RESUMEN
Knowledge of the importance of docosahexaenoic acid (DHA), arachidonic acid (AA), and long-chain polyunsaturated fatty acids (LCPUFAs) in neurodevelopment was originally obtained from animal studies. These fatty acids are rapidly accreted in brain during the first postnatal year in animal and human infants, and they are found in high concentrations in breast milk. Reports of enhanced intellectual development in breast-fed children, and reports linking LCPUFA deficiency with neurodevelopmental disorders have stressed the physiological importance of DHA in visual and neural systems. In addition to high concentrations of fatty acids in breast milk, they are also present in fish and algae oil and have recently been added to infant formulas. Esterified poplyunsaturated fatty acids act in cellular membranes, in signal transduction, in neurotransmission, and in the formation of lipid rafts. Nonesterified polyunsaturated fatty acids can modulate gene expression and ion channel activities, thus becoming neuroprotective agents. The conversion of linoleic acid and alpha-linolenic acid into ARA and DHA have led to randomized clinical trials that have studied whether infant formulas supplemented with DHA or both DHA and ARA would enhance visual and cognitive development. This review gives an overview of fatty acids and neurodevelopment, focusing on the findings from these studies.
Asunto(s)
Encéfalo/crecimiento & desarrollo , Ácidos Grasos Insaturados/fisiología , Fenómenos Fisiológicos Nutricionales del Lactante/fisiología , Leche Humana/química , Sistema Nervioso/efectos de los fármacos , Necesidades Nutricionales , Encéfalo/metabolismo , Femenino , Humanos , Lactante , Fórmulas Infantiles/química , Recién Nacido , Masculino , Sistema Nervioso/crecimiento & desarrollo , Embarazo/fisiologíaRESUMEN
The mechanisms of bone loss involve a predominance of osteodestructive cell activity over bone repair. Age and gender are the most significant biological risk factors; perimenopausal women constitute the most susceptible population group. Hormone-related phenomena, such as pregnancies and lactational performance, as well as heredity and ethnic origin, are also associated with osteoporosis. Alcohol and caffeine have been linked with progressive bone demineralization. A reduced body mass increases the probability of fractures. Dietary factors, such as adequate intakes of calcium, phosphates, and vitamin D, exert a protective action while the effect of fluoride and dietary fiber is still controversial. A constant physical activity promotes an appropriate development and maintenance of bone mass and architecture.