Whether you realize it or not, much of what we know about the health of our nation is due to a nation-wide survey of Americans… and tractor-trailers. The National Health and Nutrition Examination Survey (NHANES) is a survey that measures almost everything we can think of related to health in randomly selected populations all over the US. They do this by driving “mobile health units” (tractor trailers) to different places all over the country to make measurements, take blood samples and collect questionnaires. One measurement that has yet to be included in this survey is the Omega-3 Index. Canada, on the other hand, has a similar survey and has become the first nation to include the Omega-3 Index, the results of which have been reported in this paper by Langlois and Ratnayake.
Main findings:
– First nationally representative sample of a population to measure the Omega-3 Index.
– The average Omega-3 Index in adults was 4.5%. Less than 3% of Canadians had Omega-3 Index levels >8%, in the low risk range. Remarkably, 43% had Omega-3 Index levels below 4%, in the high risk zone. This suggests that Canadians could benefit from higher omega-3 intakes.
– A higher Omega-3 Index was found in:
Women vs men
Older individuals vs younger
Asians and other non-white Canadians vs. whites
People reporting fish oil supplement use or regular fish consumption
Normal weight vs. obese people, and
Non-smokers vs smokers
– All of these relationships have been seen in other studies, confirming their validity.
– Less than half of the variability in the Omega-3 Index was explained by these 7 factors, therefore other unknown factors are important determinants of the Index. This means that you can’t guess what your Omega-3 Index is just knowing these facts – the only way to know it is to measure it.
Hopefully, the next time these tractor trailers, I mean “mobile health units,” are sent out across this great country to measure the health of the nation, the Omega-3 Index will be included.
- Photo Credit: kcxd, flickr.com
