carboxylic acids
Types
1. Simple carboxylic acids
2. Saturated fatty acids
3. Unsaturated fatty acids (MUFA, PUFA)
1. SIMPLE CARBOXYLIC ACIDS
1:0 Formic acid or methanoic acid HCOOH
- found in ant venom
- Latin, formica means ant
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| http://en.wikipedia.org/wiki/Formic_acid |
2:0 Acetic acid or ethanoic acid CH3COOH
- undiluted form is called glacial acetic acid; is concentrated acetic acid, is corrosive
- diluted form is a weak acid
- main component of vinegar (8% v/v); cuka makan
- sour taste and vinegar smell
- a preservative for pickles, sandwich spread, and other foods (E260)
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| http://en.wikipedia.org/wiki/Acetic_acid |
3:0 Propanoic acid or propionic acid CH3CH2COOH
- its molecular formula is CH3(CH2)COOH
- Greek protos means first and pion means fat
- exhibits property of other larger fatty acids; forms an oily layer
- miscible in water (mixes with water; boleh larut dalam air)
- can be removed from water by adding salt (salting out)
- dilute propionic acid kills molds and some bacteria (0.1%-1% wt/wt)
- used as food additive in baked food (E280)
- produced by acne bacteria on the facial skin
The human skin is host of several species of bacteria known as Propionibacteria, which are named after their ability to produce propanoic acid. The most notable one is the Propionibacterium acnes, which lives mainly in the sebaceous glands of the skin and is one of the principal causes of acne.
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| http://en.wikipedia.org/wiki/Propanoic_acid |
2. SATURATED FATTY ACIDS
- no double bonds are present
- all are single bonds
- examples:
4:0 Butyric acid or butanoic acid CH3CH2CH2COOH
- its molecular formula is CH3(CH2)2COOH
- Greek butyro means butter; Latin butyrum or buturum means butter
- found in milk (goat, sheep and buffalo's milk), butter, Parmesan cheese
- a product of anaerobic fermentation (including in the colon and as body odor)
- has an unpleasant smell and acrid taste (bau tengik), with a sweetish aftertaste (similar to ether)
- it can be detected by mammals (dogs) at 10 ppb; humans can detect it at above 10 ppm
- forms when butter turns rancid or is denatured (butterfat breaks down); unpleasant odour (bau tengik)
- used in stink bombs
- classified as short-chain fatty acid
- is a medium-strong acid; reacts with many metals
- the acid is an oily, colourless liquid that is easily soluble in water, ethanol, and ether (organic solvents)
Butyric acid has a structural isomer called isobutyric acid (2-methylpropanoic acid).
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| http://en.wikipedia.org/wiki/Butyric_acid |
5:0 Valeric acid or pentanoic acid CH3CH2CH2CH2COOH
- its molecular formula is CH3(CH2)3COOH
- has unpleasant odour
- produced by the perennial flowering plant valerian (Valeriana officinalis)
- mainly used for synthesis of esters
- volatile esters of valeric acid have pleasant odours; used in perfumes and cosmetics
- ethyl valerate and pentyl valerate have fruity flavours; used as food additives
- similar structure to GHB and GABA
- differs from valproic acid
- it can cause irritation if it comes into contact with the skin, eyes, or mucous membranes
Valeric acid appears similar in structure to GHB and the neurotransmitter GABA in that it is a short-chain carboxylic acid, although it lacks the alcohol and amine functional groups that contribute to the biological activities of GHB and GABA, respectively.
Valeric acid differs from valproic acid by lacking a 3-carbon side-chain.
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| http://en.wikipedia.org/wiki/Valeric_acid |
6:0 Caproic acid or hexanoic acid CH3CH2CH2CH2CH2COOH
- its molecular formula is CH3(CH2)4COOH
- colourless oily liquid
- odour is fatty and smells of goat or barnyard animals (haiwan pemeliharaan di kandang)
- cheesy and waxy texture (kenyal seperti keju dan lilin)
- found in animal fats and oils
- found in decomposing fleshy seed coat of the ginkgo; characteristic unpleasant odor
- one of the components of vanilla
- used to manufacture esters for artificial flavours
- milk fat contains 15% mixture of caproic acid, caprylic acid and capric acid
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| http://en.wikipedia.org/wiki/Hexanoic_acid |
8:0 Caprylic acid or octanoic acid CH3CH2CH2CH2CH2CH2CH2COOH
- its molecular formula is CH3(CH2)6COOH
- it is an oily liquid
- it is minimally soluble in water
- it has a slightly unpleasant rancid-like smell and taste
- it is used to make esters; used in perfumery and dyes
- it is found naturally in the milk of various mammals
- it is a minor constituent of coconut oil (minyak kelapa) and palm kernel oil (minyak sawit)
- it is used in the treatment of certain bacterial infections
- it is an antimicrobial pesticide, disinfectant, algaecide, bactericide, fungicide
- it is available as soluble liquid concentrates and ready-to-use liquids
- it is linked to ghrelin and causes hunger
- its levels is used in breath test to assess gastric emptying
Treatment of bacterial infections
Due to its relatively short chain length it has no difficulty in penetrating fatty cell wall membranes (lipid bilayers), hence its effectiveness in combating certain lipid-coated bacteria, such as Staphylococcus aureus and various species of Streptococcus.
Antimicrobial pesticide, disinfectant, algaecide, bactericide, fungicide
It is used as a food contact surface sanitizer in commercial food handling establishments on dairy equipment, food processing equipment,
Causes hunger
For ghrelin to have a hunger-stimulating action on a hypothalamus, caprylic acid must be linked to a serine residue at the 3-position of ghrelin. To cause hunger, it must acylate a -OH group. Other fatty acids in the same position have similar effects on hunger.
Octanoic acid breath test for gastric emptying
The octanoic acid breath test is used to measure gastric emptying. Some potential benefit is possible from administration of octanoic acid for patients with essential tremor.
Dietary supplement in alternative medicine
Caprylic acid is taken as a dietary supplement within alternative medicine. It is believed to suppress fungal infections within the gut, notably Candida albicans (yeast) infection.
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| http://en.wikipedia.org/wiki/Caprylic_acid |
10:0 Capric acid or decanoic acid CH3CH2CH2CH2CH2CH2CH2CH2CH2COOH
- its molecular formula is CH3(CH2)8COOH
- Latin capric refers to goats or smells of goats (bau kambing; bau hamis)
- is a crystalline or wax-like substance
- used to make esters
- it is uncommon in typical seed oils except coconut oil and palm kernel oil
- it occurs naturally in coconut oil (about 10%) and palm kernel oil (about 4%)
- it is found in the milk of various mammals (warm-blooded animals; haiwan ternakan)
- it is found to a lesser extent in other animal fats (sedikit dalam haiwan selain kambing)
- it is used in making soaps (buat sabun)
- its esters are used in artificial fruit flavours and perfumes
- it is used in the manufacture of perfumes, lubricants, greases, rubber, dyes, plastics
- it is used to manufacture food additives and pharmaceuticals
Pharmaceuticals
Decanoate salts and esters of various drugs are available. Since decanoic acid is a fatty acid, forming a salt or ester with a drug will increase its lipophilicity (tingkatan tarikan drug kepada lipid) and its affinity for fatty tissue (tingkatkan daya tarikan drug kepada tisu adipos). Since distribution of a drug from fatty tissue is usually slow, one may develop a long-acting injectable form of a drug (called a Depot injection) (drug yang bertindak lebih lama) by using its decanoate form. Some examples of drugs available as a decanoate ester or salt include nandrolone, fluphenazine, bromperidol, haloperidol and vanoxerine.
