Dec 102012
Photo courtesy of yaraaa

Once upon a time, there was an oil molecule and a water molecule.

Try as they might, they couldn’t mix. So they kept to themselves. The End.

Oh, you’ve heard this one before? Well, that’s where our tale of cholesterol begins.

Humans are 75% water. Blood, our method of transporting stuff throughout the body, is water-based. (The bloodstream is like our body’s internal subway line.) So how do we transport fats—that’s oil, folks—in a water-based system? What is nature to do?

In order to transport it, our body coats the fat with cholesterol. Cholesterol is hydrophilic, meaning water-friendly. Fat is hydrophobic, meaning water-unfriendly. The more fat you eat, the more cholesterol your liver has to produce to transport the stuff. No ifs, ands or buts. Higher fat intake = higher cholesterol.

However, cholesterol isn’t just some evil demon we have to fight off. Cholesterol is used for many other things within the body, that’s why we produce it. Like this book from Harvard says:

“Cholesterol performs three main functions:

  1. It helps make the outer coating of cells.
  2. It makes up the bile acids that work to digest food in the intestine.
  3. It allows the body to make Vitamin D and hormones, like estrogen in women and testosterone in men.”

But there are many kinds of cholesterol, and they affect your cardiovascular health differently. You’ve probably heard of “good” and “bad” cholesterol. HDL is the good kind, and LDL is the bad kind. As these acronyms mean less than goat turd to me, I have devised a mnemonic to help me keep them straight:

H = Happy

L = Lame

I doubt Mark Twain could’ve come up with better.

LameDL is the cholesterol that increases with your fat intake. HappyDL’s primary goal in life is to scavenge LameDL from your blood. Because when LameDL is left to just float around in your bloodstream, it can be a problem. Trigger-happy immune cells will attack it. (Immune cells can get a little trigger-happy sometimes. Particularly when a person is unfit or under stress.)

Your body, in its infinite, mysterious wisdom, recognizes that this is a bad thing. Your body, however, is very poor at writing a blog post explaining why it’s a bad thing, so I will take the initiative here. When an immune cell decides to attack a LameDL molecule. it shoots oxidants at it. That’s how some immune cells work, you see, by using oxidants to kill foreign entities. (Whew, that’s another post entirely.) 

But shooting oxidants at the LameDL doesn’t, like, vaporize it or anything. Geez, it’s not Star Wars in there. Lower your expectations a tad.

Instead, shooting oxidants at the LameDL turns it into something different altogether. We call it a “foam cell.” Foam cells are a pain in your ass, because they are sticky. As in, they stick to the walls of your arteries. So in an attempt to keep the inner walls of your artery smooth, your artery wall literally starts to grow around the foam cell. Creepy. So after a while, there’s just a lump in the artery wall. And as time passes, it hardens.

The more foam cells stuck to your artery walls, the more your artery is obstructed. And if your artery is obstructed enough, you’re at risk for a heart attack. But that’s not the main danger. The more common danger—the cause of most heart attacks, actually—is that these hard chunks can break off under the pressure of all that blood trying to push past. Suddenly, there’s a big chunk flowing through your blood stream. What happens if it runs up against another partially-blocked artery?

Yes. Heart attack.

Or, another possible scenario: because these chunks have hard, inflexible exteriors, they’re prone to bursting. And the stuff inside is not the kind of stuff that should be floating around willy-nilly. Your body recognizes this and triggers an immune system response. More immune cells attack the stuff, which causes more foamy junk. So if a big enough chunk bursts, the resulting junk can block the entire artery.

Thankfully, as with everything nature does, there is balance:

» Eating foods that contain fat increases your LameDL, but

» doing cardio exercise increases your HappyDL.

(The real kind of cardio, mind you, not the lazy, walking or gardening kind. 30 minutes of vigorous activity, 3-5 times a week.)

See, nature gives you a way to keep all this nastiness in check. You just gotta use it.

*Interesting bonus fact for those who’ve made it this far: many people have both high blood pressure and high cholesterol, but that doesn’t mean one has caused the other. Or that the two go hand in hand

In fact, the relationship between high cholesterol and heart disease and/or stroke is not very strong. Both are complicated processes that involve more than just cholesterol. Hundreds of things can affect them.

**Bonus fact number two: High blood pressure is actually a stronger predictor of heart attack risk.

***Bonus fact number three: Guess what the strongest predictor is for mortality, including death from heart attack or stroke? A low VO2 max score.

Yes. Yes we are strumming that old harp.

So go get it.



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