published study of 10 people all with various types of cancer who voluntarily underwent short term fasting before and/or after chemotherapy. The patients reported fewer side effects as a result. In 2012 the same team of scientists who did this study, produced further research showing that fasting makes the cancer cells more sensitive to treatment by actually stopping the cancer cells producing protective proteins from their mutated genes, while the healthy cells made more protective proteins. As a result the healthy cells stopped dividing and are less attacked by the chemotherapy resulting in lowered side effects. They also discovered a second factor against cancer cells and that was that fasting deprived the cancer cells of glucose.

On another occasion a 51 year old woman with breast cancer did her first round of chemotherapy in a fasted state of 140 hours. Other than a dry mouth and hiccups she felt well enough to go to work and resume her normal daily activities. For the next two rounds she did not fast and instead ate her normal diet. The side effects were extremely pronounced, severe fatigue, diarrhoea, weakness, abdominal pain and nausea and she was unable to go to work. For her fourth round she fasted and once again she experienced minimum side effects. It was also realised that her neutrophil counts and platelet counts were all highest after the fasting regime.

Taking this a step further it also appears important to choose foods wisely when fasting, eating a high protein fat diet and one very low in carbohydrates, a bit like a stone age diet I thought that I would look at this in more detail next week.

The whole phenomena of food restriction in cancer has been christened ‘The Food Effect’.

So where does this leave us? Curious I think, and  a case of watch this space.

Other related blogs by Caroline 

Nutrition intermittent fasting  (Nov 2012)

Nutrition 2 day diet (Feb 2013)

You may also be interested in reading:

The 2-Day Diet: Diet Two Days a Week. Eat Normally for Five. Paperback – 14 Feb 2013
by Michelle Harvie  (Author), Tony Howell (Author)

Blog originally written by Caroline July2013

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