We all know how healthy omega-3 fatty acids are, in fact while we often hear the claim supplements are unnecessary and that all nutrients can be obtained from a healthy diet, the general consensus by the health industry is that we need to be taking omega-3 fish oils.
However it seems that knowing is not enough - despite great public awareness of the health benefits of omega 3 fatty acids it appears that almost all adults in the western world are highly likely to be deficient.
Omega-3s are considered "essential" because the body needs them to function but can't create them on its own instead they must come from dietary sources. The reality is, however, that diet alone may not be enough - this could be down to a number of factors including lack of knowledge when it comes to the nutritional content of food, consciously making poor food choices on a regular basis or lacking access to fresh, quality foods.
98% of people fell below optimum levels of omega-3s
The study, conducted by researchers at Purdue University and published in an issue of Nutrients, looked at the perceptions that subjects had of their diets and their awareness of the importance of these nutrients to what they were actually consuming. The latter was measured by their omega-3 index (measures the levels of omega-3 in their blood) and results showed that 98% of the participants fell below the optimum level.
The study recruited 200 adults, split between the sexes and of a wide range of ages, from teenagers to some as old as 80. Diet habits and demographic information was collected and body mass indices recorded. Participants all fell within a healthy BMI range albeit some being in a higher cardiovascular risk group than others.
Perceived omega-3 status disconnected from actual status
Interestingly the study showed a disconnect between perceived omega-3 status and actual omega-3 status - in other words there was very little difference between the omega-3 status of those who thought they were consuming enough and those who thought they weren't. Study leader, Dr Regan Bailey commented:
"I think that most people know that nutrition is important and they think that having a healthy diet is important. In this particular study, they even know the food they are, so they correctly identified fish as the primary source.. But there was still this disconnect with their omega-3 status."
Dr Bailey goes on to suggest the reasons for this by saying:
"People could be eating fish that is low in omega-3. They could be eating a lot of walnuts and flax and plant based sources and not efficiently converting those to omega-3. We really know know the reasons why, we can only speculate."
"The omega-3 content of fish really depends on what the fish eat. If the fish are eating a lot of algae it will have more omega-3 than a farm-raised fish that has a corn based diet for example. So there's a lot of variability if you're eating fish."
Why is the omega-3 index such an important measuring tool?
The omega 3 index is the sum of EPA and DHA content in the red blood cell membranes of an individual and has been validated as a biomarker that reflects long-term intake of EPA and DHA. It has also been established as a risk factor for death from coronary heart disease.
Despite this however, public awareness of the omega-3 index is almost entirely lacking and the guidelines on intake of fish required to achieve optimal status (more than 8%) have never actually been verified with studies that measure the dose response.
The current guidelines are to consume two fatty fish meals per week to put you in an optimal range. To put this into context the Japanese have an average omega-3 index of about 9% and they are high fish consumers.
Dr Bailey recommends that optimum omega-3 status try to be reached through diet in the main but also acknowledges that this might not be practical for everyone.
"There are people who either for food allergies or for preferences, like vegetarianism or veganism for example, don't want to eat fish. There are also algae based sources of omega-3s in both supplements and some fortified foods."
If you're planning to take an omega-3 supplement remember to take it as part of a meal as you'll need dietary fat in order to absorb the fat in the supplement.
"In the field of nutrition we often wonder why people do not choose to eat according to recommendations. Our results suggest that apart from knowledge, other factors may influence the intake of omega-3 fatty acids.
"It is essential to identify strategies for closing the gap between intake and concentration of omega-3 fatty acids to help reduce the risk of coronary heart disease and help support brain, joint and eye health."