A cursory skim of the web left me distraught over why I haven't been adding coconut oil to all vegetables I roast, all smoothies I blend, all cups of coffee I brew, and all spoons I put within tongue's reach of my mouth.
“Hellooo coconut oil, goodbye problems!” —My naiveté
I found 28 Science-Verified Health Benefits of Coconut Oil, 11 Surprising Benefits of Coconut Oil, and 20 Coconut Oil Benefits & Side Effects (#5 is Life Saving) (...life-saving?!), and read assertions that the oil, extracted from the meat of mature coconuts, protects organ function and heart health, wards of neurodegenerative disorders, UTIs, and cancer, and is a "long term, weight loss godsend" (speaking of subtle messaging, there's even a brand of coconut oil called Skinny & Co.).
And this was all before I dug into coconut oil's beauty benefits (goodbye acne, cellulite, stretch marks, dry skin, mind-of-its-own hair, big ears).
As Grant Stoddard summed it up on EatThis.com, "a growing body of research shows that adding coconut oil to your diet and your person could be one of the easiest ways to improve your health, well-being, appearance, and even your sex life." Hellooo coconut oil, goodbye problems. If only I could live on coconut oil alone!
“Rarely has a food gone through as dramatic a transformation from dietary villain to superhero as coconut oil and, indeed, all things coconut.” —Berkeley Wellness
But not so fast. Coconut oil might be the it oil of the moment (and yes, it helps that it's vegan, dairy-free, gluten-free, Paleo, and Whole30-compliant, too), and a branch of the rapidly-growing tree of commercial coconut products, but is it all it's advertised to be?
Just thirty years ago, writes Melissa Clark in the New York Times, coconut oil was demonized as "the devil himself in liquid form, with more poisonous artery-clogging, cholesterol-raising, heart-attack-causing saturated fat than butter, lard or beef tallow."
So what is true and what is, uh, gobbledygook?
While coconut oil has certain distinct characteristics that may confer health benefits, "the evidence to support those claims is very thin," says Dr. Qi Sun, assistant professor in the Department of Nutrition at the Harvard T.H. Chan School of Public Health.
Below, we'll explore what we do know for certain about coconut oil, from heart health to weight loss claims—and what's still up for debate (or, at least, for more research).
1. There is a significant health difference between partially hydrogenated coconut oil and virgin coconut oil, which has not been chemically treated.
Much of the demonization of coconut oil in the 1980s and 90s can be attributed to the fact that those studies were conducted using partially hydrogenated (aka trans fat–containing) coconut oil, explains Thomas Brenna, a professor at Cornell University's Division of Nutritional Sciences. "Virgin coconut oil, which has not been chemically treated, is a different thing in terms of a health risk perspective," he tells Melissa Clark, and it still contains the antioxidants and essential fatty acids that are destroyed in the hydrogenation process.
2. Coconut oil that is not partially hydrogenated, however, is still one of the most concentrated food sources of saturated fat (more so than butter, beef fat, or lard).
Coconut oil is about 90% saturated fat (for context, butter is about 64% saturated fat, and beef fat and lard are about 40%, and olive oil sits at 14%). Coconut oil has about 12 grams of saturated fat per tablespoon as compared to butter’s 7 grams. Considering the American Heart Association recommends limiting saturated fat intake to 13 grams per day, that's only a little more than one tablespoon of coconut oil per day.
3. Yet there is evidence to suggest that the distinct composition of coconut oil makes it less detrimental—and maybe even neutral or beneficial—for heart health as compared to other saturated fat sources.
While research in humans is limited (and far from conclusive), "the saturated fats in coconut oil (like those, for example, in chocolate and dairy products) appear to be more neutral in their effect on blood cholesterol than those in, say, meat," explain the team at Berkeley Wellness, an online resource for evidence-based wellness information out of the University of California, Berkeley, School of Public Health.
“Much of the research has important limitations that warrant caution when interpreting results, such as small sample size, biased samples, inadequate dietary assessment, and a strong likelihood of confounding.”—Eyres et al., Nutrition Reviews
The main saturated fatty acid in coconut oil is lauric acid, and some research has shown that lauric acid (which is a medium-chain triglyceride, or MCT) raises levels of the "good" cholesterol HDL. It raises levels of the "bad," plaque-forming cholesterol LDL, as well—though, as an April 2016 article in Nutrition Reviews concluded, but not as much as butter did.
The net effect of coconut oil depends, of course, on what it is replacing (if anything) in the diet: If it's replacing butter and lard, both of which raise LDL levels more than coconut oil, than increasing coconut oil consumption might lessen or stabilize LDL; but if coconut oil is replacing unsaturated oils (like olive oil), which do not raise LDL levels to the same extent, it will likely increase LDL.
Studies have shown that South Pacific islanders who eat a lot of coconut oil have low levels of heart disease, but these findings cannot be extrapolated to people outside of the region, as South Pacific Islanders have an entirely different activity level and diet.
4. But even the benefits of HDL—the "good" cholesterol boosted by coconut oil—are not entirely clear.
HDL has long been touted as the hero of the cholesterol crew—the good guy that carries excess cholesterol to the liver, where it can be excreted—but there are new studies that show that "good cholesterol alone has little ability to lower heart-disease risks, and more is not necessarily better" (read more about the evidence in the Washington Post).
