So … is coconut oil actually healthy or just a passing health fad? And, if it is healthy, why did we used to think it was so bad for us?

Coconut oil is everywhere these days — as a butter substitute in vegan baking, a smoothie topper for natural health nuts and even a beauty treatment, for moisturizing skin and hair and improving oral health via oil pulling.

But … wasn’t it just a generation ago that we were decrying coconut oil as the worst of the worst, due to its high levels of heart-harming saturated fat? Did we get it very wrong back then or is the reemergence of the tropical oil nothing but a slick stunt?

According to Tom Brenna, a professor of nutritional sciences at Cornell University’s College of Human Ecology, the answer is some combination of both. Not all coconut oils are created equal. The flakey, fragrant stuff you might find in a superfood smoothie is a very different type of coconut oil than the partially-hydrogenated fat found in junk food in the ’80s, which was a highly-processed version of the plant oil, containing trans fats and other dangerous, cholesterol-promoting compounds.

“The older refined-deodorized bleached coconut oil causes rapid and very unhealthy looking rises in cholesterol, for sure, no doubt,” Brenna said in an email to HuffPost Healthy Living. “There is no evidence that that is the case for virgin coconut oil, which is available today but was not in the 1970s and ’80s when people were using RDB coconut oil.”

Virgin coconut oil and even a refined version (most studies have been conducted on refined coconut oil) are now available in grocery stores and health stores and are being touted for their ability to help us lose weight, stave off illness and even prevent Alzheimer’s. Sure, it’s better than its junk food predecessor, but is it quite all that?

“It has properties that are promising, but we need a lot more research before we can say this is the superfood of 2014,” says Kristin Kirkpatrick MS, RD, LD, manager of wellness nutrition services for the Cleveland Clinic Wellness Institute.

Recently, a study conducted on mouse cells and published in the Journal of Alzheimer’s Disease got some attention when it found that treatment with coconut oil helped protect cortical neurons in a lab setting. Can we extrapolate that to a protective brain effect in living humans quite yet? Of course not.

Coconut oil may also help encourage weight loss, as in a 2009 study during which women with abdominal obesity who supplemented their diet with coconut oil were able to lose more weight than those who were given a soy bean oil supplement. But Kirkpatrick cautions against the “health halo effect,” in which we give a pass to foods that we think are healthy and lose sight of portion control. “Just because we think there are some health benefits doesn’t mean you can use a whole jar of coconut oil to cook,” she says.

Natural coconut oil is made of 90 percent saturated fat (butter, a distant second, contains a comparatively puny 64 percent saturated fat), but the kind of saturated fat matters just as much as the amount. About half of virgin coconut oil’s saturated fat is lauric acid, a medium-chain triglyceride that turns out to have a number of health-promoting properties, including the ability to improve levels of “good” HDL cholesterol. People can also more easily digest medium-chain triglycerides and convert them to energy, according to The Wall Street Journal, making coconut oil a good choice for athletes. That said, because it’s so high in saturated fat, even the purest, most natural coconut oil could be problematic for longterm heart health, according to a Harvard nutrition professor.

“Most of the research so far has consisted of short-term studies to examine its effect on cholesterol levels. We don’t really know how coconut oil affects heart disease,” wrote Walter C. Willett, M.D., chair of the Department of Nutrition at the Harvard School for Public Health, in a newsletter. “And I don’t think coconut oil is as healthful as vegetable oils like olive oil and soybean oil, which are mainly unsaturated fat and therefore both lower LDL and increase HDL.”

Kirkpatrick herself cooks with coconut oil about once a week for taste, but is hesitant to use any more than that until there’s more research. “I really stick with olive oil,” she says. “It’s not as sexy, but there are so many more studies about its benefits.”