Dietary Hazard - Processed Fat

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Dietary Hazard-Processed Fat

JoAnn Guest Jun 14, 2004 15:43 PDT

 

www.amazingdiet.org

 

In today’s world the appearance, texture and colour of food is often

considered of greater importance than the nutrient value of such food.

 

In an instant world we need instant food, and to avoid spoilage and

financial loss, such food is often chemically manipulated to obtain all

these desired effects.

 

When the chemical nature of our food is changed so that it meets the

requirements of the marketplace, then the risk is great that it no

longer meets the requirements of the body.

 

Our bodies are designed to interact with the environment in a highly

specialized way, and any interference with this delicate balance may

impact negatively on the system.

 

Modern Oil Refining Techniques

 

Extracted oil undergoes a series of steps which adversely affects its

nutritional value. Free fatty acids are removed by vacuum extraction and

precipitation. Furthermore, the oil is filtered and heated to 220 °C to

obtain a clear liquid.

 

In order to obtain a less fluid oil, suitable for the production of

margarine, the oil is further subjected to the process of hydrogenation,

to which liquid oils nowadays are also partially subjected.

 

This process was developed by W. Norman in the year 1900 and involves a

catalytic reaction which changes cis fatty acids to trans fatty acids,

thus rendering them less fluid by changing the shape of the molecules.

 

Polyunsaturated fats contain double bonds, and this gives rise to the

possibility of cis-trans conversions.

 

In nature, fatty acids occur mainly in the cis configuration, which

means that the carbon chains on either side of the double bond are

spatially arranged on the same side of the double bond. (See table)

 

Trans fats do not form part of the normal diet and should not be

introduced into the system as they can result in a number of biochemical

changes, and together with saturated fats and cholesterol, can lead to

altered membrane structure and concomitant hardening of the arteries.

 

The essential fatty acids (linoleic and linolenic acids) also naturally

have the cis configuration but the free use of extracted, partially

hydrogenated oil,

rich in linoleic acid (found in corn, safflower and sunflower oils),

has been associated with cancer promotion.

 

Linoleic acid is the substrate from which prostaglandins are

manufactured, and trans-linoleic acid can result in altered

prostaglandins, thus modifying the effect of these hormones or even

producing opposite effects.

 

Because leucotrienes play an essential role in regulating the immune

system in that they are involved in the production of antibodies and the

destruction of viruses and cancer cells,

it is essential that these molecules be produced from essential fatty

acids that have the correct configuration so that the delicate balance

and the function may not be jeopardized.

 

The molecular changes found in even partially hydrogenated oils can

adversely affect the relationship between the various prostaglandins as

well as changing them structurally.

 

Trans fatty acids depress serum levels of prostaglandins. Moreover,

hydrogenated oils do not share the properties of normal unsaturated fats

and will also not lower cholesterol levels as do the natural oils in

whole foods.,[ii]

The consumption of trans fatty

acids in the Western world is quite high, and it has been estimated that

in the US and in Canada, men of 20-39 years of age consume 11-12 g per

person per day of these fats.2

The British Medical Committee on Cardiovascular Diseases proposed new

guidelines in 1994 on recommended consumption of fatty acids.

Recognizing that trans fatty acids have an undesirable effect on HDL and

LDL cholesterol and coronary disease mortality, they suggested that no

more than 2% of caloric intake come from this source, and that the

amount should even be reduced.[iii]

Margarine

Margarine is typically manufactured from the oil of soya beans, maize,

sunflower seeds, coconut and palm, with the addition of substances which

enhance the flavour and act as preservatives and texturisers.

The typical ingredients of margarine include a combination of oils,

water, sodium chloride, vitamins A, D and E, lecithin or other

emulsifier, preservatives such as sodium benzoate and/or potassium

sorbate, milk solids including casein, colorants such as beta-carotene

and retinyl esters, flavourants such as butter distillate or simulated

butter taste chemicals.

The manufacturing process of margarine involves a combination of a

number of steps.

The fat-insoluble gums and other substances from the crude oil are first

removed and then the oil is neutralized with alkali.

Subsequently it is bleached, filtered, deodorized and in most cases

hydrogenated.

After this the product is again subjected to further filtration,

neutralixation, bleaching, deodorization and blending.

Finally, colorants, flavourants, vitamins, emulsifiers and

preservatives are added, and proportioning (creating the desired balance

between water and fat), emulsification, chilling and packaging round off

the final product.

In most cases, margarines exceed the recommended maximum levels for

saturated and trans-unsaturated fatty acids, but some countries

(Germany) have taken cognizance of the detrimental effects of trans

fatty acids and many of the margarines,

shortenings and cooking fats in Germany are being produced essentially

free from trans fatty acids.

Nevertheless, a concentrated, chemically manipulated, unnatural food

such as margarine must place excessive demands on the system, and viable

alternatives should be sought.

Artificial foods are however the vogue, and large quantities of spreads

and non-dairy creamers are consumed annually.

Non-dairy creamers also contain extracted saturated and hydrogenated

plant oils of coconut and palm origin, and therefore contain no less fat

than dairy cream.

There are many ways to prepare palatable meals without the use of

extracted oils, and their use can thus be limited.

The best way of obtaining chemically sound fats, suitable for

maintaining the fine chemical balances of the body, is to eat whole food

that has not been changed by modern refining techniques.

Whole grains, seeds, nuts as well as oil-rich fruits such as avocado,

pears and olives, together with other plant sources will supply an

abundance of fats of the variety required by the body.

