About the author : victoriafenton

I have written about Functional Medicine and Cancer before. In that article I made the justification for utilising Functional Medicine when addressing a Cancer diagnosis. But I stopped short of explaining what tools and strategies I use as part of an Integrative Oncology approach, basically because every patient is different and I have always resisted being specific when there are risks to self-directed therapy. This is especially dangerous than when the stakes are as high as they can be with Cancer.

However, the more I research into Cancer, and the more patients I help with this condition, the more I realise that the risks of sharing the information are eclipsed by the amount of misinformation that can persist around so-called “alternative” cancer treatments.

So here, I return to the topic of Functional Medicine’s approach to Cancer – and whilst I will stop short of recommending specific doses of treatments, I will go deeper into detailing what therapies we are finding to have benefit in integrative oncological care.

This week, I start with the basics – Food.

And yet, diets for Cancer are anything but simple, as I will explain.

Next week I will go onto to discuss ‘therapies’ such as vitamins, supplements and holistic treatments which show promise in Integrative Oncology.

But first… some definitions:




Before I start with the details, I have to make the point (as I did in my last article) that when I deal with Cancer patients I am utilising Integrative Oncological strategies. This can be taken absolutely literally: I rarely if ever take on a Cancer patient who isn’t also under the care of a conventional medical team – or at least, has recently been cared for by one. Whether I am dealing with patients who have just been diagnosed, are in the middle of treatment, are post-surgery or have been declared as ‘in remission’ and are desperate to remain that way, I am always interested in working with their oncology treatment team. The need is for my “functional” methods to be integrated into the conventional therapeutics.

The same is actually true for any health condition that I deal with – and the reason for this integrative approach is simple. Both ‘conventional’ and ‘functional’ medicine approaches exist is because both are necessary.

In acute care and illness, the targeted, prescription pharmaceuticals are invaluable. What I have witnessed – perhaps more so within Cancer care than in many other health conditions – is that Functional Medicine approaches can not only improve the efficacy of traditional Cancer treatments, but also support the physiology whilst patients are undergoing often quite gruelling courses of drug therapies.


This is why within Integrative Oncology we talk about a host of so-called “Adjunct Therapies”. These are supportive strategies which go alongside traditional medical treatments – helping them to actually work better whilst minimising the collateral damage that medical treatments often cause.


So what are these so-called “Adjunct Therapies”…?



It is perhaps boring but nevertheless true that the foundation of health begins with the building blocks our bodies have available to them to perform essential functions. For this reason, nutrition is the foundation of any healing strategy – irrespective of the diagnosis or prognosis. It’s so important that today’s whole article will discuss this one, single element of Cancer care: what to eat.

The specific condition that someone is dealing with (from Cancer to autoimmunity, viral infection or toxic burden etc.) can give us an insight into the specifics of the dietary ‘prescriptions’ we recommend. And yet, nutritional guidance should start more simply than that. There are sweeping generalisations that can be universally applied to being ‘healthier’:

  • Eat whole foods … which is a fancy way of saying cook your own meals and use ingredients that you might be able to find in farmer’s markets and butchers/fishmongers (rather than factories)
  • Eat as little ‘junk’ as possible
  • Eat variety – and eat the full rainbow of plant foods so you’re getting the full complement of polyphenols and antioxidants that come with that way of eating
  • Don’t eat toxic foods

The differentiation comes when you get into debates about what qualifies as ‘toxic’ – and this may vary according to the health condition that you are dealing with.

When it comes to Cancer, certain foods (red meat for example) have been specifically linked to poorer health outcomes. I have discussed the potential issues with that data here – and this affirms that whilst the mechanism behind the red meat/Cancer link is accurate – it doesn’t pose as great a risk when eaten in the context of a plant-rich diet and the meat itself is good quality… but the protein/red meat/cancer story really isn’t simple – so I will cover this in more depth in the “Protein” section below.

So, scientific data consistently affirms that diets rich in plant matter with minimal added sugars and little processed or artificial foods are best for overall health. This is true irrespective of whether that diet contains or does not contain meat – though there is an issue with proteins which I will discuss later. It is also true whether you add in legumes/beans/pulses/whole grains (as in the Mediterranean Diet), or whether you drink the occasional glass of red wine. It is also true irrespective of whether foods are cooked or raw – eaten whole or juiced into oblivion. And it is even true whether you’re manipulating macronutrients to be high or low carb, high or low fat, high or low protein – or cycling between all of these strategies.

