It probably won't surprise you to learn that not all doctors share my enthusiasm for natural medicine. One common criticism is that complementary therapies are unscientific and unproven.
Personally, I would caution doctors against camping out on this particular high ground: many established medical practices are simply untested, and some persist even once they have been shown to be quite ineffective. A good example of this is the practice of prostate cancer screening. Research published recently in the British Medical Journal found that while screening does indeed help detect prostate cancer earlier, this does not translate into improved survival. Bearing in mind that a diagnosis of cancer is usually a significant psychological downer, and that resultant treatment may have nasty side effects, then it appears that prostate cancer screening may be doing more harm than good.
While men appear not to benefit from an earlier diagnosis of prostate cancer, it's not a condition we can afford to ignore. Currently, prostate cancer is the second most common cause of cancer death in men in the UK, and its incidence is rising. However, a man's risk of developing prostate cancer seems to be intimately related to what he eats, and relatively minor adjustments to the diet seem to offer considerable protection from this disease. Studies suggest, for instance, that the omega-3 fats found in oily fish such as salmon, trout, mackerel, herring and sardines help keep the prostate free of cancer.
Men looking for added protection would do well to accompany their oily fish with some vegetables. Last week, I reported on research which suggests that consuming allium vegetables such as garlic, spring onions and leeks appears to reduce risk of prostate cancer. Other vegetables that seem to offer significant protection are the cruciferous vegetables which include broccoli, cauliflower, Brussels sprouts, cabbage and bok choy. One study found that men eating three servings of cruciferous vegetables each week had a 40 per cent reduced risk of developing prostate cancer.
While some foods appear to reduce prostate cancer risk, others have the reverse effect. There is some evidence that men who consume more dairy products are more susceptible to prostate cancer. One study has found that drinking soya-based milk was associated with a significantly reduced risk of prostate cancer.
One nutrient that seems to be particularly useful in warding off prostate cancer is selenium. In addition to eating a handful or two of selenium-rich brazil nuts each day, men might also benefit by supplementing with 200mcg each day of this nutrient. One study found that long-term supplementation with this dose of selenium reduced risk of dying from prostate cancer by two-thirds. Now, that's what I call effective.
Many women during or after the menopause will be mindful of the risk of osteoporosis, and the need to get plenty of calcium in the diet. However, it is well known that healthy bone formation is dependent not just on calcium, but on a range of other nutrients including magnesium, vitamin D, boron and zinc. Another nutrient that is commonly overlooked for its role in bone-building is vitamin K. A recent study published in the American Journal of Clinical Nutrition found that women with the highest intake of vitamin K tended to have higher bone density compared to women with low levels of this nutrient. Previous studies have shown that women with high vitamin K intakes are at lower risk of bone fracture. Vitamin K is found most abundantly in green leafy vegetables. These vegetables also help to prevent the loss of calcium from bone. Eating plenty of green leafy vegetables such as broccoli, spinach and kale makes good sense for those wanting to preserve the health and strength of their bones.
I know that some people sport copper bracelets to prevent arthritis. Is there any substance to this, or is it just folklore?
Toby Booth, by email
Copper is an important nutrient for bone-building, and also contributes to the health of soft tissues such as ligaments, tendons and cartilage. Last and not least, copper is believed to have natural anti-inflammatory and painkilling properties.
Any benefit from a copper bracelet will depend on this metal being absorbed through the skin. In one study, researchers compared individuals wearing copper bracelets with those wearing identical looking copper-coloured bracelets made of aluminium. By measuring the weight of the copper bracelet before and after the study, they deduced that significant amounts of copper had been absorbed through the skin over the course of a month. And those wearing the real copper bracelets reported fewer arthritic symptoms than those wearing the mock aluminium variety. It seems as though copper bracelets may indeed be effective in reducing the development of symptoms of arthritis.