When I asked my doctor about diet he just shrugged his shoulders – and that was the end of the conversation. I am a nutritionist and so you can imagine my disappointment at his response. And it was all downhill from there. The publications provided at support groups unequivocally state that diet does not affect cancer – just follow the standard national dietary guidelines (which is code for ‘eat whatever’).
There is a long list of compounds found in food that have known anti-cancer effects. These are phyto-chemicals that have researched, established effects on cancer. For example Allicin. It is lethal to cancer, inducing apoptosis and autophagy along with other effects. There is a decent amount of science available on Allicin  – it is found in Garlic. Last time I checked, garlic is a food.
The list of phyto-chemicals in food is extensive. Apiginin, resveratrol, quercitin, ursolic acid, curcummin, artimisinin, berberine, falcaranol to name just a few. They all have powerful cancer-mitigating properties, are well researched – and they are all found in food. So how does diet not matter?
The flip side of this is that there are compounds in foods that actually promote cancer. Any of these compounds can be eliminated from your diet simply by excluding the foods that they are found in. For example, methionine. This is an amino acid required for cellular proliferation in healthy people. Unfortunately it also enables cancer to thrive. However if methionine is restricted through diet, normal cells can recycle it through a process of remethylation – but cancer cells can’t. So the cancer is missing a major growth factor but your healthy cells are unaffected. Methionine restricted diets can put the brakes on cancer while you take in cancer-mitigating compounds like Allicin.  . Methionine is most abundant in animal produce, including beef, eggs and dairy. Last time I checked, these are foods.
Diet must matter. So why is it dismissed by oncologists? A big part of it is the dominant idea that cancer is a genetic disorder – therefore it is a problem with your DNA. Just ‘bad luck’ (how very sciencey), or perhaps a virus like HPV. But nothing directly to do with food. It is accepted that poor diet can lead to obesity which increases cancer risk – but still, diet doesn’t matter.
But this begs the question, if cancer is a genetic disorder why are cancer rates increasing so rapidly? Currently it is expected that 50% of the population will be diagnosed with cancer. By 2030 that will be 70%. The rate of childhood cancer has increased by 12% in the last 5 years (can’t find the ref right now, but it’s there somewhere). So are humans becoming genetically defective at unprecedented rates? Or is there another factor? Perhaps because dietary patterns are deteriorating generationally? The diet of a typical 30 year old today is significantly less nutritious than their grandparents. And incidentally I know three 30 year olds who have been diagnosed with cancer recently – fit, hard working people who, like their generation, live on fast food. Your body is made from the food you eat – including your DNA. The 21st century diet is so lacking in micronutrients that it becomes a case of what you are not eating, as much as it is about what you are eating.
The other concern for me is how the issue is researched. The studies that seek to establish a relationship between diet and cancer are population studies in which people typically self report their dietary intake. This is then compared to data on cancer patients to seek a correlation. This process is so flawed that any conclusion made from it can only be unreliable – at best. Self reporting produces notoriously unreliable data, and the list of confounds is virtually infinite. Research of this type can be described as opaque at best, yet it forms the basis of cancer treatment – “diet doesn’t matter”.
Common sense will tell you that diet matters. The very first thing people will ask about when they get a cancer diagnosis is ‘what about my diet?’ This is simply intuition at play. Your body ‘wants’ you to give it the nutrients in needs in order to be well – and to stop quaffing the rubbish that got you here (respectfully).
Nutrition for cancer is straight forward – eat foods that contain cancer-mitigating compounds and avoid foods that contain cancer promoting compounds.
I don’t think that is a difficult concept to grasp. But unfortunately your oncologist won’t tell you that – which is why you need to be the decision maker in your cancer treatment.
I must emphasize that diet is only a part of the solution. Exercise, complementary medicines, and off-label drug protocols can all be integrated into your standard cancer treatment – all premised on quality science.