Friday, 2 March 2018
Sugar and Cancer: sweet surrender? Taking the lid off the sugar controversy - by Robin Daly
In cancer, you don’t have to look too far to find divided opinions on most aspects of theory, causation, diagnosis, treatment and more, but few are more polarised or more hotly debated than the role - or maybe irrelevance - of dietary sugar.
Here’s what the two largest cancer charities in the UK have to say on the subject:
And Macmillan state confidently that ‘Sugar in your diet doesn't directly increase the risk of cancer, or encourage it to grow.’
At the other end of the spectrum we have views such as Dr Mark Hyman’s. Hyman is the leading voice in the Functional Medicine movement that is now gaining significant traction in the US.
‘The number one thing you can do to prevent or control cancer is to control insulin levels with a high-fiber diet rich in real, fresh, whole foods and minimize or eliminate sugary, processed, insulin-raising foods.’
And top oncologist and advocate of Lifestyle Medicine Professor Robert Thomas wraps up an extensive review of all the science demonstrating a link between refined sugars and carbohydrates and cancer by saying:
‘In conclusion, although much of the evidence for the cancer promoting risks of sugar and high GI carbohydrate is from laboratory or large cohort trials, considering all the studies together its link to cancer is becoming increasingly convincing. Instead of the pro-sugar camp claiming that more trials are needed to prove the link, perhaps a more sensible approach is to assume there is a link, unless proven otherwise, as certainly no study to date has ever suggested sugar is healthy, and the problem is getting worse.
Where did it all start?
Back in the 1920s, Nobel prize-winning German scientist Otto Warburg discovered that one of the distinctive features of cancer cells is that they have damaged mitochondria. Mitochondria are the cells’ energy generators, and the damage means that cancer cells turn away from oxygen as an energy source and instead use fermentation. Fermentation is an inefficient process that doesn’t require oxygen, but that does need large quantities of glucose. This led Warburg to hypothesise that damaged mitochondria are the source of cancer, and that this provides a universal way of targeting cancers, by starving them of the steady supply of glucose they require.
This view of cancer as a ‘metabolic’ issue, was surpassed during the twentieth century by the somatic mutation theory, which lays the blame firmly on genetic defects. Although the gene theory has substantially failed to deliver on the targeted cures that were at one time considered a future certainty, the division between the two theories - in which both see each other as preoccupied with a side effect - lives on. It’s a testament to the power of marketing that, despite giving so little bang for the immense number of bucks invested, gene theory remains predominant, and sugar remains a facet of outdated metabolic theory.
The cautionary principle
Prof Thomas makes the point that, given the sheer volume of good evidence pointing towards dietary refined sugars and carbohydrates as both a source and driver of cancer, along with the catastrophic way that the grim reaper, cancer, is scything its way through developed nations around the globe, a zero-cost, safe intervention such as reducing intake of refined foods should be seen as eminently worth trying. Making utterly confident pronouncements about the absence of a relationship between sugar and cancer depends entirely on a totally suspect system that seeks to portray evidence as a binary ‘evidence/no evidence’ scenario, rather than as a more nuanced sliding scale of ‘more evidence’, ‘better evidence’.
All down the centuries, scientists have sought to equate scientific understanding with absolute certainty. Given the repeated experience of just how wrong science can be, a degree of uncertainty and even humility would, at this point, be both pragmatic and realistic. It’s well past time that scientists ditched the permanent ‘they used to think they knew, but now we know’ stance, for good. Clinging to increasingly untenable certainties is not just foolish, in public health it wreaks hell with people’s lives. The most obvious recent example of this is the ‘low fat’ myth that held sway for half a century and even now is a continuing mantra of organisations which have yet to find a way to reverse their position without completely losing face. Corporations are often nimbler than governments or charities when it comes to seeing the writing on the wall; protecting their bottom line is always a higher priority than sticking to dogma. Unilever, who have recently struck out in a new direction by buying Pukka, have sold off their margarine interests - which it describes as a ‘declining sector’ - including major brands such as Flora and Bertolli.
