Is there a link between sugar and cancer?
We have covered the dangers of sugar in our diet on this site many times, and know the stats can be alarming when it comes to sugar and health. At the last count, the University of California, Los Angeles (UCLA) held sugar responsible for over 35 million deaths per year globally. Depending on how we qualify the link between sugar and death, I would put the number far higher than that.
In fact, the health risk posed by sugar is so high that many countries around the world are looking into controlling the sale of high-sugar products through taxes and on-pack health warnings – as is already the case with other harmful products such as tobacco and alcohol.
But what exactly is sugar putting us at risk of? By now, most of us are well aware of the links between sugar and diabetes, obesity and even heart disease. But does it stop there? The evidence suggesting that the answer is an unequivocal “no” is piling up.
And with that let’s get to the heart of this week’s topic, which is the link between sugar and cancer. We will put the rhetoric and anecdotal evidence aside and delve into the science behind the question.
Does sugar cause cancer?
A recent ground-breaking study published in the Journal of Clinical Investigation points to sugar not only being a fuel source for existing cancers, but also cites it as a primary factor in the initiation of cancerous characteristics in previously healthy cells.
The study goes on to suggest that rather than increased glycolysis (the breakdown of glucose to provide energy) being a consequence of cancer, it is rather the activation of sugar-based metabolism in a cell driven by high sugar quantities on the cell membrane that actually causes cancer to form in the first place. And it is far from the only study to suggest as much.
Similar research conducted at University Rey Juan Carlos in Madrid uncovered a key mechanism which links both diabetes and obesity with cancer – namely, high sugar levels that increase production of the hormone growth inhibitory peptide (GIP).
The Spanish university’s study, which particularly focused on pancreatic cancer, looked at how cells in the intestine respond to sugars and signal to the pancreas to release insulin. The study found that high sugar-levels within the intestine triggers cells to release GIP – which in turn leads to increased activity of a protein called beta-catenin – known to be a major factor in the development of cancer.
Studies suggest that the risk of pancreatic, prostate and colon cancers may in fact be most influenced by sugar – meaning sugar may be the number one cause of cancer
The university’s research was lauded by a leading oncology professor from England’s Oxford University, who credited the study with “identifying a key molecular mechanism through which high blood glucose would predispose to cancer.”
There is further support for the link between sugar and cancer from the other side of the Atlantic as well, with a study conducted by Harvard Medical School finding that those who ate a high-sugar diet in their teens had a higher incidence of breast cancer in later life. But it goes beyond breast cancer, with studies suggesting that the risk of pancreatic, prostate and colon cancers may in fact be most influenced by sugar – meaning sugar may well be the number one cause of cancer.
One particular study by the National Center for Biotechnology Information – a branch of the US National Library of Medicine – showed that those who ate a diet with a high glycemic load (GL) increased their chances of developing prostate cancer by almost 30%. The study went on to highlight that a high GL diet led to a 44% increased risk of rectal cancer and a 41% increase in risk of developing pancreatic cancer too.
Sugar and the spread of cancer
If the studies into sugar and the initiation of cancer weren’t startling enough, the evidence to suggest that sugar also exacerbates the growth of cancer cells is even more alarming. For decades now it has been widely accepted that high sugar levels fuel the spread of cancer. In fact, this viewpoint dates back as far as the early 1920s, when researchers at the Huntsman Cancer Institute in Utah became some of the first to discover that glucose effectively feeds tumours.
In more recent years, UCLA’s Jonsson Cancer Center once again conducted research into the correlation between sugar and cancer, this time highlighting how cancers use both glucose and fructose to fuel their growth – showing cancer cells to readily metabolise the sugars to increase their proliferation.
A report by the Cancer Treatment Centers of America went one step further, calling sugar “cancer’s favourite food”, and even going so far as to suggest that it was foolish to overlook dietary treatments – i.e., cutting out sugar – for slowing the spread of a number of cancers.
There are several reasons for cancer’s affinity to sugar, as Nobel laureate in medicine Otto Warburg pointed out. Fundamentally, cancer cells have a different energy metabolism when compared to healthy cells, with malignant tumours exhibiting increased glycolysis — the process whereby cells convert glucose into energy – which ultimately fuels their growth. Sugars acidity is also a great boon when it comes to exacerbating existing cancers. Essentially, cancer cells thrive in acidic environments and, as we know, sugar is highly acidic.
Over two-thirds of men and women in the UAE are overweight.
Sugar’s rap sheet stretches even further than this too. By suppressing a key immune response known as phagocytosis, sugar has been shown to deplete the immune system by almost 50% for up to five hours after ingesting high quantities – essentially rolling out the red carpet for the growth of cancerous cells.
Finally, there is the obesity factor. By now, we all know sugar is the single-biggest contributor to obesity – a huge issue in the UAE where obesity rates are double the world average. But did you know that obesity has itself been identified as a cause of cancer? So much so that the American Institute for Cancer Research estimates more than 100,000 cases of cancer each year are caused by excess body fat.
What a mess
Cancer is the third biggest killer in the UAE, and our Western-style diet is one of the most high in sugar in the world – evidenced by the fact that over two-thirds of men and women in the UAE are overweight. Coincidence? Of course it is not.
It really is a mess. And I say that because the majority of us – medical professionals and non-medical professionals alike – are simply not having this conversation. The conversation that goes something like this: “Sugar should have no place in our diets because it is causing diabetes, heart disease, cancer, autoimmune disease, Alzheimer’s, and a number of other life-altering or life-threatening conditions.”
But it is time to start this conversation and it has to be done on a collective level, with a concerted effort coming from government, the food industry, the medical community, our education system – and above all else, you parents out there. Aside from that extremely rare treat, banish sugar from your homes and your diets. It is literally good for nothing.
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Graham Simpson, MD is Chief Medical Officer and Founder of Intelligent Health, a preventive medical centre located in Jumeirah. Dubai. He graduated from the University of the Witwatersrand Medical School in Johannesburg, South Africa, and is board certified in Internal Medicine and Emergency Medicine. As a founding member of the American Holistic Medical Association (AHMA) Dr Simpson is also a licensed homeopath.