Headlines hit recently, warning that we should take caution in thinking a ‘high’ omega-3 diet is as good for us as we previously thought just because the Inuit had low cardiovascular illness, including reduced incidence of metabolic syndrome markers such as high LDL cholesterol and poor insulin sensitivity. The article warned that we should not all go mad for omega-3 and expect the same benefits, since the Inuit had an enzyme that switched off the production of long-chain omega-3s to reduce its accumulation in the body.
What the study actually found
The study was conducted to look at changes in the Inuit genetic code as a result of their diet and environment. They found a number of genetic ‘alterations’, known as SNPs, present in almost 100% of Inuit genetic codes and their ancestors, but found in the genetics of less than 2% of Europeans (Danish controls were used). The researchers determined that these genetic alterations directly impact the amount of short chain omega-3 and 6 that is converted in the body to long chain fats. The media somehow extrapolated from this that the mechanism that reduced the conversion rate of ETA to EPA, which other populations do not have to the same degree, protected them from the potentially negative effect of a high omega-3 diet and that we should therefore question whether it is sensible to increase omega-3 intake.
To explain this further, the Inuit consumed a huge amount of long chain omega-3 rich foods – several times the amount we eat, even if we have a portion of salmon each day. As such, their genes have adapted to reduce the amount of additional long chain EPA – but not the other omega-3 fats – being made by the body. For the Inuit, it was unnecessary for the body to produce more long chain omega-3s when an abundance was already available from the diet and so reducing the activity of the enzyme responsible for converting ETA to EPA helped prevent too much of this fat being made.
What the media got entirely wrong
The genetic adaptation seen in the Inuit population is a fantastic example of how populations adapt to their dietary environment to ensure homeostasis. Our environment is so far from that of the Inuit; our omega-3 intake a fraction of what the Inuit would have consumed, and thus the absence of this adaptation in non-Inuit populations is not a signal to reduce our omega-3 intake. In fact, it is quite the opposite; omega-3 intake is very low in Europe, for example, and especially in the UK, where adults eat on average less than 250 mg of total omega-3 per day, whereas the government recommendation is 450mg.
The key point that the media have misunderstood is that there is an optimal omega-3 intake, reflected by a validated health biomarker called the omega-3 index (referring to the percentage of long-chain omega-3 EPA and DHA out of total fat in cell membranes) and optimal levels are a minimum of 8%. To put this study in perspective, with current European average intake, most adults tend to fall in the range of 2-6%. In our experience of testing blood fatty acid levels, when you factor in body weight (a key determinant of your omega-3 index), suggested omega-3 intakes to achieve a healthy omega-3 index usually in excess of 500mg and can be up to 2000mg.
Fortunately for the Inuit, who ate copious amounts of omega-3, their genetic adaptation enabled them to thrive on a high omega-3 intake, by down-regulating the body’s own production of long-chain omega-3, to prevent levels becoming too high and an unhealthily high omega-3 index (cell membranes could become too fluid and flexible and inhibit cell function, for example).
In contrast, not only do we not need a so-called ‘protective’ genetic alteration to reduce unnecessary conversion and further accumulation of long chain omega-3, we actually need to positively enhance all omega-3 pathways and significantly increase our intake of fish and omega-3 fatty acids to get anywhere near the scientifically validated ‘healthy’ omega-3 index levels.
Take heed: media reporting of scientific studies is prone to error
The misleading media headlines imploring that we should question the benefits of omega-3 are the perfect example of why journalists should not be trusted with scientific reporting and left to run riot with detrimental and inaccurate health advice.
The headlines seem to have jumped on this quote from project leader Rasmus Nielsen, professor of integrative biology at UC Berkeley: “We’ve now found that they have unique genetic adaptations to this diet, so you cannot extrapolate from them to other populations. A diet that is healthy for the Inuit may not necessarily be good for the rest of us.” The trouble is, the subsequent media coverage ran off in completely the wrong direction. One paper reported that “Fish oil is good for you… if you’re an Inuit: Native Greenlanders possess genetic mutations that enable them to reap the benefits of omega-3 fatty acids. Inuit and Siberian ancestors possess genetic mutations related to fat metabolism, suggesting that benefits they reap do not extend worldwide.” This is a total misinterpretation of the science and none of the media reports even suggest the journalists are aware of the omega-3 index as a health biomarker – which itself recognises that you can have both too much and too little omega-3. The Inuit intake of omega-3 was clearly far more than is necessary for health, but the genetic adaptation enabled them to thrive despite this excess. Meanwhile, we need not worry that fewer than 2% of Europeans have this same adaptation, since our intake is at the opposite end of the spectrum – approximately half of the recommended amount that is required to maintain a healthy omega-3 index. The only concern this study raises for Europeans is for anyone planning to emigrate to Greenland – 98% of Europeans would not thrive on a traditional, very high fat Inuit diet!