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01/30/2003
Good Fat, Bad Fat
As a self-appointed music critic, I feel it’s my duty to help you
avoid a painful experience. OK, I admit that I have no musical
credentials but if, like me, you enjoy works by Tchaikowsky,
Beethoven or any of the Strausses, do not attend a performance
of works by Anton Webern. Last week, I looked forward to the
appearance of Zubin Mehta and the violinist Midori with the
New York Philharmonic Orchestra. Mehta chose, for the whole
first half of the program, to examine the life of Webern. The first
number, composed by Webern at age 20, was harmless enough.
Unfortunately, Webern later came under the influence of a guy
named Schoenberg, one of those avant-garde types.
Webern’s Six Orchestral Pieces were termed “slow, moving,
moderate, very moderate, very slow and slow” while his
Concerto for Nine Instruments contained “somewhat lively, ver
slow and very spirited” movements. To me they all sounded like
something a two-year old could produce with random pounding
of the keys. The Concerto was something else, subverting the
talents of nine highly accomplished musicians. The playing
rotated within the group with, except for the piano, each
instrument playing no more than two or three notes before
handing off to the next instrument with a different tempo. Not a
hint of a melody or unifying theme. Our bus group unanimously
declared Webern a disaster.
It was enough to drive a man to drink, the subject of last week’s
column. As a follow-up on that column, you may recall that I
quoted cardiologist Arthur Klatsky as saying that there is solid
evidence supporting the finding that alcohol increases HDL.
However, he said there is only moderately supporting evidence
for a decrease in fibrinogen, a protein that promotes clotting in
the blood. This week I came across an article suggesting this
anti-clotting benefit is on more solid ground. In the January 20
issue of Chemical and Engineering News, K. M. Reese cited a
study published last month in Nature by Shela Gorinstein and her
colleagues in Israel.
The Israeli workers took 48 men with coronary artery problems,
split them into two groups and, for the next 30 days, one group
drank mineral water while the other group drank one beer a day.
The diets otherwise were quite similar in the two groups. At the
end of 30 days, 21 of the 24 alcohol imbibers had beneficial
changes in their blood chemistry from the standpoint of heart
health. Their blood had lower cholesterol, more antioxidants and
less fibrinogen. In addition, the structure of the fibrinogen was
altered in a manner making it less effective in clotting. For Brian
Trumbore’s benefit, their drink was “standard pale lager”, but the
scientists expect other beers would have the same benefits. As in
the previous column, I stress the message that moderate alcohol
consumption, no more than 1-2 drinks per day, is the key to these
heart health benefits.
Having dispensed with the beverage issue, let’s consider the
other burning dietary issue of the day – fat. I’m indebted to an
article by Wilder D. Smith in the November 2002 issue of
Today’s Chemist at Work for stimulating this column. The
article was a short, succinct article summarizing the chemical
nature of fats. However, I was concerned about one seemingly
incorrect statement in his article and I scoured the Web to
confirm my concern. I was especially enlightened by material on
Nutrition Australia, the Web site of the Australian Nutritional
Foundation.
Unless you’ve been in hibernation for the last few decades,
you’ve been bombarded with information on saturated,
monounsaturated, polyunsaturated and trans fats. What is a fat?
A fat is a compound that combines three fatty acids and glycerin
into a single molecule. When we talk about saturation, we
should be talking about the fatty acids that make up a particular
fat. In natural fats, the fatty acids in a given fat are not all of one
degree of saturation. When it comes to oils, for example olive
oil, we have to consider the different fatty acids to decide as to
whether to call it monounsaturated, polyunsaturated or saturated.
We’ll see shortly that it’s a mixture of all three.
What are saturation or unsaturation and what are fatty acids?
