In an exclusive interview, omega-3 pioneer Dr. Jörn Dyerberg shared his thoughts on the rise of the omega-3 phenomenon and gave his inimitable insight into its future directions.
Dr. Dyerberg holds a unique place in nutritional research. As a young doctor, curious about the Inuit's high fat diet and low incidence of heart disease - and attracted by the opportunity to dog sled over the ice and snow - he set off with fellow countrymen Hans Olaf Bang and Aase Brondum Nielsen for the north-west coast of Greenland.
The young Danes sought to understand how the Greenland Eskimos, or Inuit as they prefer to be called, could eat a high fat diet and still have one of the lowest death rates from cardiovascular disease on the planet.
"We set off with the plan to first look at their blood, and then look at their diet," he said.
Back in the early 70s the Inuit were still a hunter and fisherman society, living mostly on seal meat and fish. And yet heart disease accounted for 5.3 per cent of deaths amongst Greenland males, aged 45 to 64, compared to their US counterparts eating a vastly different diet where 40 per cent of deaths were due to coronary heart disease (CHD). These early studies yielded a landmark paper in The Lancet, published in 1971.
The researchers reported favorable blood lipid levels among the Inuit, but this, in itself, could not explain the far lower heart disease incidence, he said.
"After presenting the lipid data in The Lancet, we had a very old gas chromatogram that enabled us to do sample analysis on 130 blood samples. After two years of analysis (today it would take about a fortnight) we reported that we'd found two fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid," said Dr. Dyerberg.
"From that moment omega-3 was born."
The science explosion
"I have done some computing," said Dr. Dyerberg with a smile, "and since we published the first paper in 1971 there are now some 14,000 published papers [on omega-3], including close to 8,000 human studies."
"It was easy to calculate for 1971 - there was only us!" he said.
Dr. Dyerberg points out that no mention of the omega-3 fatty acids EPA and DHA was made in The Lancet paper. That followed in 1975 in another landmark paper, this time in the American Journal of Clinical Nutrition.
The young doctors wrote about the "remarkable differences" in levels of long chain fatty acids between the Inuit and the Danes. Most notable were the high levels of timnodonic acid - that's EPA to you and me. Dyerberg, then in his mid-thirties, wrote: "We feel strongly that the last word in the problem: dietary habits - especially related to the intake of polyunsaturated fatty acids - plasma lipid and lipoprotein concentrations, and coronary atherosclerosis has not yet been spoken."
And despite the explosion of omega-3 in science and the marketplace, it looks like the last word is a long way from being spoken. Dr. Dyerberg quoted literature reporting improvements in blood lipid levels, a reduced tendency of thrombosis, blood pressure and heart rate improvements, and improved vascular function.
The science explosion has been followed by consumer and product blast-off. Different ratios for EPA (C20:5 n-3) to DHA (C22:6 n-3) are being marketed, or DHA alone, or products containing alpha-linolenic acid (ALA, C18:3 n-3), a shorter long-chain omega-3 from plants. It's all a bit confusing…
"The ratios of EPA and DHA are not important," said Dr. Dyerberg, "as they can be interconverted.
"But consumption should include both, and a decent combination is 3:2 EPA:DHA."
So what about docosapentaenoic acid (DPA), labelled by some as "underrated" amongst the omega-3 fatty acids? "I don't know any specific effects of DPA," he said. "But it is an intermediate in the conversion of EPA to DHA, so it will be present in the body all the time."
As for ALA, an omega-3 from plants that is converted in the body to EPA and subsequently DHA, he was unconvinced. In terms of biological effects of DHA and EPA, Dr. Dyerberg said there are many. "We don't know of any specific biological effects of ALA," he said. "Tissue experiments give you an ALA concentration of zero. This omega-3 is either burnt or converted," he said. "And the conversion is low.
"If we want the benefits of omega-3, we have to eat them as long chain," he said, referring to EPA and DHA.
But it wasn't all doom and gloom for ALA, as Dr. Dyerberg said it could be effective: "If you change your diet dramatically, you can achieve the same EPA and DHA levels in cells on an ALA diet, but you have to change your diet totally," he said. "Diet compliance will be poor," he added.
Into the future
"The most pressing issue for the 21st Century is nutrition, with obesity, diabetes and cardiovascular disorders all linked to diet. In that aspect, omega-3 will play a major role," said Dr. Dyerberg.
For heart health, he said he expects EPA and DHA to be established for the prevention of cardiovascular disorders, with public health recommendations introduced.
Recommendations will also become broader and broader, he said, including supplements during pregnancy and early childhood. This is because of the benefits reported for mental development, and there are studies that show omega-3 supplementation can influence breast milk composition and subsequently a child's brain, he said.
"My grandchildren have a lot of omega-3, and they're very smart!"
Less certain was the potential of omega-3 to prevent the development of cancers, he said, despite some epidemiological and animal studies reporting interesting data for breast and prostate cancer.
"Studies are beginning to emerge," said Dr. Dyerberg, "but there is a big question over whether they offer primary prevention."
The future of omega-3 will also involve resource issues. "The sea is limited, and alternative sources could be needed," he said.
Many have already started down this path, with companies sourcing omega-3 DHA from algae, and scientists looking to genetically engineer plants to produce EPA, and maybe one day, DHA.
The final word
By all accounts, Dr. Dyerberg is a pioneer, scientist, gentleman and grandfather. His early prediction about the last word on dietary habits and heart health not yet being spoken make him a visionary, too.
Editor's Note: Dr. Dyerberg was medical and scientific adviser for omega-3 fatty acids at Cognis Nutrition & Health and Napro Pharma AS at the time of this interview.