Transfats cause nutritional deficiencies

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Transfats cause nutritional deficiencies

Apr 19, 2007 16:18 PDT

 

 

Written for the tfX website by medical researcher Jennifer Swift.

With additional thanks to Dr Jane Karlsson, Professor Fred A.

Kummerow and Dr Alex Richardson for their assistance in preparing

this article.

This page was updated and greatly expanded in November 2006.

 

http://www.tfx.org.uk/page13.html

 

What are omega-3 and omega-6?

Most people know that if you want to stay healthy, your diet has to

include sufficient amounts of vitamins and minerals, but few people

know that two special fats are also essential for human health. They

are the polyunsaturated fatty acids omega-3 and omega-6. Our bodies

need them to make both cell membranes and signalling molecules such

as hormones, but unlike other forms of fat they can't be

manufactured inside the body and must come from our diet. Because

every cell in our body needs them, most of the bad effects of eating

trans fats stem from the ways they disrupt our bodies' use of these

essential fatty acids (EFAs).

 

Modern Western diets are deficient in omega-3

While omega-6 (linoleic acid) is plentiful in the modern Western

diet because it is found in most vegetable oils, omega-3 has become

very scarce in the food we eat.

 

Small amounts are found in leafy green vegetables, walnuts,

flaxseeds and wheat germ, but this is short-chain omega-3 (alpha-

linolenic acid) and not the long-chain forms our brains and nerve

cells require for healthy functioning (docosahexaenoic acid or DHA

and eicosapentaenoic acid or EPA).

 

The best source of these long-chain omega-3s is cold-water oily

fish, such as herring and mackerel, but we are eating much less of

this than in the past.

 

It used to be assumed that most people's bodies could build the

long-chain forms given an adequate intake of short-chain omega-3,

but we now know that without sufficient quantities of other vitamins

and minerals (also deficient in many people's diets) this conversion

cannot take place. Other factors, such as old age or the stress so

common in modern life, can also hinder this process.

 

Trans fats make this deficiency worse

 

On top of all this, consumption of trans fats throws a further

spanner into the works as our bodies attempt to build long-chain

omega-3.

 

We know that trans fats hinder the work of the delta-6 desaturase

enzyme, which together with elongation enzymes converts short-chain

omega-3s into long-chain omega-3s.

 

The other ways in which they interfere with the metabolism of omega-

3 are not as well understood.

 

However, our cells need both short- and long-chain omega-3s to build

their membranes and some of the molecules which they use to signal

each other.

 

The body has no way of distinguishing between trans and natural

forms of omega-3, so if you eat trans fats, you will end up with

twisted molecules in your cell walls and hormones. So they are not

likely to work as well as they should, just as a shed built from

warped timber will not keep out the rain as effectively as one built

with straight boards.

 

Omega-3 deficiency linked to many diseases

 

So it may well be the case that even if you eat enough omega-3

(dining on oily fish twice a week, say), but also consume trans

fats, you will be deficient in properly-formed long-chain omega-3.

 

The health consequences of this can be seen in almost every chronic

disease that afflicts modern society.

 

Low levels of EPA and DHA are a major factor in heart disease and

strokes, but they also worsen inflammatory conditions such as

arthritis and allergies.

 

They are also known to promote insulin resistance, which leads to

diabetes, and to accelerate the development of cancer.

 

And as if that weren't bad enough, we are increasingly discovering

that lack of omega-3 (particularly of EPA) plays a major role in the

development of mental illnesses, such as clinical depression,

including post-natal depression, and hyperactivity in children.

 

Ratio of omega-3 to omega-6 is also crucial

The foods eaten by human beings prior to agriculture (and by our pre-

human ancestors), such as wild game, leafy green vegetables and

fruit, contained relatively high amounts of omega-3 and low amounts

of omega-6, so that our ancestors consumed equal amounts of both

essential fatty acids, in other words, a ratio of 1:1.

 

This is the ratio that our bodies have evolved to expect.