And in a world where nutritional information is plentiful, and there is increased awareness of the role of food in healthcare, it becomes incredibly easy to lose sight of the simple truths: more vegetables, more plants, less rubbish and you will be improving your wellbeing. This means that if you are eating what is typically known as the Standard American Diet then switching to more vegetables, getting carbohydrates from starchy veg rather than grains/sugars/sugar-sweetened beverages and cutting out processed, packaged, highly salted/artificially flavoured foods, you will automatically be investing in your health.

And yet, this answer cannot satisfy the patient who has already been doing ‘everything right’ and yet still has a Cancer diagnosis. And there are many of these patients.

Side note here: there are advocates of juicing therapies for cancer. I am undecided about this. Some treatment centres exist which aim to solely feed Cancer patients on green smoothies, no protein and only ever raw foods pureed up. Now, mechanistically I do understand this approach (and, ironically, it covers some of the bases of the strategies I recommend below). However, I also see the flaws in this plan – namely absorption issues, social life and emotional issues, bolus of liquid nutrition issues, simple caloric lack issues… therefore this raw-food, smoothie-only approach is NOT a strategy I utilise in my practice.

Back to what I do recommend, then.

When we dig down into diets for Cancer you could literally fill a whole book. And people have – two of the best resources are as follows:

Beating Cancer with Nutrition

The Essential Cancer Treatment Nutrition Guide & Cookbook

And perhaps one of the best, most concise – most well-referenced – review of the cancer/nutrition literature (and, to be honest, the most up-to-date) appears in Outside The Box Cancer Therapies by Dr Mark Stengler and Dr Paul Anderson.

But what are the takeaways? Well, let’s first address what the diet is trying to achieve for the Cancer patient:


The essential nugget of how integrative medicine approaches Cancer is that we are not trying to directly attack the cancer – that’s the role of surgery, drugs and toxic chemicals.

Instead, we are doing two complementary, though different, things: firstly, we assist the Cancer patient’s immune system to realise that Cancer cells are not self-cells and we help their innate cell-clearing-out and clearing-up programs (known as autophagy) to get rid of Cancer cells by pushing them into unfavourable metabolic states where they are forced to enter cell-death programs.

Secondly, and concurrently, we provide the right environment for Cancer cells to become metabolically stressed enough such that they are especially vulnerable to conventional treatment agents being used.

This means that nutritional practices that upregulate immune function, encourage autophagy and cell turnover whilst also creating an unfavourable environment for the survival of Cancer cells will all provide the right basis for Cancer care.


And in this case, nutritionally – more than just eating lots of vegetables – there are two strategies currently leading the way: fasting and lowering carbohydrate levels.



There are those who will take this to an extreme – lengthy fasts or strict 5% carbohydrate diets (known as extreme ketosis). Whilst this might work, we don’t have the evidence that this is a ‘better’ strategy than the more moderate approach. Reviews reveal that the 24 hour plus fasts have consequences – most notably cachexia (loss of muscle) and weight loss. This is extremely undesirable, especially for those who are undergoing Cancer treatment in which cachexia is a risk anyway. Moreover, whilst fasting can improve tolerance of chemotherapy in certain cases, this is not yet proven to be totally safe, nor entirely necessary.

Additionally, longer term fasting has a central nervous system affect which changes hunger signals. In those who are going through treatments which increase nausea and gastrointestinal issues, playing with hunger signals is not an advisable strategy.

And yet, there are some common-sense, mechanistic justifications for fasting for at least 12-13 hours overnight – because this is when we see evidence of autophagy starting to occur (that natural cell clean-up process). Some suggest that this doesn’t begin until after 16 hours, but actually these ‘hourly’ targets are somewhat arbitrary.

Countless studies suggest that autophagy begins once the liver has run out of glycogen. This could begin at 8 hours, but seems to most often begin after a 12-13 hour overnight fast – especially if a lower carbohydrate approach is taken (of which more below). Autophagy is seen to massively increase after 16 hours, but this is when other dietary strategies aren’t followed.


