Dietary ω3 and ω6 Fatty Acids: Biological Effects and Nutritional Essentiality

433 Pages·1989·15.24 MB·English

by  Konrad Bloch (auth.)

Dietary w3 and
w6 Fatty Acids
Biological Effects
and Nutritional
Essentiality
NA TO ASI Series
Advanced Science Institutes Series
A series presenting the results of activities sponsored by the NA TO Science Committee,
which aims at the dissemination of advanced scientific and technological knowledge,
with a view to strengthening links between scientific communities.
The series is published by an international board of publishers in conjunction with the
NATO Scientific Affairs Division
A Life Sciences Plenum Publishing Corporation
B Physics New York and London
C Mathematical Kluwer Academic Publishers
and Physical Sciences Dordrecht, Boston, and London
o Behavioral and Social Sciences
E Applied Sciences
F Computer and Systems Sciences Springer-Verlag
G Ecological Sciences Berlin, Heidelberg, New York, London,
H Cell Biology Paris, and Tokyo
Recent Volumes in this Series
Volume 166-Vascular Dynamics: Physiological Perspectives
edited by N. Westerhof and D. R. Gross
Volume 167-Human Apolipoprotein Mutants 2: From Gene Structure to
Phenotypic Expression
edited by C. R. Sirtori, G. Franceschini,
H. B. Brewer, Jr., and G. Assmann
Volume 168-Techniques and New Developments in Photosynthesis Research
edited by J. Barber and R. Malkin
Volume 169-EvolutionaryTinkering in Gene Expression
edited by Marianne Grunberg-Manago, Brian F. C. Clark,
and Hans G. Zachau
Volume 170-ra8 Oncogenes
edited by Demetrios Spandidos
Volume 171-Dietary w3 and w6 Fatty Acids: Biological Effects
and Nutritional Essentiality
edited by Claudio Galli and Artemis P. Simopoulos
Volume 172-Recent Trends in Regeneration Research
edited by V. Kiortsis, S. Koussoulakos, and H. Wallace
Series A: Life Sciences
Dietary w3 and
w6 Fatty Acids
Biological Effects
and Nutritional
Essentiality
Edited by
Claudio Galli
Institute of Pharmacological Sciences
University of Milan
Milan, Italy
and
Artemis P. Simopoulos
ILSI Research Foundation
Washington, D.C.
Springer Science+Business Media, LLC
Proceedings of a NATO Advanced Research Workshop on
Dietary w3 and w6 Fatty Acids: Biological Effects
and Nutritional Essentiality,
held June 20-23, 1988,
in Belgirate, Italy
Library of Congress Cataloging in Publication Data
NATO Advanced Research Workshop on Dietary [Omega] 3 and [Omega] 6 Fatty
Acids: Biological Effects and Nutritional Essentiality (1988: Belgirate, Italy)
Dietary [omega] 3 and [omega] 6 fatty acids.
(NATO ASI series. Series A, Life sciences; v. 171)
"Proceedings of a NATO Advanced Research Workshop on Dietary [Omega] 3
and [Omega] 6 Fatty Acids: Biological Effects and Nutritional Essentiality, held
June 20-23,1988, Belgirate, Italy"-T.p. verso.
"Published in cooperation with NATO Scientific Affairs Division."
Includes bibliographies and index.
1. Omega-3 fatty acids-Physiological effect-Congresses. 2. Omega-6 fatty
acids-Physiological effect-Congresses. 3. Unsaturated fatty acids in human
nutrition-Congresses. I. Galli, Claudio. II. Simopoulos, Artemis P., 1933-
III. North Atlantic Treaty Organization. Scientific Affairs Division. IV. Title. V.
Series. [DNLM: 1. Dietary Fats, Unsaturated-congresses. 2. Fatty Acids, Un·
saturated-congresses. 3. Fish Oils-congresses. QU 90 N2789d 1988]
QP752.F35N38 1988 612.3/97 89-8583
ISBN 978-1-4757-2045-7 ISBN 978-1-4757-2043-3 (eBook)
DOI 10.1007/978-1-4757-2043-3
© 1989 Springer Science+Business Media New York
Originally published by Plenum Press, New York in 1989
Softcover reprint of the hardcover 1st edition 1989
All rights reserved
No part of this book may be reproduced, stored in a retrieval system, or transmitted
in any form or by any means, electronic, mechanical, photocopying, microfilming,
recording, or otherwise, without written permission from the Publisher
PREFACE
On June 24-26, 1985, a major International Conference on the Hea1th
Effects of P01yunsaturated Fatty Acids in Seafoods was held in Washington,
D.C. The conference had two objectives: (1) to review the research data
on the health effects of polyunsaturated fatty acids in seafoods in terms
of the impact of omega-3 fatty acids on eicosanoid formation, thrombosis
and inflammation, and the role of docosahexaenoic acid in membrane
function and metabolism, and (2) to develop a research agenda to determine
the spectrum of the health effects of polyunsaturated fatty acids of
seafood origin in the American diet.
