Fatty Acids are Needed for Growth Essay -- Health Nutrition Papers

Fatty Acids are Needed for Growth The lipids of our central nervous system contain high proportions of arachidonic acid (20:4 n-6, AA) and docosahexaenoic acid (22:6 n-3, DHA) which are the two most important polyunsaturated fatty acids in the brain. Levels of linoleic acid (18:2 n-6) and alpha-linolenic acid (18:3 n-3) are low, usually less than 1% to 2% of total fatty acids (Innis, S78-79). Linoleic acid and alpha-linolenic acid are precursors to AA and DHA; they are elongated and desaturated to form AA and DHA (Clandinin, 27). The brain growth in humans begins early in the third trimester of pregnancy. This is the most important period for brain AA and DHA accumulation (Innis, S78-79). Therefore, the composition of fat in the brain during this period is very important for normal growth and development of the brain. Any changes in the balance of the fatty acids in the dietary fat intake will result in changes in the membrane functioning of brain cells. During this prenatal life, lipids are mostly needed for structural and regulatory functions. After birth, the infant is challenged by changes in the lipid sources. The response to these changes can be altered by changes in the diet composition. For example, a newborn infant’s response to human milk is considered to be ideal, therefore baby formulas try to mimic that response (Biervliet, S101). Studies have shown that fatty acid accumulation in the brain increases as the pregnancy progresses. It reaches the maximum level of accumulation toward the end of the pregnancy. But there are differences in the rate of accumulation of these fatty acids. For example, DHA levels in the cerebrum increase as the percentage of the total fatty acid, whereas AA levels decrease during ... ...awlosky, Robert J, and Salem, Norman Jr. "Ethanol exposure causes a decrease in docosahexaenoic acid and an increase in docosapentaenoic acid in feline brains and retinas." The American Journal of Clinical Nutrition. 61 (6). June 1995, 1284-9. Stryer, Lubert. Biochemistry. Fourth edition. W.H. Freeman and Company, New York. 1995, 687-88. Uavy, Ricardo, Birch, Eileen, Birch, David, and Peirano, Patricio. "Visual and brain function measurements in studies of n-3 fatty acid requirements of infants." The Journal of Pediatrics. 120 (4)(pt 2). Apr 1992, S168-80. Van Biervliet, J.P., Vinaimont, N., Vercaemst, R., and Rosseneu, M. "Serum cholesterol, cholesteryl ester, and high-density lipoprotein development in newborn infants: Response to formulas supplemented with cholesterol and gamma-linolenic acid." The Journal of Pediatrics. 120(4)(pt 2). Apr 1992, S101-8.