5. The moral of the story? We don't know very much about coconut oil and heart health.
Compared to the "wealth of data showing that diets rich in unsaturated fat, especially olive oil, may lower the risk of cardiovascular disease," writes Julie Corliss for the Harvard Health Blog, there is "no evidence that consuming coconut oil can lower the risk of heart disease, according to an article in the April 2016 Nutrition Reviews." That 2016 review paper ("Coconut oil consumption and cardiovascular risk factors in humans" by Eyres et al.) pointed out that "evidence of an association between coconut consumption and risk factors for heart disease is mostly of very poor quality."
“I really stick with olive oil,” Kristin Kirkpatrick MS, RD, LD, manager of wellness nutrition services for the Cleveland Clinic Wellness Institute told Huffington Post: "It’s not as sexy, but there are so many more studies about its benefits."
Weight Loss & metabolic function
6. Evidence that coconut oil can lead to significant weight loss is not likely to have significant real world application.
But what about coconut oil as a weight loss "godsend"?
The assertion that coconut oil can promote significant weight loss is based on the fact that lauric acid is a medium-chain triglyceride, with lab research showing that MCTs are metabolized differently than other fats, with slightly more calories burned in the process. But, as explained on Berkeley Wellness, the few human studies have had inconsistent results and “any calorie-burning effect would be insignificant” compared to the total nutritional value of the oil.
In more detail, Marie-Pierre St-Onge, Associate Professor of Nutritional Medicine at Cornell University Medical School, who has researched the relationship between MCTs and metabolic rate, told Time that her studies have shown that eating medium-chain triglycerides may increase the rate of metabolism more than eating long-chain triglycerides. But in order for the results of her studies—which were done "using a 'designer oil' containing 100% medium-chain triglycerides" (compared to coconut oil's 13% to 15% MCTs) —to have any real world application, people would have to consume a ton of high-calorie coconut oil, thereby offsetting any metabolism-revving weight loss benefits.
St-Onge's March 2017 study, in fact, showed that smaller does of MCTs, like the amount found in coconut oil, did not increase calorie burn in overweight adolescents, Time reported.
7. Coconut oil is a source of antioxidants—but so are foods that don't contain nearly as much saturated fat.
"Virgin coconut oil contains small amounts of antioxidant compounds that may help curb inflammation, a harmful process thought to worsen heart disease," says Harvard Medical School professor Dr. Bruce Bistrian. "But to date, proof of any possible benefit is limited to small studies in rats and mice."
You can get antioxidants from a balance of vegetables, fruits, and whole grains.
8. Lauric acid, which makes about about half of the fatty acids in coconut oil, has strong antimicrobial properties, but how that plays out within the human body is less known.
And we're back to lauric acid, which, as Fabian M. Dayrit wrote in a 2014 review paper in the Journal of the American Oil Chemists' Society, has "demonstrably significant antimicrobial activity against gram positive bacteria and a number of fungi and viruses."
As Dr. Glen D. Lawrence, a professor of chemistry and biochemistry at Long Island University, explained in the Wall Street Journal, however, even if lauric acid kills a wide range of viruses and bacteria in the laboratory, it remains unknown whether the fatty acids of coconut oil have this same effect in vivo.
9. There is no clinical evidence that coconut oil can treat Alzheimer's (though anecdotal evidence and theoretical research does exist).
The theory behind claims that coconut oil can treat Alzheimer's disease goes like this: MCTs (again, lauric acid) boost the liver's production of ketones, which are byproducts of fat breakdown; these ketones act as an alternative energy source for the disease-affected brain cells that have lost their ability to use glucose. There are no published studies to back these claims, and the 2012 book that publicized the assertion was based on theoretical research, animal studies, and anecdotal evidence.
The Alzheimer's Association has stated that while a few "people have reported that coconut oil helped the person with Alzheimer’s, [...] there’s never been any clinical testing of coconut oil for Alzheimer’s, and there’s no scientific evidence that it helps."
So what can you make of this information?
If you're avoiding dairy-based fats for whatever reason, coconut oil is a viable, plant-based substitute for recreating the tender flakiness that's normally associated only with butter. Unlike olive or canola oil, coconut oil is solid at room temperature (that's those saturated fats at work!), which means you can use it for vegan waffles, sticky buns, doughnuts, cake, scones, and pie dough.
Even if you are a butter-eater, you may still use coconut oil to make moist, fragrant desserts, like this Banana, Coconut, Chocolate Chip Snack Cake. Virgin coconut oil, in particular, has a nutty, almost sweet, and distinctly coconutty taste and aroma that lends great flavor to roasted sweet potatoes; or use it to sauté vegetables for the base of a coconut milk curry.
“It seems safe to say that if I eat it just once in a while, coconut oil probably isn’t going to give me a heart attack, make me thinner or ward off the flu.” —Melissa Clark, The New York Times
So coconut oil is delicious and versatile, yes. But will it fight my cold, fire up my metabolic rate, volt me to supermodel status, or give me the power to fly? Nope. (I've shed a tear.)
But used in moderation, it probably won't clog up my arteries either. Onward with the coconut oil!
Orignal post Food52: Sarah Jampel, May 31, 2017