Fat is one of the three main macronutrients, along with carbohydrate and protein. Fats molecules consist of primarily carbon and hydrogen atoms, thus they are all hydrocarbon molecules. Examples include cholesterol, phospholipids and triglycerides.
Omega−3 fatty acids, also called ω−3 fatty acids or n−3 fatty acids, are polyunsaturated fatty acids (PUFAs) characterized by the presence of a double bond three atoms away from the terminal methyl group in their chemical structure. They are widely distributed in nature, being important constituents of animal lipid metabolism, and they play an important role in the human diet and in human physiology. The three types of omega−3 fatty acids involved in human physiology are α-linolenic acid (ALA), found in plant oils, and eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), both commonly found in marine oils. Marine algae and phytoplankton are primary sources of omega−3 fatty acids. Common sources of plant oils containing ALA include walnut, edible seeds, clary sage seed oil, algal oil, flaxseed oil, Sacha Inchi oil, Echium oil, and hemp oil, while sources of animal omega−3 fatty acids EPA and DHA include fish, fish oils, eggs from chickens fed EPA and DHA, squid oils, and krill oil.
A triglyceride is an ester derived from glycerol and three fatty acids. Triglycerides are the main constituents of body fat in humans and other animals, as well as vegetable fat. They are also present in the blood to enable the bidirectional transference of adipose fat and blood glucose from the liver, and are a major component of human skin oils.
Essential fatty acids, or EFAs, are fatty acids that humans and other animals must ingest because the body requires them for good health but cannot synthesize them.
α-Linolenic acid (ALA) is an n−3 fatty acid. It is one of two essential fatty acids, so called because they are necessary for health and cannot be produced within the human body. They must be acquired through diet. ALA is an omega-3 fatty acid found in seeds, nuts, and many common vegetable oils. In terms of its structure, it is named all-cis-9,12,15-octadecatrienoic acid. In physiological literature, it is listed by its lipid number, 18:3, and (n−3); its isomer GLA is 18:3 (n−6).
Cod liver oil is a dietary supplement derived from liver of cod fish (Gadidae). As with most fish oils, it contains the omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Cod liver oil also contains vitamin A and vitamin D. Historically, it was given to children because vitamin D had been shown to prevent rickets, a consequence of vitamin D deficiency.
Palmitic acid, or hexadecanoic acid in IUPAC nomenclature, is the most common saturated fatty acid found in animals, plants and microorganisms. Its chemical formula is CH3(CH2)14COOH, and its C:D is 16:0. As its name indicates, it is a major component of the oil from the fruit of oil palms (palm oil). Palmitic acid can also be found in meats, cheeses, butter, and other dairy products. Palmitates are the salts and esters of palmitic acid. The palmitate anion is the observed form of palmitic acid at physiologic pH (7.4).
Oleic acid is a fatty acid that occurs naturally in various animal and vegetable fats and oils. It is an odorless, colorless oil, although commercial samples may be yellowish. In chemical terms, oleic acid is classified as a monounsaturated omega-9 fatty acid, abbreviated with a lipid number of 18:1 cis-9. It has the formula CH3(CH2)7CH=CH(CH2)7COOH. The name derives from the Latin word oleum, which means oil. It is the most common fatty acid in nature. Salts of oleic acid are called oleates.
Omega-6 fatty acids are a family of polyunsaturated fatty acids that have in common a final carbon-carbon double bond in the n-6 position, that is, the sixth bond, counting from the methyl end. Members of the family can have pro-inflammatory or anti-inflammatory effects.
The term mustard oil is used for two different oils that are made from mustard seeds:
Gamma-linolenic acid or GLA, is a fatty acid found primarily in vegetable oils. When acting on GLA, Arachidonate 5-lipoxygenase produces no leukotrienes and the conversion by the enzyme of arachidonic acid to leukotrienes is inhibited.
Linoleic acid (LA), a carboxylic acid, is a polyunsaturated omega-6 fatty acid, an 18-carbon chain with two double bonds in cis configuration. A shorthand notation like "18:2 (n-6)" or "18:2 cis-9,12" may be used in literature. It typically occurs in nature as a triglyceride ester; free fatty acids, the form not combined with glycerol to form triglyceride, are typically low in foods. It is very soluble in acetone, benzene, diethyl ether and ethanol.
Fish oil is oil derived from the tissues of oily fish. Fish oils contain the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), precursors of certain eicosanoids that are known to reduce inflammation in the body and improve hypertriglyceridemia. There has been a great deal of controversy in recent years about the role of fish oil in cardiovascular disease, with recent meta-analyses reaching different conclusions about its potential impact. The most promising evidence supports supplementation for prevention of cardiac death.
In biochemistry and nutrition, monounsaturated fatty acids (abbreviated MUFAs, or more plainly monounsaturated fats) are fatty acids that have one double bond in the fatty acid chain with all of the remainder carbon atoms being single-bonded. By contrast, polyunsaturated fatty acids (PUFAs) have more than one double bond.
Lauric acid or systematically, dodecanoic acid, is a saturated fatty acid with a 12-carbon atom chain, thus having many properties of medium-chain fatty acids, is a bright white, powdery solid with a faint odor of bay oil or soap. The salts and esters of lauric acid are known as laurates.
Docosahexaenoic acid (DHA) is an omega-3 fatty acid that is a primary structural component of the human brain, cerebral cortex, skin, and retina. In physiological literature, it is given the name 22:6(n-3). It can be synthesized from alpha-linolenic acid or obtained directly from maternal milk, fish oil, or algae oil.
Omega-9 fatty acids are a family of unsaturated fatty acids which have in common a final carbon–carbon double bond in the omega−9 position; that is, the ninth bond from the methyl end of the fatty acid.
Perilla oil is an edible vegetable oil derived from perilla seeds. Having a distinct nutty aroma and taste, the oil pressed from the toasted perilla seeds is used as a flavor enhancer, condiment, and cooking oil in Korean cuisine. The oil pressed from untoasted perilla seeds is used for non-culinary purposes.
The uropygial gland, informally known as the preen gland or the oil gland, is a bilobed sebaceous gland possessed by the majority of birds. It is located dorsally at the base of the tail and is greatly variable in both shape and size. In some species, the opening of the gland has a small tuft of feathers to provide a wick for the preen oil. It is a holocrine gland enclosed in a connective tissue capsule made up of glandular acini that deposit their oil secretion into a common collector tube ending in a variable number of pores (openings), most usually two. Each lobe has a central cavity that collects the secretion from tubules arranged radially around the cavity. The gland secretion is conveyed to the surface via ducts that, in most species, open at the top of a papilla.
Marula oil is extracted from the kernels (nuts) of the fruits of the Marula trees, from the Anacardiaceae family. There are two types of marula oil, the oil extracted from the seeds and the oil extracted from the nut's hard shell. Marula oil is traditionally used in cosmetics, in food as a cooking oil, and as a meat preservative and to treat leather.
