Some studies indicate that eating a Mediterranean diet can protect against the most aggressive forms of prostate cancer. Photo / 123rf
Studies indicate that lifestyle factors can play a big role in mitigating a man’s biological risk of the disease.
Prostate cancer kills 12,000 men in Britain every year. Some 56,000 British men are diagnosed with the disease in the same space of time – that’s equivalent to the entire population of Greenland.
The sad fact is that genetics play an enormous role in whether a man develops prostate cancer, with black men at twice the risk compared with white men because of their increased likelihood of carrying risky mutations of the BRCA gene (which are linked to more aggressive cancers). Men whose close relatives have had prostate cancer or breast cancer are also at greater risk, and the likelihood of developing it also increases with age – most steeply after 50.
But men can help to protect themselves from developing prostate cancer. As with so many other illnesses, lifestyle factors, in particular, can play a big role in mitigating a man’s biological risk of this disease. (Not everyone who is at a genetic risk of prostate cancer will go on to develop it, while white men with no family history may still get prostate cancer.)
Take one study, which examined the rates of latent prostate cancer (prostate cancer only discovered after death) in men of Japanese descent in their home country and on the west coast of America, compared with men with Japanese heritage who had spread out further across the west.
“In Japan and San Francisco, the rates of latent prostate cancer were similar,” says professor Derek Rosario, consultant urological surgeon at Sheffield Teaching Hospitals. “In those men who had moved further across the world, the rates were higher, even after generations. We know that this must be attributable to lifestyle.”
The extent of lifestyle influence on prostate cancer is still being teased out, experts say, but the evidence already points to some simple measures that you can take that could help cut your risk of developing prostate cancer in your lifetime. Here is what the science says about how to do it.
Diet is a huge risk factor when it comes to a man’s vulnerability to certain cancers. Bowel cancer, for example, is 20% more likely to occur in someone who eats at least 76g of red meat or processed meat (about one large pork sausage) per day, compared with those who eat just 21g (roughly one chipolata sausage) per day.
The link between diet and prostate cancer is less well-established. “Red meat could possibly increase a man’s risk of prostate cancer, but diet is very hard to observe accurately. People often don’t eat quite as healthily as they believe they do,” says professor Nick James, from the Institute for Cancer Research. “Meat eaters have a slightly higher risk overall, but it’s hard to work out exactly why that is. Vegetarians might be more likely to exercise or eat more healthily in general, for example.”
What is known, however, is that “what’s good for the heart is good for the prostate,” as Rosario puts it. Some studies indicate that eating a Mediterranean diet can protect against the most aggressive forms of prostate cancer, with other research showing that adherence to this diet can reduce both incidence and mortality by 10%.
In other words, “eating lots of oily fish and unsaturated fats, and eating fewer carbs and highly processed foods, may reduce your risk, though we don’t yet have definitive evidence,” Rosario says. Lycopene from raw tomatoes may be especially helpful, he adds.
Exercise is proving to be an especially effective tool for men who already have prostate cancer in combating the disease’s progression and improving their quality of life in general.
“Data going back decades shows that cancer patients who exercise regularly have better outcomes, fewer complications and fewer recurrences down the line than those who do not,” says Prof James.
Meanwhile, Rosario points to an observational study carried out with doctors who went on to develop prostate cancer: “The ones who became more active after their diagnoses and exercised for at least 90 minutes a week had lower mortality than those who didn’t.”
Some studies suggest that exercise can protect against the development of prostate cancer, too. A Harvard study from 2019 found that men who exercised vigorously were, on average, 30% less likely to develop advanced prostate cancer than those who carried out vigorous exercise less frequently. They also had a 25% reduced risk of mortality from prostate cancer.
NHS guidelines recommend that everyone gets 150 minutes of moderate-intensity exercise, or 75 minutes of vigorous exercise, every week. This could be as simple as going on a brisk 30-minute walk every weekday, which would mean that you hit these targets and may reduce your prostate cancer risk.
“The primary function of the prostate is to produce fluid when you ejaculate,” says Robinson. The prostate sits at the bottom of the bladder and this is why men who have prostate cancer find that they need to urinate more regularly, as the prostate is getting larger and irritating the bladder.
There is some evidence that ejaculating more frequently (either having more sex or masturbating more often) can bring down your risk of prostate cancer. “It might be the case that if you never ejaculate, then you build up fluid in the prostate that’s stagnant and could potentially accumulate toxins,” Robinson says. “Ejaculating regularly could have a cleansing effect.”
One study has shown that men who ejaculated more than 21 times per month were 20% less likely to develop prostate cancer than those who ejaculated four to seven times per month. This was a large study that followed more than 30,000 men for more than 20 years to track their ejaculation habits and the number of prostate cancer cases that developed.
“It could just be the case that men who have sex more often are fitter and live healthier lifestyles, and are therefore less likely to carry a number of different diseases,” says Rosario. But given that this study only counted the number of times the participants ejaculated each month – and not the frequency at which they had sex with another person – it may be worth making sure that you have sex or masturbate about five times a week, or 20 times a month. “It’s certainly good for your health in general to have more sex if you can,” Robinson points out.
Just as there appears to be a link between diet and prostate cancer risk, there is also a link between a man’s weight and his chances of developing prostate cancer. Both being obese as an adult and gaining weight in adulthood have been linked to a greater risk of developing advanced prostate cancer, and to prostate cancer coming back after it is treated for the first time.
One study, which followed 170 men for 10 years, found that those who gained at least four inches of fat around their waists in that time were at a 40% greater risk of developing aggressive prostate cancer.
Weight is also known to impact a man’s prospect of recovery after he develops prostate cancer. “In one study, for every 10 centimetres (around four inches) increase in abdominal fat in men diagnosed with prostate cancer, there was an increased risk of mortality in 10 years’ time, by 15 to 20 per cent,” says Prof Rosario.
Maintaining a healthy weight is a good way to lower your risk of all cancers and many other illnesses, too. Any amount of weight loss can boost your protection if you are already overweight, but the four inches highlighted in research may be a significantly helpful amount of abdominal fat to lose.
“Sleep is one of the pillars of good health that’s crucial to a high quality of life,” says Rosario. Some research suggests that poor sleep quality in the long term may be associated with a 15 to 20% greater risk of prostate cancer, based on data from 30,000 men collected by the UK Biobank.
Other studies have demonstrated that consistent poor sleep can increase your risk of developing any kind of cancer (though the link between cancer and sleep is very complicated, and something that scientists are continuing to explore).
There might not be a direct connection between the two, but getting at least seven hours of sleep each night has been shown to protect against a number of different common diseases. It’s a reminder that much of the advice given to cut prostate cancer risk “means living a healthy life in general,” says Jones. If you are already slim, active, eating well and having enough sex, prioritising your sleep could be the best step to lower your risk as much as possible.