Welcome back to my blog! In my last article (An Eggcellent Idea, check it out!), I promised you all an article unveiling the facts about
cholesterol. So let’s start with what I think you guys already know, and let me
know if it sounds familiar:
There are two types of
cholesterol: HDL and LDL. HDL is good cholesterol, so we want high levels
(H-igh for HDL), while LDL is bad cholesterol, so we want low levels (L-ow for
LDL). If our blood levels of cholesterol are high, then we need to cut out
dietary sources of cholesterol.
Sounds about right?
Wrong.
First Things First, What Is Cholesterol?
Cholesterol is a molecule that makes up part of your cell membrane to
ensure structural support and membrane fluidity for nutrient transport. It is
also used for myelin synthesis (the protective sheath around your neurons), brain
plasticity (your brain’s ability to change or reorganize it’s neural pathways according to the stimulation it receives), bile acid production (to digest fats), hormone
synthesis (testosterone, estrogen, progesterone, cortisol, vitamin D), etc.
Needless to say that cholesterol plays a very important role in your body.
But I didn’t mention LDL and HDL yet. Actually, they aren’t
even cholesterol at all. They are low-density and high-density LIPOPROTEINS,
which are protein-based carriers of cholesterol, triglycerides and other
fat-soluble molecules, since fat-soluble molecules don’t mix in your blood.
Think of it this way: oil and water don’t mix, but cholesterol is like oil and
your blood is 92% water, so the oil needs a carrier to be transported across
the water.
How Does LDL Get A Bad Rep?
For this next part, I will borrow an analogy from a book
called Genius Foods, by Max Lugavere. I will cite it at the end of this article
and I strongly recommend reading it.
Imagine two highways. Highway A has one hundred cars on the
road, each with one passenger, while highway B has 5 buses with 20 passengers
each. As you know, highway A will be more prone to accidents and traffic. Which
highway would you choose to take to work? I would definitely choose highway B.
In our body, cholesterol passengers all start on highway B,
in big buses. As the buses empty out, when the cholesterol passengers reach
their destination, they shrink to be more like cars, making them “small and dense”, thus becoming like highway A. Now this isn’t an issue
if the lipoproteins go back to the liver to be recycled, avoiding congestion.
The issue arrives when the LDL particles become oxidized (oxygen sticks to them
and changes the molecule, like a rusty car) or glycated (sugar sticks to them),
damaging the molecules OR that there is an issue with your liver reabsorbing
them altogether because it is too busy processing concentrated carbs, alcohol,
toxins or oxidative stress. Then, the small dense LDL particles clog up your
bloodstream, making it look more like highway A, leading to plaque formation.
How Do I Reduce My Cholesterol?
As I mentioned in my last article, your liver makes 80% of
the cholesterol that you need. Studies have repeatedly shown that the
cholesterol you eat doesn’t significantly change your blood cholesterol levels
at all! For this reason, what we want is to avoid our LDL particles becoming damaged or our liver being too busy to recycle them. This involves eating plenty of antioxidants, which are in most fruits and
vegetables, such as dark leafy greens and berries. You also want to keep your
liver happy by reducing sources of toxins, alcohol, but also very high levels
of carbohydrates that it would need to process. Eating good sources of fibre
(also found in most fruits and vegetables) will also give your liver a chance
to slowly process the food you eat instead of overloading it with work. And
most of all, you’ll want to reduce the amount of processed foods that you eat.
The more whole the food is, the better.
High-DL
As for HDL, they are like clean-up trucks that pick up
excess cholesterol and bring it back to your liver to be converted into bile
and sent away. There are a few ways to increase your HDL levels, including
eating sources of monounsaturated fats (extra virgin olive oil being the best
example, but also coconut oil, avocado oil, macadamia nuts, etc.), reducing
alcohol intake and EXERCISE. EXERCISE. EXERCISE.
So it isn’t as much the level of LDL that is harmful, but
the type of LDL particles that you have (small dense LDL being unwanted) and
the ratio of LDL to HDL that is in your body (wanting as low a ratio as
possible). And as a quick side note, saturated fats increase both your LDL and
your HDL, but bending the ratio in your favor by increasing your HDL more.
When medical doctors ask to lower your LDL and raise your HDL, they
are asking for you to move a mountain because HDL production is actually
controlled by your amount of LDL. The more LDL you have, the more easily your
body will produce HDL. You can’t do both. The important part is to have a lower
LDL to HDL ratio. And if you increase your HDL, your total cholesterol will
also increase, which your medical doctor might also ask you to reduce simultaneously.
For a mathematical explanation on this topic, please read this very interesting article.
The next time your medical doctor talks about raising good and lowering
bad cholesterol, do me a favor and reply that LDL and HDL are not cholesterol,
but cholesterol carriers!
*** Disclaimer: As usual, recommendations made on this blog are for the general healthy population. If you have any doubts regarding your nutritional health, I strongly recommend that you consult a registered dietitian. Stay tuned, as I will be graduating from McGill university and be a registered dietitian recognized by the OPDQ in December 2018!
Sources:
Lugavere, Max. (2018). Genius Foods. Harper Wave. 388 p.
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