We've had a few questions lately about whether we should avoid sugar after a diagnosis of CLL, from members concerned about the influence of sugar in their diet on their CLL progression and of course because of the simplistic claim that sugar feeds cancer cells, so starving ourselves of sugar will starve the cancer. So what's the real story?
Cancer and sugar: Does changing your diet starve cancerous cells?
You may have heard that 'sugar feeds cancer cells', fuelling their rapid growth.
Or that eliminating sugar from our diet can starve or stymie cancer growth.
But is there any truth to these beliefs?
Well, the oft-repeated claim that sugar feeds cancer cells is true in a strict sense — and that may seem scary. But of course, it's not the whole story.
The reality is that alongside cancer, sugar feeds most cells in the body and is vital to our everyday function.
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"Stopping sugar getting to cancer cells would also mean that your body's healthy cells get starved of necessary sugars," says the CEO of Cancer Council Australia, Professor Sanchia Aranda.
"I think that would make you lose weight, [and] would make your immune system less efficient and more likely that a cancer would progress."
What's more, our bodies are clever — they have other ways of getting glucose.
Even if you do try and cut it out, the body will just convert fat and protein stores into glucose where necessary.
From Australia's national, independent broadcaster, which is modelled on the United Kingdom's BBC: abc.net.au/news/health/2017...
CLL is a chronic cancer, with CLL cells only slowly multiplying. That's why CT scans rather than PET scans are used for checking CLL and PET scans are used to check for possible Richter's Syndrome/Transformation, where CLL may have transformed into a fast growing large cell lymphoma. PET scans use a radiolabelled glucose molecule,18F-fluorodeoxyglucose or 18F-FDG, which is taken up by the fast growing lymphoma cells. August 2020 update
Solid evidence that sugar does not drive CLL progression: healthunlocked.com/cllsuppo...
By reducing your food intake, you are going to starve many other body cell types before you can hope to affect your CLL. We need a nutritious diet to ensure our bodies continue to function well when we have cancer, particularly when we are under treatment. Note that CLL can interfere with our ability to metabolise what we eat. One of the triggers for starting treatment according to the IwCLL Guidelines is -
Disease-related symptoms as defined by any of the following:
Unintentional weight loss ≥10% within the previous 6 months.
According to this paper on the energy metabolism of CLL, in addition to finding that CLL cells were heterogeneous in this aspect (what a surprise ), "We found that, although CLL cells and B cells have a similar basal glycolytic activity, CLL cells had a significantly higher glycolytic capacity and glycolytic reserve, which are both indicators for the cell’s potential to switch to glycolysis as an energy source when necessary. Interestingly, we also found glycolytic capacity and reserve, but not basal glycolysis, to be novel predictors for OS in our cohort; CLL patients with higher glycolytic capacity and reserve showed worse prognosis."
haematologica.org/content/1...
So my take from that is that CLL cells will survive better than normal B-cells when under energy supply stress.
Sugar and cancer – what you need to know
Where the myth came from, why it's a myth, and why reducing our sugar intake can indirectly reduce our risk of developing cancers.
From the Cancer Research UK - last updated July 2019:
Search for sugar and cancer on the internet and it doesn’t take long to find alarming warnings that sugar is the “white death” and “cancer’s favourite food”.
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Glucose is the basic fuel that powers every single one of our cells. If we eat or drink things that are high in glucose, such as fizzy drinks, the glucose gets absorbed straight into our blood ready for our cells to use. If a starchy food, such as pasta, is on the menu, the enzymes in our saliva and digestive juices break it down and convert it into glucose. And if for some reason there’s no carbohydrate in our diet, cells can turn fat and protein into glucose as a last resort, because they need glucose to survive.
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Cancer cells usually grow quickly, multiplying at a fast rate, which takes a lot of energy. This means they need lots of glucose. Cancer cells also need lots of other nutrients too, such as amino acids and fats; it’s not just sugar they crave.
Here’s where the myth that sugar fuels cancer was born: if cancer cells need lots of glucose, then cutting sugar out of our diet must help stop cancer growing, and could even stop it developing in the first place. Unfortunately, it’s not that simple. All our healthy cells need glucose too, and there’s no way of telling our bodies to let healthy cells have the glucose they need, but not give it to cancer cells. (but see final reference below - Neil)
There’s no evidence that following a “sugar-free” diet lowers the risk of getting cancer, or boosts the chances of surviving if you are diagnosed.
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If cutting out sugar doesn’t help treat cancer, why then do we encourage people to cut down on sugary foods in our diet advice?
That’s because there is an indirect link between cancer risk and sugar. Eating lots of sugar over time can cause you to gain weight, and robust scientific evidence shows that being overweight or obese increases the risk of 13 different types of cancer. In fact, obesity is the single biggest preventable cause of cancer after smoking...
scienceblog.cancerresearchu...
What about ketogenic diets, the Warburg Effect, Dr. Thomas Seyfried, Dr Joseph Mercola? Well it's as usual, more complicated than is portrayed and "the evidence is so darned thin and unconvincing thus far":
sciencebasedmedicine.org/ke...
Note the conclusion - "Clearly, ketogenic diets are not ready for prime time as a treatment for cancer, either alone or in combination with conventional therapy. Unfortunately, that hasn’t stopped it from being touted by all manner of alternative cancer practitioners".
Starving cancer cells of sugar could be the key to future treatment
or how to block cancer cells from taking up sugar while allowing our healthy body cells to continue to do so.
You may have seen articles or websites advocating that starving patients of sugar is crucial for getting rid of tumours or that eating less sugar reduces the risk of cancer. The story is not that simple. Cancer cells always find alternatives to fuel their tank of glucose, no matter how little sugar we ingest. There is not a direct connection between eating sugar and getting cancer and it is always advisable to talk to your doctor if you have doubt about your diet.
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In a recent study published in Nature Communications we showed that cancer cells stimulate the over-production of the protein known as PARP14, enabling them to use glucose to turbocharge their growth and override the natural check of cell death.
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This means that a treatment which could block the protein could represent a significant revolution in the future of cancer treatment. What’s more, unlike traditional chemotherapy and radiotherapy, the use of PARP14 inhibitors would only kill cancer cells and not healthy ones. The next step is to design and generate new drugs that can block this protein and work out how to use them safely in patients.
by Concetta Bubici, Lecturer in biomedical science, Brunel University London and Salvatore Papa, Senior scientist, Institute of Hepatology, Birkbeck, University of London: theconversation.com/starvin...
So while it makes excellent sense to aim for a more balanced diet and achieve a healthy weight, do so for the rewards that that brings and not with any expectation that your CLL progression will slow. Don't feel guilty about enjoying the occasional sugary treat! Remember that "There’s no evidence that following a “sugar-free” diet lowers the risk of getting cancer, or boosts the chances of surviving if you are diagnosed."
This is an unlocked post, discoverable on the Internet
Neil