The 1985 conference established the fact that omega-3 fatty acids of
marine origin - eicosapentaenoic acid (EPA) and docosahexaenoic acid
(DHA) - play important roles in prostaglandin metabolism, thrombosis and
atherosc1erosis, immunology and inflammation, and membrane function.
In response to the conference recommendations, the Congress of the
United States provided special funding for the establishment of a "test
materials 1aboratory" within the US Department of Commerce to produce
under documented quality contr01 the types and quanti ties of omega-3 te~3t
materials required by biomedica1 researchers. The forms of test
materials to be produced include refined fish oil, polyunsaturated fatty
acid enhanced triglycerides, concentrates of esters of fatty acids,
purified omega-3 fatty acids, and omega-3 mono-, di- and tri~lyceride
mixtures. The proceedings of the conference were published (1) and in
response to the conference recommendations the National Institutes of
Health (NIH) developed a program announcement that led to expansion of
research on omega-3 fatty acids. This 1985 conference and other
conferences held in 1986, 1987 (2) and 1988 (3,4) focused on the role of
omega-3 fatty acids of marine origin. A NATO Advanced Research Workshop
was also held in 1986 devoted to "Advanced Technologies and Their
Nutritional Implications in the Production of Edible Fats" (5), in which
selected aspects concernings the biological effects of highly unsaturated
fatty acids of the omega-3 series were presented and discussed. Only
slight attention was given to the role of omega-3 fatty acids from
terrestrial sources such as alpha-linolenic acid and its metabolism to
its longer chain derivatives and its relationship to omega-6 fatty acids,
specifically lin01eic acid and arachidonic acid, and most important1y the
question of the essentiality of omega-3 fatty acids. Research on these
issues has expanded over the past 5 years and the role of omega-3 fatty
v
acids in growth and development has been progressing in parallel to the
research on the role of omega-3 fatty acids in thrombosis, atheroscleroHis,.
inflammation, cancer, autoimmune disorders and aging.
The long chain members of the omega-3 fatty acid series EPA and DHA
are found in relatively high concentrations in lipids from various
tissues of marine animals, whereas in terrestrial animals, e.g. mammals,
they appear to be concentrated in structural lipids of selected
membranes, such as the retina and hte synaptic membranes of the centra]
nervous system. In addition, in mammalian tissues mainly the very long
chain members of the omega-3 series, DHA is present rather than the less
unsaturated product EPA which is found in high concentrations in marine
animals.
It would thus appear that in terrestrial animals and especially in
the highest species, very complex regulatory processes are at work
favoring the accumulation of selected highly unsaturated omega-3 fatty
acids in specific sites. Also, the endogenous metabolic conversion of
the short chain precursor of dietary origin, alpha-linolenic acid, to the
long chain highly unsaturated derivatives, rather than the intake of
preformed products in the diet appears to be the major process for the
utilization of omega-3 fatty acids. Alpha-linolenic acid is very rapidly
converted to the long chain members of the omega-3 series, but the
incorporation of the formed products into cell phospholipids depends to
a large extent on the selectivity of acyl transferase reactions for
different substrates, in addition to those of the chain elongating and
desaturating enzymes.
Finally the interactions of omega-6 and omega-3 fatty acids at various
stages of their utilization (intake, desaturation and elongation,
transport and uptake in cellular lipids) are certainly important feature::;
in the overall fates of long chain polyunsaturated fatty acids of both
series.
Although the effects of the intake of omega-3 fatty acids on several
physiological parameters show interesting applications for the dietary
prevention of pathological states, it is felt that a more general and
balanced evaluation of the biological roles of both omega-6 and omega-3
fatty acid series in different biological systems, of their relative
distribution and stability in different food sources and of the
comparative utilization of short chain precursors and long chain productE;
of both series, is essential.
It was therefore thought timely and most appropriate to hold a NATO
Advanced Research Workshop on Dietary w3 and w6 Fatty Acids: Biological
Effects and Nutritional Essentiality.
The objectives of the workshop were to assess the comparative
biological significance of omega-3 and omega-6 fatty acids in relation
to the a) dietary availability, utilization and metabolism of different
members of these fatty acid series; and b) roles of endogenous long chain
members of the omega-3 (e.g. 20:5 and 22:6) and omega-6 (e.g. 20:3 and
20:4) series in different biological systems.
vi
These aspects were extensively analyzed and discussed at the workshop.
