High levels of long chain omega-3 may increase prostate cancer risk: Study

10-Jul-2013 - Last updated on 24-Jul-2013 at 07:51 GMT

A high intake of omega-3 from food or supplements puts people in the highest risk category for aggressive prostate cancers, according to the new research.

A high intake of long-chain omega-3 fatty acids from foods and supplements could increase the risk the risk of developing aggressive prostate cancer by 71%, a new study has found.

The large-scale prospective study, published in the Journal of the National Cancer Institute, follows up on findings from 2011 which suggested that a high omega-3 status may be linked to prostate cancer.

Led by senior author Dr Alan Kristal from Fred Hutchinson Cancer Research Center, USA, the new follow up study confirms the findings of the earlier research by analysing data from a in a large European population study - finding that high blood concentrations of long chain omega-3 polyunsaturated fatty acids (PUFAs) were linked to a 71% higher risk of developing high grade prostate cancer.

The study also found a 44% increase in the risk of low-grade prostate cancer and an overall 43% increase in risk for all prostate cancers.

"We've shown once again that use of nutritional supplements may be harmful," said Kristal, who added that the findings of both the 2011 study and the recent research are surprising because omega-3 fatty acids are generally believed to have a host of positive health effects based on their anti-inflammatory properties.

"The consistency of these findings suggests that these fatty acids are involved in prostate tumorigenesis and recommendations to increase long-chain omega-3 fatty acid intake, in particular through supplementation, should consider its potential risks," said the team.

"What's important is that we have been able to replicate our findings from 2011 and we have confirmed that marine omega-3 fatty acids play a role in prostate cancer occurrence," said corresponding author Dr Theodore Brasky, of The Ohio State University Comprehensive Cancer Center - and lead author of the 2011 study.

"It's important to note, however, that these results do not address the question of whether omega-3's play a detrimental role in prostate cancer prognosis," he said.

Study details

The new prospective study analysed data and specimens collected from men who participated in the Selenium and Vitamin E Cancer Prevention Trial (SELECT), a large randomised, placebo-controlled trial in Europe which aimed to test whether selenium and vitamin E, either alone or combined, reduced prostate cancer risk.

Using data from the SELECT study, the team analysed blood plasma omega-3 status for 834 men who had been diagnosed with prostate cancer - of which 156 were high-grade cancer - along with a comparison group of 1,393 men selected randomly from the 35,500 participants.

Compared with men with the lowest blood plasma levels of long chain omega-3 polyunsaturated fatty acids (PUFA) those with the highest levels had increased risks for low-grade (44% increased risk), high-grade (71% increased risk), and total prostate cancer (43% higher risk).

The team added that these associations were 'similar' for individual long-chain omega-3 fatty acids - noting that higher linoleic acid (omega-6) was associated with reduced risks of low-grade and total prostate cancer; but noting that there was no dose response.

The authors noted that it remains unclear from their results exactly why high levels of omega-3 fatty acids could increase prostate cancer risk, however, they suggested that replication of their finding in two large studies indicates the need for further research into possible mechanisms.

Two further articles have been published regarding this study on NutraIngredients, countering the claims made in this study. They can be found by clicking here and clicking here.

Sources: Journal of the National Cancer Institute
Published online ahead of print, doi: 10.1093/jnci/djt174
"Plasma Phospholipid Fatty Acids and Prostate Cancer Risk in the SELECT Trial"
Authors: Theodore M. Brasky, Amy K. Darke, Xiaoling Song, et al

36 comments

Fish Oil is NOT the best way to get EFA's

Posted by Carri, 07 October 2013 - 03:47 GMT

The study found "...higher levels of linoleic acid (Omega-6) was associated with REDUCED RISKS of low-grade and total prostate cancer..."! That coincides with Brian Peskin's research that finds the human body was designed to use more omega-6 than omega-3; that's why eating flax doesn't result in high blood levels of DHA/EPA--our body won't convert it b/c we don't need it. High levels of omega-3 and fish oil is NOT natural, and even unhealthy! The problem is with the refined & oxidized vegetable oils, not with omega-6 fats.

"Many of the EFAs sold in the stores consist of manufactured EFA derivatives. To be clear, your body doesn’t need or want these derivatives, because it makes its own derivatives out of the Parent Essential Oils (PEOs) you consume as it needs them. Taking fish oil and other health food-store “EFAs” often overdoses you with derivatives, which can be very harmful."

I didn't believe Peskin's information at first, but after reading his research, as well as many other studies, I became a believer.

http://www.brianpeskin.com/BP.com/reports/CAMB-Fish-Oil-Fallacies-Report.pdf
http://www.brianpeskin.com

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Is the problem related to fish or Mercury levels

Posted by Harley Thor, 24 July 2013 - 21:15 GMT

I don't like to eat Salmon etc. but want
a good HDL/LDL ratio.
I take 3 types of Omega 3 supplements.
Krill oil, Flaxseed oil, and Fish oil.
Krill is said to have less of a Mercury problem because its found in waters far away from Mercury polluted waters.
Flaxseed Oil I take is Organic plant derived. And this fish oil is filtered to remove Mercury from it.

So far I don't see details on type of Omega 3 that is the problem.

If you use Flaxseed or Krill is that safer way to get Omega 3 benefits?

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Alan Kristol Is A Crappy "Scientist"

Posted by B, 19 July 2013 - 19:43 GMT

I just heard this arrogant Alan Kristal on Science Friday on NPR. He makes a lot of unscientific assumptions.

They looked at 834 men with prostate cancer and it turned out these men had higher levels of omega-3.

If you were diagnosed with cancer wouldn't you be more likely to increase your fish intake and take fish or flax oil in an attempt to get well & deal with the toxic cancer treatments?

This could certainly account for the higher omega-3 levels.

I have personal experience with omega-3 supplementation. I had VERY painful veins in my legs that my doctor said was probably phlebitis. But there was nothing he could do until it got worse, he said. Then he could operate on my veins.

A more enlightened doctor suggested I take flax oil for the omega-3s. The pain disappeared in two days! So I know that our bodies need omega-3s and if they don't get enough problems arise.

This arrogant Alan Kristal person said on NPR that his study shows that supplements of all kinds are unnecessary and harmful. This is a broad, irrational conclusion to draw from this limited, flawed study.

(Flawed because it doesn't account for the probability that participants with cancer were more likely to take omega-3s after being diagnosed.)

When the "scientists" can't even think logically we're in trouble.

This guy has a huge ego. Listen to him on NPR and you'll see what I mean. He has a vested interest in making a "groundbreaking" conclusions to make a name for himself. I wanted to increase my intake of supplements of all kinds after listening to his drivel.