The Tropical Oils
Are tropical oils good for us and the planet? Saturated fats raise cholesterol levels, and decades ago fears about the saturated fat in tropical oils led to their replacement in processed foods by hydrogenated oils. That was a nutritional disaster. Now some alternative health groups consider tropical oils healthy while mainstream health organizations still call for us to minimize their use. Who’s right?
The tropical oils palm, palm kernel, and coconut oil are the only naturally saturated vegetable fats. All are from the fruits of palm trees, and all contain palmitic acid, a dietary fat found in palms (and some other foods). The World Health Organization calls the evidence that palmitic acid consumption increases cardiovascular risk ‘convincing.’ That’s one notch above its assessment of the evidence that dietary cholesterol increases cardiovascular risk, which is only ‘probable.’
Yet there are nuances. The three tropical oils are chemically distinct from each other. The structure of tropical oils is not exactly the same as that of animal saturated fats and may have different effects in our bodies. All this has led to a re-evaluation of the health effects of tropical oils in recent years.
Palm oil, pressed from the red fruit of the oil palm tree, has a saturated fat content of 48%, much lower than the other two tropical oils. Virgin, or red, palm oil gets its red color from a high concentration of beta-carotenes and lycopene. Those powerful antioxidants are lost when red palm oil is refined into the regular palm oil we find in processed foods, though Vitamin E is also in the oil and remains after refining.
Recent research on the health effects of palm oil in general is pretty scarce. It hasn’t been a big part of the US diet until recently so there hasn’t been much interest in studying it. A 2005 study from Costa Rica of over 2,000 survivors of a first heart attack randomly matched against controls found that people who cooked with palm oil were 30% more likely to have had a heart attack than those who cooked with soybean oil. A tiny US study showed that palm oil raised triglyerides and cholesterol as much as partially hydrogenated soybean oil, while groups consuming canola or regular soybean oil showed better blood lipid profiles by comparison.
None of this research was specifically on virgin red palm oil, and it would be interesting to know if the carotenoids and other nutrients in virgin palm oil make it healthier than processed palm oil.
Palm Kernel Oil
Palm kernel oil is pressed from the large seed at the center of the oil palm fruit. At 82% saturated fat it’s highly saturated. It can be further refined, or fractionated, removing most of the remaining unsaturated oil. The resulting fractionated palm kernel oil is extremely solid, ideal for confectionary coatings. Yogurt raisins, marketed as healthy snacks, usually contain fractionated palm kernel oil. So do many energy bars and carob-based treats.
Modified Palm Oil
It’s possible to process tropical oils even more than fractionated palm kernel oil. As food makers have moved away from hydrogenated oils because of food labeling for trans fats, they’ve embraced a new process called intersterification to modify oils. Like hydrogenation, intersterification chemically changes the structure of the oil. Manufacturers use it for the same reason: to create oils with the desired degree of solidity and ‘mouthfeel.’ You’ll often see this on a label as ‘modified palm oil.’
It’s unclear what effect these intersterified oils might have on our health, but this quote by a Canadian food scientist should give you pause: “In the end, you have molecules that aren’t really fat or oil molecules anymore. They’re something in between.”
Environmental Issues with Palm Oil
What about the planet? You’d think a field of oil palms would be a planet-friendly crop– trees are good for the atmosphere and oil palms produce for up to 25 years. And oil palm gives a much greater yield of oil per acre than temperate crops like rapeseed (for canola oil), soy, or sunflower, meaning less land is needed for production.
The problem comes when virgin rainforest is cleared to make way for oil palm production. This is a serious problem in Indonesia and Malaysia, the two main areas of palm oil production for the international market. With increasing world-wide demand for palm oil, this further threatens endangered species such as the orangutan.
Despite protest, Girl Scout cookies continue to use palm oil from undocumented and likely unsound sources. Some other companies like Ferrero (makers of Nutella) use palm oil from environmentally certified sources, but the certification process itself has problems that are still being solved.
Coconut oil, which is 86% saturated fat, comes in unrefined and refined versions. Unrefined, or extra virgin, coconut oil, has been promoted a lot recently for its possible, but unproven health benefits such as antiviral and anti-fungal properties. Coconut oil is about 65% medium chain triglycerides, which are easily metabolized and burned rapidly by the liver for energy. It makes an excellent natural moisturizer or massage oil.
Hydrogenated coconut oil, sometimes used for its higher melting point, has trans fats and therefore would be expected to have a especially negative effect on blood lipid profiles. Some older studies showing a negative effect of coconut oil on blood lipid profiles used hydrogenated coconut oil.
There’s uncertainty over whether the lauric acid in coconut oil has a negative effect on cardiovascular disease risk. One small study shows coconut oil having a more beneficial effect on blood chemistry than butter, but a less beneficial effect than safflower oil.
An observational study from the Philippines found that coconut oil consumption was associated with a favorable blood lipid profile in pre-menopausal women. The discussion in that paper suggested coconut oil as a healthier alternative to butter and hydrogenated oils, positing that coconut oil only looked bad in other studies in comparison with polyunsaturated oils which are known to lower cholesterol.
Fine, but shouldn’t we lean toward using those polyunsaturated oils, or even better, monounsaturated oils like olive? I think so (topic for another post), though I’m happy using a small amount of virgin coconut oil when I want its flavor or as a butter alternative. I have not tried red palm oil, and try to avoid all of the processed tropical oils.
For further reading:
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