The workshop consisted of review papers on various aspects of omega-3
fatty acids and on selected topics on utilization, metabolism and
interaction between the fatty acids of the two-series omega-3 and omega-6.
There were extensive discussions following each presentation and a special
round table discussion on the essentiality of omega-3 fatty acids.
Approximately 120 scientists from 15 countries participated. The
program consisted of papers presented at plenary sessions and a poster
session. There were seven sessions on the following topics: Dietary
Sources of Omega-3 and Omega-6 Fatty Acids; Chemistry, Biosynthesis and
Interactions of Omega-3 and Omega-6 Fatty Acids; The Role of Omega-3 and
Omega-6 Fatty Acids in Development; Biological Effects of Omega-3 and
Omega-6 Fatty Acids on Cell Activation Processes; two sessions on The
Role of Omega-3 and Omega-6 Fatty Acids in Human Diseases; and a Round Table
on the Essentiality of Omega-3 Fatty Acids. Thirthy-two papers and an
equal number of posters were presented.
The Executive Summary, at the end of the Proceedings, highlights the
presentations, discussions, poster session papers and is followed by
comprehensive "General Recommendations". We are indebted to the presenters
at the workshop, and at the poster session for their excellent papers,
and we are confident that the proceedings of this workshop will be an
important milestone in the field. Many of the participants emphasized
the importance of this workshop and recommended to hold such a workshop
every 2 years in order to present new findings and exchange ideas and
views in this very rapidly advancing field.
Finally, we would like to express our gratitude to the program and
workshop participants and the financial sponsors of the workshop, mainly
NATO, the Division of Nutritional Sciences-ILSI Research Foundation and
the Nutrition Foundation of Italy, and the following cosponsors: BSN,
Canola Council, DNA Plant Technology Corporation, Hoffmann-La Roche,
ILSI-Europe, Nestle', Procter & Gamble Company, Quaker-Chiari & Forti S.p.A.,
Ross Laboratories, Star S.p.A., u.s. Department of Commerce-National
Marine Fisheries Service, and Warner-Lambert Company.
As a last point in this preface, we would like to thank all those who
contributed to the success of the workshop. Special thanks are addressed
to Daniela Galli for all the burden of the local organization and of the
preparation of this volume, to Brita Rolander-Chilo' for the administrative
responsabilities, to Peggy Roberts for her help with the international
liaisons, in addition to all the others who participated to the organization.
Claudio Galli
Artemis P. Simopoulos
vH
REFERENCES
1. A.P. Simopoulos, R.R. Kifer and R.E. Martins,eds., "Health Effects
of Polyunsaturated Fatty Acids in Seafoods", Academic Press,
Orlando, Fl (1986)
2. The American Oil Chemists' Society (AOCS) Short Course on
Polyunsaturated Fatty Acids and Eicosanoids, held May 14-17, 1987
in Biloxi, Mississippi
3. Health Effects of Fish and Fish Oils: An International Conference
held July 30-August 2, 1988 in st. John's, Newfoundland
4. The Fifth Acta medica Scandinavica Symposium on N-3 Fatty Acids
in health and Disease held August 11-13, 1988 in Tr~mso, Norway
5. C. Galli and E.Fedeli, eds.,"Fat Production and Consumption -
Technologies and Nutritional Implications", Plenum Press, New York
(1987).
viii
CONTENTS
Dietary sources of w3 and w6 fatty acids
Early studies on the biosynthesis of polyunsaturated
fatty acids ..................................................... .
K. Bloch
The food chain for n-6 and n-3 fatty acids with
special reference to animal products ............................. 5
M.A. Crawford, W.Doyle, P.Drury, K.Ghebremeskel,
L.Harbige, l.Leyton, G.Williams
Some aspects of omega-3 fatty acids from
di fferent foods ................................................. 21
l.L. Beare-Rogers
Linoleic and linolenic acids intake ................................... 33
O. Adam
Omega-3 fatty acids from vegetable oils ............................... 43
1 . E. Hunter
Preparation of fish oil for dietary applications ...................... 57
H.l. Wille, P.Gonus
Chemistry, Biosynthesis and Interactions
of w3 and w6 fatty acids
(N-3) and (N-6) fatty acid metabolism ................................. 69
H. Sprecher
The effect of dietary fish oil supplementation and
in vitro collagen stimulation on human platelet
phospholipid fatty acid composition ............................. 81
H.M. Aukema, B.l.Holub
In vitro studies on docosahexaenoic acid in
human platelets ................................................. 91
M. Lagarde, M.Croset, M.Hajarine
ix