As this 16-24-hour level of fasting may overtly stress the body (part of the survival mechanisms which are ‘turned on’ during fasting involve an upswing in cortisol and also human growth hormone) there is an argument that combining the 13 hour fast with a lower carbohydrate approach might be the perfect middle ground for the Cancer patient.


Asking about carbohydrates in Cancer care can be like opening up a can of worms. There are die-hard advocates of ketogenic diets for cancer online and who point to the studies which sing its praises.

– and those who point towards the studies which ring alarm bells about ketogenic diets, suggesting that ketosis cannot be healthy long-term and should not be used in a state where the precise metabolic needs of the Cancer cells may be unknown.

I have tried many times to write a definitive guide to ketosis – but it just isn’t possible. Yet. There is so much nuance depending on how the ketogenic diet is made up. Clearly a ketogenic diet based on steak (high protein – see below, but also low carb, but also high in haem iron and the amino acids which activate growth and proliferation pathways) is not going to benefit the cancer patient.

So when it comes to serious conditions such as Cancer this means that we must proceed with caution – and really work to understand the mechanisms being activated and how they can support the Cancer patient’s prognosis.


Ketogenic diets change the metabolic fuel available for all cells of the human body – and if you are a patient with Cancer, this will change the fuel available for your Cancer cells as well as your healthy cells.

The concept that ‘sugar feeds Cancer’ has some merit, and is based on the work of Otto Warburg who investigated the metabolic machinery of Cancer cells (note: the cells of SOME Cancers) and evaluated that their mitochondria preferentially burned only glucose for fuel and were unable to utilise other molecules of energy such as ketones.

The ketogenic diet, by definition, encourages the liver to produce ketones to be used as fuel by healthy human cells. The argument in Cancer is that low carbohydrate diets limit access to sugar, thereby ‘starving’ those cells which rely solely on sugar and cannot utilise ketones… i.e. Cancer cells.

This is a bit of a basic understanding, however. What ketogenic diets really do is push Cancer cells into a state of metabolic oxidative stress due to lack of available fuel. This doesn’t cause the cancer cell to just die because it has run out of energy. Instead, a state of oxidative stress will sensitise the Cancer cell to the conventional chemotherapy and radiotherapy, making it vulnerable to the toxic agents being administered to kill it. Essentially, not allowing Cancer cells their fuel makes them vulnerable – and able to more easily be killed by targeted drug therapies.

This is what we mean by “Adjunct” Therapies. Ketosis alone is not going to cure cancer. It is the metabolic shifts it provides which, when coupled with a host of other therapies (which can include conventional treatments) can prove impactful and therapeutic.

And ketosis doesn’t work for every cancer. Some Cancers retreat dramatically when ketosis is followed. However, others progress. So how to choose, how to know what to do?

This is why I recommend working with practitioners and not doing this alone.

This may frustrate you if you’re reading this article for prescriptive answers – so what I suggest when I am speaking generally is always moderation. I have seen that Ketogenic diets, low in carbohydrate all the time, can do more harm than good – for many conditions and I am often begging my clients with autoimmune conditions and/or hormonal issues to eat more carbs.

And yet I see a generally lower-carbohydrate approach work very well in many, many health conditions – particularly those in which metabolic derangement and neurological issues have occurred, because fats and ketones suit the brain.

Ketosis requires around 80% plus of calories to come from fat. This is hard to do on many levels: practically, digestively, in terms of taste preferences etc. Not to mention the fact that fat is difficult to stomach when nauseous, as happens when undergoing drug therapies for cancer.

And yet keeping carbohydrate sources to starchy vegetables and the occasional piece of fruit or spoonful of honey is already minimising the intake of easy-access sugars. In fact, this lowering of junk and ‘quick-burning’ carbohydrates is enough to remove the easy fuel from Cancer cells. This, combined with the overnight fasting strategy, means that ketones will be produced at least part of the time – and sooner than they would be if you were not keeping carbs low.


This is why I couple the two strategies together – because the uptick in autophagy from fasting is easier when the liver glycogen (sugar/glucose from carbs) stores empty sooner… as is the case on a lower carbohydrate diet. This achieves much of the benefits from both approaches, without tripping into the stressful and potentially damaging characteristics of either.


