By Jerome Burne
Last week the front page of The Times carried a story that was an opening shot in a revolution. I’m sure that the editors didn’t intend it as that and that the readers didn’t see it that way either. It was a story about shifting from the long recommended low fat diet to one that cut back on carbohydrates instead. Standard fare for the cuddly lifestyle pages, hardly material for social upheaval.
But I don’t think it is too fanciful to suggest that this may come to be seen as a Martin Luther moment for medicine. It may not split the profession as Luther’s divided the church but it does have the potential to dramatically change the way medicine is practiced. To begin with it is significant that doctors were involved; nutritionists would never have made the front page. Insiders, such as the monk Luther or the aristocrats who signed the Tennis Court Oath before the French revolution, are often key to giving revolutionary change lift off.
The doctors had largely been convinced of the benefits of low carbs by trying it themselves and seeing the effect on their patients. But this is more than just another of those irritating nutritional U-turns: ‘Last year we had to avoid eggs because they were packed with cholesterol, now we can safely have six a week. Can’t they make up their minds?’
If there is a U-turn in official advice about fat/carb quantities, and the physiological case seems to me to be unarguable, the knock on effect would be far reaching; it could be the tug on a loose strand of wool that unravels a whole sweater.
The revolutionary charge of low carb
To begin with it would involve admitting that nutrition can be a safe, effective and cheaper treatment for some lifestyle disorders than drugs. One of the campaigners, Dr Unwin, has already cut 40,000 pounds a year from his practice’s drug bill as a result of the drop in diabetic drug prescriptions. Inevitably there would be pressure to make greater use of other nutritional approaches such as the Mediterranean diet to cut the risk of heart disease.
Such developments seem sensible and unthreatening but they carry a revolutionary charge. At the moment diet is regarded as a useful but relatively ineffective handmaiden to real medicine. But if diet is going to start growing medical muscles, that raises fascinating regulatory problems, that doctors, who may well have emerged from medical school with only a few hours of nutritional classes, are probably unaware of.
First there is what might be called a legal falsehood about food. The official position is that it cannot modify physiology – ludicrous and patently untrue but that’s fundamental assumption about diet that all nutritionist have to learn to tip-toe around. Even a skilled theological debater such as Martin Luther might have a problem with some of tangled food and medicine orthodoxy.
For instance: it logically follows from this that no food or natural substance can “prevent, treat or cure’ any disorder. Equally ridiculous, you cry, and ask: but what about if you run a big trial and show that low carb or curcumin or vitamin C can do just that? Well yes good point. Interestingly even the government healthy eating campaigns ran into problems here with their five-a-day fruit and vegetable promotion. It verged on claiming this was a way to prevent disease.
How food is transformed into a drug
Officially the only substances that can prevent, cure or treat are drugs/medicines. The implication of this is that if you do demonstrate the effectiveness of a diet, food or supplement – say curcumin for inflammation or B vitamins to lower the homocysteine linked with Alzheimer’s - then it is logically a drug. This is a claim that requires a greater leap of faith than transubstantiation – the Catholic doctrine that the bread and wine given in communion literally turn into flesh and blood when eaten, which Luther thought profoundly wrong .
But then the substance has to be licenced which involves large and expensive trials, which are almost never done because food and natural substances are not patentable. Even doctors cannot properly prescribe non-drug remedies however good the evidence.
So the revolutionary potential should be becoming a bit clearer. Suppose a 100 or so GPs started using nutrition to treat their diabetic patients? What might come next? Once they start investigating nutrition physiology it would become clear that vitamins, minerals and other supplements also play a vital role in health. In the case of diabetes, for instance, there is quite a bit of good evidence that chromium and cinnamon help to improve blood sugar control.
Checking for vitamin and mineral deficiencies and topping up if needed would start to seem sensible. Could they all be hauled in front of the GMC for using unlicensed treatments or might the common slogan that you can get all the minerals and vitamins you need from a healthy balanced diet start to look as implausible as the low fat orthodoxy?
But talking about a low carb diet and suggesting some supplements along with specific exercise regimes is still just splashing about on the surface of lifestyle treatments. If a growing number of doctors stay on the low carb path they will start to encounter much more interesting and unfamiliar dietary territory.
