Fruit and vegetables are known to help inhibit tumours but so can treats such as chocolate and wine…
WHEN we think of cancer we rarely associate it with food. Yet a colourful diet rich in fresh fruit, vegetables, beans, soya, fatty fish, nuts and even chocolate, tea and wine can significantly lower our risk of the disease.
According to the World Cancer Research Fund and American Institute for Cancer Research up to 30 per cent of all cancers can be prevented by lifestyle and nutritional measures. Meanwhile research published in the journal Nutrition estimates some of the most common forms of cancer such as breast, bowel and prostate, could be cut by up to 70 per cent and lung cancers by up to 50 per cent by eating certain foods.
Only last week scientists at Oregon State University in the US found sulforaphane, a nutrient found in broccoli, cabbage and cauliflower, can destroy prostate tumours while leaving normal cells healthy and unaffected. This offers new hope for sufferers and for scientists researching drugs to fight the disease.
Nutrition is not a stand-alone cancer treatment nor is it a foolproof prevention. Nonetheless what and how you eat before, during and after cancer treatment may have a crucial impact on its outcome.
Our immune system can only do its job and identify and destroy cancer cells when we are well-nourished. Without prevention one in two men and one in three women living in the industrialised west will eventually develop some form of cancer so it is important to know how changes in diet can tip the odds in our favour.
Ellagic acid, found in raspberries and strawberries, is thought to slow the growth of tumours and aid the body in detoxifying potentially cancer-causing substances.
Blackberries, blueberries and cranberries contain an antioxidant that may help prevent the binding of carcinogens (cancer-causing properties) to DNA and protect against gastrointestinal cancers.
Did you know that Japanese mushroom growers are nearly 50 per cent less likely to develop stomach cancer than their non-mushroom farming neighbours?
This may be because they eat their produce and benefit from cancer-protective nutrients. Shiitake mushrooms are a rich source of lentinan, a molecule believed to stimulate the immune system to slow or even stop tumour growth.
Everyday button mushrooms are thought to contain substances that can block production of oestrogen in the body. This means they may protect against breast and other cancers dependent on oestrogen.
Researchers at The University of Western Australia in Perth recently found that Chinese women who ate 4g of dried button mushrooms daily reduced their breast cancer risk by 47 per cent while those eating 10g cut theirs by 64 per cent.
Beans which are also called legumes, are rich in several types of plant chemicals such as saponins, protease inhibitors and phytic acid that may play a role in cancer prevention. Many also contain compounds that resemble a weak form of oestrogen and these could protect against certain cancers notably breast and prostate.
Good-quality dark chocolate with more than 70 per cent cocoa contains an antioxidant compound called procyanidin.
Research into the link between cancer and cocoa is still in its infancy but scientists have observed these molecules slow the development of breast cancer in lab cell cultures and prostate cancer in rats.
The most efficient way of getting cocoa procyanidins into the bloodstream is by consuming chocolate drinks. It used to be thought milk (in chocolate drinks or bars) blocks the absorption of procyanidin but studies now show it merely slows its uptake.
A recent study found flaxseeds may protect against cancer of the prostate which is the most common cancer among men in Britain.
Males with the disease who ate 30g (three tablespoons) of ground flaxseed each day for one month had decreased cancer cell proliferation compared to patients who did not eat flaxseed. To reap the benefits grind the seeds into a fine powder as this allows the body to absorb more nutrients.
Tomatoes in all their forms, fresh, tinned, processed in ketchup, soup and juice, are rich in lycopene which is the nutrient that gives them their red colour.
Lycopene is a powerful antioxidant
Studies show lycopene may protect against breast, prostate and lung cancer. Don’t worry about only eating them raw. Cooked tomatoes release more lycopene than uncooked.
Know your onions
The onion or allium family includes garlic, leeks, shallots, spring onions and chives.
All contain compounds such as diallyl sulphide and quercetin which may help prevent the onset or progression of certain cancers especially stomach, laryngeal, bowel and oesophagus. Slice thinly as the more finely you chop an onion the more of the healthy compounds you eat.
Garlic has anti-inflammatory, antiviral, antibacterial and antifungal effects which may induce the self-destruction of cancer cells and prevent formation of new blood vessels by tumours. As with onions, it is at its most powerful when eaten raw.
Oily fish such as mackerel, sardines, salmon, trout, pilchards, anchovies and herring are particularly rich in two types of omega 3 fatty acids called eicosapentaenoic acid (EPA) and docosahexaenoic acid (DPA).
These are vital to health and are thought to have anti-cancer properties. Ideally eat oily fish two or three times a week.
Wonder of wine
Red wine contains high levels of resveratrol, a plant chemical which has been shown to reduce tumours in lab tests.
Not all wines are created equal and some contain more antioxidants than others depending on the soil and climate in which the grapes grew.
Wines grown in the South-west of France for example, are particularly high in procyanidin the same compound found in dark chocolate.
Don’t glug it. Sipping and letting wine linger in the mouth may increase the effectiveness of resveratrol. This is because it is best absorbed through the membranes in the mouth.
Nuts, seeds and butters made from them contain a high proportion of antioxidants such as beta-carotene and vitamin E. Hazelnuts and pecans are high in ellagic acid which is thought to slow down the growth of tumours.
Zest for life
Studies suggest that eating oranges, lemons, grapefruit, limes and tangerines may lower the risk of certain cancers especially those along the digestive tract.
This may be due to a variety of protective factors in the juice and peel of citrus fruits (d-limonene in lemon zest and tangeretin and nobiletin in tangerine peel) that are thought to help remove potentially carcinogenic substances from the body and inhibit cancer-cell growth.
Citrus fruits are also excellent sources of pectin which is also thought to prevent or slow the spread of cancer cells.
The cabbage family (known as brassicas and cruciferous vegetables) includes cauliflower, broccoli and Brussels sprouts, watercress, turnips, radish and kohlrabi.
Sulforaphane, the molecule that gives brassicas their sharp taste, is thought to eliminate toxic compounds linked to the development of cancer and may trigger the self-destruction of types of cancer cells.
A new study has found sulforaphane can specifically destroy prostate cancer cells.
Broccoli is the best source and sprouted broccoli seeds contain between 10 and 100 times more sulforaphane than fully-grown broccoli. Brassicas should be briefly steamed rather than boiled to preserve their cancer-protective nutrients.
Time for tea
Green tea is thought to have cancer-protective effects which include inhibiting angiogenesis (tumour growth) and triggering apoptosis (destruction) of cancer cells.
It may also reinforce the effects of certain chemotherapy agents while lessening their negative side effects so it is a good choice for patients having treatment.
Soya so good
Soya, commonly found in tofu, soya beans and soya milk, is full of phytoestrogens. These are plant chemicals that resemble oestrogens, the sex hormones produced by our bodies. Asian women are less prone to breast cancer than Western women and some researchers believe this is because they eat more soya.
There is some disagreement over whether soya is safe for breast cancer survivors although data from the Shanghai Breast Cancer Survival Study found women eating the most soya protein (up to 11g a day) had a 32 per cent lower risk of breast cancer recurrence compared to those with the lowest intake of soya protein.