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Over the course of the last 30 years, cardiovascular disease have become a major concern in the industrialized societies, but in many countries its incidence appears to have peaked and declining mortality rate from CHD has been observed. Nevertheless, it is still A Major Killer.
For some considerable time, dietary fats have been shown to have a distinct influence on cardiovascular disease. It affects both Arteriosclerosis, a process leading to the occlusion of arteries, and Arterial Thrombosis, the formation of blood cloths in arteries. This has been determined with various animal models and has been observed in human studies.
In general, fats rich in long-chain, saturated fatty acids tend to promote arteriosclerosis and thrombosis, while oils rich is poly-unsaturated fatty acids inhibit their development.
In 1971, Dr. G. Hornstra* and co-workers, undertook an intensive study into the effect of different dietary fats on the incidence of arterial thrombosis in rats. The study used 11 different oils and fats with widely varying fatty acid composition. Palm Oil was on of the oils studied.
They found that despite a relatively high saturated fatty acid content, Palm Oil unexpectedly showed an ANTI-THROMBOTIC effect. This suggested that Palm Oil may contain certain substances, which can over-ride the pro-thrombotic effect normally associated with saturated fatty acids.
In 1984, the Palm Oil Research Institute of Malaysia (PORIM), commissioned Dr. Honstra** to repeat this study on Palm Oil, to confirm his earlier findings.
Once again, Palm Oil was found to be anti-thrombotic.
A more detailed study was initiated in 1985 in which Palm Oils, which had been processed in different ways, were used. This study has shown that the method of processing used can improved the anti-thrombotic effect of Palm Oil.
The possible anti-thrombotic mechanisms involved were investigated. Research was directed in two main directions:
(a) COAGULATION and PLATELET AGGREGATION:
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| Figure: Role of blood platelets in atherogenesis |
The simultaneous clumping of blood platelets (aggregation) and it's clotting (coagulation), results in formation of an Arterial Thrombus. Both those processes are interlinked and are initiated by a slight injury to an intact artery.
Earlier research by Renaud and co-workers in France showed that enhanced platelet aggregation and blood coagulation are associated with a diet rich in saturated fats.
In Dr. Hornstra's study however, Palm Oil feeding was shown to enhance NEITHER of these processes.
(b) PLATLET and VASCULAR PROSTANOIDS:
It has been shown that a group of compounds, Prostaglandin's and thromboxanes produced by blood platelets and vascular walls are important regulators in thrombosis and related phenomena.
Thromboxane A2, (TXA), a powerful pro-thrombotic agent, is produced during platelet activation and causes platelets to aggregate. Blood vessels produced Prostacyclin, PGI, which deactivates blood platelets and causes platelets aggregates to break up. In these pro-and anti-thrombotic activities, it is the balance between the production of TXA, and PGI, which determines the tendency towards Arterial Thrombosis.
It was found that with Palm Oil feeding, the formation of pro-thrombotic TXA/PGI balance may well explain, at least in part, the Antithrombotic effect of Palm Oil.
As platelet aggregation, blood coagulation and arterial thrombosis have all been implicated in the development of arteriosclerosis, the effect of Palm Oil on experimentally induced arteriosclerosis was investigated in a rabbit model.
This research was undertaken in 1980, by Dr. Honstra and co-workers, with the co-operation of Unilever, Vlaardingen.
The study showed that Palm Oil caused the lowest degree of arteriosclerosis in comparison with a range of highly unsaturated oils, which included Olive, Sunflowerseed, Linseed and Fish oils.
They also found that Palm Oil caused the highest production of anti-thrombotic Prostacyclin from vascular tissue, without affecting the production of Thromboxane A2 platelets. This again results in favorable shift in the TXA/PGI ratio. Thus, the influence of Palm Oil feeding on the formation of pro-and anti-thrombotic Prostanoids may, in part, explain the unexpected, low Atherogenic effect of Palm Oil.
A report detailing the beneficial, Anti-Thrombotic and Anti-Atherogenic effects of Palm Oil was presented at the Second International Congress on Essential Fatty Acids, Prostaglandin and Leukotrienes in London, UK, in March 1985.
These finding were also reported at the July 1985 meeting of the International Society on Thrombosis and Haemostasis, held in San Diego, California, USA. An abstract can be found in the Journal of Thrombosis and Haemostasis: 54, (1), 1985.
In conclusion, although Palm Oil has a relatively high saturated fatty acid content (+/- 50%), it exhibits both anti-thrombotic and an anti-atherogenic effects.
Further research into the causes and mechanisms of those beneficial effects from Palm Oil when used as dietary fat, continues, both at Dr. Hornstra's laboratory in Holland and at the laboratories of PORIM, Malaysia.
* At Unilever - Vlaardingen, Holland.
** At the University of Limburg, Holland.
For Further Information, Please Contact:
PALM OIL INSTITUTE OF MALAYSIA
No 6, Persiaran Institusi,
43000 Bandar Baru Bangi, Selangor.
P.O. Box 10620, Kuala Lumpur, MALAYSIA.
Tel: 03-8335775, 8335155 Telex: MA 31604, 31609.
Telegram: PALMSERCH, Kuala Lumpur.
PORIM:
Technical Advisory
Servide Regional Office
Post Box No. 1352
GPO Karachi
Pakistan
Tel: 523772. Telex: 23962 PALM PK.
PORIM Unit:
Brickendonbury, (MRPRA)
Hertford
SG13 8NL,
United Kingdom
Tel: (STD) (0992) 554 347
Telex: 817449 MRRDBL G.
Useful Address
Ministry of Primary Industry
67th, 7th and 8th Floor, Dayabumi Complex
Jalan Sultan Hishamuddin
50654 Kuala Lumpar, MALAYSIA.
Tel: 03-2747511. Telex: MA 30808 |