 

When humans started growing cereal grains, which are high in omega-

6, our diet began to shift away from that fundamental ratio, yet

people in many pre-modern societies enjoyed good health and freedom

from degenerative diseases because they continued to eat many foods

high in omega-3, such as meat from grazing animals, wild fish and

wholemeal bread.

 

But when it was discovered that wheat could be milled by high-speed

rollers in such a way that all the bran and germ could be stripped

out, leaving only starch, and then that cattle and other animals

could be fattened cheaply on a diet of grain, and finally that

chemicals and industrial processes could be used to extract oils

from seeds such as cotton and soy, human diets changed far more

profoundly.

 

White bread lacked any essential fatty acids as well as most other

nutrients (a few of these are now put back into flour but not the

EFAs).

 

Meat-and dairy products as well-became high in omega-6.

 

The new oils were cheap but almost all were also very high in omega-

6.

 

So now the typical modern Western diet, instead of having equal

amounts of the two essential fatty acids, has 20 to 25 times more

omega-6 than omega-3.

 

While not all experts agree that we must return to the ancient ratio

of 1:1 (some believe that humans can enjoy long-term good health on

a ratio of omega-6 to omega-3 as high as 4:1), the consensus is that

we are eating far too much omega-6 compared to omega-3 and that this

by itself, quite apart from trans fats, is causing serious harm to

our health.

 

However, most trans fats are made from the high-omega-6 seed oils,

so if you are scrupulous about cutting out all trans fats from your

diet, you will already have gone a long way towards redressing the

balance, and as Dr Artemis Simopoulos has pointed out,

 

" a diet such as the traditional Greek diet balanced in omega-6 and

omega-3 fatty acids and rich in vitamins C and E (fruits and

vegetables) is associated with decreased rates of heart disease and

cancer more so than any other diet or drug intervention. "

(Simopoulos, p.427, emphasis mine)

 

 

References

Food and Behaviour Research. See also www.fabresearch.org. The

website of this charity gives authoritative and up-to-date

information on the latest discoveries about mental health and

nutrition. It includes pages on recognizing and treating probable

omega-3 deficiency and is especially useful for parents of children

with dyslexia, dyspraxia, and ADHD.

 

Kummerow, Fred A. et al.. " Trans fatty acids in hydrogenated fat

inhibited the synthesis of the polyunsaturated fatty acids in the

phospholipid of arterial cells " , Life Sciences 74 (2004), pp.2707-

23. This paper describes an experiment in which seven-week-old

piglets whose mothers had been fed a diet containing trans fats

before they were born were shown to have insufficient quantities of

long-chain omega-6 in the cells of their arteries and early signs of

heart disease. Without enough long-chain omega-6 in their membranes,

the cells of their arteries let in too much calcium, causing plaques

to begin building up on their artery walls.

 

Mafouz, M. M. et al. " Effects of dietary fats on desaturase

activities and the biosynthesis of fatty acids in rat liver

microsomes " , Lipids 19 (1984), pp.214-22. This paper describes in

detail how trans fats prevent the construction of long-chain omega-3

by inhibiting the action of the delta-6 desaturase enzyme even when

sufficient amounts of short-chain omega-3 are present.

 

Simopoulos, A.. " Evolutionary aspects of omega-3 fatty acids in the

food supply " . Prostagladins, Leukotrienes and Essential Fatty Acids

60:5 & 6 (1999), pp.421-29. This paper contrasts the modern Western

diet with the diet of our Palaeolithic ancestors, focusing

especially on changes in the levels and ratios of omega-3 and omega-

6. The author argues that the traditional diet of Crete best

reflects the levels of nutrients and especially essential fatty

acids that evolution requires us to eat for lifelong good health.

 

Stoll, A. L.. The omega-3 connection: the groundbreaking omega-3

antidepression diet and brain program. Simon & Schuster, New York

2001. This book, by the scientist who discovered that fish oil

dramatically benefited patients suffering from bipolar disorder, is

a good introduction for the general reader on how and why omega-3

can be used to treat a range of mental illnesses.

 

JoAnn Guest

mrsjo-

www.geocities.com/mrsjoguest/