Generating a different form of energy
How low, for instance, should you go with your carbs? At the moment the definition of low carbs is pretty elastic. Compared to 300 or more grams of carbs that a conventional diabetic diet can provide, getting that down to 100 grams seems pretty low. But what if you go down to 50, 20 grams?
What we know for certain is that once you get below about 20 your metabolism makes a step change, like the transition from water to ice. It stops relying on carbohydrates (blood sugar) for energy – because you aren’t getting enough – and it starts to release fat from your fat stores (you can see why this would be popular) to provide a different source of energy. The fat is transported to the liver where it is turned into ketones which the brain and muscles can also use as fuel.
There are all sorts of debates around this – it’s hard to get enough food for your gut bacteria on very low carbs. So some claim a low glycaemic diet is preferable; fasting may be able to get you all the benefits of very low carbs. But I’m going ignore those for now and just mention a very radical but very plausible idea – the ketogenic diet might one way to help you fight cancer.
It is a perfectly logical follow on from the idea that low carbs should help with diabetes. Low carbs makes sense for diabetes because it does what the drugs do – brings down blood glucose and insulin, because carbs get turned into blood sugar. And there are links between diabetes and cancer – having diabetes raises your risk of cancer and being treated with the diabetes drug metformin cuts that risk.
From low carbs to a new theory of cancer
So what is link between cancer and blood glucose and insulin? Simply that cancers use up a lot of glucose, far more than normal healthy cells. This makes very low carbs a reasonable option for cutting a tumour’s energy supply. Then insulin is a hormone involved in cell growth – not what you want too much of when you are tackling cancer. Known as the metabolic theory of cancer, this is out in the left field at the moment but it is generating a lot of fascinating research. It presents a challenge to the mainstream theory that cancer is all about genetic mutations. I’ve written about it here.
I bring it up to show that the physiology that makes treating diabetes with low carbs also applies to trying it to help with cancer. It would of course mean venturing into an area of medicine where the dogma that only medicines and medical procedures can prevent, treat or cure disease is enshrined in law in the form of the Cancer Act.
However there is preliminary but promising research to show that a ketogenic diet can make chemotherapy and radiotherapy more effective. What might be the effect of GPs using their new found nutritional confidence to start trespassing on the jealously guarded territory of oncologists? Would legal sanctions be rolled out?
Of course the usual response to such an incursion is to cry “quack” and “selling false hope” on the grounds that the required randomised trials aren’t there. But this is not quite the trump card that it was since a key part of the radical doctors case is that the trials showing the benefits of low carb are there but they are simply ignored. Certainly oncologists are not known for their interest in investigating any evidence for the dietary route in cancer treatment.
How the heresy might spread
This challenge to the Manichean division between scientific medicine and the other fake stuff may be one of the biggest effects of a switch to low carbs. The idea that medicine is evidence based and scientific is fundamental to modern medicine. This means that trials are done openly and fairly and that practice changes when the evidence changes.
However the gap between doctrine and practice that drove Luther to action is equally wide in today’s medicine. There are strong suspicions that official food guidelines owe more to the influence of Big Food than to research evidence. Something similar is going on with increasing scepticism about, for example, the statin risk/benefit ratio and the value of treating elderly people with a number of disorders simply by stacking up the number of prescriptions.
This opens the door for doctors to interpret guidelines far more flexibly and focus on individual patients and their symptoms rather than blood tests. This is certainly not going to happen overnight but already there is a handful of doctors involved in the low carb campaign who are doing just that. Two of them are the TV doctor Rangan Chatterjee and GP Joanne McCormack, and there have been HIUK posts on both of them (Chatterjee post and McCormack post).
Dr McCormack described how she became increasingly disenchanted with the official low fat advice and then spent two years educating herself about nutrition. She now enjoys the extreme challenge of trying to do the same for Public Health England. Dr Chatterjee’s TV series was based on the idea, never tested in an RCT, that the best way to begin treating a patients’ chronic disease was to find out what their home life was like.
The princes of the medical church will disapprove of such heresy but the response of the parishioners seems much more favourable.