Letter to NZ Listener: Fish oil study conclusions a red herring

 

Is it safe to take fish oil supplements, or isn’t it? Consumers reading the Listener’s article Can Fish Oil Cause You Harm? could understandably be left wondering.

At first glance the Liggins Institute’s fish oil supplement study findings appear to raise causes for concern but closer analysis reveals that all is not as it seems.

A number of independent sources, including the Ministry for Primary Industries and Professor Murray Skeaff from Otago University, have publicly questioned the way the most recent study was run and assured consumers that fish oil supplements are safe and effective.

The study’s negative conclusions were based on scenarios that could not occur in real life. Lab rats were given dosages that were ten times higher than the upper limit the industry has voluntarily set and which are codified in regulations around the world.

The excessive dosage levels used in the study were way above the recommended dosage and far beyond what consumers would ever conceivably take even if they dosed with a ‘more is better’ approach.

The researchers also artificially deteriorated the oil by super-oxidizing it to make it go rancid. This adulteration damaged the product to a degree that could not possibly occur in the usual industry standard controlled harvesting, manufacturing, distribution and storage processes.

Tellingly, the study showed beneficial outcomes for rats fed normal doses of unadulterated fish oil supplements. For example rat pups from those mothers fed normal doses of unadulterated fish oil had a reduced level of oxidative DNA damage

The Listener’s article also referred to a 2015 Liggins study that suggested many fish oil products were oxidized. However, it did not point out that a scientist at Australia’s Commonwealth Scientific and Industrial Research Organisation has publically stated that, following the 2015 study, the Australian Therapeutic Goods Administration performed follow-up analyses and found that none of the tested oils were oxidised.

Likewise, a number of our members who make fish oil supplements checked their own products and despite their best efforts, not one could replicate the study’s findings.

All are committed to producing high quality, effective products so they were keen to understand if there was indeed a problem with the way any of their products were being stored or handled during the distribution and retail processes covered by the study. To this day the Liggins Institute has refused to identify which products were tested and which shops they were bought from, making it impossible for anyone understand what the study’s findings actually meant.

As the umbrella group for this country’s natural products sector, Natural Products NZ has made numerous unsuccessful attempts to engage with the Liggins Institute.

This makes a mockery of Professor Cutfield’s assertion in the Listener article that that the industry is shooting the messenger for criticizing the research and instead should focus on “fixing the problem”.

We believe that “the problem” lies in the flawed way that the Liggins fish oil research projects have been run and their refusal to engage with the sector so as to ensure future studies are realistic and meaningful.

So far the Liggins Institute’s only meaningful findings have been those that suggest fish oil is perfectly safe and beneficial to use.

 

Download PDF:  Fish oil letter to Listener