By Rod Navajas
Increasing longevity and optimising human health & performance goes beyond doing infrequent walks and eating a salad every now and then. Optimal health requires work! Lifestyle choices and practices are key, as It is estimated that only 25% of the variation in human longevity is due to genetics factors.
Not surprisingly, diet is the most important modifiable factor when optimal health and healthy aging is the desired outcome. Nutrient deficiencies for example, including Iodine and Vitamin C, can severely impact human health and be the cause of many diseases. Vitamins and Minerals are essential nutrients – they cannot be synthesised by the body from other nutrients – and must be supplied from the diet in regular intervals. Essential nutrients also include specific amino acids such as leucine, water and essential fatty acids such as the Omega-3s family. In the past 2 decades, the Omega-3s DHA and EPA gained a lot of popularity due their health benefits including healthy ageing.
Omega-3 and its Health Effects
There are 2 essential fatty acids: the omega-6 Linoleic Acid (LA), and the omega-3 Alpha-Linoleic Acid (ALA)(Figure 1). Derivatives from these fatty acids, mainly DHA and EPA from ALA, have been shown to be very beneficial to human health, including well studied cardiovascular benefits such as reduction of triglycerides, reduction of blood pressure and endothelial function improvement. These fatty acids also affect brain health and are powerful anti-inflammatory agents.
One of the reasons these fatty acids influence such a broad range of tissues and system, is due to their incorporation into phospholipids, which form the major structural components of all cellular membranes (Figure 2). Cellular membranes from some tissues (e.g, retina, brain, myocardium) are particularly enriched with these fatty acids. For example, about 30% of all fatty acids in the outer segment membrane of retinal photoreceptors are composed of Omega-3 fatty acids.
Food sources of Omega-3
Fish such as tuna, trout and salmon are especially rich sources of these fatty acids, specially DHA and EPA. Although ALA can be found in plant sources like flax seeds and canola oil, the conversion to DHA and EPA (found in fish) is limited in people who consume a typical Western diet. Consequently, following the consumption of foods containing ALA, conversion and incorporation of DHA and EPA into our tissues is poor. Consumption of fish and fish oils which are the preferred way to ensure adequate intake of these essential nutrients.
Am I consuming enough? The Omega-3 index test and longevity
The best way to ensure you are consuming adequate amounts of Omega-3s is to get tested. The Omega-3 Index Test is a measurement of the amount of the specific Omega-3s EPA and DHA in the red blood cell membranes and is a reflection of the long-term consumption of these essential fatty acids. The result is reported as a percentage. For example, if you have 50 fatty acids in a cell membrane and 5 are EPA and DHA, you will have an Omega-3 Index of 10%.
As consumption of fish is mainly dictated by geographical location and cultural dietary behaviour, there is a wide variability between countries. Consequently, the Omega-3 Index also varies greatly amongst countries. A study by Stark et al. has demonstrated the estimate omega-3 index worldwide. As shown in the map (Figure 3), the countries with the highest Omega-3 Index values were those in Scandinavia, the Sea of Japan and areas where indigenous people do not eat a Western diet. The areas with the lowest Omega-3 Index values were North and South America, parts of the Middle East and India. Considering the traditional diets of these countries, the Omega-3 Index values match what we would expect to see.
Interestingly, having a low Omega-3 index score (<4.2%) has been to shown to subtract 4.7years of life. The equivalent of being a current smoker at age 65. Not surprisingly, countries like Japan where the Omega-3 index is high (>8%), have a 5-year longer life expectancy than of the United States.
It’s important to note that there is large variability amongst people in terms of their ability to respond to nutrient intake and supplementation. For this reason, getting the Omega-3 Index Test is the best way to individualise consumption and supplementation recommendations.
The Omega-3 Index Test can be ordered through Fitness Lab Wellness through Metagenics.
 Stark, K. D., Van Elswyk, M. E., Higgins, M. R., Weatherford, C. A., & Salem Jr, N. (2016). Global survey of the omega-3 fatty acids, docosahexaenoic acid and eicosapentaenoic acid in the blood stream of healthy adults. Progress in lipid research, 63, 132-152.
 Passarino, G., De Rango, F., & Montesanto, A. (2016). Human longevity: Genetics or Lifestyle? It takes two to tango. Immunity & Ageing, 13(1), 1-6.
 McBurney, M. I., Tintle, N. L., Vasan, R. S., Sala-Vila, A., & Harris, W. S. (2021). Using an erythrocyte fatty acid fingerprint to predict risk of all-cause mortality: the Framingham Offspring Cohort. The American Journal of Clinical Nutrition.