Health effects of dietary phospholipids

From the majority of the studies it became evident that dietary PLs have a positive impact in several diseases, apparently without severe side effects. Furthermore, they were shown to reduce side effects of some drugs. Both effects can partially be explained by the fact that PL are highly effective in delivering their fatty acid (FA) residues for incorporation into the membranes of cells involved in different diseases, e.g. immune or cancer cells. The altered membrane composition is assumed to have effects on the activity of membrane proteins (e.g. receptors) by affecting the microstructure of membranes and, therefore, the characteristics of the cellular membrane, e.g. of lipid rafts, or by influencing the biosynthesis of FA derived lipid second messengers. However, since the FAs originally bound to the applied PLs are increased in the cellular membrane after their consumption or supplementation, the FA composition of the PL and thus the type of PL is crucial for its effect. Here, we have reviewed the effects of PL from soy, egg yolk, milk and marine sources. Most studies have been performed in vitro or in animals and only limited evidence is available for the benefit of PL supplementation in humans. More research is needed to understand the impact of PL supplementation and confirm its health benefits.Phospholipids (PLs) are amphiphilic lipids found in all plant and animal cell membranes, arranged as lipid bilayers (Figure 1). The PLs found in most cell membranes are basically glycerophospholipids (GPLs), which consist of fatty acids (FAs) esterified to a glycerol backbone, a phosphate group and a hydrophilic residue (e.g. choline, resulting in phosphatidylcholine or lecithin). The backbone of a PL can also be the long chain amino-alcohol sphingosin instead of glycerol. These PL are classified as sphingophospholipids, the most representative being sphingomyelin, found in high quantities in brain and neural tissue, consisting of sphingosin esterified to one FA and ph