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As we enter into the latter third of the 1990's, many Americans would characterize the growing interst in health, fitness, and nutrition as a trend of the decade. More Americans than ever before have shown concern over their cholesterol level, joined an exercise facility, or been caught in the grocery store examining the label on a food product. If all this is true, then why do we hear on the news and read in magazines that Americans are heavier than ever before?
A few years ago, the Food and Drug Administration (FDA) began requiring
that food companies label products with the percentage of the daily value
of carbohydrates, proteins, fats, sodium, and certain vitamins as well
as the standard amount per serving in grams. This new regulation has not
only given consumers more information about the make up of food products
but has contributed to America's heightened nutritional awareness. As each
of us read over these labels, it has probably crossed your mind, as it
often does mine, is this information really accurate? How can a piece of
chocolate cake have only one gram of fat and taste like "the real
thing"? A french bread pizza with pepperoni, only five grams of fat,
is that possible?
Some companies may reveal information about monosaturated fat, and polyunsaturated
fat, but they are only required to list saturated fat as well as total
fat content. While most consumers look only for a product's total fat content,
a more knowledgeable shopper may also examine the amount of saturated fat
a product contains. Only the most observant consumer may notice that the
amount of unsaturated and saturated fats on the label often times do not
add up to equal the total amount of fat. How is that possible? What is
this excess fat? Trans fat. A man made substance which researchers
suggest may be as bad for your health as saturated fat. Because food companies
are not required to list trans fat on product labels, its quiet existence
may be potentially worse. Could trans fat be the secret which is keeping
health conscious Americans from losing weight?
In order to understand the nature of and secret behind trans fat, it
is necessary to explain what fatty acids are. Fatty acids can be described
as chains of carbon which are able to combine with other molecules. These
acid chains vary in length and may be either saturated or unsaturated.
Saturated fatty acids have adequate hydrogens and therefore a straight
configuration which allow them to pack into a solid crystal at ambient
temperatures. On the other hand, unsaturated fatty acids are missing adequate
hydrogens, so rather than solidifying at ambient temperatures, a liquid
oil is produced. Unsaturated fatty acids are labeled either monounsaturated
or polyunsaturated depending upon the number of hydrogens which are missing.
Polyunsaturated fatty acids lack the greatest number of hydrogens making
it the most unstable. Trans fat is monounsaturated or polyunsaturated fat
which is altered by partial hydrogenation. This process of partial hydrogenation
forces the oils which are naturally liquid at room temperature to become
solid, therefore modifying the fat so it is more similar to saturated fat.
While trans fatty acids are considered unsaturated by chemical definition,
the transformation is so severe that trans fat can not be legally labeled
as monounsaturated or polyunsaturated fat on packages.
The hydrogenation of vegetable oils began in the United States in 1910.
Shortly afterwards, crisco went on the market as a replacement for lard.
In the 1950's, the growing fast food industry as well as the baking and
snack food industry, began to capitalize on the ability to turn liquid
oils into solid fats. The hydrogenation process is controlled by a number
of factors including room temperature, pressure, duration, and source of
fats. Partial hydrogenation of fats and oils results in a mixture of fatty
acids. As the degree of hydrogenation increases, the proportion of polyunsaturates
decreases, monounsaturates and trans fatty acids increase, and saturated
fats increase slightly. The FDA informally defines a hydrogenated fat as
one that is solid at room temperature. Such fats typically contain 15-20%
trans fatty acids whereas partially hydrogenated oils are liquid at room
temperature and are lower in trans fatty acids.
As mentioned earlier, the development of crisco in the early 1900's was the onset of hydrogenated cooking and vegetable oils. Today, these oils still maintain a good amount of trans fat as a result of the man induced hydrogenation process. Other foods which are major contributors to trans fatty acid intake are baked goods such as doughnuts and pastry, deep fried foods such as fried chicken and french fried potatoes, and imitation cheese. Snack chips, cookies, and crackers often contasin high amounts of trans fat as well. Trans fat can also be found in some natural sources including milk, sheep, goats, deer, buffalo, and marsupials. These sources have been found to have significantly lower levels of trans fatty acids than those which are a result of manual hydrogenation. For a detailed list of many commonly eaten foods which have a significant amount of trans fat, click HERE.