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| http://en.wikipedia.org/wiki/Decanoic_acid |
Caproic, caprylic and capric acids
Milk fat from goats
Caproic acid (C6), caprylic acid (C8), and capric acid (C10) are named after goats. These total 15% in goat's milk fat.
Uses of goat oil
Caproic acid and caprylic acid are liquid oils. Capric acid is a crystal- or wax-like substance. They are not only used for the formation of esters, but also commonly used "neat" in: butter, milk, cream, strawberry, bread,
12:0 Lauric acid or dodecanoic acid CH3CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2COOH
- its molecular formula is CH3(CH2)10COOH
- classified as medium-chain fatty acid
- is a white, powdery solid with a faint odour of bay oil or soap
- Lauric acid, as a component of triglycerides, comprises about half of the fatty acid content in coconut oil, laurel oil, and in palm kernel oil (not to be confused with palm oil)
- it is relatively uncommon
- it is also found in human breast milk (6.2% of total fat), cow's milk (2.9%), and goat's milk (3.1%)
- it is inexpensive, has a long shelf-life, and is non-toxic and safe to handle
- it is mainly used for the production of soaps and cosmetics
- it is neutralized with sodium hydroxide (NaOH) to give sodium laurate, which is a soap
- Most commonly, sodium laurate is obtained by saponification of various oils, such as coconut oil. These precursors give mixtures of sodium laurate and other soaps.
- it is used to determine an unknown substance by its molar mass via freezing-point depression
- it is antimicrobial
Determination of molar mass by freezing-point depression
In the laboratory, lauric acid is often used to investigate the molar mass of an unknown substance via the freezing-point depression. Lauric acid is convenient because its melting point (mp) when pure is relatively high (43.2 °C). Its cryoscopic constant is 3.9 K·kg/mol. By melting lauric acid with the unknown substance, allowing it to cool, and recording the temperature at which the mixture freezes, the molar mass of the unknown compound may be determined.
Antimicrobial properties
Lauric acid has been claimed to have antimicrobial properties.
HDL metabolism and atherosclerosis
Of all fatty acids, lauric acid has been found to increase total cholesterol the most. But most of the increase is attributable to an increase in high-density lipoproteins (HDL) cholesterol or "good" cholesterol. As a result, lauric acid has "a more favourable effect on total:HDL cholesterol ratio than any other fatty acid, either saturated or unsaturated"; a lower total/HDL cholesterol ratio suggests a decrease in atherosclerotic risk.
Lauric acid converts to the monoglyceride monolaurin in the body.
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| http://en.wikipedia.org/wiki/Lauric_acid |
14:0 Myristic acid or tetradecanoic acid CH3CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2COOH
- its molecular formula is CH3(CH2)12COOH
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| http://en.wikipedia.org/wiki/Myristic_acid |
16:0 Palmitic acid or hexadecanoic acid CH3CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2COOH
- its molecular formula is CH3(CH2)14COOH
- it is the most common fatty acid (saturated) found in animals, plants and microorganisms.
- Its molecular formula is CH3(CH2)14CO2H.
- As its name indicates, it is a major component of the oil from palm trees (palm oil, palm kernel, and palm kernel oil)
- it can also be found in meats, cheeses, butter, and dairy products
- Palmitate is a term for the salts and esters of palmitic acid. The palmitate anion is the observed form of palmitic acid at basic pH.
Production of Napalm in WWII
Aluminium salts of palmitic acid and naphthenic acid were combined during World War II to produce napalm. The word "napalm" is derived from the words naphthenic acid and palmitic acid.
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| http://en.wikipedia.org/wiki/Palmitic_acid |
18:0 Stearic acid or octadecanoic acid CH3CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2COOH
- its molecular formula is CH3(CH2)16COOH
- it is a waxy solid
- its chemical formula is CH3(CH2)16COOH
- its name comes from the Greek word στέαρ "stéar", which means tallow
- the salts and esters of stearic acid are called stearates
- it is one of the most common saturated fatty acids (SFA) found in nature following palmitic acid
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| http://en.wikipedia.org/wiki/Stearic_acid |
3. UNSATURATED FATTY ACIDS
- 1 or more double bonds are present
- double bonds are cis
- double bonds are spaced at 3-carbon intervals
- examples:
16:1∆9 Palmitoleic acid or (Z)-9-hexadecenoic acid
- is classified as an omega-7 monounsaturated fatty acid (MUFA)
- its molecular formula is CH3(CH2)5CH=CH(CH2)7COOH
- is a common constituent of the glycerides of human adipose tissue
- is present in all tissues, but generally found in higher concentrations in the liver
- is biosynthesized from palmitic acid by the action of the enzyme delta-9 desaturase
- is a beneficial fatty acid; it has been shown to increase insulin sensitivity by suppressing inflammation, as well as inhibit the destruction of insulin-secreting pancreatic beta cells.
- Dietary sources of palmitoleic acid include animal oils, vegetable oils, and marine oils
- Macadamia oil (Macadamia integrifolia) and sea buckthorn oil (Hippophae rhamnoides) are botanical sources with high concentrations, containing 17% and 40% of palmitoleic acid, respectively.
- influences fatty liver (lipokine; signaling molecule) and contributes to obesity
Fatty liver
In an analysis of numerous fatty acids, palmitoleate was shown to possibly influence fatty liver deposition/production, insulin action, palmitate, and fatty acid synthase, leading to proposal of a new term, "lipokine" having hormone-like effects. As one such effect may include improved insulin sensitivity, palmitoleic acid (C16:1 n-7) was shown in diabetic mice to attenuate hyperglycemia and hypertriglyceridemia by increasing insulin sensitivity, in part owing to suppression of pro-inflammatory gene expressions and improving hepatic lipid metabolism. Other preliminary research indicated that palmitoleic acid could have a role as a signaling molecule affecting body weight, a finding consistent with previous observations that palmitoleic acid, among other fatty acids available in the diet, may be used by enzymes affecting fat oxidation. Consequently, oil types manufactured with high palmitoleic acid content may have a role in addressing obesity.
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| http://en.wikipedia.org/wiki/Palmitoleic_acid |
18:1∆9 Oleic acid
- is classified as a monounsaturated omega-9 fatty acid
- is abbreviated with a lipid number of 18:1 cis-9
- occurs naturally in animal and vegetable fats and oils
- is an odourless, colourless oil
- commercial samples may be yellowish
- has the formula CH3(CH2)7CH=CH(CH2)7COOH
- The term "oleic" means related to, or derived from, oil or olive, the oil that is predominantly composed of oleic acid.
