What is Cholesterol?
The truth is, cholesterol isn’t a bad thing. This fat (or lipid) plays a number of crucial roles in the body, including forming cell membranes; acting as a building block for many hormones; and helping to create bile acids, which help break down dietary fat.
It becomes a problem, however, when you have too much of it in your bloodstream. It can build up into a fatty substance called plaque that can restrict blood flow, causing heart disease.
With this in mind, you’d think the logical solution would be to reduce your intake of cholesterol—animal-based foods such as eggs, shellfish, and other meat. Fortunately for you omelet fans out there, it doesn’t quite work that way. Dietary cholesterol is just a tiny part of your total cholesterol. Don’t fret, though. There are other ways to get your cholesterol in check, but before I share them with you, let’s geek out a little on how cholesterol works in your body.
1. The Nerdy Details on Cholesterol in Your Bloodstream
Most of your body’s tissues make the stuff, but your liver is particularly good at making it. So to shuttle that top-shelf cholesterol around, your liver also creates lipoprotein “taxicabs” made of protein and fat that transport cholesterol around the body via the bloodstream.
When a lipoprotein leaves the liver, it’s full of cholesterol to deliver to other body parts, where it’ll help build cells, among other activities. These lipoproteins are called low-density lipoproteins, or LDL. It’s called this because fat (including cholesterol) is less dense than protein. LDLs have a higher fat-to-protein ratio, making them less dense.
Once lipoprotein has delivered their cholesterol payload, the protein-to-fat ratio switches. This reversed ratio makes them denser, so they’re called high-density lipoprotein, or HDL. The job of HDLs is to sweep the bloodstream, picking up stray cholesterols and returning them to the liver.
Cholesterol becomes problematic when you have too many LDLs in your bloodstream. Excess cholesterol starts to break down improperly and results in a buildup of the aforementioned plaque. This is why, despite the fact that LDL does an important job in the body, it is often referred to as “bad cholesterol.” HDL, on the other hand, is referred to as “good cholesterol.”
2. What should my cholesterol be?
In truth, it’s not so much that you want to completely eradicate the “bad” and crank up the “good.” A better way to look at it is that you want a healthy balance of the two. According to the National Heart, Lung, and Blood Institute, your total cholesterol should ideally be below 200 milligrams (mg) per deciliter (dL) of blood. Ideal LDL is 100–129 mg/dL (lower for people at risk). HDL should be at least 60 mg/dL.
When you get bloodwork done, your “lipid profile” will also contain a number for triglycerides. These are another type of fat that the body uses for energy. I didn’t discuss them much in this article, but for the record, you want to keep that number below 150 mg/dL. If you’re looking to lower triglycerides, you can follow all the advice I’m about to give below.
Now, back to the original question . . .
The relationship between cholesterol intake and LDL levels shifts from person to person. It’s all a roll of the genetic dice. The human body can produce cholesterol itself, so—for most people—so many experts, including myself, don’t believe you need to deliberately include cholesterol in your diet. However, it doesn’t necessarily need to be completely avoided either. Some experts argue that some people require it in their diet because they are unable to synthesize it properly. And, for most of us, when we eat cholesterol, the body lowers its own production of it, so moderate amounts probably have little to no impact.
Following this logic, some dietary cholesterol is fine, provided it comes from quality sources. Think of it the same way you might think of simple carb consumption. Bananas, for example, are high in sugar, but their nutritional value makes up for that. Similarly, egg yolks are high in cholesterol, but they’re also very nutritious, so the good outweighs any possible bad, if it exists at all.
Aside from this, there are plenty of ways you can tweak your lifestyle to positively influence cholesterol, starting with a diet high in soluble fiber. Soluble fiber clings to dietary cholesterol and flushes it out of your system. You’ll get that from fresh fruits and veggies. Whole grains, particularly oats, also contain soluble fiber, but most people are too grain-reliant as is, so I think you’re better off targeting produce, where you’ll also get vitamins such as niacin, vitamin E, and vitamin C, as well as polyphenols, polysterols, and flavonoids, which have been shown to balance LDL and HDL levels.
You may also want to limit your sugar intake as mounting research, including a recent study in the Journal of the American Medical Association, links refined sugar to low HDL levels. It’s also well established that trans fat lowers HDL and raises LDL, so instead of avoiding the shrimp cocktail, stay away from sugary, fatty junk foods, particularly store-bought confections that use trans fat to prolong shelf life.
Over the years, various foods have been shown to help with cholesterol levels, including raw nuts and fish oil, due to the healthy fats, and green tea, due to the antioxidants. Moderate alcohol consumption has also been shown to raise HDLs, but if you don’t already drink, there’s no reason to start. There are plenty of other great, healthy foods to hedge your bets with.
3. Beyond Diet
Don’t limit yourself to just perfecting your diet. Exercise has been shown to have a profound positive effect on cholesterol levels. On the other hand, smoking has been shown to have a severe negative effect.
The role cholesterol plays in your body may seem complex, but the good news is that getting it under control is fairly simple, at least in concept. As usual, a whole-foods, predominantly fruit-and-veggie diet can work wonders for your HDLs, your LDLs, and any other DLs that might come your way.