While cancer was previously considered a disease of bad luck, it is now more widely accepted as multifactorial in nature – with genetics, the ageing process and lifestyle all playing a part. And although there’s little any of us can do to alter our genetics, or stop from getting older each year, we can certainly adjust our lifestyles. And a huge part of that is what we eat.
Nine out of 10 cancers are caused by lifestyle, and this means we all have more control over our likelihood of developing cancer than we realise. And with cancer rates projected to rise from the 14.1 million cases seen in 2012 to 24 million by 2035, the news that we can all influence our risk of cancer could not have come at a better time.
When we talk about lifestyle factors, of course tobacco smoke comes to mind. But what about the food-cancer link? Well, it’s strong – and the evidence is growing. So today we’re going to look at what you should be eating, rather than what you shouldn’t. That’s not to say the ‘avoidance’ list isn’t vital – the studies in particular into the cancer-causing properties of red and processed meat, trans fatty acids – in fact the Western diet in general – do not make easy reading.
But today I want to focus on foods that can actually fight off cancer. In other words, what should you be eating to potentially lower your cancer risk?
There are many reasons to eat your greens, from boosting your iron levels to keeping your bowels regular. What is less talked about is how green, leafy and cruciferous vegetables like broccoli and spinach can reduce your risk of many types of cancer. A reduced risk of colon cancer is linked to eating green vegetables because the green chlorophyll molecules found in them prevent the damage that dietary haem (a molecule found in red meat) does to the colon. And eating green and yellow vegetables also lowers the risk of other cancers, including stomach and lung cancer. This is due to the cancer-protecting effects of the high levels of beta-carotene – a well-known antioxidant – in green vegetables.
A reduced risk of colon cancer is linked to eating green vegetables because the green chlorophyll molecules found in them prevent the damage that dietary haem (a molecule found in red meat) does to the colon.
Antioxidants, like beta carotene, are thought to protect against cancer because they neutralise molecules called free radicals, that otherwise damage healthy cells and trigger the abnormal cell growth that underlies cancer.
Interestingly, while it’s widely believed that cooking destroys the health benefits of vegetables, cancer-reducing properties of green vegetables are in fact boosted by eating them cooked instead of raw. Why? Because of an increase in the free-radical-trapping antioxidant content of courgettes and broccoli that results from cooking them.
Garlic, onions and mushrooms
If you’re keen to minimise your risk of stomach cancer, it may also be worth stocking up on onions and garlic. This is because a high intake of alliums (like onions and garlic) helps to protect against stomach cancer. The theory is that the high sulphur content of these vegetables may slow down the growth of cancer cells as well as the activity of carcinogens that trigger cancer.
And how about those mushrooms? Well, mushrooms have long been favoured as a cancer treatment in Chinese medicine, particularly shiitake and maitake varieties. Studies indicate that fungus-specific chemicals in shiitake mushrooms can prevent growth of different types of cancer cells (including breast and bone cancer), and clinical studies have shown that extracts of medicinal mushrooms improved the health and quality of life in breast cancer patients.
Beans, berries and seeds
The cancer-protecting properties of beans first came to light in research carried out in the 1980s, which showed a lower risk of colon, breast, and prostate cancer among populations that had diets rich in beans and other legumes. Additional studies have since backed up these findings, revealing that eating beans and lentils was associated with a reduced risk of breast cancer in premenopausal women, and that a diet rich in beans strongly protects against recurrence of a benign colorectal tumour called adenoma.
And just as with green vegetables, it’s thought that the cancer-protecting effects of beans and other legumes are due to their high antioxidant content.
Berries, such as blueberries and strawberries, are also rich in antioxidants, and unsurprisingly, they too are known anti-cancer foods. Interestingly however, it’s the high vitamin C content of berries that most likely underlies their association with reduced colorectal and oesophageal cancer risk.
Berries, such as blueberries and strawberries, are rich in antioxidants, and unsurprisingly, they too are known anti-cancer foods.
An antioxidant called ellagic acid, found in all berries, has also been shown to help prevent skin, lung, bladder, breast, and oesophageal cancer, with one study concluding that ellagic acid protects against these cancers by a variety of methods, including blocking tumour cell growth, virus infection, and inflammation.
Seeds, such as flax, sunflower and pumpkin, are recognised as health foods due to the wide variety of nutrients, including unsaturated ‘heart healthy’ fatty acids and fibre, they provide. However, research shows that their benefits extend beyond keeping the heart health and waistline slim. One study showed that women who ate a diet high in nuts and seeds had a lower risk of colon cancer than those who didn’t. But as this protective effect was not seen in men, the researchers suggested that the plant hormones, including oestrogens, found in these foods may be responsible for their anti-cancer benefits.
Let food be thy medicine and medicine be thy food
Hippocrates said this around 400 BC and it appears the brilliant Greek physician – known as the ‘father of modern medicine’ – understood all that time ago what many doctors today still fail to grasp: eating right is your ticket to keeping healthy throughout your years.
And the evidence is clear: if you want to minimise your risk of all cancers, adjusting your diet is an effective way of doing so and… it’s never too late to start. Best of all, unlike your genes and age, the food you eat is something that is within your control.
If you want to minimise your risk of all cancers, adjusting your diet is an effective way of doing so and… it’s never too late to start.
It’s true that a lot of questions remain unanswered by research into this area – how much of these cancer-protecting foods should you eat each day? How are they best prepared?
But these are answers that I believe will come to light as further research is carried out.
In the meantime, given that the positive evidence seen so far has come from observing people incorporating these foods into their diets without any guidance on how to do so, we can say that simply adding these foods into your diet whenever possibly can only help to keep your body in optimum condition.
Why not start today?