There seems to be plenty of talk these days about dangers of partially hydrogenated vegetable oil c.f. Oreos. One thing I am heard on the worst of cites (Morning Radio) is that natural animal fats are supposedly better for you than these trans-fats. Is there any solid supporting evidence for this?
Personally, I have always preffered the taste of the animal fats (butter, lard, suet) but believed the vegitarian hydroginated fats were better for me, is this view now wrong?
Cheers, Bippy (thinking of Lardy Bread and drooling)
Interesting and helpful link, thanks.
It seems from my reading of the link, that partially hydrated vegetable oils (a.k.a. trans-fats) are not significantly better for someone than heavy fats such as fully hydrogenated vegetable oils and animal based fats. Only the non hydrogenated vegetable oils are significantly better for you than the heavier oils and fats.
From the point of view of a non-vegitarian home cooking scientist, this seems to suggest that substitution of margarine for butter, or vegetable suet for meat suet will have no significant health advantage (though it should be remembered that all the above fats are ‘bad for you’ ingredients). Considering the significant (imho) flavour advantage from the animal derived fats this should lead to tastier pastries and baked cakes in the Bippy oven.
The WHO’s new dietary guidelines come down very hard on trans fats; They aren’t thrilled with any solid fats, but IIRC they recommend that trans fats should contribute less than 1% of your dietary calories - they are more lenient with natural saturated fats, including animal fats, though they recommend that most of your fats come from olive oil, fish oil, etc. I wonder how they feel about coconut oil…?
From Dogface’s link:
Hydrogenated fats, whether partially or completely, form trans fats, and not only are they not significantly better than saturated fats, they are worse, and IMHO, significantly worse for the above reason. But, hey, if you like them, go for them. You can’t live forever. 
My entirely scientific point of view is that trans fats have a nasty-ass mouth-feel. Something like chewing on a plastic Solo cup. Ick.
My high school AP Biology explained the difference between saturated and trans-fats thusly:
Both types of fat are solid at room temperature because their atomic structures are zig-zags of carbon atoms that stack nicely together. Saturated fats zig-zag because the are just a chain of single-bonded carbon atoms. The inner workings of our cells can sense that chemical structure, and deal with them appropriately.
However, trans fats are unsaturated fats that have been chemically processed. Normal unsaturated fats have double-bonds in the carbon chain that cause portions of it to curl up, in a cis formation:
\ /
C == C
/ \
\ / \ /
C C
/ \ / \
The “kinkiness” of the molecule is what keeps it fluid, even below room temperature. Incidentally, the difference between monounsaturated and polyunsaturated fats is the number of double bonds in the chain.
Where we run into trouble with trans fats is the double bond. Again, the cell looks at the fat, sees a double bond, and begins to treat it like a fluid cis fat. However, the orientation of the hydrogen and carbon atoms coming off the double-bonded carbon is reversed, giving a structure somewhat like this:
\ /
C
/ \
\ /
C == C
/ \
\ /
C
/ \
It’s a compact structure, physically similar to saturated fats, but chemically, nearly identical to normal unsaturated fats. In other words, the body treats it like it does all unsaturated fats, even though the molecule doesn’t act that way.
In terms of fats as being discussed. Does ‘Saturated’ mean ‘Fully Hydrogenated’ ?
If not, what does ‘saturated’ mean?
Am I correct in believing that ‘Fully Hydrogenated’ means that the carbon chain has no double bonds, and is made up of just CH[sub]2[/sub] subunits?
If all the carbon atoms in a fat are hooked up with hydrogen atoms, the fat is a saturated fat. If there are more than one C which is not, then it is a polyunsaturated fat. If only one is not, then it is a monounsaturated fat, and each of them has its virtues.
When an unsaturated fat is hydrogenated, H is artificially hooked up with the C which were “empty.” If it is a polyunsaturated fat and not all the Cs are hooked up, it is partially hydrogenated. If all the Cs are hooked up, it is completely hydrogenated.