Fatty acids are compounds consisting of long chains of carbon
atoms ending with a group consisting of carbon, oxygen and
hydrogen, written as COOH. We’ve discussed on occasion the
fact that carbon has four electrons that want to pair up with four
electrons from other atoms. Each shared pair of electrons is a
chemical bond; hence carbon forms 4 bonds. Hydrogen has only
one electron and can share it with a carbon electron, resulting in
a C-H bond. In a fatty acid the first carbon in the chain will have
3 hydrogens bonded to it, CH3, known as a methyl group. In a
saturated fatty acid, the rest of the carbons will each typically
have two hydrogens bonded to them and have two bonds to the
adjacent carbon atoms in the chain. The chemical formula looks
like CH3CH2CH2CH2…….CH2COOH, where the ……
indicates more CH2 groups. In stearic acid there are 16 of these
CH2 groups. These saturated fatty acids have all the hydrogens
the carbon atoms can accommodate.
Suppose two hydrogens are missing. Now the formula is
CH3CH2CH=CHCH2……CH2COOH. The = sign signifies
what we chemists call a double bond – the two carbon atoms
have fewer hydrogens to share with and consequently have to
share two pairs of electrons with each other. This fatty acid, with
one double bond, is called a monounsaturated fatty acid. If even
more hydrogen is missing and we have two or more double
bonds, we call the fatty acid polyunsaturated. Saturated fatty
acids tend to be solid at room temperature while polyunsaturated
fatty acids tend to be liquid.
Let’s consider now some of our fatty foods. It’s instructive to
look at the PMS ratios (not what you think, ladies), the
percentage ratios of Polyunsaturated:Monounsaturated:Saturated
fatty acids in the foods. Take olive oil, commonly called a
monounsaturated oil. Its PMS ratio is 10:76:14. Some other
PMS ratios are: Canola oil (30:63:7); Butter (7:36:57). Olive oil
is highly recommended for health diets and you can see why,
with 76 percent monounsaturated fatty acids. Butter, on the
other hand has 57 percent saturated fatty acids. Better to dip
your bread in olive oil than spread it with butter.
Margarine, which in Australia has a P:M:S of 33:33:34, was long
thought to be better than butter for your health but you no doubt
have heard the relatively recent findings about trans fats (fatty
acids) in the margarine. Where do trans fats come into the
picture? Trans fats are introduced when some of the ingredients
in margarine are hydrogenated. This addition of hydrogen helps
make the margarine the right consistency and also helps preserve
it longer.
What are “trans” fatty acids? How do they differ from natural
so-called “cis” fatty acids? Let’s look at the two structures
around the double bond:
```````H````H````````````````````H`````````````````````````````````
`````````````/```````````````````````````````````````````````````````
````````-C=C-``cis```````````````-C=C-``trans```````````````````
```````````````````````````````````````````````````````````````````````
````````````````````````````````````````````H``````````````````````````
(Ignore the ```s. Pretend they’re not there. The #$%^* !+&
software transferring my text onto the site won’t recognize my
blank spaces. I had to resort to ```s to line up the hydrogens.)
Simplistically, in a cis fatty acid, hydrogens are on the same
side (above or below) of the double bond. In trans fatty acids, the
hydrogens are on opposite sides (above and below) of the double
bond. The chemical formulas are the same but the relative
positions of the hydrogens are different. Offhand, you might not
think this slight difference would have much effect on the
properties. However, judging from the reported bad effects of
trans fats in our bodies, it’s clear that there’s a big difference in
the chemistry. The trans fatty acids have come to be known as
villains in our diets and their presence in all sorts of products is
now a matter of considerable concern in the field of nutrition.
As for musical nutrition, Mehta and Midori compensated for the
Webern with a fine second half performance of Elgar’s Violin
Concerto. And that evening, Leslie Uggams and the cast of
“Blue” were superb at the Paper Mill Playhouse. Lest I forget,
our cultural diet that day was also enriched by our morning at the
Metropolitan Museum of Art’s exhibit of original sketches by
Leonardo Da Vinci. It was a full day!
Allen F. Bortrum
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