Via Cancer Research UK – Science blog
Google ‘cancer’ and you’ll be faced with millions of web pages. And the number of YouTube videos you find if you look up ‘cancer cure’ is similarly vast.
The problem is that much of the information out there is at best inaccurate, or at worst dangerously misleading. There are plenty of evidence-based, easy to understand pages about cancer, but there are just as many, if not more, pages spreading myths.
And it can be hard to distinguish fact from fiction, as much of the inaccurate information looks and sounds perfectly plausible. But if you scratch the surface and look at the evidence, many continually perpetuated ‘truths’ become unstuck.
In this post, we want to set the record straight on 10 cancer myths we regularly encounter. Driven by the evidence, not by rhetoric or anecdote, we describe what the reality of research actually shows to be true.
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Myth 1: Cancer is a man-made, modern disease
It might be more prominent in the public consciousness now than in times gone by, but cancer isn’t just a ‘modern’, man-made disease of Western society. Cancer has existed as long as humans have. It was described thousands of years ago by Egyptian and Greek physicians, and researchers have discovered tell-tale signs of cancer in a 3,000-year-old skeleton.
While it’s certainly true that global lifestyle-related diseases like cancer are on the rise, the biggest risk factor for cancer is age.
The simple fact is that more people are living long enough to develop cancer because of our success in tackling infectious diseases and other historical causes of death such as malnutrition. It’s perfectly normal for DNA damage in our cells to build up as we age, and such damage can lead to cancer developing.
We’re also now able to diagnose cancers more accurately, thanks to advances in screening, imaging and pathology.
Yes, lifestyle, diet and other things like air pollution collectively have a huge impact on our risk of cancer – smoking for instance is behind a quarter of all cancer deaths in the UK – but that’s not the same as saying it’s a modern, man-made disease. There are plenty of natural causes of cancer – for example, one in six worldwide cancers is caused by viruses and bacteria.
Myth 2: Superfoods prevent cancer
Blueberries, beetroot, broccoli, garlic, green tea… the list goes on. Despite thousands of websites claiming otherwise, there’s no such thing as a ‘superfood’. It’s a marketing term used to sell products and has no scientific basis.
That’s not to say you shouldn’t think about what you eat. Some foods are clearly healthier than others. The odd blueberry or mug of green tea certainly could be part of a healthy, balanced diet. Stocking up on fruits and veg is a great idea, and eating a range of different veg is helpful too, but the specific vegetables you choose doesn’t really matter.
Our bodies are complex and cancer is too, so it’s gross oversimplification to say that any one food, on its own, could have a major influence over your chance of developing cancer.
The steady accumulation of evidence over several decades points to a simple, but not very newsworthy fact that the best way to reduce your risk of cancer is by a series of long-term healthy behaviours such as not smoking, keeping active, keeping a healthy body weight and cutting back on alcohol.
Myth 3: ‘Acidic’ diets cause cancer
Some myths about cancer are surprisingly persistent, despite flying in the face of basic biology. One such idea is that overly ‘acidic’ diets cause your blood to become ‘too acidic’, which can increase your risk of cancer. The proposed answer: increase your intake of healthier ‘alkaline’ foods like green vegetables and fruits (including, paradoxically, lemons).
This is biological nonsense. True, cancer cells can’t live in an overly alkaline environment, but neither can any of the other cells in your body.
Blood is usually slightly alkaline. This is tightly regulated by the kidneys within a very narrow and perfectly healthy range. It can’t be changed for any meaningful amount of time by what you eat. And while eating green veg is certainly healthy, that’s not because of any effect on how acid or alkaline your body is.
There is something called acidosis. This is a physiological condition that happens when your kidneys and lungs can’t keep your body’s pH (a measure of acidity) in balance. It is often the result of serious illness or poisoning. It can be life-threatening and needs urgent medical attention, but it’s not down to overly acidic diets.
We know that the immediate environment around cancer cells (the microenvironment) can become acidic. This is due to differences in the way that tumours create energy and use oxygen compared with healthy tissue. Researchers are working hard to understand how this happens, in order to develop more effective cancer treatments.
But there’s no good evidence to prove that diet can manipulate whole body pH, or that it has an impact on cancer.
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