"I'm sorry to say this, but you have cancer."
Practically everyone has a personal connection to someone with a cancer diagnosis, and are therefore all-too familiar with the unpleasant and sometimes unbearable side effects of chemotherapy and radiation.
What if there was a better way to treat cancer? Or a way to lower the dose of chemo and radiation required? The secret may depend on how we metabolize sugar.
A recent study showed that simply by changing the type of sugar fed to mice, from glucose to mannose, investigators could reduce cancer cell growth. (Mannose is a simple sugar - or monosaccharide - like glucose, but it is far less common in the body.) Furthermore, the study authors also showed the cancer cells become more susceptible to chemotherapy in the mannose-fed mice.
Nature: Mannose impairs tumour growth and enhances chemotherapy
Their success gives further backing to the concept that cancer cells have an altered cellular metabolism. Cancer cells depend on glucose for their fuel and have enhanced glucose uptake -the so-called Warburg Effect. Finding a safe and effective way to change cellular fuel, therefore, seems to have potential for impairing cancer cell growth and improving outcomes from conventional treatments such as radiation, chemotherapy and surgery.
One interesting caveat to the findings in this study was that only those mice with a low level of the enzyme phosphomannose isomerase saw significant benefit. It turns out, this enzyme converts mannose into fructose. It is possible that the cancer cells were able to use fructose for fuel whereas they could not use mannose.
While these are interesting findings, they may be meaningless. The most effective way to alter cellular energy supply away from glucose isn't eating a different sugar like mannose. It's not eating sugar at all - a combination of nutritional and fasting ketosis.
When we are in a state of ketosis, our body shifts from utilizing glucose as fuel and instead turns to fatty acid oxidation with the production of ketones. This shift, from glucose to ketones, is something cancer cells are unable to do, and thus ketosis is a potential powerful adjuvant therapy for cancer.
It seems clear glucose is the enemy. Fortunately, we all have the tools to reduce our body's dependence on glucose.
Will this result in improved cancer treatment outcomes? We don't have definitive evidence to say that yet.
There are, however, numerous ongoing studies to investigate this exact question, and there is reason to be hopeful. Mannose not required.
Thanks for reading,
Bret Scher MD FACC
Comment: Whether it was something about the mannose or the simple absence of glucose that proved effective in the above study is unknown, but the evidence for the ketogenic diet's effectiveness against cancer continues to grow.
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