Although not much research has been done on the effects of trans fat
in relation to health concerns, research has correlated trans fat intake
with heart disease, diabetes, cancer, low birth weight, obesity, and immune
dysfunction. It is to be noted that nearly all of these claims suggest
that further research be done in the area. Much of the discrepancy contends
that research has not been able to differentiate whether these trends are
a result of saturate fat or trans fatty acid. For example, those people
who discontinue the use of butter and replace it with margerine, have lowered
their intake of saturated fat but increased trans fat intake. Not enough
research has been done to differentiate between the two and draw significant
Another notable concern suggests that trans fatty acids disrupt cellular
functioning and therefore may effect enzymes such as delta-6 desaturase
which may in turn interfere with the conversion of omega-6 and omega-3
essentail fatty acids resulting in future deficiency of these acids.
Of course there are alternatives, doesn't everything today seem to have
an alternative? It should be mentioned that trans fat is not bad in moderation,
it is excessive intake which will more than likely be the cause of problems.
It has been suggested that vegetable oils are best consumed when in their
natural, unhydrogenated form, for example olive and sesame oils. The processed
oil industry has argued that trans fatty acids only replace solid, saturated
fats, but this is not necessarily true. Also, it has been shown that margerines
and shortenings can be made without trans fatty acids. There appear to
be many ways to avoid trans fatty acids, the healthiest would require individual
changes in eating styles, but to do so, we must have the help of the producers.
For starters, it can be assumed that not many people have even heard
about trans fat, at least in comparison to other saturated and unsaturated
fats. This fatty acid is an essential part of the diet which not much is
known about. It is critical for those trying to lose weight to understand
this fat because replacing saturated fats unknowingly with trans fat could
result in weight gain concurrent with what the American population is presently
On the other hand, the FDA requires that saturated fat be labeled on food products and limits the extent to which they can label their items as low cholesterol. But without labeling trans fat, a company is able to label their product cholesterol free when in reality, the product may contain a substantial amount of cholesteral by means of trans fat. Click HERE for more information on what food labels don't tell you.
Overall, strong arguments are being made by researchers and nutritionists
nationally for the labeling of trans fat on food products. This labeling
of food would at least improve the ability of the consumer to make appropriate
choices. It should be reiterated though, that simply knowing the secret
behind trans fat will not do the trick. It takes change and maintenance
of a healthy diet and lifestyle to lose weight and narrow one's risk of
Anonymous. Position Paper on Trans Fatty Acids. American Journal of
Clinical Nutrition, 1996, 63, 663-70.
Ascherio, A. & Willett, W. Trans Fatty Acids: Are the Effects Only
Marginal? American Journal of Public Health, 1994, 84, 722-4.
Beardsley, T. Trans Fat: Does Margerine Really Lower Cholesterol? Scientific
American, 1991, 264, 34.
Chen, Z., Cunnane, S., Fortier, L., Ratnayake, W., & Ross, R. Similar
Distribution of Trans Fatty Acid Isomers in Partially Hydrogenated Vegetable
Oils and Adipose Tissues of Canadians. Canadian Journal of Physiology and
Pharmacology, 1995, 73, 718-23.
Dupont, J., Feldman, E., White, P. Saturated and Hydrogenated Fats in
Food in Relation to Health. Journal of the American College of Nutrition,
1994, 75, 190-2.
Hornstra, G. & Mensink, R. Alternatives for Nutritional Trans Fatty
Acids. World Review of Nutrition & Dietetics, 1994, 75, 190-2.
Hornstra, G. & Von Houwelingen, A. Trans Fatty Acid in Early Human
Development. World Review of Nutrition and Dietetics, 1994, 75, 175-8.
Jones, D. Trans Fatty Acids and Dieting. Lancet, 1993, 24, 1093.
Marckmann, P. Trans Fatty Acid and Dieting. Lancet, 1993, 24, 1094.
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