Prostate cancer is the most common cancer in men, with around 1 in 8 men being diagnosed in their lifetime – now including former US President Joe Biden. But not all prostate cancers are life-threatening – in fact, many are so slow-growing that they’ll never cause harm.
“There are essentially two types of prostate cancer,” Dr Hayley Luxton, head of research impact and engagement at Prostate Cancer UK, explains. “I refer to them as ‘pussycats’ and the ‘tigers’. A pussycat is a slow-growing prostate cancer – the man will not die because of it.
“Tigers are really aggressive – these men need urgent treatment, otherwise they will die.”
Autopsy studies show that more than 50 per cent of men aged over 90 have prostate cancer cells – many of them never diagnosed during life.
“Most men eventually will have prostate cancer cells,” Dr Cody Watling, a postdoctoral fellow at the US National Cancer Institute, adds. “But whether that becomes clinically significant–whether it causes symptoms or spreads – is another matter entirely.”
These three things matter most
So, what actually increases your risk of prostate cancer?
According to science, most of your risk comes down to three – sadly, uncontrollable – factors:
- Age – Risk rises sharply after 50. Most diagnoses are in men over 70.
- Ethnicity – Black men are twice as likely to develop prostate cancer as white men. We don’t yet know why, but genetics may play a role.
- Family history – You’re at higher risk if your father, brother or grandfather had it – especially if they were diagnosed under 60. A family history of breast or ovarian cancer may also increase risk, particularly if a mutation of a gene known as BRCA2 is involved.
Watling adds that these risk factors are linked not just to prostate cancer in general, but also to aggressive disease: “There’s evidence that age, family history and Black ethnicity increase your risk of both overall and aggressive prostate cancer.”
What about lifestyle?
Some headlines suggest you can cut your risk through lifestyle choices – but the reality is murkier.
“A lot of research has been done to try to disentangle if there are modifiable risk factors for prostate cancer,” says Watling, who studied diet and prostate cancer risk at the University of Oxford. “And to date, nothing has really shown strong evidence.”
Some studies suggest a possible link between high dairy intake, especially milk, and a slight increase in prostate cancer risk, possibly due to a growth factor called IGF-1. But, Watling says, “the evidence there is still a bit hazy, and there’s not a really strong association.” In short, more research is needed to identify any causal link.
One possible exception is body weight. “There’s some evidence that being overweight is linked to a higher risk of aggressive or fatal prostate cancer,” Watling says. “But it’s difficult to untangle whether that’s due to biology or because people with higher body weight are less likely to be screened early.”
Luxton agrees: “Maintaining a healthy, balanced diet and doing some exercise – even if that's just a 10-minute walk – is better than doing nothing.”
What you should do
If you're over 50, or over 45 and at higher risk (because you’re Black or have a family history of cancer), Prostate Cancer UK recommends starting a conversation with your GP.
You can check your risk in under a minute using Prostate Cancer UK’s online risk checker.
From there, your doctor may perform some screening tests, including a prostate specific antigen (PSA) blood test, examinations, MRI scans and more, depending on what you need.
The bottom line
Joe Biden’s diagnosis has understandably shaken people, but it’s also prompted a flood of misleading or oversimplified advice. Here’s the truth:
- You can’t eliminate your prostate cancer risk.
- Most of the risk comes from age, family history and ethnicity, not diet or lifestyle.
- That said, healthy habits still matter for aggressive prostate cancer and for reducing your risk of other diseases.
- If you're at higher risk, you need to start the conversation with your doctor.
About our experts
Hayley Luxton is the head of research impact and engagement at Prostate Cancer UK, responsible for identifying examples where the charity's research programme has led to impact as well as nurturing research projects and strategic initiatives to deliver as much impact as quickly as possible. Prior to that, she conducted research at University College London and Cancer Research UK.
Cody Watling is a postdoctoral fellow at the National Cancer Institute. His research has been published in journals including BMC Medicine, Clinical Nutrition and The British Journal of Cancer.
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