Notes from the Maryland Mensa Monthly Meeting
by The Boreal Badger (a.k.a. Thomas Weinbaum
For more than one reason, most Mensans are interested in fat. Some of us who are among this country's growing number of the overweight and obese wish to lose weight. Some, who are healthy, want to stay that way by reducing the amount of dangerous fat in our diet. And some are just 'chubby chasers'. [G]
That's probably why there was a goodly turnout at the monthly meeting at the Christian Temple on the 16th. of March, to hear Bill Todd speak about fats. (Actually, the topic was lipids, a category which includes fats, oils and fatty acids. If a lipid is solid at room temperature it is considered a fat, and if liquid at room temperature it is considered an oil.) A 'fatty acid' is a lipid composed entirely of three elements: hydrogen (H), carbon (C) and oxygen(O). If one imagines atoms of these three elements as tiny spheres (like back in chemistry class), they each have little 'hooks' with which they can bond to each other, to form more complex molecules. Hydrogen has one such 'hook', oxygen has two and carbon has four. Here are two examples of relatively simple molecules made up of those three elements:
So far so good, right? Let’s take a chain of carbon atoms (five, in this example):
You can see how each has four joins. (A molecule with repeating elements in a chain is called a polymer. The repeating element here is a carbon atom, but the repeating element can be a more complex grouping, like ethylene, styrene, etc. Hence the terms polyester, polyethylene, polycarbonate, polystyrene, etc.) The left and right hand sides of our sample are referred to as the alpha and omega sides, after the first and last letters of the Greek alphabet. We’re going to populate the carbon on the left-hand (omega) side with an oxygen and a hydroxyl, and all the rest of the joins with hydrogen atoms.
We now have a fatty acid. Note that aside from the leftmost carbon, all the other joins are taken up with hydrogen atoms. This fatty acid is now said to be
saturated with its maximum load of hydrogen atoms. (Now you know what is meant when you read the ingredients on a package of food and find the word ‘polyunsaturated’.) Now let’s look at a poly-unsaturated version of our fatty acid; As you might expect (you’re Mensans, after all), it has fewer hydrogen atoms that it might, like this:
You’ll note that each atom is still connected by the right number of joins; the second and third carbons from the right have the joins which used to connect to hydrogen atoms, to connect to each other, making them bond more strongly. This type of polyunsaturated fatty acid, with both hydrogen atoms missing from the same side, is called a
cis fat acid, and it is the sort found in margarine. If the hydrogen atoms are taken from opposite sides of our molecule, it’s called a
trans fat (you’ve probably come across the term in the popular press, as well as in the nutrition panel on packaged foods), and is the sort that one finds in olive oil. It looks like this:
Hang in there, readers! You’ve got nearly all of it now, and it wasn’t all that hard, was it? All that’s left is the position of that double join between carbon atoms, and that’s pretty easy. The double join (chemists cal them ‘bonds’) is the third (count ‘em) from the omega end of our molecule, and is thus called an “omega-3” fatty acid. And for those of you who’ve had a blood test with a ‘lipid panel’, you’ll want to know about triglycerides. That’s simple. A triglyceride is three fatty acids joined (by their omega ends) to glycerin.
Whew! That’s it. The toughest part is over now. You just have to remember that the trans-fats are bad for you, and the omega-3 fatty acids (found in fatty fish like salmon and char) are the ones that are good for you. Oils are usually polyunsaturated, and fats are usually saturated. Margarine (which not so long ago used to be marketed as a healthy substitute for butter) becomes saturated during manufacture by processing a vegetable oil with hydrogen, so it’s actually worse for you than butter. Old, used fry oil is worse for you than fresh, A trans fat is bad for you, because it lowers your ‘good’ cholesterol and increases your ‘bad’ cholesterol. Omega-3 and Omega-6 fatty acids are good for you. (Cholesterol itself is a topic deserving of its own presentation. For one thing, the human brain is a cholesterol-burning engine, so we need some fat in our diet. Cholesterol is also needed by the body for the production of testosterone, which has all sorts of roles in the body’s biochemistry.)
Of course, being Mensans, you will want to know about chocolate, right? Well, there’s some good news for all you chocoholics. High-cacao dark chocolate (which should melt at body temperature) is actually good for you! Yes, and the higher the cacao percentage, the better. So damn the calories, full feed ahead!