DHA IN CHILDREN

DHA Introduction :

Docosahexaenoic acid (DHA) is an omega–3 fatty acid which is an essential fatty acid. Essential fatty acids cannot be synthesized in the body. They are also called polyunsaturated fatty acid (PUFA). These PUFA must be obtained from dietary food. There are 2 types of PUFA – omega 6 and omega 3. Omega 3 fatty acids are also known as Long Chain polyunsaturated fatty acids (LC PUFA’s). The most important omega 6 (n-6) fatty acid is arachidonic acid (ARA) that is formed from linoleic acid (LA) while most important omega 3 (n-3) fatty acid is DHA which is formed from alpha – linolenic acid (ALA ) (1).

Throughout most of life, there is a very limited metabolic capacity to convert ALA to DHA (2). Essential fatty acids are structural components of all tissues and are indispensable for cell membrane synthesis; the brain, retina and others neural tissues are particularly rich in long chain PUFA. These fatty acids serve as specific precursors for eicosanoids, which regulate numerous cell and organ functions (3). The most abundant brain PUFA are DHA (n-3); arachidonic acid (n-6) and adrenic acid (n-6) (4) and DHA is most abundant in the outer rod photoreceptors in the eye.

DHA :

DHA is an omega 3 PUFA which has very limited synthesis in the body. In the human body, DHA is derived from eicosapentaenoic acid (EPA) via docosapentaenoic acid (DPA) as an intermediate by desaturase enzyme and beta oxidation in peroxisomes (5). During early life, there is limited metabolic capacity to convert ALA to DHA. Thus in fetal life, infancy and early childhood, DHA should be acquired from dietary sources to maintain optimal health (6).

Sources of DHA :

Fish oils are rich in DHA. Most of the DHA in fish and other organisms originate from microalgae. ALA is present in vegetable oils such as flaxseed or linseed oil, rapeseed or canola oil, peanut oil, olive oil, soya oil, walnut oil, green leafy vegetables, fenugreek seeds, kidney beans and dry fruits (7). DHA is also manufactured from microalgae in vegetarian form (1) for commercial use.