Essential fatty acids in health and disease.

Essential fatty acids (EFAs) form an important component of cell membranes, are eicosanoid precursors and are therefore required for both the structure and function of every cell in the body. EFAs can modulate the activity of protein kinase C, T and B cell response, free radical generation and lipid peroxidation, lymphokine secretion and cell proliferation. EFAs also have anti-mutagenic, anti-bacterial, anti-fungal and anti-viral properties. EFAs and their metabolites lower serum cholesterol, triglycerides and blood pressure. EFAs appear to be of benefit in atopic eczema, premenstrual syndrome, psoriasis, auto-immune disorders especially rheumatoid arthritis and systemic lupus erythematosus, prevention of target organ damage in diabetes mellitus, peptic ulcer disease, ulcerative colitis, coronary heart disease and atherosclerosis. EFAs and their metabolites can selectively kill tumor cells both in vitro and in vivo without harming normal cells. In addition, EFAs seem to play a fundamental role in inflammation and immune response. In view of their actions and relative safety, it is anticipated that EFAs may be useful in the management of several diseases.

La dieta como determinante del desarrollo del sistema nervioso central: rol de los ácidos grasos asenciales / Diet as a determinant of the central nervous system development: role of essential fatty acids

El sistema nervioso central es el segundo tejido más rico en lípidos del organismo, luego del adiposo. Los fosfolípidos constituyentes de las membranas cerebrales poseen un alto contenido de ácidos grasos poliisaturados de cadena larga (AGPICL) de las familias n-3 y n-6, derivados de los respectivos ácidos grasos esenciales. Las mayores concentraciones de AGPICL en tejido nervioso corresponden al ácido docosahexaenoico (22:6n-3), en membranas de materia gris de corteza cerebral y fotoreceptores de retina. La deficiencia de AGPICL n-3 en recién nacidos, especialmente de pretérmino, modifica la función nerviosa, provocando dificuldades de aprendizaje y alteraciones de la función visual. El período de mayor acumulación de estos lípidos en cerebro es perinatal. Por esta razón, es importante la alimentación adecuada de la embarazada, antes y durante la gestación, y de la mujer que amamanta, que transfieren los AGPICL al feto y recién nacido, respectivamente. En niños de pretérmino, que nacen con menores reservas de AGPICL, estos tienen la calidad de condicionalmente esenciales. La formulación de las preparaciones destinadas a la alimentación de lactantes, especialmente si son prematuros, debe incluir AGPICL n-3 y n-6 en proporciones adecuadas.

Efecto de la preñez y la lactancia en el estado nutricional de los ácidos grasos esenciales en la rata / Effect of pregnancy and lactation in nutritional state of essential fatty acids in rats

To study the effect of pregnancy and lactation on red blood cell phospholipids percentual fatty acid composition of virgin, pregnant and lactating rats,,24 pregnant rats of 50ñ1 days of age were supplement with soy and 24 with fish oil during 21 days. Twelve rats of each group were sacrificed after 18 days of lactation, 24 non pregnant rats received soy oil and acted as controls of pregnant and lactating rats. Red blood cell phospholipid fatty acid composition was analized by gas chromatography. The percentage of total w-6 fatty acids of red blood cell phospholipid was 37.8ñ5.9, 32,6ñ0.6 and 38.3ñ3.5 percent in non pregnant, pregnant and lactating rats respectively (p<0.001). The figures for total w-3 fatty acids were 6.33ñ1.52, 4,31ñ0.39 and 2.7ñ0.46 respectively (p<0.001). There was no change in eicosatrienoic fatty acid percentage. Supplementation with fish oil reverted the decrease in w-6 and w-3 fatty acid percentage of pregnant and lactating rats. In conclusion, pregnancy and lactation decrease the capacity to transform precursors of essential fatty acids in long chain polyunsaturated fatty acids