Fuel for the feud
It’s also important not to overlook the role of business in perpetuating scientific ‘certainties’. Once a story takes hold - such as ‘fat is bad’ - the wheels of industry gear up and soon there is an avalanche of food products and medicines riding on it, generating huge profits, and a determination to keep everyone ‘on message’ for the marketing plan, whatever that may take. And so industry starts buying the science it wants, buying the scientists who are prepared to deliver the sales lines, and in no time ‘fat is bad’ is a religion with devotees around the globe. By this time, the resistance to a change of direction is, unsurprisingly, overwhelming.
The soil not the seed
The growing science of epigenetics is making it increasingly clear that just as we are deeply connected with and affected by our environment, our cells are intrinsically linked to and dependent on the microenvironment of the body. Mina Bissell, former Head of Life Sciences at Lawrence Berkeley Laboratory in California, performed a breakthrough experiment in which she demonstrated that a cancerous cell, when placed within a healthy extracellular environment, reverts to a normal healthy cell. And conversely, a healthy cell transplanted into a cancerous environment quickly becomes cancerous.
This understanding is starting to creep into the mainstream. Best-selling author and oncologist Siddhartha Mukherjee writes at length in the New Yorker, giving examples from nature of species that, in their native environment, are in step with everything around them; but move them elsewhere and they can quickly become a destructive menace.
Both Bissell and Muckerjee are giving indications that cancer is more about the health of the body than the state of a few genes, and absolutely no-one is currently arguing that refined sugars and carbs are good for your health.
So here’s a picture:
• Refined sugars and carbs are bad for our health
• In tandem with other lifestyle issues, they drive the body towards inflammation and encourage a cellular environment conducive to fermentation
• Fermentation is the the method of choice for cancer cells to get their energy
Common sense conclusion: refined sugar is a bad idea if you want to remain cancer free, and it’s a bad idea if you have cancer, as you are supporting its preferred environment. In fact Mina Bissell has gone on to demonstrate in the lab that this is indeed the case - sugar promotes the inception of cancer and fuels it once the process is under way.
Public health messages seem, on the face of it, to be a good idea. But when they are conceived within an environment fuelled by business interests and in which scientists are clinging to certainties well past their ‘sell-by’ date, they can go horribly, horribly wrong. The results can be far worse than if the public had been left to their own devices. Millions of people, thinking they are making healthy choices, are being utterly misled. Big, simplistic messages are the supertankers of public health: nigh-on impossible to turn around.
Sugar and cancer is one such supertanker. You can already read the first attempts to ‘manage’ the turnaround, as the rhetoric inches away from ‘sugar definitely has nothing to do with cancer whatsoever’ towards ‘it’s complicated’. Meanwhile, a recent Daily Mail headline blares out in a singularly uncomplicated manner: ‘Revealed: How sugar feeds cancer and makes it harder to treat’. We are told the conclusion from a 9 year ‘breakthrough’ study (audible yawns from the Integrative and Functional Medicine camps) that ‘This link between sugar and cancer has sweeping consequences’.
What price for being ‘right’?
So far it has taken almost a century for one simple, but vital piece of information to make its way into the mainstream…. and it’s far from there yet. Cancer patients in leading hospitals across the land are still being exhorted to eat high-calorie junk food in order to keep their strength and weight up. This dogmatism looks set to kick the twenty-year refusal by doctors to wash their hands between procedures into absolute insignificance, in terms of the level of human suffering generated.
Eventually the science will force change, but of course, in reality, the science changes nothing. If it’s true that excess dietary sugar both causes and feeds cancer, then it is just as true right now, before sufficient science arrives to bludgeon the nay-sayers into submission. The effects on the lives of those with cancer is real and it is happening today on the cancer wards. If the cautionary principle were always to the fore - as of course it should always be when dealing with people’s lives - then avoiding sugar, along with many other simple precautions, would be routine, until such time as proved safe. And had this been the case, who knows, the Daily Mail might just have been able to announce the same ‘breakthrough’ a whole lot sooner - possibly even half a century or more sooner.