Mead acid

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Mead acid
IUPAC name (5Z,8Z,11Z)-Eicosa-5,8,11-trienoic acid
Identifiers
CAS number [20590-32-3]
PubChem 5312531
SMILES CCCCCCCCC=CCC=CCC=CCCCC(=O)O
Properties
Molecular formula C20H34O2
Molar mass 306.48276
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)
Infobox disclaimer and references

Mead acid is an omega-9 fatty acid, first characterized by James F. Mead.[1] Mead acid is the only polyunsaturated fatty acid that the body can make de novo. Its elevated presence in the blood is an indication of essential fatty acid deficiency.

Contents

[edit] Chemistry

Chemically, Mead acid is a carboxylic acid with a 20-carbon chain and three methylene-interrupted cis double bonds. The first double bond is located at the ninth carbon from the omega end. In physiological literature, it is given the name 20:3(n-9). In the presence of lipoxygenase, Mead acid can form various hydroxy products (HETE).[2]

[edit] Physiology

Humans and other mammals require essential fatty acids (EFA). During dietary EFA insufficiency—especially arachidonic acid deficiency—the body will make Mead acid by the elongation and desaturation of oleic acid.[3] [4] [5] Mead acid thus serves as an indicator of EFA deficiency. One study examined patients with intestinal fat malabsorption and suspected EFA deficiency. They were found to have blood-levels of Mead acid 1263% higher than reference subjects.[6]

[edit] Alternative views

The biologist Ray Peat suggests that the term essential fatty acid is a misnomer and that the human body can make eicosanoid-equivalents from Mead acid.[7] This view is disputed.[1]

[edit] References

  1. ^ a b Mary Enig (Spring, 2005). "A Reply to Ray Peat on Essential Fatty Acid Deficiency". Wise Traditions in Food, Farming and the Healing Arts. 
  2. ^ Cyberlipid Center. PROSTAGLANDINS AND RELATED COMPOUNDS. Retrieved on 2007-10-24.
  3. ^ Phinney, SD, RS Odin, SB Johnson and RT Holman (1990). Reduced arachidonate in serum phospholipids and cholesteryl esters associated with vegetarian diets in humans. Retrieved on February 11, 2006. (reference is to 20:3n–9)
  4. ^ Lipomics. Mead acid. Retrieved on February 14, 2006.
  5. ^ Gerard Hornstra (September 2007). "Essential Polyunsaturated Fatty Acids and Early Human Development". Fats of Life Newsletter. 
  6. ^ EN Siguel, KM Chee, JX Gong and EJ Schaefer (1987). "Criteria for essential fatty acid deficiency in plasma as assessed by capillary column gas-liquid chromatography". Clinical Chemistry 33: 1869–1873. 
  7. ^ Peat, Ray (2006). Aspirin, brain, and cancer. Retrieved on 2007-10-22.

[edit] See also