Omega-3 Fatty Acids: worth all the fuss?

In the realm of nutritional supplements, few have received as much attention as omega-3 fatty acids. These essential nutrients (referred to as “essential” because we cannot synthesise them in our bodies) appear to play a crucial role in human health and performance, offering a wide array of benefits that span from cardiovascular health to cognitive function. Having spent the first decade of my professional life researching the role of omega-3 fatty acids (by way of Masters and PhD degrees, and post-doctoral fellowships), I have remained an advocate while also maintaining a good dose of scepticism, simply because the number of health claims tied to omega-3 fatty acids is uncountable.? Furthermore, if I’m not mistaken, omega-3 fatty are the highest (or near enough to highest) selling supplement class of all-time.? At one point, and probably still to this day, you could buy omega-3 enriched eggs, bread and milk!? This brief article summarises my current position on omega-3 fatty acids.

Omega-3s are a family of polyunsaturated fats that are essential for human health. The three main fatty acids are alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). ALA is primarily found in plant sources such as flaxseeds, chia seeds, and walnuts, while EPA and DHA are predominantly found in fatty fish and seafood.? Omega-6, found in other naturally-occurring plant and animal fat sources, and omega-3 compete for the enzymes that convert shorter, less active fatty acids into the longer, more physiologically-important ones.? Western diets typically feature a much higher intake of omega-6 compared with omega-3 fatty acids.

There have quite literally been thousands of studies, papers, critical reviews and meta-analyses performed on the health effects of omega-3 fatty acids.? I’m going to briefly summarise the outputs of these, but I want to go from big to small.??

All-cause mortality. A meta-analysis of 17 prospective cohort studies (and something like 45,000 subjects in total) found that those with the highest (quintile) levels of circulating omega-3 fatty acids were at a 15-18% lower risk of mortality from all causes, when compared with people in the lowest quintile for omega-3 levels.? Based on this analysis, I see no reason to not supplement my diet and that of my patients, with a quality source of omega-3 fatty acids, especially EPA and DHA. It’s easy and cheap and confers a benefit of greater magnitude than practically any drug or supplement ever invented.?

Based on my own research in the 1990s, the above meta-analysis and a favourable cost-benefit ratio, I test my patients omega fatty acid levels with an easily accessible direct to consumer test (that can also be arranged by a doctor).? It is comprehensive and features measures not only of red cell omega-3 levels but also omega-6 and trans fatty acids.? Almost without exception, my patients are in the middle quintile for omega-3 fatty acids including EPA and DHA, and this includes those that are very strict about their diets. What’s also interesting is that some of my patients with middling levels of omega-3 fatty acids have been taking omega-3 supplements for years! This suggests it’s worth experimenting with different supplements (I take a liquid fish oil, rather than one that’s encapsulated).? I’d also recommend regular (at least annual) testing.

Cardiovascular Health.? Omega-3 fatty acids, particularly EPA and DHA, have drawn significant attention in cardiovascular health research. While the evidence is promising, it remains not entirely conclusive. Omega-3 polyunsaturated fatty acids (particularly those from marine sources) do appear on balance to have multiple beneficial effects on cardiac health, potentially reducing the risk of coronary heart disease and heart failure [5]. Some studies suggest they might lower the risk of cardiovascular events and mortality. However, it's important to note that the benefits appear to be dose-dependent [2], with the greatest benefits seen in supplementation of EPA and DHA in high levels.??

Cognitive Function and Brain Health.? My own research looked into the importance of long chain omega-3 fatty acids in retinal development and function. Indeed, omega-3 fatty acids play a crucial role in brain growth and maintenance. Omega-3 fatty acids may inhibit neuronal cell death and reduce inflammation, potentially contributing to improved cognitive outcomes. Several studies have demonstrated that omega-3 supplementation can enhance learning, memory, and overall cognitive well-being [6].? That said, I think it would be a stretch to expect to feel smarter or even mentally sharper simply by taking an omega-3 supplement (or any supplement for that matter)!

Anti-inflammatory Effects.? Several studies indicate that omega-3s actively compete with proinflammatory substances, effectively reducing their impact. Furthermore, they activate specific receptors that downregulate inflammatory pathways. This dual action mechanism contributes to their overall anti-inflammatory effect. The anti-inflammatory actions of omega-3 fatty acids appear to attenuate the glucose-induced increase in multiple inflammatory agents, including TNF-α and IL-6. These effects, along with their ability to attenuate thrombosis and decrease triacylglycerol levels, result in cardiovascular benefits and also reduce the risk of macrovascular complications [7].

Omega-3s and Athletic Performance.? For athletes and fitness enthusiasts, omega-3 fatty acids offer several potential benefits. Some studies suggest these fats might improve blood flow, reduce inflammation, and enhance muscle protein synthesis. However, once again as is often true of nutritional intervention studies, the evidence isn't conclusive. While omega-3s may help with recovery by reducing muscle soreness, their direct impact on performance metrics like VO2max or endurance is less clear [2]. As with many nutritional supplements, individual responses can vary. For athletes looking to optimise their diet, omega-3s are worth considering, but they're not a magic bullet for performance enhancement.

On balance, omega-3 fatty acids are essential nutrients that seem to offer wide-ranging benefits for health and performance. From supporting cardiovascular health and cognitive function to potentially extending lifespan, these essential fats play a crucial role in optimal health. Whether through dietary sources or supplementation, incorporating adequate amounts of omega-3s into your daily routine could be a key step towards enhancing your health, performance, and longevity.

References:

[1] Poggioli R, Hirani K, Jogani VG, Ricordi C. Modulation of inflammation and immunity by Omega-3 fatty acids. CellR4. 2021.

[2] Harris WS, Tintle NL, Imamura F, et al. Blood n-3 fatty acid levels and total and cause-specific mortality from 17 prospective studies. Nat Commun. 2021;12:2329.

[3] Thota RN, Ferguson JJA, Abbott KA, et al. Science behind the cardio-metabolic benefits of omega-3 polyunsaturated fatty acids: Biochemical effects vs. clinical outcomes. Food Funct. 2018;9:3576-3596.

[4] Zárate R, El Jaber-Vazdekis N, Tejera N, Pérez JA, Rodríguez C. Significance of long chain polyunsaturated fatty acids in human health. Clin Transl Med. 2017;6(1):25.

[5] J. K. Innes and P. C. Calder, "Marine Omega-3 (N-3) Fatty Acids for Cardiovascular Health: An Update for 2020," International Journal of Molecular Sciences, vol. 21, no. 4, p. 1362, Feb. 2020.

[6] I. M. Dighriri et al., "Effects of Omega-3 Polyunsaturated Fatty Acids on Brain Functions: A Systematic Review," Cureus, vol. 14, no. 10, p. e30091, Oct. 2022.

[7] E. Tortosa-Caparrós, D. Navas-Carrillo, F. Marín, and E. Orenes-Pi?ero, "Anti-inflammatory effects of omega 3 and omega 6 polyunsaturated fatty acids in cardiovascular disease and metabolic syndrome," Critical Reviews in Food Science and Nutrition, vol. 57, no. 16, pp. 3421–3429, 2017.

[8] R. J. Shei, M. R. Lindley, and T. D. Mickleborough, "Omega-3 polyunsaturated fatty acids in the optimization of physical performance," Mil Med, vol. 179, no. 11, pp. 144-156, 2014.