Dr Paul Clayton 2013
According to Cancer Research UK, 1 in 3 adults will face having to deal with cancer. So the conclusion of Harvard University researchers that nearly 70% of all cancer deaths can be attributed to lifestyle factors, which can be altered, is relevant to everyone.
In 2008, the University of Cambridge EPIC – NORFOLK study reported how engaging in just 4 lifestyle behaviours gained an average of 14 years of life compared to people who did not do any of them. By the end of the study, these people were less likely to have died from cancer or heart disease.
The lifestyle choices were: not smoking; keeping active (doing more than 30 minutes of exercise a day); moderating how much alcohol you drink (1-14 units a week); and eating five daily portions of fruit and vegetables.
Although 5-a-day seems to be enough to reduce the risk of heart disease, the American Cancer Association – and the US departments of Health and Human Services – now recommend 9 portions a day to reduce the risk of cancer.
Nine a day is a stretch for most of us, so a relevant dietary question is ‘which fruits and vegetables appear to confer the highest level of protection – and can supplements help’?
Variety and combination is the key.
The Norwich-based Institute of Food Research, showed in 2003 that the combination of selenium plus sulphurophane (a sulphur compound present in brassica greens like cabbage, kale and Brussels sprouts) is 13 times more cancer-protective than either compound on its own.
The group then did another study, this time combining sulphurophane with apigenin, a flavonoid found in fruits such as apples, cherries, beans and broccoli, and in wine and tea. Both compounds have anti-cancer properties; including the ability to encourage the body to increase production Phase 2 enzymes. These enzymes detoxify carcinogens by making them more excretable, and can also delete genetically damaged cells before they can become cancerous.
Either compound on its own increased levels of the Phase 2 enzymes four-fold – but the combination of the two phyto-nutrients led to a 12-fold increase.
The general principle that micro- and phyto-nutrients work best together is supported by US research which showed the benefits of combining broccoli with tomatoes both of which are linked to a reduced risk of prostate cancer. Rats fed on whole broccoli and tomatoes had markedly fewer cases of prostate cancer than those given either broccoli or tomatoes alone.
So what else can we add for a true cancer risk reduction diet?
Lutein and zeaxanthin are carotenoids found in such yellow foods as corn and egg yolks. They are also found in avocados, broccoli, green beans and kale. These nutrients are strongly linked to protection against Age-Related Macular Degeneration and to a reduced risk of coronary artery disease. Moreover, data suggests that they may reduce the risk of certain kinds of cancers.
There are several possible mechanisms which could explain this reduction in risk. For example, the carotenoids are antioxidants, and reduce free radical damage. They also have the ability to force cancer cells to re-differentiate (i.e.normalise) or encourage apoptosis in cancer cells (i.e.the abnormal cells commit ‘suicide’).
Add Lycopene (another carotenoid).
Following recent epidemiological studies which suggest that consumption of tomato products protects against prostate cancer, researchers from the Cancer Institute in Detroit, evaluated the effect of a lycopene-rich tomato extract on patients with existing prostate cancer.
This study followed 30 men with localized prostate cancer who were scheduled to undergo surgical removal of the prostate. For three weeks prior to surgery, the patients were randomly assigned to receive either 30 mg of lycopene a day or a placebo.
During the trial, levels of serum PSA (Prostate Specific Antigen, a marker used to detect prostate cancer) fell in the patients who received lycopene. After surgery, the investigators found that the treated group had smaller tumours, which were less likely to have spread beyond the prostate, and the tumours showed signs of decreased malignancy.
“Our findings suggest that lycopene as tomato extract may not only help prevent prostate cancer, but also may be useful in treating prostate cancer”, said the lead researcher.
Lycopene is the red colour in tomatoes. The evidence that tomato extracts in general, and lycopene in particular, reduce the risk of various cancers (prostate, breast, and gastro-intestinal tract), is becoming hard to ignore.
Beta carotene appears another protective nutrient, found in mangoes, sweet potatoes, and carrots of course.
Add Folic Acid
The first proven health benefit of folate supplements was a reduction in the incidence of neural tube defects (such as spina bifida) in the newborn. Then came evidence that it could reduce the risk of colorectal cancer, and, by lowering levels of homocysteine in the blood, protect against heart disease, Alzheimer’s disease, and osteoporosis.
The Americans have responded by making folate fortification of flour mandatory, and in the last few years have seen significant falls in spina bifida babies, and heart attacks in older men. The UK Government have not taken action – but you can with a supplement that includes folic acid.
Add Vitamin D and Fibre
Research from the Portland VA Medical Centre in Oregon saw over 3000 people screened for polyps in the colon. (These polyps are a common precursor to full-blown colorectal cancer, which can often be prevented if the polyps can be removed early enough).
Those people in the study who ate a diet rich in Vitamin D (645 IU/day or more) were significantly protected; as were those who consumed 4g or more of cereal fibre, or took daily aspirin. A simple A-Z supplement helped to a lesser extent. Other research supports garlic as a risk reducer for colon cancer.
Add flavonoid rich fruit
A 2000 meta-analysis in Nutrition and Cancer clearly showed that increased consumption of fruit is correlated with a reduced risk of cancer.
Citrus fruits are of course rich in vitamin C but the darker berry fruits (raspberries, blackberries, blueberries, black grapes, strawberries) have the highest concentration of flavonoids, which have both anti-inflammatory and anti-oxidant properties and appear to confer significant protection against cancer.
Easy ways to up your fruit and veggie portions and flavonoid intake are to:
Drink green tea, add some fruit to breakfast cereal, throw some veggies like broccoli into omelettes, have a salad a day, make a spicy dish with turmeric (which contains curcumin a particularly powerful anti-inflammatory), add some fruit to the cheese board, and make a dried fruit snack with flax seeds that contain lignans that are linked to lower levels of breast cancer.
How can supplements help?
While the first priority is upping your daily intake of fresh fruit and vegetables, there is extensive research to support the addition of a comprehensive supplement that includes flavonoids, lycopene, lutein, beta carotene, soy isoflavones, plus grapeseed extract, green tea extract and curcumin – all of which have a high flavonoid content.
The body metabolises most supplements the same way as in food, and in the case of folic acid supplements appear to be better absorbed than from food.
Go here for our recommended supplement
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