It appears that we’re well into “outrageous media frenzy over terrible or misleading claims by nutrition scientists” season….
Last week I covered the “low-carb” and mortality study, and for this week’s edition of Dear Mark I’m covering the (latest) coconut oil controversy. A Harvard professor recently launched a dramatic harangue against coconut oil, calling it “pure poison.” Is it true this time? Are we indeed killing ourselves?
Let’s find out:
Speaking of fat, I’d be interested in Mark’s take regarding the latest attempt to put the kibosh on consumption of coconut oil–specifically, a Harvard professor saying it’s pure poison, probably because it’s so heavily saturated.
I can’t stand the stuff, personally. I don’t like anything made with coconut, and it doesn’t like me either, possibly because I’m sensitive to the overload of lauric acid. However, this and many other websites tout coconut products as being super healthful.
So is there any truth to these new claims that coconut oil is actually bad for us? Is there any hard evidence that points to related health issues? Or is this just more of the same-old, same-old that we saw with eggs, red meat, etc.?
I won’t even talk about the Tokelau, a Pacific Island people who obtained most of their calories from coconut. Or the Kitavans, who ate a relatively low-fat diet but got most of their fat from coconuts. Both showed pristine metabolic health, and in the case of the Tokelau, they actually got incredibly unhealthy after switching from their coconut-rich diet to one rich in mainland foods, including seed oils.
Nor will I talk too much about the animal studies, most of which have found favorable effects on health as a result of eating coconut oil.
Let’s just focus on the human trials—the intentional studies in which actual living humans ate coconut oil and then underwent lab tests to determine the health effects. Concrete, objective effects. If coconut oil is as toxic as this Harvard professor claims, the evidence should be overwhelmingly negative. A Harvard professor would never misrepresent the evidence, right?
First, there is 2017’s Effect of a Diet Enriched with Fresh Coconut Saturated Fats on Plasma Lipids and Erythrocyte Fatty Acid Composition in Normal Adults. Healthy adults either added coconut oil or peanut fat to their diet for 3 months, and researchers examined how the different fat sources affected their biomarkers. Coconut oil increased HDL levels and the proportion of an anti-inflammatory lipid subfraction in red blood cell membranes. All told, coconut oil had a neutral to beneficial effect on health.
2017 also had Physical Form of Dietary Fat Alters Postprandial Substrate Utilization and Glycemic Response in Healthy Chinese Men. As far as coconut oil’s toxicity goes, this one was a dud. Whether the men ate coconut oil or sunflower oil made no difference in their metabolic response to meals (though when the fats were in gel form, there was an effect).
Oh, but this one sounds negative: Coconut Oil Has Less Satiating Properties Than Medium Chain Triglyceride Oil. Finally! We’ve found a kink. Unfortunately, this one isn’t bad for coconut oil either. Although MCTs proved more satiating than coconut oil, the latter was still more satiating than the control oil—vegetable oil. This is actually a strong counter to the Harvard professor’s main contention that coconut oil is bad because it’s so high in saturated fat; MCTs are pure saturated fat and performed very well here. Also, most MCT oil products come from coconut oil.
Next is The Impact of Virgin Coconut Oil and High-Oleic Safflower Oil on Body Composition, Lipids, and Inflammatory Markers in Post-Menopausal Women. There were no differences in body composition. Coconut oil raised total cholesterol, HDL, and LDL, but it was a wash. Both groups ended up with the same TC/HDL ratio (one of the best markers of overall heart health we have). One person had increased inflammation due to coconut oil, but most of the others had lower inflammation. Overall, though, the “impact of VCO and SO on other [inflammatory] cytokines varied on an individual basis.” The implication is that different people had different responses to the different oils. This is known, and it’s good to see researchers admit that people are different and the individual response arguably matters more than the statistical average of the responses.
In 2016, this came out: Postprandial serum endotoxin in healthy humans is modulated by dietary fat in a randomized, controlled, cross-over study. At first glance, it doesn’t look good for coconut oil. Compared to fish oil (which reduced it) and high omega-6 oil (which was neutral), coconut oil eaten with the meal increased the levels of serum endotoxin. Endotoxins are produced by bacteria in our guts and tend to increase systemic inflammation when they make it into our bodies. Coconut oil was pretty good at helping endotoxin make it past the gut and into the body. The good news is that this did not increase systemic inflammation—but keep in mind that these were “healthy humans.” An increase in serum endotoxins may have stronger effects on inflammation in unhealthy or obese humans. Another bit of good news is that pairing coconut oil with, say, fatty fish should mitigate any rise in serum endotoxins.
There’s also A Randomized Study of Coconut Oil Versus Sunflower Oil on Cardiovascular Risk Factors in Patients with Stable Coronary Heart Disease. The title tells it: patients with heart disease added either coconut oil or sunflower oil to their diets for two years. Researchers tracked basic risk factors and the number of “events,” or heart attacks. Despite people with actual heart disease eating the “worst” oil possible, “there was no statistically significant difference in the anthropometric, biochemical, vascular function, and in cardiovascular events after 2 years.” No difference.
Heck, according to 2016’s The Effect of Coconut Oil Pulling on Streptococcus Mutans Count in Saliva in Comparison to Chlorexidine Mouthwash, the coconut oil “myth” all the “experts” love to malign—that swishing coconut oil in your mouth can reduce harmful bacterial colonization—is actually true.
It’s obvious just from looking at these very recent studies, even some of the ones with negative or neutral effects, that coconut oil is far from poison. “Experts” do themselves no credit when they ignore and misrepresent the evidence like this.
Luckily, we can read for ourselves. And we can try for ourselves.
Thanks for reading, everyone. Thoughts on this coconut oil controversy—or other health related media hype? Other studies you’d like me to look at? Have a great week.
- Nagashree RS, Manjunath NK, Indu M, et al. Effect of a Diet Enriched with Fresh Coconut Saturated Fats on Plasma Lipids and Erythrocyte Fatty Acid Composition in Normal Adults. J Am Coll Nutr. 2017;36(5):330-334.
- Tan SY, Peh E, Lau E, Marangoni AG, Henry CJ. Physical Form of Dietary Fat Alters Postprandial Substrate Utilization and Glycemic Response in Healthy Chinese Men. J Nutr. 2017;147(6):1138-1144.
- Kinsella R, Maher T, Clegg ME. Coconut oil has less satiating properties than medium chain triglyceride oil. Physiol Behav. 2017;179:422-426.
- Harris M, Hutchins A, Fryda L. The Impact of Virgin Coconut Oil and High-Oleic Safflower Oil on Body Composition, Lipids, and Inflammatory Markers in Postmenopausal Women. J Med Food. 2017;20(4):345-351.
- Lyte JM, Gabler NK, Hollis JH. Postprandial serum endotoxin in healthy humans is modulated by dietary fat in a randomized, controlled, cross-over study. Lipids Health Dis. 2016;15(1):186.
- Vijayakumar M, Vasudevan DM, Sundaram KR, et al. A randomized study of coconut oil versus sunflower oil on cardiovascular risk factors in patients with stable coronary heart disease. Indian Heart J. 2016;68(4):498-506.
- Kaushik M, Reddy P, Sharma R, Udameshi P, Mehra N, Marwaha A. The Effect of Coconut Oil pulling on Streptococcus mutans Count in Saliva in Comparison with Chlorhexidine Mouthwash. J Contemp Dent Pract. 2016;17(1):38-41.
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