- is a greasy viscous edible oil
- is the most abundant fatty acid in human adipose tissue.
Greasy oils
Fatty acids (or as their salts) do not often occur as such in biological systems. Instead fatty acids like oleic acid occur as their esters, commonly the triglycerides, which are the greasy materials in many natural oils. Via the process of saponification, the fatty acids can be obtained.
Edible oils
Triglycerides of oleic acid compose the majority of olive oil, although there may be less than 2.0% as free acid in the virgin olive oil, with higher concentrations making the olive oil inedible. It also makes up 59-75% of pecan oil, 61% of canola oil, 36-67% of peanut oil, 60% of macadamia oil, 20-85% of sunflower oil (the latter in the high oleic variant), 15-20% of grape seed oil, sea buckthorn oil, and sesame oil, and 14% of poppyseed oil. It is abundantly present in many animal fats, constituting 37 to 56% of chicken and turkey fat and 44 to 47% of lard.
Pheromones: Disposal of dead bees and ants
Oleic acid is emitted by the decaying corpses of a number of insects, including bees and Pogonomyrmex ants, and triggers the instincts of living workers to remove the dead bodies from the hive. If a live bee or ant is daubed with oleic acid, it is dragged off for disposal as if it were dead. The oleic acid smell also may indicate danger to living insects, prompting them to avoid others who have succumbed to disease or places where predators lurk.
Biosynthesis of oleic acid
The biosynthesis of oleic acid involves the action of the enzyme stearoyl-CoA 9-desaturase acting on stearoyl-CoA. Stearic acid is dehydrogenated to give the monounsaturated derivative oleic acid.
Oleic acid undergoes the reactions of carboxylic acids and alkenes. It is soluble in aqueous base to give soaps called oleates. Iodine adds across the double bond. Hydrogenation of the double bond yields the saturated derivative stearic acid. Oxidation at the double bond occurs slowly in air, and is known as rancidification in foodstuffs or drying in coatings. Reduction of the carboxylic acid group yields oleyl alcohol. Ozonolysis of oleic acid is an important route to azelaic acid. The coproduct is nonanoic acid:
H17C8CH=CHC7H14CO2H + 4"O" → H17C8CO2H + HO2CC7H14CO2H
Esters of azelaic acid find applications in lubrication and plasticizers.
Isomers of oleic acid
The trans isomer of oleic acid is called elaidic acid (hence the name elaidinization for a reaction that converts oleic acid to elaidic acid. A naturally occurring isomer of oleic acid is petroselinic acid.
Separation of fatty acids by GC
Separation of isomers by TLC
In chemical analysis, fatty acids are separated by gas chromatography (GC) of methyl esters. Separation of unsaturated isomers is possible by argentation thin-layer chromatography (TLC).
Uses
- Oleic acid (in triglyceride form) is included in normal human diet as part of animal fats and vegetable oil.
- Oleic acid as its sodium salt is a major component of soap as an emulsifying agent.
- It is also used as emollient.
- Small amounts of oleic acid are used as an excipient in pharmaceuticals
- Oleic acid is used as an emulsifying or solubilizing agent in aerosol products
Drug testing in animals
Oleic acid is also used to induce lung damage in certain types of animals, for the purpose of testing new drugs and other means to treat lung diseases. Specifically in sheep, intravenous administration of oleic acid causes acute lung injury with corresponding pulmonary edema.
Premature newborns
Research on the lungs has been of particular benefit to premature newborns, for whom treatment for underdeveloped lungs (and associated complications) often is a matter of life and death.
Decreased LDL cholesterol
Incresased HDL cholesterol
Oleic acid is a common monounsaturated fat in human diet. Monounsaturated fat consumption has been associated with decreased low-density lipoprotein (LDL) cholesterol, and possibly increased high-density lipoprotein (HDL) cholesterol. However, its ability to raise HDL is still debated.
Adrenoleukodystrophy (ALD)
Oleic acid may hinder the progression of adrenoleukodystrophy (ALD), a fatal disease that affects the brain and adrenal glands.
Hypotensive
Oleic acid may be responsible for the hypotensive (blood pressure reducing) effects of olive oil. Adverse effects also have been documented.
Breast cancer
Both oleic and monounsaturated fatty acid levels in the membranes of red blood cells have been associated with increased risk of breast cancer.
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| http://en.wikipedia.org/wiki/Oleic_acid |
18:2∆9,12 Linoleic acid
- Linoleic acid is abbreviated as LA
- is an unsaturated omega-6 fatty acid
- It is a colourless liquid at room temperature.
- In physiological literature, it has a lipid number of 18:2 cis,cis-9,12.
- Chemically, linoleic acid is a carboxylic acid with an 18-carbon chain and two cis double bonds; the first double bond is located at the sixth carbon from the methyl end.
- Linoleic acid belongs to one of the two families of essential fatty acids. The body cannot synthesize linoleic acid from other food components. Linoleic acid must be obtained from the diet.
- The word "linoleic" comes from the Greek word linon (flax). Oleic means "of, relating to, or derived from oil of olive" or "of or relating to oleic acid"
- saturating the omega-6 double bond produces oleic acid
- Some medical research suggests that excessive levels of certain omega−6 fatty acids relative to certain omega-3 fatty acids, but likely in conjunction with exogenous toxins, may have negative health effects.
- LA is a polyunsaturated fatty acid
- it is used in the biosynthesis of arachidonic acid (AA) and some prostaglandins (precursor)
- It is found in the lipids of cell membranes.
- It is abundant in many vegetable oils, comprising over half (by weight) of poppy seed, safflower, sunflower, and corn oils.
Essential fatty acids (EFA)
Linoleic acid is an essential fatty acid (EFA) that must be consumed for proper health. A diet only deficient in linoleate causes mild skin scaling, hair loss, and poor wound healing in rats. However, achieving a deficiency in linoleic acid is nearly impossible consuming any normal diet and is thus not considered to be of clinical concern.
Pheromones: Death of cockroaches
Along with oleic acid, linoleic acid is released by cockroaches upon death which has the effect of preventing other roaches from entering the area. This is similar to the mechanism found in ants and bees, in which oleic acid is released upon death.
Metabolism of LA and eicosanoids
The first step in the metabolism of LA is performed by Δ6desaturase, which converts LA into gamma-linolenic acid (GLA). There is evidence suggesting that infants lack Δ6desaturase of their own, and must acquire it through breast milk. Studies show that breast-milk fed babies have higher concentrations of GLA than formula-fed babies, while formula-fed babies have elevated concentrations of LA.
GLA is converted to dihomo-gamma-linolenic acid (DGLA), which in turn is converted to arachidonic acid (AA). One of the possible fates of AA is to be transformed into a group of metabolites called eicosanoids, a class of paracrine hormones.
