Fish oil and prostate cancer: research results

When a hot topic breaks in health, you can expect to read about it in every media outlet under the sun – enter fish oil and prostate cancer.

The problems arise when the ‘hook’ is based on the results of a clinical paper. And we’ve recently witnessed some of these problems in the world of omega-3 fatty acids.

The study that caught everyone’s attention examined associations between plasma phospholipid fatty acids and prostate cancer risk among participants in the Selenium and Vitamin E Cancer Prevention Trial.

Researchers suggested an increased prostate cancer risk among men with high blood concentrations of long chain omega-3 polyunsaturated fatty acids.

Fish oil and prostate cancer – study results

First, a little disclaimer: I’m not writing this blog to defend or oppose the outcome. If you’re interested, Examine.com have written thorough responses to this study which refute the claims in detail.

My issue is with the media.

This study looked at levels of omega-3 in the blood.

There was no data on whether the men took fish oil supplements or ate fatty fish.

We don’t know how many – if any – took supplements. Nor do we know which other confounding factors may have contributed to the increased risk.

To accurately report this study would be to state that the results suggest an association between higher plasma levels of omega-3 fatty acids and those whom the researchers advise had an increased rate of prostate cancer.

But that doesn’t exactly sound sexy, does it?

Not exactly the kind of headline you’d want to click on, is it?

The media hype on fish oil and prostate cancer 

It wasn’t surprising that the media didn’t take the high road when this story broke.

The evening news, most papers, and news websites were quick to report that taking fish oil supplements increases prostate cancer risk by 71%.

I followed this issue with interest in the first 72 hours, and here’s a little sample of the fish oil and prostate cancer headlines I collected:

• Fish oil supplements increase prostate cancer risk, says study – this story wins the award for choosing sensationalism over fact, and unfortunately it’s the one article I’ve seen the most, as it’s been syndicated across many national newspapers. (SMH)
• Fish oil supplements may raise prostate cancer risk – while I like the use of the word “may”, the writer has used fish oil supplements in the headline which is misleading (Fiji News)
• Supplements link to prostate cancer confirmed – supplements link confirmed? Where? (The Australian)
• Taking omega-3 fish oil supplements may increase the risk of aggressive prostate cancer by 70% – falsely implying the risk is associated with fish oil supplements. (Daily Mail)
• Now they tell us – high omega-3 fatty acids levels increase risk of prostate cancer – “now they tell us?” (Labonline.com.au)
• Omega-3 supplements ‘could raise prostate cancer risk’ – fair enough with the inverted commas (Telegraph)

I did read balanced, accurate reports on Medical Observer and Ninemsn. SBS also ran a piece with the headline “Study indicates Omega 3 health risks” – so it wasn’t all bad.

You can’t make assumptions in health reporting

While the study didn’t explicitly mention fish oil supplements or dietary intake of fish, these men were clearly getting their omega-3s somehow.

Many of us would assume they were taking supplements. However, we don’t know, so we can’t make assumptions.

There is no evidence that anyone in this study took fish oil supplements, so writers shouldn’t be claiming or implying that supplements cause an increased prostate cancer risk.

All we should report, to be fair, is exactly what the study found: High levels of omega-3s in the blood may be associated with an increased risk in prostate cancer.

Does that mean men concerned about their prostate cancer risk should stop taking fish oil supplements cut out fatty fish from their diets?

Herein lies the problem with research: One study can’t answer that level of detail.

However, there are ways to mention fish oil supplements without directly associating them with the study outcomes. For example, a writer could find a medical expert willing to offer a quote that this study does mean you should stop taking your fish oil supplements.

Health writers should always refer to the original paper

As health writers, we have a responsibility to refer to the original research paper, read it, and determine that we’ve reported on the outcomes accurately.

If we feel we don’t have the skills or understanding to do this (ie if the outcome is too technical or complex for our understanding) we should work with researchers or experts who can help us translate the facts.

Whether due to inexperience, laziness or third party sub-editing, messages do get lost in translation. In these situations, Chinese whispers occurs. And we have a whole population of men concerned about fish oil and prostate cancer risk, returning their fish oil supplements.

Have you read any inaccurate research reports in the media lately?