Making changes to your diet can reduce the risk significantly

Pomegranate is rich in cancer-inhibiting compounds

What can men do to protect themselves against prostate cancer? It’s a question that has arisen again this week after a key study revealed that men who take a test for the disease as a routine precaution may do themselves more harm than good.

The study, funded by Cancer Research UK, suggested that the PSA (prostate-specific antigen) blood test offered by GPs was more likely to detect harmless tumours than those that were fatal. The result was that many men ended up taking unnecessary treatment with significant side-effects, including impotence and incontinence.

So what else can men do to ward off a disease that accounts for 26 per cent of cancers in men in the UK? The one thing we do know is that a healthy lifestyle, including cutting down on alcohol and improving diet, plays a significant part in protecting against it. These are the foods that the experts say carry specific benefits.

There is strong evidence that tomatoes protect against prostate cancer

Tomatoes
Rich in lycopene
Of all the foods thought to help to ward off prostate cancer, tomatoes have the strongest reputation. They are rich in lycopene, an antioxidant that can protect against DNA and cell damage, and more so when cooked or heated, because heat helps to break down the cell walls, increasing the amount of lycopene released.

The prostate-cancer risk in men who consume more than ten portions a week of tomatoes — such as fresh tomatoes, tomato juice and baked beans — was reduced by 18 per cent, a study at Bristol University found four years ago.

Pomegranate
Rich in lycopene and flavones
Pomegranate juice and extract are rich in beneficial cancer-inhibiting compounds such as flavones, lycopene and conjugated linoleic acid, and they have been linked in several studies to helping to reduce the risk of prostate cancer. In 2013 researchers at the University of California found that tumour cells treated with pomegranate juice were less likely to grow. Another trial by oncologists at Bedford Hospital and Addenbrooke’s, part of Cambridge University Hospitals, found that men with prostate cancer who took a daily capsule containing essence of pomegranate, turmeric, green tea and broccoli had blood PSA (a protein produced by prostate cells) levels 63 per cent lower than those who had taken a placebo.

Be aware of the high sugar content of some pomegranate juices, though.

Green tea
Rich in polyphenols
Twenty per cent of green tea is consumed in Asian countries, where prostate-cancer death rates are among the lowest in the world. Numerous studies have shown that polyphenol plant compounds in green tea, called catechins, inhibit cancer-cell growth, motility and invasion, and stimulate cancer-cell death. Other polyphenols in green tea, including theaflavins, tannins and flavonoids, are also powerful antioxidants shown to have disease fighting capabilities. Most studies suggest three to five cups a day as optimal and that your intake needs to be consistent.

Broccoli
Rich in sulforaphane
Broccoli contains plenty of selenium and zinc, minerals that can have a powerful effect in reducing the likelihood of prostate cancer, and it is also rich in a dietary compound called sulforaphane. Last year Oregon State University researchers reported that sulforaphane could play a crucial role in cell metabolism, preventing so-called junk DNA from triggering cells to become malignant.

When scientists at the Institute of Food Research in Norwich compared the effects of a 400g serving of broccoli with a 400g serving of peas in men at risk of developing prostate cancer a decade ago, they found greater changes in gene expression among the broccoli eaters — changes they said could be associated with lower risk of the disease.

Carrots
Rich in carotenoids
A 2014 study in the European Journal of Nutrition found men to be 18 per cent less likely to develop a prostate tumour if their diets contained lots of carrots. According to the Japanese team of researchers, there was a “significantly decreased risk of prostate cancer” among men who ate the vegetable three to five times a week compared with those who consumed carrots once a week or less. Carrots are rich in carotenoids, but they are also powerful antioxidants shown to protect cells from oxidative damage and reduce the risk of cancers.

Apple (peel)
Rich in ursolic acid
Apples are best eaten baked or whole with the skin on, because the peel is rich in ursolic acid, a waxy natural chemical that has been shown to help to thwart the growth of prostate cancer. Last year a team from the University of Texas tested a range of plant compounds on laboratory animals with prostate tumours and found ursolic acid to be one of the most promising active ingredients. “These nutrients have potential anti-cancer properties and are readily available,” wrote the lead author, Stefano Tiziani. “We only need to increase concentration beyond levels found in a healthy diet for an effect on prostate cancer cells.”

Coffee
Rich in bioactive substances
Three cups of coffee a day may be a good habit to maintain. Just make sure your brew is prepared the Italian way. Typical Italian coffee is made using beans subjected to high pressure, high temperature (think espresso) and no filters. A study of 7,000 men published in the International Journal of Cancer last year found it to be an effective cocktail for helping to fight prostate cancer. During the four-year study men who drank three or more cups of coffee a day were found to be at a 53 per cent lower risk than those who drank less or no coffee. It seemed to be the bioactive compounds in caffeine that had the positive effect — when they tested with decaffeinated coffee they found no such improvement.

Walnuts
Rich in zinc, magnesium and selenium
Nuts are known to be rich in omega-3 fatty acids, linked to reductions in the risk of heart disease and forms of cancer because of their anti-inflammatory effects. However, scientists at the University of California suggested that it is other compounds in walnuts that make them a powerful weapon against the disease. In a laboratory trial published in the Journal of Medicinal Food they found that animals fed walnuts and walnut oil exhibited slowed prostate-cancer growth, but that those on an omega-fat-only diet did not. They suspected antioxidant compounds such as zinc, magnesium and selenium, which help to destroy damaging free radicals in the body, were also at play.

Other nuts, including Brazils and almonds, have also been shown to help.

Why doctors aren’t keen on screening. By Dr Mark Porter

Offering middle-aged men a one-off PSA screening test does not save lives, according to the world’s largest prostate cancer trial carried out by Cancer Research UK.

The findings, published this week, won’t surprise most doctors. We have long known that PSA is a flawed tool for looking for silent cancers of the prostate and, contrary to what celebrities with the disease so often advise, otherwise healthy men should not ask their doctor for the blood test. I know that it seems counterintuitive, but here’s why.

PST (prostate-specific antigen) is a chemical produced exclusively by the prostate gland to liquefy semen. Higher-than-normal levels suggest a problem with the prostate, albeit not just cancer. It is not very accurate. Most men with high readings do not have cancer, and in a significant minority of those who do the test comes back as normal. And even if PSA does work in your case, we are still not very good at picking out the minority of cancers that are aggressive and life-threatening from the majority that are not, meaning that too many men end up having radical treatment — surgery or radiotherapy — they don’t need.

It is estimated that we have to treat about 40 men to save one of their lives. Great if you are that lucky one, not so clever if you are one of the other 39 left with side-effects (which can include incontinence and erection problems) after treatment that you might never have required had you not gone looking for trouble.

And last, for most men with average-grade tumours (the most common type) the latest evidence shows that it makes little difference if you treat them aggressively, or just monitor the cancer. The death rate (from prostate cancer) is the same in both groups, and reassuringly small at only 1 per cent after a decade.

My advice? PSA can save lives, but at too high a human cost to use as a screening tool, because it picks up too many cases that are best left alone. As such I would never ask my GP for a test, unless he or she suggested one (using PSA to aid diagnosis in symptomatic men being very different from screening otherwise-healthy ones). And until a better test comes along I suggest you do the same.