Jacqueline Jumpsen

Influence of dietary gangliosides on neonatal brain development

Gangliosides are sialic acid-containing glycosphingolipids. Gangliosides are found in human milk; understanding of the potential role of gangliosides in infant development is emerging, with suggested roles in the brain and gut. Ganglioside accretion in the developing brain is highest in utero and in early neonatal life, during the periods of dendritic branching and new synapse formation. Further, brain contains the highest relative ganglioside content in the body, particularly in neuronal cell membranes concentrated in the area of the synaptic membrane. Gangliosides are known to play a role in neuronal growth, migration and maturation, neuritogenesis, synaptogenesis, and myelination. In addition to their roles in development and structure of the brain, gangliosides also play a functional role in nerve cell communication. It is less well known whether dietary gangliosides can influence the development of cognitive function. This review summarizes current knowledge on the role gangliosides play in brain development.

Effect of w3 fatty acid on plasma lipids, cholesterol and lipoprotein fatty acid content in NIDDM patients

Summary This study was conducted to examine the effect of ω3 fatty acid supplementation on plasma lipid, cholesterol and lipoprotein fatty acid content of non-insulin-dependent diabetic individuals consuming a higher (0.65, n = 10) or lower (0.44, n = 18) ratio of dietary polyunsaturated to saturated fatty acid (P/S). The participants were initially given an olive oil supplement (placebo) equivalent to 35 mg of 18:1 · kg body weight–1· day–1 for 3 months. This was followed by two ω3 supplement periods in a randomized crossover. In these 3-month periods, participants were given a linseed oil supplement equivalent to 35 mg of 18:3ω3 · kg body weight–1· day–1 or a fish oil supplement equivalent to 35 mg of 20:5ω3 + 22:6ω3 · kg body weight–1· day–1. At the end of each supplement period, a blood sample was drawn from each participant for lipid, lipoprotein, insulin, glucagon and C-peptide analyses. At the end of each 3-month period a 7-day dietary record was completed to calculate dietary fat intake and P/S ratio. Results indicate that fish oil significantly reduced plasma triacylglycerol level (p < 0.05) and increased 20:5ω3 and 22:6ω3 content of all lipoprotein lipid classes. Linolenic acid supplementation had no effect on plasma triacylglycerol level, but it increased 18:3ω3 content of lipoprotein cholesterol ester fractions (p < 0.05). A slight increase in 20:5ω3, but not 22:6ω3, content was noted in lipoprotein lipid classes as a result of 18:3ω3 supplementation. LDL and HDL cholesterol, insulin, glucagon and C-peptide levels were not affected by either ω3 supplement. It is concluded that a modest intake of ω3 fatty acids, such as could be obtained from consuming fish regularly, will reduce plasma triglyceride level without affecting LDL or HDL cholesterol levels. [Diabetologia (1997) 40: 45–52]

Omega-3 fatty acid intake results in a relationship between the fatty acid composition of LDL cholesterol ester and LDL cholesterol content in humans

The relationship between the fatty acid composition of the low density lipoprotein (LDL) cholesterol ester and LDL cholesterol content was assessed in 26 free-living, normal subjects. Dietary intakes of 14:0, 16:0, 18:0, 18:1, 18:2omega6, 18:3omega3, 20:4omega6, 20:5omega3, 22:6omega3 were calculated from seven-day food records kept by each subject at baseline and after three months of supplementation with olive, flaxseed or fish oil, respectively. A randomized cross-over design was used. The fatty acid content of specific foods was calculated. Fasting blood samples, taken at the beginning and end of each supplementation period, were analyzed for the fatty acid content present in individual lipoproteins. There was a significant correlation between 20:5omega3 and 22:6omega3 intake and the content of these fatty acids in the LDL cholesterol ester fraction. During the fish oil treatment period the 16:0 and 18:0 content of the LDL cholesterol ester was highly predictive of LDL cholesterol content. This relationship was not observed during the baseline or placebo (olive oil) supplement period.

During neuronal and glial cell development diet n-6 to n-3 fatty acid ratio alters the fatty acid composition of phosphatidylinositol and phosphatidylserine.

Brain development was examined in the neonatal rat in response to feeding increased levels of 18:3n - 3, 20:4n - 6 or 22:6n - 3 at levels proposed for infant formula. Diets varying in n - 6 to n - 3 fatty acid ratio, with or without 20:4n - 6 and 22:6n - 3 alone or in combination, were fed to nursing dams at parturition and subsequently to weaned pups until six weeks of age. Neuronal and glial cells were isolated from the frontal, cerebellar and hippocampal brain regions of rat pups at birth, one, two, three and six weeks of age. Fatty acid analysis of inositol- and serine- phosphoglycerides indicated that small changes in dietary n - 6 to n - 3 fatty acid ratio significantly affect neuronal and glial cell membrane composition. Fatty acid composition of phosphatidylinositol and phosphatidylserine was distinct and exhibited change with age. Individual brain regions and cell types varied in amount and rate of 20:4n - 6 and 22:6n - 3 accretion. Alteration of brain fatty acid composition reflected the fatty acid composition of the diet fed. If analogous changes occur during human brain development, feeding infants 20:4n - 6 and 22:6n - 3 or a reduced 18:2n - 6 to 18:3n - 3 ratio may alter fatty acid profiles of brain cells.

Fatty Acid Metabolism in Brain in Relation to Development, Membrane Structure, and Signaling

Composition of the brain is unique in its high concentration of lipid and particularly long-chain polyenoic fatty acids of the omega-6 and omega-3 series. Lipids and fatty acids have an important role in the structural integrity of cellular membranes and as messengers in cell signaling systems. Thus, the composition and balance of these molecules in the brain are critical to the proper development and functioning of the nervous system. Research has shown dietary alterations of omega-6 and omega-3 series fatty acids can trigger dramatic alterations in brain lipid composition. These alterations are associated with changes in physical properties of membranes, alterations in enzyme activities, receptors, carrier-mediated transport, and cellular interactions. This chapter discusses the effects of diet on cell membranes and cell signaling systems; brain growth; brain lipid composition and the synthesis of specific brain lipids, including reference to glycolipids and gangliosides; brain fatty acid synthesis; essential fatty acids and brain development; and the effects of deficiency, excess and balance in terms of ratios and absolute amounts. It discusses the response of the developing brain, specifically the phosphoglycerides in brain cells and brain regions, to diet formulations varying in omega-6/omega-3 fatty acid ratios within the range recommended for infant formulas. Thus, even a variation of omega-6 and omega-3 fatty acids between 4:1 and 7:1 can dramatically affect the lipid composition of the developing brain. In this regard it is important to optimize diet-induced alterations during brain development.