10 Dec 2020

Not enough evidence to show plant polyphenols benefit men with prostate problems.

We take a look at the claims suggesting certain plant chemicals called polyphenols can treat prostate cancer and separate fact from fiction.

We’ve recently been alerted to an advert that suggests certain plant chemicals called polyphenols can treat prostate cancer and other prostate problems. The advert makes some bold – and inaccurate – claims, so we’ve taken the opportunity to look at the evidence and separate fact from fiction.

What are polyphenols?

Polyphenols are chemicals that are naturally present in certain plant-based foods – they can be found in pomegranates, for example. They’re also an active ingredient in some dietary supplements and herbal remedies (also known as ‘complementary therapies’).

What does the evidence show?

Overall, there isn’t currently enough evidence to say whether polyphenols slow the growth of prostate cancer or have any other benefits for men with prostate problems. 

Although there have been several clinical trials looking at the impact of polyphenols on the progression of prostate cancer, these studies haven’t been robust. This means they either haven’t included enough people, or they haven’t followed people for long enough.

The evidence simply isn’t strong enough to support claims that polyphenols are beneficial for men with prostate problems – so we’re concerned to see adverts making such bold statements.
Lisa O'Sullivan Senior Specialist Nurse

These studies have also had conflicting results, so we need more research before we can confidently say whether or not polyphenols can help to treat prostate cancer. 

Some studies suggest that polyphenols may help to reduce inflammation, but these studies have all taken place in the lab, rather than testing the effect in people (in human clinical trials). So we don’t yet know whether this possible anti-inflammatory effect might help men with prostate cancer or other prostate problems.


Always speak to a medical professional

If you experience possible symptoms of prostate cancer or another prostate problem, it’s really important that you speak to your GP. They can help you find out what’s causing your symptoms and recommend proven treatments, if needed.

If you’ve been diagnosed with prostate cancer or another prostate problem and you’re thinking about using dietary supplements or herbal remedies, you should always speak to your doctor, nurse or a dietitian first. This is because some complementary therapies may interfere with your treatment for prostate cancer and have harmful consequences.

If you want to try pomegranate juice (which contains polyphenols), choose a variety with no added sugar. However, you may need to avoid pomegranate altogether if you use certain prescription drugs. If you’re not sure, ask your pharmacist or medical team for advice.  

We would never advise trying a dietary supplement or herbal remedy in the place of proven treatments for prostate cancer or other prostate problems. 

“We would always advise men to tell their GP if they experience urinary problems – you should never try to self-diagnose", says Lisa O'Sullivan, Specialist Nurse. "And if you’re living with prostate cancer or another prostate problem, it’s important to speak to your medical team before trying any supplements.”

Find information you can trust

If you’re living with prostate cancer or another prostate problem and want to find out more about treatments that are approved for use in the UK, our health information is a good place to start.

Read more about treatments for:

If you have any questions about anything in this article, or about treatments for prostate problems, speak to your doctor or nurse or contact our Specialist Nurses.