The news rocketed around the internet last week under headlines declaring “Coconut oil is not a magical health food after all,” “Coconut oil ‘as unhealthy as beef fat and butter,’” and “Careful: Coconut oil may not be safe.”
Behind the furor was an innocuous American Heart Association report reviewing the health harms of saturated fats and urging Americans to eat less of them. But the finding that seemed to come as the biggest surprise to the public was the inclusion of coconut oil on the list of the most egregiously unhealthy fats. Coconut oil has more saturated fat than butter or lard, the report pointed out, and studies have shown it increases unhealthy LDL cholesterol.
But those facts have been known for years — and still, a survey conducted last year by the polling firm Morning Consult found, 7 out of every 10 Americans consider coconut oil a healthy food.
So how did that healthy reputation come to be? The answer traces back in part to the work of Marie-Pierre St-Onge, a professor of nutrition at Columbia University. Two papers published by St-Onge’s group in 2003 showed that eating and cooking with medium chain fatty acids — a type of molecule found in coconut oil — can help dieting adults burn fat. Study participants ate specially prepared meals rich in medium chain fatty acids for four weeks. MRI and metabolic data showed that medium chain fatty acids reduced their overall fat levels and helped dieters burn energy.
But, St-Onge points out, coconut oil is only 14 percent medium chain fatty acids. Participants in her studies received 100 percent medium chain fatty acids, a custom-made concoction.
Still, in subsequent years that research has been seized upon by health food marketers. Dieting blogs praise coconut oil as a “fat-burning diet miracle” and dietary supplements containing the oil advertise their supposed weight-loss benefits on the label.
“I think the data that we’ve shown with medium chain fatty acids have been extrapolated very liberally,” said St-Onge. “I’ve never done one study on coconut oil.”
Another aura of healthfulness around the oil is in boosting “good” cholesterol. Some studies have found that people who eat more coconut in general have higher healthy HDL cholesterol.
“Fat in the diet, whether it’s saturated or unsaturated, tends to nudge HDL levels up, but coconut oil seems to be especially potent at doing so,” Harvard nutrition professor Dr. Walter C. Willett wrote in a blog post on the subject.
But, Willett noted, alternatives such as olive oil and soybean oil, which are mainly unsaturated fat, both lower LDL and increase HDL — making them a clearly healthier choice for cholesterol overall.
For those wondering what to cook with, St-Onge suggests healthier options supported by the scientific literature.
“The state of the science right now supports mono-unsaturated fats and poly-unsaturated fats — vegetable oil, olive oil, corn oil — as being healthy options,” she said.