Cholesterol is a type of waxy lipid – a fat. Thus, it doesn’t dissolve in water, and it makes a great barrier (along with other fats) for each and every cell membrane in our body. So it’s a divider. But wait, it’s also a uniter (it plays both sides against the middle. It can’t help itself). We use cholesterol to make bile, and without bile, you can’t digest fat. It’s an emulsifier. That means it brings fat and water together (think salad dressing – the oil and other stuff are held together with emulsifiers. You’ll see if you read the package. Be not afraid). Anyway, bile gobbles up fat and holds it in droplets where enzymes can come along and break it down so we can cushion our organs, insulate ourselves and scream about the efficient fat storehouse that is our rear end.
Bile is made in the liver and stored in the gall bladder. Consume or make too much cholesterol, pack on the pounds by eating too much fat, or lose weight too quickly, and you could make some crunchy little gallstones. Gallstones are made of cholesterol. If you have a gallstone, you suddenly have no trouble at all locating this organ: It’s tucked right under the liver on the right hand side. Sometimes this necessitates removing the gallbladder. When the gallbladder is removed, the liver still makes bile and you can still digest fat.
We make Vitamin D under our skin using cholesterol. Ten minutes in the sun without sunscreen (and no more) will do it. Estrogen and testosterone, those pesky hormones are made using cholesterol. It’s pretty useful stuff when all is said and done, so long as there isn’t too much.
Cholesterol is made in our liver, and it makes all we need. That’s how other animals make it too – so it stands to reason that if an animal has a liver, the animal’s flesh contains cholesterol, and if a product comes from an animal with a liver (like egg yolks), those have cholesterol too. (And for heaven’s sake, is this not enough reason to just say no to EATING an animal’s liver?!)
If the fat is removed from an animal-based food, so is the cholesterol, because it’s a type of fat. Thus, 2% milk has cholesterol, but fat free milk does not. Fat free cheese? No cholesterol. Avocados and nuts? They’re off the hook: No liver, no cholesterol. If it comes from a plant, it doesn’t have cholesterol.
Shrimp are high in cholesterol, and yes, they have a (very busy) little liver-like organ in there.
If you’re consuming cholesterol, the recommendation is that you keep consumption under 300 mg a day. Cholesterol content is listed right there on the food label, and when there isn’t a food label, you can use this link (http://www.ars.usda.gov/Main/docs.htm?docid=15869) to download a list of foods with their cholesterol content. Page down and choose “cholesterol,” download the “A” pdf, and be happy you have a food-geeky friend in me. Unfortunately, cholesterol alone isn’t the only contributor to high blood cholesterol.
Blood cholesterol? You want that under 200 mg/deciliter. (Ask for a copy of your blood test results so you have them on file to have and hold — it’s your body, your blood, your info and no one will get mad about it). Many doctor’s prefer total blood cholesterol lower than that (150 is a good place to be if you want to remain heart-attack free). This is where statins come in. But blood cholesterol isn’t just affected by cholesterol: Overall fat consumption, especially of saturated and trans fats, will raise blood cholesterol. (Please see the LDL/HDL post below this for a link about guidelines for the proper ratio of each).
And what of this soluble fiber, ala oatmeal? Well, that stuff tends to bind to bile and take it out of our system. We usually recycle a fair amount of bile (our body is one heck of a recycling center), but if the soluble fiber from consuming apple pectin and oatmeal and such drags bile out of us, our liver has to make more, and that means it has to use the cholesterol we have on hand. The liver takes it out of the bloodstream, lowering our blood cholesterol. Good deal, right? It also stands to reason that if you’re eating oatmeal for breakfast instead of eggs, bacon and buttered white toast that you won’t be taking in as much cholesterol either.
Just as a little extra tidbit, plants make sterols and stannols of their own, and they are chemically similar to animal cholesterol but for one really important difference: they appear to exert healthy effects on us and lower our cholesterol by decreasing cholesterol absorption. Benecol and several other products tout their plant sterol and stannol content. Just thought you should know what they’re on about.