Fish Oil Supplementation: A Matter of DHA Enzymatic/Non-Enzymatic Oxidation Balance?

Cardiovascular disease (CVD) and Alzheimer's type dementia (AD) are leading causes of death amongst aged people, with rates expected to rise due to increased longevity. Dietary polyunsaturated fatty acids may contribute to the development and maintenance of the functional capacities of the brain and reduced levels of docosahexaenoic acid (DHA) may be indicative of an increased risk of AD. Moreover, epidemiological studies have shown a strong correlation between fish consumption and reduction in sudden death because of myocardial infarction. Not only does fish oil decrease thrombosis, but it also prevents cardiac arrhythmias. The molecular mechanism underlying the many benefits of n-3 fatty acids remains a significant challenge for medicine. Human recombinant cyclooxygenase (COX)-2 converts DHA to hydroxy-DHA and novel oxygenated products (resolvins, neuroprotectins, maresins) generated by enzymatic processes have recently been identified. With low-dose aspirin (ASA) - which acetylates COX-2 - more stable epimeric ASA-triggered oxygenated forms are synthesized. In conclusion, both DHA and acetylCOX-2 seem to cooperate - in synergy that goes well beyond our current understanding - in the prevention of many diseases that involve inflammation, including CVD and AD. Often the analogy is the key for new advances.