Lipids in Human Nutrition: An Appraisal of Some Dietary Concepts

185 Pages·1981·5.22 MB·English

by  Germain J. Brisson Ph.D. (auth.)

Lipids
I• n
Human
Nutrition
Lipids in
Human
Nutrition
An Appraisal of Some
Dietary Concepts
GERMAIN J. BRISSON, Ph.D.
Professor of Nutrition
Universite Laval, Quebec, Canada
MTP!it
LIMITED
International Medical Publishers
Published in UK 1982 by
MTP Press Limited
Falcon House
Lancaster, England
Published in USA and Canada by
Jack K. Burgess, lnc.
44 Engle St.
Englewood, New Jersey, USA
Copyright © 1981 Springer Science+Business Media New York
Originally published by Jack K. Burgess, lnc. in 1981
Softcover reprint of the hardcover 1s t edition 1981
First published 1981
Ali rights reserved. No part of this publication
may be reproduced or transmitted in any form
or by any means, electronic, mechanical,
photocopying, record ing or otherwise,
or stored in any information retrieval system,
without the prior written permission of the
publishers.
International Standard Book Number
ISBN 978-94-015-7214-9 ISBN 978-94-015-7212-5 (eBook)
DOI 10.1007/978-94-015-7212-5
To my wife Yvette
and children
Jacques
Jean-Claude
Suzanne
Paul-Andre
Lise
Contents
Foreword xi
Preface XlII
Chapter 1: Dietary fats and body lipids: terms used
INTRODUCTION
Properties of lipids
FATTY ACIDS
Saturated, monounsaturated and polyunsaturated
fatty acids 2
Nomenclature 2
Chain length and melting point 5
Properties associated with unsaturation 5
GLYCERIDES 9
PHOSPHOLIPIDS 11
Phosphoglycerides 12
Sphingolipids 13
GLY COLIPIDS 14
Cerebrosides 14
Gangliosides 14
CHOLESTEROL AND OTHER STEROIDS 14
BILE ACIDS 18
LIPOPROTEINS 20
Historical 22
Classification 22
Apolipoproteins 25
PROSTAGLANDINS 26
CONCLUSION 29
REFERENCES 29
vii
viii Contents
Chapter 2: The technology of edible fats and oils 31
INTRODUCTION 31
EXTRACTION AND PURIFICATION OF EDIBLE
OILS 32
Extraction 33
Degumming 33
Refining 33
Bleaching 34
Deodorization 34
PARTIAL HYDROGENATION OF VEGETABLE
OILS 35
REFERENCES 40
Chapter 3: The enigma of the trans fatty acids 41
INTRODUCTION 41
TRANS FATTY ACIDS IN MARGARINES 43
TRANS FATTY ACIDS IN ANIMAL FATS 46
INTAKE OF TRANS FATTY ACIDS 48
METABOLISM OF TRANS FATTY ACIDS 50
Digestibility and absorption 50
TRANS fatty acids as sources of cellular energy 51
TRANS fatty acids, phospholipids and cholesterol
esters 55
TRANS FATTY ACID DEPOSITS IN THE BODY 58
TRANS FATTY ACIDS DEPOSITED IN THE
FETUS 59
TRANSFER OF TRANS FATTY ACIDS TO MILK 60
TRANS FATTY ACIDS IN THE BRAIN 62
TRANS FATTY ACIDS AND CANCER 62
TRANS FATTY ACIDS AND ATHEROSCLEROSIS 64
TRANS FATTY ACIDS AND THE ESSENTIAL FATTY
ACIDS 65
REFERENCES 68
Contents ix
Chapter 4: Cholesterophobia 73
INTRODUCTION 73
BLOOD CHOLESTEROL AS A RISK FACTOR FOR
CORONARY HEART DISEASE 74
EFFECT OF DIETARY CHOLESTEROL ON SERUM
CHOLESTEROL 79
Epidemiological studies in different countries 80
Studies with sub-groups in given populations 84
Controlled experiments with humans 87
REFERENCES 92
Chapter 5: Saturated and polyunsaturated fats 95
INTRODUCTION 95
COMPOSITION OF EDIBLE FATS AND OILS 96
EPIDEMIOLOGICAL STUDIES 97
CONTROLLED EXPERIMENTS 99
THE POLYUNSATURATED/SATURATED (P/S)
RATIO 101
REFERENCES 109
Chapter 6: Lipoproteins 113
INTRODUCTION 113
SyNTHESIS OF LIPOPROTEINS 114
Chylomicrons 114
Very low density lipoproteins (VLDL) 115
Low density lipoproteins (LDU 118
High density lipoproteins (HDL) 118
THE FUNCTIONS OF LIPOPROTEINS 119
LIPOPROTEINS AND CORONARY HEART DISEASE 121
Blood VLDL and triglycerides 123
LDL and total blood cholesterol 124
HDL-cholesterol or the "good" cholesterol 124
FACTORS INFLUENCING THE HDL LEVELS IN
BLOOD 1~
Sex and serum HDL 129
Obesity and serum HDL 129
x CoMen~
Exercise and serum HDL 132
Cigarette smoking and serum HDL 132
Alcohol and serum HDL 134
Diet and serum HDL 135
REFERENCES 137
Chapter 7: The major intervention studies 143
INTRODUCTION 143
PRIMARY PREVENTION STUDIES 144
Effect of changes in the lipid composition of the diet 144
Use of a hypocholesterolemic drug 149
SECONDARY PREVENTION INTERVENTION
STUDIES 151
Changes in the lipid composition of the diet 151
Use of hypocholesterolemic drugs 153
SUMMARY 156
REFERENCES 157
Chapter 8: General conclusions 161
REFERENCES 163
Index 165
Foreword
Throughout its history, medicine has benefited from scientific discov
eries made in complementary fields such as chemistry, physics and biology.
Thus, in the middle of the last century, the works of Pasteur, a chemist
and biologist, by revealing the world of micro-organisms, bacteria and
viruses, made it possible to control a considerable number of often fatal
diseases.
Guided by the work of this inspired biologist, the English surgeon, Sir
Joseph Lister, developed aseptic techniques which have rendered possible
the spectacular achievements of modern surgery. It is largely due to such
advances that the life-expectancy of man, 50 years at the turn of the century
(1900), approaches 75 years in 1981.
Even today, however, in spite of this, two groups of ailments, arter
iosclerosis and cancer, are responsible for 70 per cent of human deaths
both in Canada and in the United States of America. The former is a
degenerative process of the arterial system, the latter an uncontrolled and
destructive cellular proliferation.
Although several predisposing factors are known, the essential cause
of these conditions is wholly unknown. As long as this ignorance of the
etiology persists, all forms of therapy can be no more than palliative.
Congenital impairment of lipid metabolism enables us to ascertain the
disastrous effects of hypercholesterolemia in subjects aged from 20 to 40
who exhibit degeneration of the arterial walls normally seen in older people
aged 70-80. But the significance of the cholesterol level in normal subjects,
that is those who are not genetically deficient, is much less convincing.
The role of certain lipids, particularly cholesterol, long thought to be
risk factors in sclerosis of the arteries, is today again an open question. In
cancer, recent studies tend to establish a relationship between the ingestion
of certain lipids and the frequency of malignant tumors of breast and
intestine.
In trying to throw light on the enigma of the "trans" fatty acids, a by
product of the vegetable-oil industry, and in explaining the effects of blood
cholesterol and lipoproteins in the development of cardiovascular disease,
Professor Brisson acquaints us with some real problems of modern
medicine.
xi