Tuesday, 17 August 2010

Which fat is fatter?

I have decided to pay more attention to fat, this time guilt-free. But I am still a bit biased against palmitic acid (16:0) and would rather go for other options.

There are three fatty acids in a triglyceride and I remember reading that position sn-2 is the most important, as fatty acids at sn-2 are most readily absorbed by humans. It appears that beef fat has the least 16:0 at sn-2: 11.6%, compared to 20.8% in lamb and 54.8% in pork. Here are the details in Table 3.

I also remember a study showing that different fatty acids abound in different cuts and that brisket was supposed to have the healthiest fatty acid profile. It was not clear if the analysis was done on a grass or grain fed animal. (BTW, grass is not natural feed for cows; their ancestors, aourochses, fed mostly on bushes and trees).

Fortunately the local organic farm sells brisket, which is otherwise had to get organic.

But the real good stuff is bone marrow and I am now searching for a source. Last time the butcher offered me a hip bone, rather than a marrow bone - the dog will enjoy this one as well. Problem is, I have no dog. Too embarassing to rectify.

Interestingly, the fatty acid composition depends not only on what animals eat, but on the temeperature. Studies showed that the Eskimos prefered the marrow from reindeer's smaller bones closer to the cold arctic ground (more unsaturated) to the more abundant marrow from large femur or humerus (more saturated).

Whoever comes up with a patent for cheap synthetic pure oleic acid production might hit the jackpot. The Chinese have already made some progress:
http://english.xjipc.cas.cn/rh/rps/200910/t20091022_45899.html

3 comments:

  1. Have you looked at Human Milk Fats for guidance ?

    There is quite a lot of palmitic, myristic and stearic among others. Here is a link.

    http://www.springerlink.com/content/606x3q2x0n291241/

    If it were not for the adaptation giving rise to lactose intolerance in some adults, milk has an ideal representation of Paleo proportions!

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  2. Hi Rover,

    Which is probably why human milk is best for human babies. Interestingly, the composition of human milk is never constant, but changes, possibly reflecting baby's needs! It would be interesting to know if percentage of palmitic acid decreases (or increases) with breasfeeding time.

    I am more of a fan or reinactment than replacement and believe there is no room for dairy. But also believe that some tribes have been milking animals for long enough to become more or less adapted.

    But this is irrelevant, as there is no way to get "real" unadulterated milk these days. With regard to fat, I am now thinking about getting deer suet and using it as a staple, complemented by nuts and olive oil.

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  3. Also, it appears that breast milk of women who eat less meat and fat has less palmitic acid (about 11% of all fat):
    http://www.nature.com/ejcn/journal/v59/n4/full/1602099a.html
    But the comparator is women eating modern meat and fat, rather than hunted game.

    Also, if the "original" Paleo diet was more in line with the !Kung, then possibly less palmitic acid was needed.

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