This dovetailed, dual approach can ensure metabolic processes are stacking the decks in the Cancer patient’s favour. And then, alongside conventional treatments when indicated, I will also utilise a host of adjunct therapies – all of which support antioxidant levels, push Cancer cells into metabolic oxidative stress and eventually cell death, and massively support the rest of the physiology whilst all of this is going on. The diet forms the foundation and supports the antioxidant levels (vegetables and eating the rainbow) that will stand the body in good stead. The other therapies provide the nudge into programmed death for Cancerous cells.



And finally, a word on protein. Protein has a bad reputation in Cancer (and in ageing and longevity) because of the way certain amino acids switch on cell pathways which signal for growth. Clearly, when some of your cells are cancerous, any activation of a pathway which triggers growth can be potentially dangerous.

I have read a lot of the research on this and there is strong evidence to suggest that excess protein really can upregulate all sorts of pathways that can prove damaging in the long run. However, studies on this protein-signalling damage have not been done in the context of healthier diets – where the protein is good quality (no excess hormones or antibiotics) and balanced with a tonne of vegetables. That doesn’t mean it’s wrong, just that there’s understanding we still don’t have here.

Moreover, all amino acids don’t activate growth pathways in the same ways. It seems that Leucine is the chief trigger for growth pathways, along with Arginine. But in truth – this whole thing is ridiculously complicated. The body has many feedback mechanisms and regulatory pathways – focusing on one (and one amino acid) is not enough. That said, Leucine has also been shown to inhibit the autophagic processes we’re trying to stimulate in the Cancer patient – but this inhibition is prevented in the presence of other amino acids.

Moreover, evidence suggests that the stimulation of IGF1 on the consumption of protein (not a great thing in a Cancer patient) is NOT a concern for those under 65. Over 65 and your background levels of IGF1 are so low that this doesn’t actually matter. Moreover, the ageing patient actually has a MUCH higher requirement for protein to be healthy and retain muscle mass and wellbeing.So Cancer in the elderly comes with entirely different protein needs and recommendations.

I hope this helps you see that protein is not a simple question. Nor are all proteins created equal. That leaves me typically recommending fish over red meat to my Cancer patients – but not to the total exclusion of all red meat. It also leaves me definitely recommending sources of animal protein over solely vegetarian sources of protein – simply because Cancer is an energetically demanding state and having easily bioavailable nutrients (as in animal protein over vegetable protein) is less draining on the body. Moreover, to meet protein requirements from vegetable sources requires eating quite some quantity – and most vegetable proteins come along in a package with quite a bit of carbohydrate. And yet, we don’t need to be mainlining protein in hydrolysed micro-particle form for fear of malabsorption…

It’s complicated, you see – and sometimes the best strategy is actually not about one strategy – it’s about using multiple strategies, all founded on healthy practices but that encourage variety.




The more I work in Functional Medicine – and, in fact, the more I live inside my own body – the more I become a believer in the way the body responds to change and variations in routine. I also trust the benefit of hormetic stressors – those things which challenge the body just enough to allow for adaptation (usually, because they are new stimulus – as happens when you cycle or change things around).

When you’re trying to factor adaptation into everyday life, the one thing that I feel ensures that this takes place is cycling. This is the rotating in and out of phases, undulating intakes of protein to ensure that some days you don’t trigger too much metabolic growth pathways at all, other days a bit more. Similarly with the carbohydrates – creating metabolic flexibility in healthy cells by fluctuating levels of carbohydrate intake is something that creates strength within the human body.

It is from this place of strength within the healthy cells that success in Cancer therapy can be attained: utilising the antioxidants and cycling in and out of the dietary strategies mentioned above, coupled with the conventional drug treatments AND some of the adjunct therapies that I will discuss next week.

Next week I will talk about all the ‘other stuff’ you may have heard of in the world of Cancer therapeutics – some of it popular, some of it more ‘out there’. All of it natural – but all to be undertaken under the care of a practitioner.

Because that’s one thing that must be recognised. No two Cancers are the same – because even if they are identical types of Cancer they are occurring in different bodies, at different ages (see the protein question above) with different genetics, different histories and different experiences.

Everything listed above dietarily may be rendered irrelevant given someone’s unique situation – and this is why I would still encourage that regardless of the answers I give or that you find elsewhere, please work with someone to support your progress in facing this disease. If you would like to work with me, do just reach out to me and I’ll be delighted to help.

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