Omega-3 fatty acids (highly abundant in fatty fish and sea foods) are important part of diet, since they bring numerous health benefits. Upon consumption, these fatty acids incorporate in cell membranes where they regulate membrane fluidity and other functions. Also, omega-3 fatty acids are important for the synthesis of complex lipids, particularly in the nervous system. This is why these fatty acids are important for proper brain development and functioning. In addition, omega-3 fats affect multiple molecular pathways and act on risk factor for cardiovascular and other chronic disease development. These include beneficial effects on endothelial function, levels of blood lipids, and blood pressure. Omega-3 fatty acids are a precursor of important signaling molecules with anti-inflammatory and other biological activities.
Cardiovascular disease is one of the most frequent chronic diseases worldwide. Numerous risk factors contribute to its development, including high blood lipids and sugar, and increased blood pressure. The effects of omega-3 supplementation on cardiovascular risk factors were investigated in a study including overweight schoolchildren with metabolic syndrome. Both boys (n=20) and girls (n=19) receiving omega-3 fatty acids for one month had reduced levels of blood glucose, lipids and blood pressure at the end of intervention.
Another study tested the impact of omega-3 fatty acids in subjects at low or high cardiovascular risk with hypertriglyceridemia. In patients with high risk of cardiovascular disease, 12 weeks of omega-3 intake significantly improved endothelial function and arterial stiffness, suggesting beneficial effects of omega-3 on vascular ageing.
The effects of omega-3 fatty acids on heart rate, as novel risk of all-cause cardiovascular mortality, were evaluated in meta-analysis including 51 placebo controlled trials with approximately 3000 participants. Results of this analysis demonstrated reducing effects of omega-3 fatty acids on heart rate, which was more pronounced for DHA (docosahexaenoic acid) than EPA (eicosapentaenoic acid), as two main members of omega-3 family.
- García-López S, Villanueva Arriaga RE, Nájera Medina O, et al. One month of omega-3 fatty acid supplementation improves lipid profiles, glucose levels and blood pressure in overweight schoolchildren with metabolic syndrome. J Pediatr Endocrinol Metab. 2016;29(10):1143-1150.
- Casanova MA, Medeiros F, Trindade M, et al. Omega-3 fatty acids supplementation improves endothelial function and arterial stiffness in hypertensive patients with hypertriglyceridemia and high cardiovascular risk. J Am Soc Hypertens. 2017;11(1):10-19.
- Hidayat K, Yang J, Zhang Z, et all. Effect of omega-3 long-chain polyunsaturated fatty acid supplementation on heart rate: a meta-analysis of randomized controlled trials. Eur J Clin Nutr. 2017;doi:10.1038/s41430-017-0052-3.
Since omega-3 fatty acids are important parts of brain lipids, it is assumed that they play an important role in brain development, as well as in the proper brain functioning throughout the whole lifespan. Thus, omega-3 fatty acids may reduce the incidence and severity of developmental disorders in children as well as improve cognitive functions in older subjects.
The benefits of supplementation with DHA were investigated in subjects with mild cognitive impairments aged 65 or over. Total of 240 subjects were recruited and assigned to receive either DHA or placebo for 12 months. At the end of the intervention period, DHA significantly improved the cognitive functions (measured by different scales) in comparison with the placebo, and reduced the atrophy of hippocampus, condition which associate with cognitive impairments and dementia.
Attention deficit hyperactivity disorder (ADHD) represents one of the most common psychiatric disorders in children. The effects of omega-3 supplementation on ADHD symptoms were investigated in young boys with or without ADHD. As a result, 16 weeks of supplementation reduced ADHD symptoms, i.e. improved parent-rated attention score in treated boys (n=40) comparing with the placebo group (n=39).
- Zhang YP, Miao R, Li Q, Wu T, Ma F. Effects of DHA Supplementation on Hippocampal Volume and Cognitive Function in Older Adults with Mild Cognitive Impairment: A 12-Month Randomized, Double-Blind, Placebo-Controlled Trial. J Alzheimers Dis. 2017;55(2):497-507.
- Bos DJ, Oranje B, Veerhoek ES, et al. Reduced Symptoms of Inattention after Dietary Omega-3 Fatty Acid Supplementation in Boys with and without Attention Deficit/Hyperactivity Disorder. Neuropsychopharmacology. 2015;40(10):2298-2306.
Whorl Health Organization (WHO) recommends that intake of omega-3 fatty acids should make 1-2 % of total caloric intake. This means that regular intake of fish (ideally salmon, herring, mackerel and other fatty fish; minimum two servings per week) should be ensured followed with intake of omega-3 containing oils (flaxseed oil is the best source) and nuts. In subjects whose consumption of these food items is low, supplementation with omega-3 fatty acids should be considered.