Eicosanoids
The three types of eicosanoids are prostaglandins, thromboxanes, and leukotrienes. Eicosanoids produced from AA tend to be inflammatory. For example, both AA-derived thrombaxane and leukotrieneB4 are proaggretory and vasoconstrictive eicosanoids. The oxidized metabolic products of linoleic acid, such as 9-hydroxyoctadecanoic acid and 13-hydroxyoctadecanoic acid, have also been shown to activate TRPV1, the capsaicin receptor, and through this might play a major role in hyperalgesia and allodynia.
Inflammation
An increased intake of certain omega–3 fatty acids with a decrease in omega-6 fatty acids has been shown to attenuate inflammation due to reduced production of these eicosanoids.
Myocardial infarction (MI)
One study monitoring two groups of survivors of myocardial infarction concluded “the concentration of alpha-linolenic acid was increased by 68%, in the experimental group, and that of linoleic acid reduced by 7%...the survivors of a first myocardial infarction, assigned to a Mediterranean alpha-linolenic acid rich diet, had a markedly reduced rate of recurrence, other cardiac events and overall mortality.”
Industrial uses
Linoleic acid is used in making quick-drying oils, which are useful in oil paints and varnishes. These applications exploit the easy reaction of the linoleic acid with oxygen in air, which leads to crosslinking and formation of a stable film. Reduction of linoleic acid yields linoleyl alcohol.
Surfactant
Linoleic acid is a surfactant with a critical micelle concentration of 1.5 x 10−4 M @ pH 7.5. Linoleic acid has become increasingly popular in the beauty products industry because of its beneficial properties on the skin. Research points to linoleic acid's anti-inflammatory, acne reductive, and moisture retentive properties when applied topically on the skin.
Antioxidant
Linoleic acid can be used to show the antioxidant effect of natural phenols. Experiments on linoleic acid subjected to 2,2′-azobis (2-amidinopropane) dihydrochloride-induced oxidation with different combinations of phenolics show that binary mixtures can lead to either a synergetic antioxidant effect or to an antagonistic effect.
Obesity
Linoleic acid may be linked to obesity by promoting overeating and damaging the arcuate nucleus in the brain's hypothalamus.
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| http://en.wikipedia.org/wiki/Linoleic_acid |
18:3∆9,12,15 Linolenic acid
- Chemically, linolenic acids are carboxylic acids with 18-carbon chains and three cis double bonds.
- Linolenic acid can refer to either of two octadecatrienoic acids, or a mixture of the two.
- Linolenate (in the form of esters of linolenic acid) is often found in vegetable oils;
- traditionally, such fatty acylates are reported as the fatty acids:
α-Linolenic acid, an omega-3 (n-3) fatty acid
γ-Linolenic acid, an omega-6 (n-6) fatty acid
α-Linolenic acid (ALA)
α-Linolenic acid (ALA) is an essential omega-3 fatty acid and organic compound found in seeds (e.g. chia, flaxseed, nuts (walnuts), and many vegetable oils. In terms of its structure, it is named all-cis-9,12,15-octadecatrienoic acid. In physiological literature, it is given the name 18:3 (n−3). α-Linolenic acid is a carboxylic acid with an 18-carbon chain and three cis double bonds. The first double bond is located at the third carbon from the methyl end of the fatty acid chain, known as the n end. Thus, α-linolenic acid is a polyunsaturated n−3 (omega-3) fatty acid. It is an isomer of gamma-linolenic acid, a polyunsaturated n−6 (omega-6) fatty acid.
Sources of α-linolenic acid
1. Seed oils
Seed oils are the richest sources of α-linolenic acid, notably those of chia, perilla, flaxseed (linseed oil), rapeseed (canola), and soybeans.
- Chia (Chia sage, Salvia hispanica) contains 64% ALA.
- Kiwi fruit seeds (Chinese gooseberry, Actinidia chinensis) contains 62% ALA.
- Perilla (shiso, Perilla frutescens) contains 58% ALA.
- Flax (linseed, Linum usitatissimum) contains 55% ALA.
- Lingonberry (cowberry, Vaccinium vitis-idaea) contains 49% ALA.
- Camelina (camelina, Camelina sativa) contains 35-45% ALA.
- Purslane (portulaca, Portulaca oleracea) contains 35% ALA.
- Sea buckthorn (seaberry, Hippophae rhamnoides L.) contains32% ALA.
- Hemp (cannabis, Cannabis sativa) contains 20% ALA.
- Rapeseed (canola, Brassica napus) contains 10% ALA.
- Soybean (soya, Glycine max) contains 8% ALA.
2. Leaf oil
Alpha-linolenic acid is also obtained from the thylakoid membranes in the leaves of Pisum sativum (pea leaves).
Baking
ALA is not suitable for baking, as it will polymerize with itself, a feature exploited in paint with transition metal catalysts. Some ALA will also oxidize at baking temperatures.
Essential fatty acids (EFA)
α-Linolenic acid, an n−3 fatty acid, is a member of the group of essential fatty acids (EFAs), so called because they cannot be produced within the body and must be acquired through diet. Most seeds and seed oils are much richer in an n−6 fatty acid, linoleic acid. Exceptions include flaxseed (must be ground for proper nutrient absorption) and walnuts. Linoleic acid is also an EFA, but it, and the other n−6 fatty acids, compete with n−3s for positions in cell membranes and have very different effects on human health. α-Linolenic acid can only be obtained by humans through their diets because the absence of the required 12- and 15-desaturase enzymes makes de novo synthesis from stearic acid impossible.
Sources of EFA
Eicosapentaenoic acid (EPA; 20:5, n−3) and docosahexaenoic acid (DHA; 22:6, n−3) are readily available from fish and algae oil and play a vital role in many metabolic processes. These can also be synthesized by humans from dietary α-linolenic acid, but with an efficiency of only a few percent. Because the efficacy of n−3 long-chain polyunsaturated fatty acid (LC-PUFA) synthesis decreases down the cascade of α-linolenic acid conversion, DHA synthesis from α-linolenic acid is even more restricted than that of EPA.
Desaturation
Linoleic acid (LA; 18:2, n−6) is generally assumed to reduce EPA synthesis because of the competition between α-linolenic acid and LA for common desaturation and elongation enzymes.
Anxiety, stress and cortisol levels
A 2005 study found that daily administration of α-linolenic acid significantly reduced both self-reported anxiety, stress levels, and objective measured cortisol levels in college age students.
Prostate cancer
A large 2006 study found no association between total α-linolenic acid intake and overall risk of prostate cancer. Multiple studies have shown a relationship between alpha-linolenic acid (ALA), which is abundant in linseed oil, and an increased risk of prostate cancer. This risk was found to be irrespective of source of origin (e.g., meat, vegetable oil).
A recent (2009) meta-analysis, however, found evidence of publication bias in earlier studies, and concluded that if ALA contributes to increased prostate cancer risk, the increase in risk is quite small. In contrast, alpha-linoleic acid was recently shown to negatively regulate the growth of cancer cells, but not healthy cells, in vitro.
