I’m not trying to spoil your Christmas dinner. In fact, I was sort of hoping to make you laugh. We’ve been told that just about everything else causes cancer, why not turkey?
But there is a serious point underneath my seasonal silliness. Stay with me…
In order to thrive, cancer needs a combination of abnormal growth signals and abnormal fuel supplies, and we suspect that food is involved in both these mechanisms. A lot of effort has gone into trying to identify and arrest the mechanisms behind this adaptation. We know for sure that tumour cells eat too much: they fuel their unlimited growth by up-regulating their energy intake and commandeering more nutrients than normal cells.
There are two apparently conflicting nutritional theories doing the rounds at the moment: some people (the Warburg/Seyfried camp) believe that carbs are the only fuel cancer cells can use, so restricting them is the way to starve it into submission; others (devotees of T. Colin Campbell and The China Study) insist that restricting protein is the answer to killing cancer – particularly protein of animal origin.
The answer is probably a bit of both: excess carbs create abnormal growth signals via constantly elevated blood insulin, while excess animal protein provides the raw materials for uncontrolled cell replication.
Before you start frantically looking up recipes for nut roast, let’s explore that a bit more.
The animal protein theory arose from research carried out by T. Colin Campbell (TCC). He noticed that animal protein (he used casein from cows’ milk) accelerated cancer cell growth, while vegetable proteins did not, suggesting to him – and others who have latched on to his work – that a vegan diet may be the optimal anti-cancer diet.
If only it were so simple! You probably know that most vegetable proteins are ‘incomplete’: very few contain all the essential amino acids needed to build a human cell. Which means that individually, in isolation, they would, of course, inhibit growth.
What TCC had observed is basic metabolism: you can’t grow new cells – cancerous or otherwise – without plentiful supplies of all the essential amino acids. It’s not a breakthrough, it’s nutrition 101.
What we can, perhaps, salvage from his observations is the knowledge that cancer cells are not the superheroes we often believe them to be: they need all the same raw materials for growth that other cells do. So limiting the supply of protein to that which your body actually needs (and no more) may be a sensible way to restrict unwanted growth.
Let’s hold on to that.
But before cancerous cells gain the ability to grow into tumours (and before that point they are harmless) they need to overcome the body’s natural tendency to share all of the fuel among all of the cells in more or less equal measure: they have to learn how to grab more than their fair share. And we know, for sure, thanks to pioneering work by Craig B Thompson’s team at the Memorial Sloan Kettering Cancer Centre, that abnormally high carbohydrate and insulin levels in the blood are responsible for this adaptation. With no restriction on its energy intake, the cancer cell is able to replicate at an alarming rate. Which is how carbs fuel cancer growth.
So when you’re hosting an active tumour, both carbs and proteins are part of the growth picture. Which brings its own set of problems: how can you tackle that with diet? How can anyone live without carbs and proteins? You may be able to starve the tumour, but surely at the expense of the whole organism?
It’s easy to see why medics have transferred their attention elsewhere,
Until recently, almost everyone would have agreed. We come from the generation that believed (past tense) that carbohydrates were essential for energy, for life itself, and that fats were public enemy number one.
But we have been badly educated. Once we discard the flawed and discredited studies carried out by Ancel Keys and co in the early 60s, and associated dogma, we discover that fats are in many ways a superior source of energy. For our purposes, the most exciting potential of relying on fats rather than carbs for energy is that cancer cells may not be able to use them.
Ironic that the only one of the three macronutrients that seems to be neutral as far as cancer is concerned – neither providing the building blocks of cancer cells, nor disrupting hormone levels and growth signals – is fat. The one we’ve been avoiding..
So if we update our knowledge about making energy from fats, and consider that we may be able to find an optimal protein intake that provides enough for normal function but not enough for cancer cell growth we may well be able to design a diet that helps both to prevent and reverse cancer. Furthermore, studies in calorie restriction suggest that cancer cells may be recognised as damaged and surplus to requirements and become targets for autophagy (literally being eaten up by the body) if the body is short of supplies.
If you are looking for chicken and eggs here (if that isn’t a bird too far) you would likely conclude that restricting carbs is the most important thing to do to prevent cancer, and that additionally restricting protein may be sensible if you have active cancer.
Why am I writing about this now?
Apart from the fact that the animal protein/China Study theory seems once again to be doing the rounds, it’s also because Christmas is a notorious time for all of us to eat (and drink) far too much – which is a great gift to cancer cells.
And it is no longer just at Christmas that we eat too much. We also celebrate St Valentine’s with food, and Mothering Sunday, and Easter, and bank holidays, and summer holidays, and Thanksgiving, and birthdays, and promotions, and home comings (and goings) and we eat and drink too much at weekends with our friends, and then we grab inappropriate food all week because we’re too busy to cook.
It never ends.
And we’re all doing it (aren’t we?) so it seems kind of normal.
If you have been led to believe that the only way cancer is linked to diet is via genetic insults – the carcinogenic effects of alcohol, smoking, pesticides, etc. – you have been misled. The reality is much simpler and more sobering. Constantly overeating (and the associated over exercising that many of us use to balance the books) may be a much bigger risk factor.
So this is a wake up call, to ask you to look after yourself with more care. To understand that the possibility of cancer in your future is not as random as it may seem. To let you know that you may be able to do more to prevent it than you think. To help you see that recovery from cancer may be more in your control than you’ve been led to believe.
After all this, it seems perverse to round off the year by wishing you a Merry Christmas. But I do. And I sincerely hope you find new ways to enjoy yourself over the holiday – and during the year ahead – that don’t focus solely on providing the perfect conditions for your body to self-destruct.
Now, where’s my extra large roasting tin?