Stearic acid 18 carbon
<p>Jan 06, 2012 08:08 PM  pronounce it STEER;  it comes from TALLOW  (Dan Hunter thinks its safe)
 
<b>Stearic acid</b> (first syllable pronounced either <i>steer</i> or <i>stair</i>) is the saturated <a title="Fatty acid" href="/wiki/Fatty_acid">fatty acid</a> with an 18 carbon chain and has the IUPAC name <b>octadecanoic acid</b>. It is a <b>waxy solid,</b> and its chemical formula is CH<sub>3</sub>(CH<sub>2</sub>)<sub>16</sub>CO<sub>2</sub>H. Its name comes from the <a title="Greek language" href="/wiki/Greek_language">Greek</a> word στέαρ <i>"stéatos"</i>, which means <a title="Tallow" href="/wiki/Tallow">tallow</a>. The salts and <a title="Ester" href="/wiki/Ester">esters</a> of stearic acid are called <b>stearates</b>. Stearic acid is noteworthy as the most common saturated fatty acid, another common one being the C16 compound <a title="Palmitic acid" href="/wiki/Palmitic_acid">palmitic acid</a>.
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<h2>Metabolism</h2>
<p>An <a class="mw-redirect" title="Isotope labeling" href="/wiki/Isotope_labeling">isotope labeling</a> study in humans<sup id="cite_ref-4" class="reference"><a href="#cite_note-4">[5]</a></sup> concluded that the fraction of dietary stearic acid <a title="Redox" href="/wiki/Redox">oxidatively</a> desaturated to <a title="Oleic acid" href="/wiki/Oleic_acid">oleic acid</a> was 2.4 times higher than the fraction of <a title="Palmitic acid" href="/wiki/Palmitic_acid">palmitic acid</a> analogously converted to <a title="Palmitoleic acid" href="/wiki/Palmitoleic_acid">palmitoleic acid</a>. Also, <b>stearic acid was less likely to be incorporated into </b><a class="mw-redirect" title="Cholesterol esters" href="/wiki/Cholesterol_esters"><b>cholesterol esters</b></a>. <b>In epidemiologic and clinical studies stearic acid was associated with lowered </b><a class="mw-redirect" title="LDL" href="/wiki/LDL"><b>LDL</b></a><b> </b><a title="Cholesterol" href="/wiki/Cholesterol"><b>cholesterol</b></a><b> in comparison with other saturated fatty acids.</b><sup id="cite_ref-5" class="reference"><a href="#cite_note-5"><b>[</b><b>6</b><b>]</b></a></sup><b> These findings may indicate that stearic acid is healthier than other saturated fatty acids</b>.
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