OMEGA-3 FATTY ACIDS: CAPSULES OR OIL? COMPARISON OF STABILITY, BIOAVAILABILITY AND EFFECTIVENESS OF EPA AND DHA SUPPLEMENTATION
Abstract
Omega-3 fatty acids, primarily eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), play a key role in human health, including protection of the cardiovascular system, support for neurological functions, and influence on anti-inflammatory processes. Despite the known importance of their consumption, the quality and form of supplementation (oil vs. capsules) are raising increasing doubts. One important aspect is the stability of these polyunsaturated fatty acids, as their susceptibility to oxidation may reduce their effectiveness or even lead to the formation of adverse products. In this context, the total oxidation index (TOTOX) is a commonly used marker for assessing the degree of oxidation of fish oils and omega-3 supplements. This article provides a comprehensive review of the scientific literature comparing oil and capsule forms of omega-3 supplements, taking into account criteria such as oxidative parameters (TOTOX, peroxide value, anisidine value), bioavailability, and user preferences. The results indicate that capsules often offer better protection against oxidation during storage (lower TOTOX values) compared to liquid forms. For example, syrup products achieved TOTOX values of ~97 meq/kg at the end of the study, while capsules achieved ~30 meq/kg under similar conditions. In addition, the bioavailability of EPA/DHA depended on the chemical form (triglycerides > ethyl esters) and the delivery system — emulsions or liquid forms showed faster absorption than traditional gel capsules.
Based on the data collected, it can be concluded that the choice of omega-3 supplement form should take into account not only the EPA/DHA content, but also the oxidative quality, chemical form, and storage method. For dietary practice, products with a low TOTOX index, adequately protected from light and oxygen, and taken with a meal containing fat to increase absorption are recommended.
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