The Use of Oil in the Frying of Food

The frying of food in oil or lard also has detrimental effects. Studies

have shown that heated oils and fats undergo autoxidation and that the

rate of autoxidation is proportional to the degree of unsaturation and

the presence of absence of pro- and anti-oxidants.

It has been established that animal fats undergo autoxidation more

readily than oils of plant origin,

in spite of the fact that animal fats are saturated fats,

but this has been attributed to the virtual absence of natural

antioxidants in animal fats.

Polyunsaturates, however, sustain the most thermo-oxidative damage when

oil is heated.

In this regard it is enlightening that a tri-unsaturated fatty acid will

undergo autoxidation 10, 000 times more readily than a monounsaturated

fatty acid (olive, avocado, macademia nut oils).[iv]

The rate and degree of autoxidation of unsaturated and saturated fats is

presented in figure 3.10.

Source: Grundy, S.M. 1989. Monounsaturated fatty acids and cholesterol

metabolism: Implications for dietary recommendations. J. Nutr. 119:529

Heat Damage Sustained By Oil

The products formed in fats and oils that are heated to high

temperatures are peroxides,

aldehydes, ketones, hydroperoxides, polymers and cyclic monomers,

any one of which can have toxic effects.

Subjecting saturated and polyunsaturated fats, such as butter and

sunflower oil to temperatures of 170 °C for two hours will also alter

the composition that if fed to experimental animals they will induce

liver ailments in these animals.

If animal fat, polyunsaturated oil, and even monounsaturated oil such as

olive oil, is however heated to 180 °C for longer periods of time,

serious liver disorders are induced in experimental animals that are fed

these oils.

[v] The peroxidised fatty acids in heated fats also affect the

cardiovascular system, possibly even causing lesions in the cardiac

muscles and arterial lining as well as enhancing clot formation.[vi]

As most processed oils are heated to 220 °C during the manufacturing

process,

and are still further heated during the frying process, the use of free

oil should for these reasons alone, not be encouraged.

The frying of food should therefore be avoided if healthful living

practices are introduced into the household.

This does not necessarily mean that taste should be sacrificed, but it

does mean that age-old habits will have to be revised and substituted

with a little bit of ingenuity.

If oil is used at all, it should be used in moderation and the

cold-pressed variety should be used as this have been least subjected to

heat during the extraction and clarifying processes.

Also oils rich in monounsaturated fats, such as olive oil, should be the

oils of choice as

monounsaturated fats

undergo the least damage during heating.

Whilst it is true that increased dietary consumption of polyunsaturated

fats has led to a decrease in cholesterolaemia and associated drop in

cardiovascular disease,

it has been accompanied by a rise in deaths from non-vascular diseases

such as cancer,[vii]

cholelithiasis[viii] and a general drop in life expectancy,[ix]

probably resulting from the peroxidation of the polyunsaturates.

Peroxidation of polyunsaturates takes place because these molecules are

unstable, and the more double bonds there are in the molecules the more

readily the process of peroxidation takes place.

During this process “free radicals” are formed which are extremely

reactive in view of their unpaired electron.

Free radical formation is largely prevented in whole foods, as natural

antixodants, which are present in these foods, prevent their formation.

A natural balance exists between antioxidants such as the fat-soluble

vitamins A and E and the quantity of polyunsaturated fats that are

present in whole foods.

An imbalance between polyunsaturates and antioxidants will result in a

rise in free radical formation with concomitant harmful results such as

an increase in the rate of the aging process,[x] inflammation,[xi]

carcinogenesis,[xii]

liver disorders and arteriosclerosis.[xiii]

Unfortunately modern food processing techniques often strip food of the

essential fatty acids and vital prepacked antioxidants and in this way

deprive the system of these essential nutrients.

During the refining process grains, for example, are stripped of the

germ,

which contains the essential oils and fat-soluble antioxidant vitamins

in a perfect biorelationship,

and the lack is then substituted for

with large intakes of disproportionate combinations of processed oils

and fats.

In this regard it is enlightening to note that the daily vitamin E

requirements (which amount to about 10 mg per day) increases 20 fold it

polyunsaturates are added to the diet.[xiv]

It is doubtful whether any diet will supply this additional requirement

without supplementation, and it is therefore not surprising that the

degenerate diseases are so prevalent in Western societies.

The eating of whole foods that have not been stripped of their essential

components will supply all the essential oils required in healthful

combinations and should therefore be encouraged.

--

Reference:

Jonnalagagadda, S.S., Mustad, V.A., Yu, S., Etherton, T.D.,

Kris-Etherton, P.M. 1996. Effects of individual fatty acids on chronic

diseases. Nutrition Today. 31 (3) May/June 1996.

[ii] Mensink, R.P., Katan, M.B. 1990. Effect of dietary trans fatty

acids on high-density and low-density lipoprotein cholesterol levels in

healthy subjects. New Enlg.J.Med. 323:439.

[iii] Nutrition Today Newsbreaks. 1995. British scientists endorse new

fatty acid guidelines. Nutrition Today. 30 (1), January/February 1995.

P.5.

[iv] Fedeli, E. 1984. La auto-ossidazione Lipidica. In: Simp. Su

Rrilettura di un problema: 1 lipidi Alimentari:, Rimini (Italia)

[v] Alexander, J.C. 1978. Biological effects due to changes in fats

during heating. (In: Symp. On frying oils, Presented at AOCS 68th Annual

meeting, New York City, New York (USA) 11.5 1977). J.Am.oil Chem.Soc.

55:711.

[vi] Giani, E., Masi, I., Galli, I. 1985. Heated fat, vitamin E and

vascualr eicosanoids. Lipids. 20:439.

_________________

JoAnn Guest

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DietaryTi-

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