Sunday April 4, 2004 - THESE days, when people hear the words saturatedfat, they jump in horror. Oh no, it makes my cholesterol go up! theyexclaim. The truth is, not all saturated fats have the same effect oncholesterol levels as they are made up of different types of fatty acids.
First, a refresher course on saturated fats. These are fats that comemostly from animal sources (lard, butter, tallow and lamb or mutton fat)and certain plant sources (coconut oil, palm oil and palm kernel oil).
Some saturated fats have a tendency to increase total cholesterol and bad(LDL) cholesterol levels. Conversely, there are saturated fats, such aspalm oil, that do not have these adverse effects. Numerous studies haveshown that palm oil does not raise bad cholesterol but increases good(HDL) cholesterol levels in normal, healthy populations.
According to Dr Koh Chu Sing, Director of the Technical MarketingDepartment, Malaysian Palm Oil Promotion Council, palm oil has equalproportions of saturated and unsaturated fatty acids. Therefore, it shouldbe classified as both a saturated fat and an unsaturated fat.
Palm oil is a rich source of tocotriencols, a form of vitamin E which hasanti-oxidative effects.The fatty acids that make up the saturated fat component are palmitic acid(40%), stearic acid (5%) and negligible amounts of myristic and lauricacids. Studies have shown that myristic and lauric fatty acids haveharmful effects on blood cholesterol levels.
On the unsaturated side, palm oil consists of 40% monounsaturated oleicacid and 10% polyunsaturated linoleic acids. The high amounts ofmonounsaturated fatty acids in palm oil could be one of the reasons why itdoes not raise blood cholesterol levels, Dr Koh explains.
There are numerous studies within and outside the country that haveindicated various other benefits of palm oil:
No more plaque
Arterial plaque is formed when cholesterol and other deposits build up inthe arteries. The formation of plaque may lead to atherosclerosis, acondition where the arteries become narrowed.
According to Dr Koh, studies have revealed that a palm oil diet does notpromote the formation of plaques in the arteries. He also makes mention ofan American study (Klurfeld et al, 1989) and a Dutch study (Hornstra,1988) which found that palm oil had the least atherosclerotic effect whencompared to other oils. These two studies were done on animals.
The formation of a blood clot may increase the risk of a heart attackbecause it blocks the blood vessel leading to the heart and deprives it ofoxygen-rich blood. If a clot forms in the blood vessel leading to thebrain, it could cause a stroke.
However, Dr Koh quotes a study by Hornstra (1988) which shows that palmoil does not promote blood clotting as compared to sunflower oil, a typeof unsaturated oil.
According to him, many other scientific findings have also demonstratedthat a palm oil diet has an anti-clotting effect because it eitherincreases the production of a hormone that prevents blood clotting(prostacyclin) or decreases the formation of a blood clotting hormone(thromboxane).
Rich in vitamins A and E
Palm oil is a rich source of tocotrienols, a form of vitamin E which hasanti-oxidative effects. Anti-oxidants are compounds that can protect bodycells from the damage caused by oxidation.
Vitamin E, particularly the tocotrienols present in palm oil, can suppressthe production of cholesterol in the liver. Therefore, tocotrienols havebeen found to lower blood cholesterol levels, says Dr Koh, quoting fromfour studies by Qureshi et al.
He goes on to explain that red palm oil is rich in carotenoids, some ofwhich may be converted to vitamin A in the body. Carotenoids have alsobeen known to possess anti-oxidative properties.
Many studies have demonstrated the beneficial effects of carotenoids inthe prevention of heart disease and other chronic diseases. Results oflaboratory and animal studies suggest that palm oil may also have a roleto play in reducing the risk of cancer. The protective role of palm oildiet in (cancer) is contributed by its high content of tocotrienols andcarotenoids.
Stable and versatile
Palm-based solid fats require no or very little hydrogenation, therefore(they contain) minimal amounts of trans-fatty acids, says Dr Koh.
As many people are already aware, trans-fatty acids are by-products of thehydrogenation process, and raise bad cholesterol while lowering goodcholesterol. Trans-fatty acids may also increase the risk of type 2diabetes and pre-eclampsia in women, and have been negatively associatedwith foetal developmental problems. Trans-fatty acids are present in foodproducts that use hydrogenated vegetable oils as an ingredient.
Dr Koh also says that palm olein (the liquid form of palm oil made intocooking oil) has excellent oxidative stability compared withpolyunsaturated oils. Frying oil must withstand high temperatures withoutbreaking down or oxidising quickly and turning rancid. Palm oil is stabledue to the presence of high levels of natural antioxidants (tocopherolsand tocotrienols) and a balanced level of saturated and unsaturated fattyacids.
The fastidious chef will be pleased to know that cooking with palm oildoes not produce excessive smoke, cause spattering and foaming, or formgummy residues in the pan.
Palm oil, one of Malaysia's natural resources, is easily available andappropriate for use in our daily cooking. As Dr Koh is proud to claim,palm oil is nature's gift to Malaysia, Malaysia's gift to the world.