N-3 PUFAs: a lifetime of benefits

摘要

The association between high fat intake and cardiovascular disease has encouraged many people to reduce their fat intake in recent years. However, it is now well-established that not all fats are harmful to health and the so called n-3 or omega-3 fatty acids are actually beneficial for cardiovascular health. Moreover, it is now emerging that the intake of n-3 fatty acids may offer neurological and immunological benefits. This article will briefly review the scientific support for neurological benefits. Fatty acids are the building blocks of lipids. As a constituent of lipids in the human body fatty acids are important for the storage of energy, as key components of cell membranes and as a key supply of energy in the fasting state. Fatty acids canbe saturated (containing no double bonds between carbon atoms), monounsaturated (one double bond) or polyunsaturated (two or more double bonds). With respect to polyunsaturated fatty acids (PUFA) two distinct families can be discriminated that are essential: the n-6 (or omega 6) and the n-3 (or omega 3) family. The n-3 family has its first double bond at the third carbon atom, whereas the first double bond in the n-6 family is present at carbon atom number six (see Fig 1). Although the human body can introduce double bonds by itself it is only able to do so at carbon atom numbers nine or higher. The precursors of the n-3 and n-6 families are the 18 carbon atoms long fatty acids, alpha-linolenic acid (ALA) and linoleic acid (LA), respectively. ALA and LA are called essential because they are required for good health and have to be provided through the diet.