Neuroprotective
Basic research has also suggested a major neuroprotective effect of α-linolenic acid in in vivo models of both global ischemia and kainate-induced epilepsy. However, if sourced from flax seed oil, residues may have adverse effect due to its content of neurotoxic cyanogen glycosides and immunosuppressive cyclic nonapeptides.
Reduced depression
A 2011 longitudinal study of over 50,000 women, conducted at Harvard University, over a period of ten years, found that a higher intake of α-linolenic acid (combined with a lower intake of linoleic acid) was positively associated with a significant reduction in depression in the same group (the same study also found that by contrast an intake of EPA and DHA found in fish oils did not reduce depression).
Hydrogenation of soy oil
Alpha-linolenic acid is relatively more susceptible to oxidation and will become rancid more quickly than many other oils. Oxidative instability of α-linolenic acid is one reason why producers choose to partially hydrogenate oils containing α-linolenic acid, such as soybean oil. Soybeans are the largest source of edible oils in the U.S., and 40% of soy oil production is partially hydrogenated.
Hydrogenations creates trans fats
However, when partially hydrogenated, part of the unsaturated fatty acids become unhealthy trans fats. Consumers are increasingly avoiding products that contain trans fats, and governments have begun to ban trans fats in food products.
Low-α-linolenic acid soy
These regulations and market pressures have spurred the development of low-α-linolenic acid soybeans. These new soybean varieties yield a more stable oil that doesn't require hydrogenation for many applications, thus providing trans fat-free products, such as frying oil. Several consortia are bringing low-α-linolenic acid soy to market.
DuPont's GMO soy oil with low α-linolenic acid and linoleic acid
DuPont's effort involves silencing the FAD2 gene that codes for Δ6-desaturase, giving a soy oil with very low levels of both α-linolenic acid and linoleic acid.
Monsanto's natural soy oil with low α-linolenic acid and linoleic acid
Monsanto Company has introduced to the market Vistive, their brand of low α-linolenic acid soybeans, which is less controversial than GMO offerings, as it was created via conventional breeding techniques.
Cardiovascular disease (CVD)
Dietary α-linolenic acid has been assessed for its role in cardiovascular health. Preliminary research has found evidence that α-linolenic acid is related to a lower risk of cardiovascular disease. Clinical benefits have been seen in some, but not all, studies. Still, a review in 2005 concluded "The weight of the evidence favors recommendations for modest dietary consumption of α-linolenic acid (2 to 3 g per day) for the primary and secondary prevention of coronary heart disease."
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| http://en.wikipedia.org/wiki/Alpha-Linolenic_acid |
- Arachidonic acid is abbreviated as AA, and sometimes as ARA
- is a polyunsaturated omega-6 fatty acid 20:4(ω-6)
- is the counterpart to the saturated arachidic acid found in peanut oil, (L. arachis – peanut.)
- is a carboxylic acid with a 20-carbon chain and four cis-double bonds; the first double bond is located at the sixth carbon from the omega end.
- Some chemistry sources define 'arachidonic acid' to designate any of the eicosatetraenoic acids. However, almost all writings in biology, medicine and nutrition limit the term to all-cis-5,8,11,14-eicosatetraenoic acid.
- is a polyunsaturated fatty acid present in the phospholipids (especially phosphatidylethanolamine, phosphatidylcholine, and phosphatidylinositides) of membranes of the body's cells, and is abundant in the brain, muscles, and liver.
- is involved in cellular signaling as a lipid second messenger
- is involved in the regulation of signaling enzymes, such as PLC-γ, PLC-δ, and PKC-α, -β, and -γ isoforms, - arachidonic acid is a key inflammatory intermediate and can also act as a vasodilator
Role
Arachidonic acid is not one of the essential fatty acids. However, it does become essential if there is a deficiency in linoleic acid or if there is an inability to convert linoleic acid to arachidonic acid, which is required by most mammals. Some mammals lack the ability to—or have a very limited capacity to—convert linoleic acid into arachidonic acid, making it an essential part of their diets.
Sources
Since little or no arachidonic acid is found in common plants, such animals are obligate carnivores; the cat is a common example. A commercial source of arachidonic acid has been derived, however, from the fungus Mortierella alpina.
ARA enzyme cascade - please refer to Wikipedia text or any textbook.
Muscle growth
Through its conversion to active components such as the prostaglandin PGF2alpha, arachidonic acid is necessary for the repair and growth of skeletal muscle tissue.
Brain
Arachidonic acid is one of the most abundant fatty acids in the brain, and is present in similar quantities to docosahexaenoic acid (DHA). The two account for approximately 20% of its fatty acid content. Like DHA, neurological health is reliant upon sufficient levels of arachidonic acid. Among other things, arachidonic acid helps to maintain hippocampal cell membrane fluidity. It also helps protect the brain from oxidative stress by activating peroxisome proliferator-activated receptor gamma (PPARgamma). ARA also activates syntaxin-3 (STX-3), a protein involved in the growth and repair of neurons.
Intelligence
Arachidonic acid is also involved in early neurological development. In one study funded by the U.S. National Institute of Child Health and Human Development, infants (18 months) given supplemental arachidonic acid for 17 weeks demonstrated significant improvements in intelligence, as measured by the Mental Development Index. This effect is further enhanced by the simultaneous supplementation of ARA with DHA.
Neurological disorders: Alzheimer's disease and Bipolar disorder
In adults, the disturbed metabolism of ARA contributes to neurological disorders such as Alzheimer's disease and Bipolar disorder. This involves significant alterations in the conversion of arachidonic acid to other bioactive molecules (overexpression or disturbances in the ARA enzyme cascade).
Alzheimer's disease
Studies on arachidonic acid and the pathogenesis of Alzheimer's disease is mixed with one study of AA and its metabolites suggests they are associated with the onset of Alzheimer's disease, whereas another study suggests that the supplementation of arachidonic acid during the early stages of this disease may actually be effective in reducing symptoms and slowing the disease progress. Additional studies on arachidonic acid supplementation for Alzheimer's patients are needed.
Sport Science: Bodybuilding supplement
Arachidonic acid is marketed as an anabolic bodybuilding supplement in a variety of products. The first clinical study concerning the use of arachidonic acid as a sport supplement found that arachidonic acid has a possible enhancement of anaerobic capacity. A significant group–time interaction effect was observed. Trends were also seen in bench press. AA supplementation during resistance-training promoted significant increases in relative peak power with other performance related variables approaching, but not reaching, significance. These findings provide some preliminary evidence to support the use of AA as an ergogenic aid.
Dietary arachidonic acid and inflammation
Under normal metabolic conditions, slightly increased consumption of arachidonic acid is unlikely to cause excessive inflammation. ARA is metabolized to both proinflammatory and anti-inflammatory molecules. However, the evidence is mixed. Some studies giving between 840 mg and 2,000 mg per day to healthy individuals for up to 50 days have shown no increases in inflammation or related metabolic activities. However, others show that increased arachidonic acid levels are actually associated with reduced pro-inflammatory IL-6 and IL-1 levels and increased anti-inflammatory tumor necrosis factor-beta. This may result in a reduction in systemic inflammation.
