Health benefits
In contrast to saturated and monounsaturated fatty acids, PUFA have at least two double bonds, a feature which crucially affects their structural, physical and chemical properties. PUFA fulfil several functions in human physiology. They are structural constituents of cell membranes, precursors of eicosanoids, structural constituents of the skin’s epidermis and, last but not least, a concentrated source of energy. PUFA have been shown to counter the effects of ‘bad’ fatty acids in our blood, and have important health benefits.
Two large families of PUFA exist: omega-3 PUFA and omega-6 PUFA. Both families can be metabolized to long-chain PUFA (LC-PUFA). The precursor of omega-6 PUFA is linoleic acid (LA), while the precursor of omega-3 PUFA is alpha-linolenic acid (ALA). LA is predominantly obtained from vegetable oils, ALA from green leaves and certain vegetable oils such as soybean oil.
In recent years, numerous studies have suggested that dietary long-chain omega-3 PUFA help maintain the performance of the heart and cardiovascular system, reduce the levels of triglycerides (fats) in the blood, help regulate blood pressure and help maintain a regular heart beat. In addition, omega-3 PUFA have been shown to be helpful in maintaining healthy bones and joints and a healthy brain. They are also very important immediately before and after birth, as they play a key role in the vision processes.
Dietary supplementation
The functional omega-3 PUFA eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA) are present in fatty fish such as salmon, menhaden, mackerel, herring and tuna. Consumption of these fish tends to be low in Western diets. One way of ensuring an adequate intake of omega-3 PUFA, especially of EPA and DHA, is to consume fortified foods or dietary supplements containing these health-giving natural compounds.
