The good oil ... or snake oil?

WORKS FOR HER: Betty Minchinton, 93, takes fish oil daily and swears by its positive health benefits.
WORKS FOR HER: Betty Minchinton, 93, takes fish oil daily and swears by its positive health benefits.

Fish oil, says Betty Minchinton, has made her as strong as an ox.

"My heart is 50 years old, according to my doctor," the 93-year-old Papakura woman says.

She has taken fish oil for a decade because "I don't like fish".

But her view is at odds with New Zealand-driven research that is rattling the multi-billion-dollar health supplement industry with claims fish oil delivers no measurable health benefits as well as raising questions about how the industry uses spin to push pills.

The research, conducted by a team at the University of Auckland Medical School and including Associate Professor Andrew Grey, "found little proof of health benefits" from fish oil, calcium and vitamin D supplements.

"Our work on fish oils was designed to point out the disconnection between accumulated evidence [showing] fish oils to be ineffective and clinical practice where they continue to be used by large numbers of people," Grey said.

The Auckland University team reviewed the results of randomised controlled trials - "the gold standard", says Grey - to show fish oils have little or no value.

"It seems wasteful and potentially harmful to continue to practise those interventions. If they are not effective, we should not be doing it."

Grey and colleague Dr Mark Bolland studied 18 randomised controlled trials and six meta-analyses of trials on fish oil published between 2005 and 2013. Only two studies showed any benefit but most media coverage of the studies was very positive for the industry.

"It's clear fish oils don't improve heart health," Grey said. "People can safely discontinue fish oil supplements and focus on pursuing health behaviours with proven efficacy."

Ross Keeley, 60, takes four capsules a day of hoki oil, convinced of future health benefits.

"Am I waking up each morning feeling as if I could leap over tall buildings? No. But do I believe that I will live to 70, or 80 or 90 and not suffer from Alzheimer's, yes."

Keeley is the chief executive of Nelson's NZX listed SeaDragon Ltd which turns hoki into fish oil capsules. He's angry at the Auckland University study, saying it was a case of bad news selling.

Keeley said more than 25,000-peer reviewed scientific papers supported the benefits of omega-3. "With that extensive amount of robust study to be then challenged by a couple of meta-analyses where negative reports are correlated together dumbfounds me."

The evidence he's citing refers particularly to omega-3 fatty acids known as EPA and DHA, which are present in oily fish. Your body can't make EPA and DHA, so you need to eat it.

In 2005, the Ministry of Health recommended 610mg per day for men and 430mg per day for women - the equivalent of eating oily fish twice a week or taking two standard pills a day.

Massey researcher Dr Welma Stonehouse has previously told the Sunday Star-Times there's good evidence fish oil improves heart health and said fish was the best source because it comes with other nutrients such as protein and selenium.

Keeley argued the cost of supplements was lower than the cost of feeding fish to a family twice a week.

The South Pacific College of Natural Medicine backs the Auckland University research.

"To be more specific, there are no clear and definite answers with regard to vitamin D, fish oils or calcium supplementation, all of which are currently very ‘topical' and which generate great difference of opinion between academics," said deputy director Robyn Carruthers.

"As Professor Grey and others will attest to, it is a difficult task to compare clinical trials where each uses a different methodology. While this article highlights one aspect of the use of fish oil, other research outlines other benefits."

One of the country's biggest fish oil retailers, Hardy's Health Stores, says a well-balanced and nutritious diet should provide all the vitamins and minerals necessary. But that is not enough for most people, a Hardy's spokesman says.

"The public, armed with unprecedented global access to information and research relating to supplementation, appears to disagree with the assertion that they are a waste of time and money."

That, Grey would argue, is due to the methods used by the supplement industry to sell their products.

In a separate research paper, Grey and the team analysed 47 industry-written press releases and 91 non-industry press releases and news stories, generated in response to 46 clinical studies of a range of dietary supplements. They found the industry "spun" the results favourable to supplements and "denigrated" results that were not favourable.

"There is an awful lot of misinformation and dubious claims of efficacy - not just in the supplement industry - and there are very powerful lobby groups pushing them," Grey said.

The supplements industry was misleading its customers and was engaged in a "process of denial" around evidence showing the supplements did not work, he said, adding the media often swallowed the supplement spin.

"I am not sure it is deliberate collaboration but I think some journalists don't appreciate the totality levels of evidence in a particular field."

Grey said: "Vitamin D is another supplement for which clinical trial evidence of lack of efficacy has been accruing for some time, yet it remains very widely used and very profitable for those who sell it.

"My job is to try and advise people about their health and part of that is to inform patients to avoid a treatment when the best available evidence tells us that it doesn't work."

Euromonitor International, a market intelligence firm, says sales of fish oil in the United States rose from US$425 million (NZ$502m) in 2007 to more than US$1 billion (NZ$1.2b) in 2012.

Sunday Star Times