"Coconut Oil and the Boost in HDL 'Good' Cholesterol"
We've known for nearly a half century,
according to 200 of the country's leading experts in cardiovascular diseases
in a report representing 29 national medical organizations,
including the American Heart Association
and the American College of Cardiology that
"Coconut oil is one of the most potent agents"
for elevating the level of cholesterol in the blood.
Studies showing coconut oil elevates cholesterol date back to 1955,
when it was first shown experimentally that switching someone from coconut oil
to something like soybean oil could drop cholesterol from like 200 down to 150.
Coconut oil can significantly raise cholesterol levels within hours
of consumption, a significantly increased blood cholesterol
within hours of eating a slice of cake made from coconut oil—
or from cod liver oil for that matter—mmm—
but not from the same cake made from flaxseed oil.
Coconut oil may even be worse than tallow, or beef fat,
but not as bad as butter.
The latest interventional trial was published in March 2017,
a month-long randomized, controlled, crossover study looking at
the impact of two tablespoons a day of virgin coconut oil,
and it elevated cholesterol about 14% over control,
consistent with the other seven interventional trials
published to date in this 2016 review.
But wait, saturated fats can make so-called good cholesterol, HDL, go up.
So, what's the problem?
The problem is that doesn't seem to help.
Having a high blood HDL level is no longer regarded as protective.
What? But wait a second.
Higher HDL is clearly associated with lower risk of heart disease.
In fact, HDL levels are among the most consistent and robust predictors
of cardiovascular disease risk.
Ah, but see, there are two types of risk factors, causal and non-causal.
Association does not mean causation, meaning that just because
two things are tightly linked doesn't mean one causes the other.
Let me give you an example.
I bet that the number of ashtrays someone owns
is an excellent predictor of lung cancer risk.
I bet study after study would show that link,
but that does not mean that if you intervene and lower
the number of ashtrays, their lung cancer risk would drop,
because it's not the ashtrays that were causing the cancer, it was the smoking.
The ashtrays were just a marker of smoking,
an indicator of smoking, as opposed to playing a causal role in the disease.
So just like having a high number of running shoes and gym shorts
might predict a lower risk of heart attack,
having a high HDL predicts a lower risk of heart attack,
but raising HDL, just like raising the number of gym shorts,
wouldn't necessarily affect disease risk.
How do you differentiate between causal and non-causal risk factors?
You put it to the test.
The reason we know LDL cholesterol really is bad
is because people who were just born with genetically low LDL
end up having a low risk of heart disease,
and if you intervene and actively lower people's LDL through diet or drugs,
their heart disease risk drops. Not so with HDL.
People who live their whole lives with high HDL levels
don't appear to have a lower risk of heart attack,
and if you give people a drug that increases their HDL, it doesn't work.
That's why we used to give people high dose niacin to raise their HDL,
but it's time to face the facts.
The lack of benefit of raising HDL seriously undermines
this concept of HDL being a causal risk factor.
In simple terms, high HDL may not protect the heart.
We should concentrate on lowering LDL.
And so specifically as this relates to coconut oil,
the increase in HDL is of uncertain clinical significance,
but the increase in LDL cholesterol you get from eating coconut oil
would be expected to have an adverse effect
on atherosclerotic cardiovascular disease risk.
But what about the MCTs (Medium-chain triglycerides)?
Proponents of coconut oil,
who lament that this whole "coconut oil causes heart disease" thing
has created this bad image for their national exports,
assert that the medium chain triglycerides—
the shorter saturated fats found in coconut oil—
aren't as bad as the longer chain saturated fats in meat and dairy.
And what about that study that purported to show low rates
of heart disease among Pacific Islanders who ate tons of coconuts?
I'll cover both these topics next.