Nonesterified fatty acids (NEFAs), also known as free fatty acids (FFAs), are organic compounds consisting of a long hydrocarbon chain with a carboxyl group at one end. NEFAs are not attached to any other molecule like glycerol, as they exist in a free, unbound form in the body. They are derived from the breakdown of triglycerides, which are the main storage form of fatty acids.
These molecules play various important roles in the human body, particularly in energy metabolism. When the body requires energy, NEFAs are released into the bloodstream by the hydrolysis of triglycerides stored in adipose tissue. They can be utilized by various tissues and organs, including skeletal muscle, liver, and heart, as an energy source through a process called beta-oxidation. NEFAs are broken down into acetyl-CoA molecules, which then enter the citric acid cycle to generate energy.
Furthermore, NEFAs also act as signaling molecules and participate in various physiological processes. They serve as ligands for specific receptors called fatty acid receptors, which are involved in regulating metabolism, inflammation, and other metabolic pathways. NEFAs can also modulate gene expression and influence insulin sensitivity.
High levels of NEFAs in the bloodstream, known as free fatty acidemia, can be associated with metabolic disorders such as insulin resistance, type 2 diabetes, and cardiovascular disease. Therefore, monitoring NEFA levels is important for assessing metabolic health and understanding lipid metabolism in the body.