Arachidonic acid does still play a central role in inflammation related to injury and many diseased states. How it is metabolized in the body dictates its inflammatory or anti-inflammatory activity. Individuals suffering from joint pains or active inflammatory disease may find that increased arachidonic acid consumption exacerbates symptoms, presumably because it is being more readily converted to inflammatory compounds. Likewise, high arachidonic acid consumption is not advised for individuals with a history of inflammatory disease, or who are in compromised health. Of note, while ARA supplementation does not appear to have proinflammatory effects in healthy individuals, it may counter the anti-inflammatory effects of omega-3 fatty acid supplementation.
Health effects of arachidonic acid supplementation
Arachidonic acid supplementation in daily dosages of 1,000–1,500 mg for 50 days has been well tolerated during several clinical studies, with no significant side effects reported. All common markers of health, including kidney and liver function, serum lipids, immunity, and platelet aggregation appear to be unaffected with this level and duration of use. Furthermore, higher concentrations of ARA in muscle tissue may be correlated with improved insulin sensitivity. Arachidonic acid supplementation of the diets of healthy adults appears to offer no toxicity or significant safety risk.
A scientific advisory from the American Heart Association (AHA) has favourably evaluated the health impact of dietary omega-6 fats, including arachidonic acid. The group does not recommend limiting this essential fatty acid. In fact, the paper recommends individuals follow a diet that consists of at least 5–10% of calories coming from omega-6 fats, including arachidonic acid. Dietary ARA is not a risk factor for heart disease, and may play a role in maintaining optimal metabolism and reduced heart disease risk. It is, therefore, recommended to maintain sufficient intake levels of both omega-3 and omega-6 essential fatty acids for optimal health.
Arachidonic acid is not carcinogenic, and studies show dietary level is not associated (positively or negatively) with risk of cancers. ARA remains integral to the inflammatory and cell growth process, however, which is disturbed in many types of disease including cancer. Therefore, the safety of arachidonic acid supplementation in patients suffering from cancer, inflammatory, or other diseased states is unknown, and supplementation is not recommended.
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| http://en.wikipedia.org/wiki/Arachidonic_acid |
20:5, n−3 Eicosapentaenoic acid (EPA) or icosapentaenoic acid
- is an omega-3 fatty acid
- In physiological literature, it is given the name 20:5(n-3)
- It also has the trivial name timnodonic acid
- In chemical structure, EPA is a carboxylic acid with a 20-carbon chain and five cis double bonds; the first double bond is located at the third carbon from the omega end.
- EPA is a polyunsaturated fatty acid (PUFA) that acts as a precursor for prostaglandin-3 (which inhibits platelet aggregation), thromboxane-3, and leukotriene-5 groups (all eicosanoids).
Sources of EPA
It is obtained in the human diet by eating oily fish or fish oil— e.g., cod liver, herring, mackerel, salmon, menhaden and sardine, and various types of edible seaweed. It is also found in human breast milk.
However, fish do not naturally produce EPA, but obtain it from the algae they consume (ikan makan rumpai laut). It is available to humans from some non-animal sources (e.g., commercially, from microalgae). Microalgae are being developed as a commercial source. EPA is not usually found in higher plants, but it has been reported in trace amounts in purslane.
Conversion of ALA to EPA
The human body converts alpha-linolenic acid (ALA) to EPA. ALA is itself an essential fatty acid, an appropriate supply of which must be ensured. The efficiency of the conversion of ALA to EPA, however, is much lower than the absorption of EPA from food containing it. Because EPA is also a precursor to docosahexaenoic acid (DHA), ensuring a sufficient level of EPA on a diet containing neither EPA nor DHA is harder both because of the extra metabolic work required to synthesize EPA and because of the use of EPA to metabolize into DHA.
Diabetes
Medical conditions like diabetes or certain allergies may significantly limit the human body's capacity for metabolization of EPA from ALA.
Clinical uses of EPA
The US National Institute of Health's MedlinePlus lists medical conditions for which EPA (alone or in concert with other ω-3 sources) is known or thought to be an effective treatment. Most of these involve its ability to lower inflammation.
Mental conditions
Among omega-3 fatty acids, it is thought that EPA in particular may possess some beneficial potential in mental conditions, such as schizophrenia. Several studies report an additional reduction in scores on symptom scales used to assess the severity of symptoms, when additional EPA is taken.
Depression
Studies have suggested that EPA may be efficacious in treating depression.
One 2004 study, took blood samples of 100 suicide attempt patients and compared the blood samples to those of controls and found that levels of eicosapentaenoic acid were significantly lower in the washed red blood cells of the suicide-attempt patients.
A 2009 metastudy found that patients taking omega-3 supplements with a higher EPA:DHA ratio experienced less depressive symptoms.
Drug metabolism
EPA has an inhibitory effect on CYP2C9 and CYP2C19 hepatic enzymes. At high dose, it may also inhibit the activity of CYP2D6 and CYP3A4, important enzymes involved in drug metabolism.
Chemotherapy
Research suggests that EPA improves the response of patients to chemotherapy, possibly by modulating the production of eicosanoid.
Hyperactivity
In a study published in 2011, EPA was shown to be significantly more effective than placebo for treating hyperactivity and attention symptoms, both together and separately.
Hepatic dysfunction
A 2011 study describes, for the first time, a prominent protection by EPA against valproate (VPA)-induced hepatic dysfunction, necrosis, and steatosis. Given that VPA is commonly used in mood disorders, this may offer protection against intentional or unintentional overdose. Further, this same study showed a synergistic effect on raising seizure threshold (in pentylenetetrazol mouse convulsion model) when EPA and VPA are used concomitantly.
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| http://en.wikipedia.org/wiki/Eicosapentaenoic_acid |
22:6(n−3) Docosahexaenoic acid (DHA) or cervonic acid
- is an omega-3 fatty acid '
- is a primary structural component of the human brain, cerebral cortex, skin, sperm, testicles and retina
- it can be synthesized from alpha-linolenic acid or obtained directly from maternal milk or fish oil
- DHA's structure is a carboxylic acid (~oic acid) with a 22-carbon chain (docosa- is Greek for 22) and six (Greek "hexa") cis double bonds (-en~); the first double bond is located at the third carbon from the omega end.
- its trivial name is cervonic acid
- its systematic name is all-cis-docosa-4,7,10,13,16,19-hexa-enoic acid
- its shorthand name is 22:6(n-3) in the nomenclature of fatty acids
- cold-water oceanic fish oils are rich in DHA
- most of the DHA in fish and multi-cellular organisms with access to cold-water oceanic foods originates from photosynthetic and heterotrophic microalgae, and becomes increasingly concentrated in organisms the further they are up the food chain.
