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Q: I see palm oil, palm kernel oil, and fractionated palm kernel oil on ingredients lists. What are the differences, and are they all bad for me?

A: They aren't all necessarily bad for you, but the vague naming differences does make it very confusing, and they do have different noteworthy characteristics.

When trans fats were removed from the market due to their aggressive negative health consequences, an inexpensive fat that had similar stability and melting properties was in high demand. Palm oil fit the bill, as it consists primarily of saturated fats, and it has become the fat of choice to replace trans fats.

You'll most often see three different variations of palm oil:

Palm oil: This is the fat that is squeezed out of the fruit from oil palm trees, hence you'll also see it called "palm fruit oil." It is rich in vitamin E. If you find that your palm oil has a red coloring, this is good, as the coloring comes from the antioxidant beta-carotene. Thanks to the E and lower sat fat content, palm oil is definitely the best of this bunch of oils. [Tweet this fact!]

Palm kernel oil: As the name suggests, this oil is derived from the kernel or seed of the fruit in oil palms. It contains more saturated fats than palm oil and is very commonly used in commercial cooking since the higher saturated fat content allows for greater stability at higher temperatures and better shelf life.

Fractionated palm oil: This is the result of a process that allows for the extraction and concentration of specific types of fatty acids found in palm oil. Food companies use the fractionation process to create an oil that has a higher concentration of saturated fats for even better stability and shelf life.

It is commonly advised to control saturated fat levels in your diet as a means of controlling blood cholesterol levels. But not all saturated fats have the same cholesterol-raising effects on blood cholesterol levels (and not to complicate the story, but your level of carbohydrate intake play a role here too). For example stearic acid is a saturated fat found primarily in dairy fat and beef; it has no impact on cholesterol levels.

One study published in the American Journal of Clinical Nutrition found that feeding coconut oil-another tropical oil rich in saturated fat-to individuals led to increases in blood cholesterol levels, while feeding individuals palm oil led to reductions in blood cholesterol levels. This suggests that the saturated fats found in palm oil provide a unique physiological effect not normally seen with saturated fats; however, this is a concept that needs to be further examined, especially considering an earlier study found the exact opposite effect.

As a general rule, I recommend healthy clients get the fat in their diet from a variety of sources, with a third coming from each type (saturated, monounsaturated, and polyunsaturated). [Tweet this tip!] In this context a little palm oil, of any variation, won't have that much of an impact on your health. But if you have the choice, opt for palm oil over palm kernel or fractionated palm oil.