Lessons from the Omega-3 Index: Why accurate testing and increasing intake is a matter of life and death
That was the view expressed by Prof Dr Clemens von Schacky, co-inventor of the Omega-3 Index (alongside OmegaQuant president and CEO William Harris), founder of international Omega-3 Index reference library Omegametrix, and head of Preventive Cardiology at the Ludwig Maximilian University of Munich.
Von Schacky was speaking at the first NutraIngredients Omega-3 Summit, which began yesterday in Singapore.
He highlighted the inconsistent and misleading results from a large number of omega-3 studies, including prominent recent trials such as REDUCE-IT, VITAL and ASCEND, which focused on cardiovascular disease.
Omega-3 obfuscation
Explaining the science that is often ignored in omega-3 research, he said: "When we talk about fatty acids, we're talking about cell membrane, which we have a lot of in our bodies. The conventional way of going about it is to look at fatty acid exposure — in other words, recording what you ate and then guessing what your cells would look like.
"However, there are a few problems with this method. Firstly, no one accurately remembers what he has eaten, so the plausibility of this kind of data is about 50%. If I were to generate data that were only 50% plausible, I would be very quiet about it…but nutritionists are not.
"Another problem with this is that nutrition is a moving target. Once diet has been assessed by questionnaire, the contents are looked up in time-honoured tables of reference, which say that salmon contains 4g or so of omega-3 per 1009. But it doesn't."
He added that one would have had to eat twice the amount of salmon in 2015 to get the same levels of omega-3 as he would have in 2006, as the content of omega-3 in salmon is now lower, thereby invalidating previously generated data that had only 50% plausibility.
He went on to criticise the nomenclature employed by nutritionists when discussing fatty acids, which are typically categorised into four main groups: saturated fatty acids, trans fatty acids, monounsaturated fatty acids and polyunsaturated fatty acids — the latter two sub-divided into omega-3s and omega-6s.
"If you look at fatty acids in the same group, they are actually very different in terms of structure and biology. For instance, there are plenty of biologically active metabolites in arachidonic acid, whereas there are only a few in linoleic acid.
"It is therefore structurally and biologically impossible to group fatty acids this way. Nevertheless, nutritionists tell us not to have any trans fats and to have less saturated fats, and that we’ll live longer if we have more polyunsaturated fats."
He further said that in addition to being structurally and biologically different, individual fatty acids in the cell membrane were also prognostically different. While some saturated fatty acids are associated with elevated mortality, others are associated with reduced mortality — the same holds true for the other types of fatty acids, which tend to be highly heterogeneous.
Problems amid progress
Von Schacky then spoke about the process behind the invention of the Omega-3 Index to tackle such issues and provide a more accurate and standardised assessment of omega-3 status.
Calling the index a "biomarker for the kind of omega-3s in a person's cells", he said, "We proposed measuring omega-3 in the red blood cells when we realised they were representative of other cells in terms of fatty acid composition.
"We then developed a method with low analytical variability — for example, HbA1C (glycated haemoglobin) gives a low noise signal, unlike blood sugar, which gives a high noise signal."
While this was a step in the right direction, he ran into a longstanding issue regarding the use of the index: an increasing number of laboratories began claiming to measure the index.
Von Schacky said, "Eventually, we had to trademark it, because so many labs were claiming that they were measuring the index.
“What we expect (with the index) is a statistically normal distribution of values, but what we've realised is there is no one who doesn't have omega-3 in his body — the lowest value is 2%, so life without omega-3 is simply impossible.
"There are also very few people with levels above 18%, so we think this is regulated (in the human body). Even dolphins don't have higher levels than that, and they eat a lot of omega-3.
"But in South Korea, for example, 20% of the population fall below that target range, and plenty of people are above it; in Japan, it's pretty much the same."
This then led Von Schacky to assert that there was a 'technical problem' with these labs that claimed to measure the Omega-3 Index, with the results they released often different from the ones he and his colleagues got, which he said were backed by science.
In fact, they sent samples to these labs, and the results that came back differed from theirs by a factor of 3.5.
A matter of life and death
Von Schacky said: "If we want to get the index into clinical medicine, we have to have a standardised measurement, and we must know what our measurements mean. I would suggest to these other labs that we join forces and get the whole thing standardised, so we can get that parameter into clinical medicine. Why is it important? It’s a matter of life and death.
"The Omega-3 Index is a powerful predictor of cardiovascular events, more powerful than cholesterol. Yet recruitment for trials has never depended on baseline levels. That's nonsense — it's like a trial with an anti-hypertensive that never measures blood pressure."
He then criticised the recent Cochrane review that reported that omega-3 had no heart health benefits, saying, "One does doesn't fit all, and data generated using the Omega-3 Index has shown that EPA and DHA have important roles in the prevention and treatment of cardiovascular disease and cognitive decline, as well as in pregnancy and lactation.
"Recruitment for clinical trials must depend on the Omega-3 Index, and researchers must know whom to recruit and what to aim for."