- DHA is also commercially manufactured from microalgae; Crypthecodinium cohnii and another of the genus Schizochytrium.
- DHA that is manufactured using microalgae is regarded as vegetarian
- animals with access to seafood make very little DHA through metabolism, but obtain it in the diet
- in strict herbivores, and carnivores that do not eat seafood, DHA is manufactured internally from α-linolenic acid, a shorter omega-3 fatty acid manufactured by plants (and also occurring in animal products as obtained from plants).
- eicosapentaenoic acid (EPA) and docosapentaenoic acid (DHA) are the principal products of α-linolenic acid metabolism in young men
- DHA is difficult to detect above dietary background in males compared with females
- DHA production is important for the developing fetus and healthy breast milk
- Giltay, Gooren, Toorians, and Katan (2004) found rates of conversion 15% higher for women
- those taking oral contraceptives demonstrated 10% higher DHA levels
- administration of testosterone or the aromatase inhibitor anastrozole, which blocks conversion of testosterone to estradiol, reduces DHA conversion
- DHA is a major fatty acid in sperm and brain phospholipids and in the retina
- dietary DHA may reduce the risk of heart disease by reducing the level of blood triglycerides in humans
- below-normal levels of DHA have been associated with Alzheimer's disease
- a low level of DHA is also spotted in patients with retinitis pigmentosa
- it is now considered so important to brain and eye development that DHA is included in most infant formulas
Central nervous system constituent
- DHA is the most abundant omega-3 fatty acid in the brain and retina
- DHA comprises 40% of the polyunsaturated fatty acids (PUFAs) in the brain and 60% of the PUFAs in the retina
- 50% of the weight of a neuron's plasma membrane is composed of DHA
- DHA modulates the carrier-mediated transport of choline, glycine, and taurine, the function of delayed rectifier potassium channels
- DHA deficiency is associated with cognitive decline
- Phosphatidylserine (PS) controls apoptosis
- low DHA levels lower neural cell PS and increase neural cell death
- DHA levels are reduced in the brain tissue of severely depressed patients.
Metabolic synthesis
- In humans, DHA is either obtained from the diet or synthesized from eicosapentaenoic acid (EPA, 20:5, ω-3) via docosapentaenoic acid (DPA, 22:5 ω-3) as an intermediate. This synthesis had been thought to occur through an elongation step followed by the action of Δ4-desaturase.
- It is now considered more likely that DHA is biosynthesized via a C24 intermediate followed by beta-oxidation in peroxisomes.
- Thus, EPA is twice elongated, yielding 24:5 ω-3, then desaturated to 24:6 ω-3, then shortened to DHA (22:6 ω-3) via beta-oxidation. This pathway is known as Sprecher's shunt.
Health Effects of DHA
Attention deficit hyperactivity disorder (ADHD)
- Research on DHA supplementation and attention deficit hyperactivity disorder (ADHD) have shown mixed results.
- One study of pure DHA supplementation on children with ADHD found no behavioral improvements
- Another study found fish oil containing both EPA and DHA did improve behaviour
- These studies and most others regarding the influence of DHA on behaviour are confounded by not controlling for gender differences.
Alzheimer's disease and decline of mental health
(i) Animal studies
- Preliminary studies indicated that DHA can slow the progression of Alzheimer's disease in mice.
- Animal studies in the TG3 transgenic mouse model of Alzheimer's disease had linked dietary DHA to decreases in amyloid plaques and tau.
- Animal studies also showed, when DHA was combined with arachidonic acid (also present in fish oil), plaque formation was greater with the arachidonic acid compared to DHA alone.
(ii) Human clinical trials
- The first large-scale human trials showed that DHA did not slow decline of mental function in elderly people with mild to moderate Alzheimer's disease. These trials were part of a large US National Institutes of Health (NIH) intervention study to evaluate DHA in Alzheimer's disease.
(a) NIAADCS
- Researchers from the National Institute on Aging-supported Alzheimer's Disease Cooperative Study conducted a double-blind, randomized, placebo-controlled clinical trial comparing DHA and placebo over 18 months in 402 people (average age=76) diagnosed with mild to moderate Alzheimer's at 51 sites.
- According to this study, treatment with DHA increased blood levels of DHA, and appeared to increase brain DHA levels, based on a measured increase of DHA in study participants' cerebrospinal fluid (CSF).
- However, DHA treatment did not slow the rate of change on tests of mental function, global dementia severity status, activities of daily living, or behavioral symptoms in the study population as a whole.
- Treatment effects did not differ between the mild and moderate Alzheimer's patients, leading study authors to conclude that the results do not support the routine use of DHA for patients with Alzheimer's.
(b) 2010 Alzheimer's study
- DHA deficiency likely plays a role in decline of mental function in healthy adults, which is indicated in a study from 2010 conducted at 19 U.S. clinical sites on 485 subjects aged 55 and older who met criteria for age-associated memory impairment.
- The study found algal DHA taken for six months decreased heart rate and improved memory and learning in healthy, older adults with mild memory complaints.
- These findings indicate the importance of early DHA intervention and provided a statistically significant benefit to cognitive function in individuals over 50 years of age.
- Higher DHA levels in middle-aged adults is related to better performance on tests of nonverbal reasoning and mental flexibility, working memory, and vocabulary.
Cancer
- In mice, DHA was found to inhibit growth of human colon carcinoma cells, more than other omega-3 PUFAs.
- The cytotoxic effect of DHA was not caused by increased lipid peroxidation or any other oxidative damage, but rather a decrease in cell growth regulators.
- However, different cancer lines may handle PUFAs differently and display different sensitivities toward them.
Prostate cancer
(i) Animal study
- DHA was shown to increase the efficacy of chemotherapy in prostate cancer cells in vitro, and a chemoprotective effect in a mouse model was reported.
(ii) Human clinical trial
- By contrast, one case-control study nested within a clinical trial originally designed to test the effect of finasteride on prostate cancer occurrence, the "Prostate Cancer Prevention Trial", found that DHA measured in blood serum was associated with an increase in high-grade prostate cancer risk.
- In addition to DHA's possible anticancer effect, it may also be used as a non-toxic adjuvant to increase the efficacy of chemotherapy.
Pregnancy and lactation (breastfeeding)
- DHA is richly supplied during breastfeeding
- DHA levels are high in breastmilk regardless of dietary choices
- DHA concentrations in breast milk range from 0.07% to greater than 1.0% of total fatty acids, with a mean of about 0.34%.
- DHA levels in breast milk are higher if a mother's diet is high in fish.
- The US Food and Drug Administration (FDA) has noted specific concerns for women who are pregnant or might become pregnant, nursing mothers, and young children regarding mercury levels in fish and shellfish.
Retinal development and eyesight
- DHA has recently gained attention as a supplement for pregnant women, noting studies of improved attention and visual acuity.
- DHA modulates the response of rhodopsin contained in the synaptic vesicles, among many other functions.
- Given the recently gained attention, the majority of pregnant women in the U.S. fail to get the recommended amount of DHA in their diets.
