The Trans Fats Dilemma
and Natural Palm Oil
By Gene A. Spiller, Ph.D., CNS
The book is about trans fats and oil extracted from the palm fruit. Partially hydrogenated fats, or transs fats, can be found in a wide variety of bakery products, fried foods, salad dressing and many other foods. This bookdelves insights from researchers and scientists who have studied natural fats and trans fats. It also hasa great description on how trans fats are constructed,understanding fats in foods and how to successfully incorporate fats into a balanced daily diet.
What you should know about Trans Fattys Acid (TFA)
Trans fatty acid in the diet comes from two main sources, namely
The hydrogenation or "hardening" of edible oils and fats which is widely-used by the food industry in margarines, vegetable ghee, shortenings, confectionery fats, etc., enhancement of product shelf-life, and as frying media for fast foods such as French fries and doughnuts
From bacterial fermentation in the gut of ruminants with TFA ending up in the meat and dairy products (milk, butter, cheese, etc)
Depending on the degree of hydrogenation, trans-fats in food products can contain anywhere from 5% to a high 40% TFA!
Trans Fatty Acids Chemical Structure
A cis unsaturated fatty acid (i.e. a fatty acid having at least one carbon-carbon double bond) has the hydrogen atoms oriented on the same side of the carbon-carbon double bond - producing a bend in the fatty acid molecule. Trans fatty acids are unsaturated fatty acids, in which the hydrogen atoms are oriented on opposite sides of the carbon-carbon double bond. As a result of this orientation, a relatively straight fatty acid chain results.
Where do you find trans fatty acids?
Widespread in the diet. Main source is from commercially hydrogenated vegetable oils - used in formulating margarines, shortenings, salad and cooking oils. Also from animal fats (beef, lamb) and milk fat.
The hydrogenation process
Hydrogen atoms added to double bonds of fatty acid using very high temperatures and a metal catalyst (e.g. nickel). Main fatty acids in vegetable oils that are hydrogenated are the 18 carbon, oleic, linoleic and linolenic acids (N.B. all have = 1 double bonds). Some shifting of double bonds occurs and many cis double bonds get converted to trans double bonds.
Partial hydrogenation produces a mixture of cis and trans isomers. Complete hydrogenation produces the fully saturated 18C stearic acid. During partial hydrogenation of polyunsaturated oils there is isomerization and migration of double bonds. This results in a distribution of cis and trans double bonds. Thus products containing trans fatty acids invariably have a distribution of isomers which will depend on the conditions employed during the hydrogenation process. A major tFA isomer is - elaidic acid (t9 - 18:1).
Dairy products and meats have appreciable levels of t9 - 16:1 and t11 - 18:1 (vaccenic acid).
This is done typically to improve plasticity, increase the melting range and improve flavor stability.
Estimates of trans fatty acid consumption
Average per capita consumption
8 g/person/day or 6% of total US fat consumption
(Hunter & Applewhite, 1991)
Upto 27 g/person/day or 24% of total fat intake in certain groups (Enig
et al, 1990)
9.6 g trans fatty acids consumed in a 1800 calorie diet - or 5% of total fat intake (Litin and Sacks 1993)
3-13 g/person/day (Craig-Schmidt,
7 g trans fatty acids /day Scottish diet - some cases upto 48 g/day (Bolton-Smith
et al, 1995)
Food sources of trans fatty acids
Stick margarines ~ 3 g/serving
Vegetable shortenings ~ 2.5 g/serving
Milk ~ 0.2 g/serving
Butter ~ 0.4 g/serving
Meats ~ 0.1 g/serving
Main contributors - pastries, fried foods (doughnuts, french fries), dairy products and meats
Check trans fatty acid content of foods in USDA
trans fatty acid
Health effects of dietary trans fatty acids
Starting with a clinical
from the Netherlands in 1990, and an epidemiological
from the United States in 1993, there is now strong scientific evidence to support the notion that trans fatty acid (tFA) consumption is detrimental to human health. The accumulated evidence on the effects of tFA consumption on blood LDL
levels, is consistent with the observations associating tFA consumption with increased risk of premature heart disease. Since the initial reports, many clinical studies as well as the results from several epidemiological studies have led various health agencies and governments
to impose restrictions on tFA, as mounting evidence shows that they may be even worse than saturated fatty acids with regards to their effects on blood cholesterol levels (specifically the ratio of LDL
cholesterol). Recently, it has been reported that tFA consumption is positively associated with markers of systemic
In addition tFA has been reported to be an independent predictor of diabetes
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