While cancer was previously considered a disease of bad luck, it is now more widely accepted as multifactorial in nature - with genetics, the aging process, and lifestyle all playing a part. And although there’s little many 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 realize. 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.
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. 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.
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 neutralize 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 minimize 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 sulfur 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 favored as a cancer treatment in Chinese medicine, particularly shiitake and maitake varieties. Studies indicate that fungus-specific chemicals in shiitake mushrooms can prevent the 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. 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.
An antioxidant called ellagic acid, found in all berries, has also been shown to 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 tumor cell growth, virus infection, and inflammation.
Seeds, such as flax, sunflower, and pumpkin, are recognized as health foods due to the wide variety of nutrients, including unsaturated ‘heart healthy’ fatty acids and fiber, they provide. However, research shows that their benefits extend beyond keeping 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 estrogens, found in these foods may be responsible for their anti-cancer benefits.
Let food be the medicine and medicine be the food. If you want to minimize your risk of all cancers, adjusting your diet is an effective way of doing so and… it’s never too late to start.