290. More Insight into Diet and Cancer

The Warburg Effect
It is clear that diet plays a major role in the development of cancer and that a change in diet may sometimes play a part in treatments that are successful. Otto Warburg has proposed that cancer cells depend on anaerobic fermentation to provide an adequate energy for their survival. This means they require a continual supply of glucose, which originates from the sugar and carbohydrates present in the diet. Hence it follows that the cancer cells can be starved of glucose by adjusting the diet so that it contains very little sugar and carbohydrates. Over the years I have posted several case histories of individuals who have made these dietary changes and overcome their cancer.
Nevertheless we still have a long way to go before we have a detailed understanding of the use of diet in the prevention and treatment of the various types of cancer. However I have just been watching a video of the presentation by Dr Dawn Lemanne at the held earlier this year. This takes us some way beyond the Warburg Effect and brings us up to date on the latest thinking on the subject (1). The title is “Carbohydrate Restriction in Cancer Therapy”. In this post I will highlight some of the key points.
Which cancers are diet-related?
First of all, it is clear that certain cancers, such as cancers of breast, colon, endometrium, some lung cancers (adenocarcinoma), prostate, pancreas and gallbladder are probably diet-related. On the other hand there are also several, for which it is unlikely that diet is critical. These include paediatric cancers, sarcomas, virus related cancers such as Hodgkin and non-Hodgkin lymphomas, and acute leukaemias.
Links with diabetes
There is no doubt that that those with diabetes have a higher risk of developing cancer and have a lower chance of surviving if they develop the disease. The most common cancers associated with diabetes (Types 1 and 2) are those of the breast and colon. The good news is that metformin decreases the risk but may increase the survival rate after diagnosis. The bad news is that the use of insulin increases the risk of cancer by a factor of two. This is not in the least surprising because this will facilitate the development of insulin resistance (IR), which in turn can lead to various other chronic conditions including cancer. It follows therefore that insulin usage for the treatment of diabetics should be kept the absolute minimum. Unfortunately this is rarely recognized by health professionals in the field.
Cholesterol
It has been established that those with high values of blood cholesterol (TC) and LDL-Cholesterol (LDL-C) have a reduced incidence of certain cancers. They also have an improved response to chemotherapy and improved chances of surviving cancer after diagnosis. Clearly this flies in the face of the conventional strategies for dealing with heart disease. Elsewhere I have shown that low cholesterol is not beneficial with respect to reducing all-cause mortality (ACM) (2).
Moderate restriction of carbohydrates
This section described the impact of restricting total carbohydrate intake to about 100g/day. The most striking information on this topic was that by decreasing carbohydrate intake by 27g/day the chances of breast cancer recurring was reduced by 50%. In older patients with breast cancer, there are indications that restriction of carbohydrates improves the success rate of treatment by chemotherapy plus tamoxifen by as much as 40%. Colon cancer patients also benefitted from carbohydrate restriction, although this was limited to those with a BMI >25. The message came through loud and clear that a reduction as small as cutting out one banana/day was worthwhile.
Ketogenesis
This is when ketone bodies are produced as the main source of energy for the body. It is also referred to as “fat burning” or ketosis. It can be achieved by a combination of fasting, prolonged exercise and a very low intake of carbohydrates. Essentially the carbohydrates are replaced by healthy fats to produce a diet that is low in carbohydrates and high in fats (LCHF). The various fats are broken down in the liver to ketone bodies, namely ?-hydroxybutyrate, acetoacetate and acetone. Healthy cells throughout the body, including those in the brain, can utilize these ketones as a source of energy whereas cancer cells must have glucose.
Although some health professionals may confuse ketoacidosis with ketosis, Dr Lemanne was adamant that the two conditions are quite different and that the ketoacidosis is not caused by a ketogenic diet.
A typical ketogenic diet would be 85% fat, 10% protein and 5% carbohydrate.
Ketosis can improve the results obtained with radiation treatment for cancer and it was suggested that this is due to:
• Differential DNA repair;
• Decreased insulin and Insulin Growth Factor One signaling;
• Normal cells enter dormancy;
• Angiogenesis suppression;
• Decreased oxidative damage in normal cells.
A note of caution
I was very interested to learn that there is one particular mutation, for which fat fuels the growth of the tumour. This is called BRAF V600E. Obviously if this is present then an LCHF diet would be unsuitable because it would make things much worse. It can be detected and so it is recommended that tests should be done to see if it is present. The big problem is that because the mainstream medicine does not recognize the potential benefits of LCHF, patients are unlikely to be alerted to desirability of these tests.
In colorectal and prostate cancers, the chances of this mutation being present are 10%. So although there is convincing evidence that LCHF can be very beneficial, it is crucial to be aware of this issue and the possibility that under certain circumstances LCHF could do more harm than good.
Caloric restriction/fasting
If glucose is not available, there is a possibility that other nutrients may be utilized by the cancer cells. These include fructose, lipids, glutamine, cysteine, acetate and lactate. If this is the case, then a sharp drop in the calorie intake may be effective as a means of controlling the cancer. Alternatively intermittent fasting (IF) may work just as well or even better. One major advantage of IF is that weight loss is not experienced. Dr Lemanne stated that positive results can be obtained with fasts as short as 13 hours, which can easily be achieved overnight with an early evening meal and a late breakfast. In fact, she advocates this strategy for everyone. When fasting is combined with chemotherapy, it was found to be well tolerated. Fatigue was reduced while there were no adverse effects on tumour volume or serum tumour markers.
Conclusion
This is a very valuable contribution to our understanding of the role of diet in cancer treatments. Although it highlights the huge potential for diet in cancer therapy it is fascinating to see how it can be combined with conventional treatments to great effect. The possibility of dangers of high fat intake in certain patients is new to me and it is important that this information is disseminated widely. It is to be hoped that the use of diet is recognized and appreciated by oncologists so that the potential is explored fully.
References
1. http://denversdietdoctor.com/dr-dawn-lemanne-carbohydrate-restriction-cancer-therapy/
2. https://vernerwheelock.com/179-cholesterol-and-all-cause-mortality/