- One recent study indicated low levels of plasma and erythrocyte DHA were associated with poor retinal development, low visual acuity, and poor cognitive development. In that same study, alpha-linolenic acid was shown as a source of fetal DHA, but preformed DHA was more readily accredited.
Recommended Daily Intake (RDA)
A working group from the International Society for the Study of Fatty Acids and Lipids recommended 300 mg/day of DHA for pregnant and lactating women, whereas the average consumption was between 45 mg and 115 mg per day of the women in the study.
- The March of Dimes Foundation recommends pregnant women consume at least 200 mg DHA per day.
Infant formula
- Docosahexaenoic acid single-cell oil (DHASCO) has been an ingredient in several brands of premium infant formula sold in North America since 2001 after Mead Johnson, the first infant formula manufacturer to add DHASCO and arachidonic acid single-cell organism oil to its Enfamil Lipil product, received a "Generally Regarded As Safe" status by the Food and Drug Administration and Health Canada (FDAH, Canada).
- Several past and recent studies indicate supplementation with arachidonic acid (omega-6) may be unsuitable for some infants and toddlers as it may potentiate the inflammatory response.
- DHASCO does not make infant formulas more like human milk than "conventional" formula containing alpha-linolenic acid and linoleic acid, which are precursors to DHA.
- Formula sold in North America uses lipids from microorganisms grown in bioreactors as sources of DHA. - Some doubt that DHA additives benefit brain development of term infants, as formula makers claim in their advertisements, which has led some public interest groups to file complaints with the Federal Trade Commission of the United States, alleging false and misleading advertising.
- There is some obvious debate about the safety of single cell DHA and AA as compared to natural sources, but original studies on the increase of the Mental Development Index were based on single cell DHA and AA added to preformed Enfamil. The following is a good review of that study:
Study 1
"The study tested the intelligence scores of 56 infants, 18 months old. One group received formula containing only DHA, while another received one containing DHA and AA. The control group's commercial formula did not contain either substance. All three groups of infants were enrolled in the study within five days of their birth, and for 17 weeks received one of the three formulas. When the children's overall intelligence was tested, they differed significantly on the Mental Development Index (MDI) that measures young children's memory, their ability to solve simple problems, and their language capabilities. The children in the control group received an average MDI score of 98 – slightly below the national average of 100 for U.S. children. The DHA group received an average score of 102.4, and the DHA plus AA group received an average score of 105."
Study 2
A study found that preterm infants fed baby formulas fortified with DHASCO provided better developmental outcomes than formulas not containing the supplement.
Study 3
A study sponsored by March of Dimes and National Institutes of Health suggests that women who take DHA supplements during pregnancy give their babies some degree of added protection against getting common colds. The babies whose mothers had taken DHA supplements seemed to get over cold symptoms faster when they did get sick.
Current research findings
Although most studies demonstrate positive effects of dietary DHA on human health, contrary results exist.
- For example, one study found that the use of DHA-rich fish oil capsules did not reduce postpartum depression in mothers or improve cognitive and language development in their offspring during early childhood (though this is not a negative effect, only shows no effect).
- Additional studies confirmed DHA benefits for other nervous system functions, cardiovascular health, and potentially other organs.
- In one study, men who took DHA supplements for 6–12 weeks decreased the concentrations of several inflammatory markers in their blood by approximately 20%.
- It has been shown that heart disease patients with higher intakes of DHA and EPA survived longer.
- A new study found that higher intake of DHA was associated with slower rates of telomere shortening, which is a basic DNA-level marker of aging.
- Preliminary studies showed that a high intake of DHA was associated with reduced risk for developing Alzheimer's disease and reduced symptoms of depression in Parkinson's Disease, consistent with DHA being the most abundant omega-3 fatty acid in the brain.
- It is important to brain and eye development and DHA is included in most infant formulas.
- In preliminary research, it was found that a diet rich in DHA might protect stroke victims from brain damage and disability and aid in a speedier recovery.
- According to a new study, DHA is very likely important in the formation of the acrosome, an arc-like structure on the top of sperm, which is critical in fertilization because it houses a variety of enzymes that sperm use to penetrate an egg.
- Because humans and other mammals are able to make their own DHA from other fatty acids, DHA deficiency isn't very common. But, if that DHA-synthesizing enzyme is defective, it could lead to problems with infertility.
- Researchers in Norway are testing a treatment for psoriasis with a synthesised molecule based on DHA.
Nutrition
- Ordinary types of cooked salmon contain 500–1500 mg DHA and 300–1000 mg EPA per 100 grams.
- Additional top fish sources of DHA include tuna, bluefish, mackerel, swordfish, anchovies, herring, sardines, and caviar.
Discovery of algae-based DHA
In the early 1980s, NASA sponsored scientific research in search of a plant-based food source that could generate oxygen and nutrition on long-duration space flights. The researchers discovered that certain species of marine algae produced rich nutrients. This research led to the development of an algae-based, vegetable-like oil that contains two essential polyunsaturated fatty acids (PUFAs), DHA and ARA (arachidonic acid), which can now be found in health supplements.
Use as a food additive
- DHA is widely used as a food supplement.
- It was first used primarily in infant formulas.
- In 2004, the US Food and Drug Administration endorsed qualified health claims for DHA
- by 2007 DHA-fortified dairy items (milk, yogurt, cooking oil) started to appear in grocery stores.
- DHA is believed to be helpful to people with a history of heart disease, for premature infants, and to support healthy brain development especially in young children along with supporting retinal development.
- Some manufactured DHA is a vegetarian product extracted from algae, and it competes on the market with fish oil that contains DHA and other omega-3's such as EPA.
- Both fish oil and DHA are odorless and tasteless after processing as a food additive.
Studies of vegetarians and vegans
- Vegetarian diets typically contain limited amounts of DHA, and vegan diets typically contain no DHA.
- Vegetarians and vegans have substantially lower levels of DHA in their bodies, and short-term supplemental ALA has been shown to increase EPA, but not DHA.
- However, supplemental preformed DHA, available in algae-derived oils or capsules, has been shown to increase DHA levels.
- While there is little evidence of adverse health or cognitive effects due to DHA deficiency in adult vegetarians or vegans, fetal and breast milk levels remain a concern.
DHA and EPA in fish oils
- Fish oil is widely sold in gelatin capsules containing a mixture of omega-3 fatty acids including EPA and smaller quantities of DHA.
- One study found fish oil higher in DHA than EPA lowered inflammatory cytokines, such as IL-6 and IL-1β, associated with neurodegenerative and autoimmune diseases.
- They note the brain normally contains DHA, but not EPA, though both DHA and EPA plasma concentrations increased significantly for participants.
Hypothesized role in human evolution
An abundance of DHA in seafood has been suggested as being helpful in the development of a large brain, though other researchers claim a terrestrial diet could also have provided the necessary DHA.
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| http://en.wikipedia.org/wiki/Docosahexaenoic_acid |
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