Lipids, in general, are compounds that are insoluble in water but soluble in organic solvents. These are fatty, waxy, or oily substances, steroids, phospholipids, specific fat-soluble vitamins, hormones, and others. While all types of lipids are crucial for numerous reasons, phospholipids are among the essential substances for living beings. But what is the significance of phospholipids, or why are these compounds required for our bodies to function properly? Here are ten reasons why phospholipids are so important.
#1. Phospholipids Have a Hydrophilic Head and Hydrophobic Tails
When it comes to chemical compounds, their structures determine their properties, and these properties make them either more or less important compared to other substances. In case of phospholipids, there is one hydrophilic head (negatively charged phosphate group) and two hydrophobic tails (fatty acids) in each phospholipid molecule. The structure of phospholipids makes them amphipathic, meaning that they have both hydrophilic and hydrophobic parts. The nature and properties of phospholipids make these substances crucial for our bodies to function properly.
#2. Phospholipids Are Major Membrane Lipids
There are three types of lipid molecules found in membranes. These are phospholipids, glycolipids, and cholesterol. While all three classes of membrane lipids are of huge importance, phospholipids are considered to be the major components of a membrane. In a biological membrane, there are typically two layers of phospholipids, called the phospholipid bilayer. This is a thin polar membrane with a hydrophobic interior and hydrophilic exterior. Without phospholipids, our cells would not have membranes that provide the passage of molecules and ions into or out of the cell.
#3. Phospholipids Boost Cognitive Functions
Another reason why phospholipids are so important is that they boost cognitive functions and memory. More specifically, phosphatidylcholine (PC) is a phospholipid renowned for its ability to improve memory. By increasing the concentration of the neurotransmitter acetylcholine in the brain, PC can boost cognitive functions. According to this research article on ScienceDirect, dietary phospholipids have a significant role in cognitive processes. Besides, several studies have revealed that phospholipids can increase working memory in humans.
#4. Phospholipids Are Widely Used for Treating Non-Alcoholic Fatty Liver Disease
Non-alcoholic fatty liver disease (NAFLD) is a term denoting a broad range of conditions caused by the accumulation of fat in the liver. While an early stage of fatty liver disease is not really harmful, it can lead to severe health issues, including cirrhosis. As phospholipids have antioxidant, anti-inflammatory, and apoptosis modulating effects, essential phospholipids rich in phosphatidylcholine are widely used for treating the disease.
#5. Phospholipids Support Metabolic Health
Phospholipids, especially phosphatidylcholine (PC), are known for improving metabolic health. PC increases the concentration of acetylcholine, a critical neurotransmitter, which plays an important role in metabolism. In addition, phosphatidylserine (PS) is another phospholipid that is involved in the regulation of lipids and lipoproteins while supporting the energy metabolism in our body. Therefore, low levels of PC and PS often lead to metabolic disorders, such as obesity or insulin resistance.
#6. Phospholipids Are Essential for Numerous Cellular Processes
Phospholipids are involved in multiple cellular processes, such as forming the permeability barrier of the cell membrane, participating in signal transduction, and acting as precursors for the synthesis of various macro and signaling molecules. For instance, phosphatidylethanolamine (PE) is a multifunctional phospholipid that is crucial for mitochondrial functionality and mammalian development. Besides, PE is the second most prevalent phospholipid in humans that can be converted to phosphatidylcholine (PC) when needed.
#7. Phospholipids Act as Ligands for Regulatory Purposes
Phosphatidylinositol (PI) is yet another essential phospholipid that is involved in various biological functions. For example, PI along with polyphosphoinositides acts as a ligand and binds to protein targets. By binding to proteins via lipid-binding domains, PI and polyphosphoinositides manage to alter the location and enzymatic activities of the target protein molecules. Besides, phosphoinositides act as second messengers in multiple cell-signaling pathways and other biological processes occurring in our bodies.
#8. Phospholipids Cover and Protect Brain Cells while Carrying Messages between Them
According to the review article on Frontiers, the brain has the second highest lipid and lipid intermediate content after adipose tissue. In terms of phospholipid content, the brain is one of the richest tissues. While phospholipids are essential in general, they are absolutely crucial for maintaining healthy brain cell membranes and neurotransmitters. Along with providing structural integrity for cell surface and intracellular membrane proteins, phospholipids carry messages between brain cells.
#9. Phospholipids Regulate the Permeability of the Membrane
The permeability of the membrane refers to the rate of passive diffusion of molecules that pass through the membrane. The nature and properties of phospholipids significantly affect the permeability of the membrane. While small uncharged (nonpolar) molecules can easily diffuse through the phospholipid bilayer, the membrane is impermeable to larger charged (polar) molecules. Without the phospholipid bilayer, our cells would not be able to regulate the permeability of the membrane, meaning that random molecules would diffuse through the membrane.
#10. Phospholipids Protect Cells against Varying Environmental Insults
Along with ensuring that numerous cellular processes occur in subcellular compartments successfully, phospholipids protect the cells. As a matter of fact, the function and structural integrity of cells depend on membranes. While the phospholipid bilayer separates the interior of the cell from the environment, it also protects the cell from various types of insults. This is done by creating barriers in cellular membranes to protect the cells.
