What is cholesterol — and what actually raises it?
Cholesterol, fat and LDL are often talked about as if they're the same thing. They're not. Here's the simple version — what raises your LDL, what doesn't, and what to do about it.
For most people, saturated fat raises LDL more than cholesterol in food. Eggs and prawns contain cholesterol, but their effect is usually small. Coconut oil contains no cholesterol — but it can still raise LDL because it's very high in saturated fat. The best move is to replace saturated fat with unsaturated fat and eat more fibre-rich foods.
Cholesterol and fat are not the same
A simple but important point. They're related, but they're different things — and that's where most cholesterol confusion starts.
Fat is what you find in oils, butter, meat, nuts and fish. Your body uses it for energy and to build cells.
Cholesterol is a different kind of molecule. The body uses it to build cell walls and hormones. Because cholesterol doesn't dissolve in water, it travels through your blood inside little carrier particles. The most important carrier is called LDL.
What actually raises your LDL?
Two things in food can affect LDL: cholesterol itself, and saturated fat. For most people, saturated fat is the bigger problem.
When you eat cholesterol, your body doesn't just absorb all of it. Some passes through, and your liver makes a bit less of its own to compensate. That's why cholesterol in food usually has a smaller effect on your blood than people think.
Saturated fat is different. It slows down the way your liver clears LDL particles out of your blood. Fewer LDL particles are removed — so more stay behind, and your LDL number rises.
So what about eggs and prawns?
Egg yolks and prawns contain cholesterol, yes — but they're low in saturated fat. For most healthy people, an egg a day is fine and unlikely to push your LDL up much. The problem is usually the bacon, butter and cheese that come with the eggs, not the eggs themselves.
If you have familial hypercholesterolaemia, diabetes, or known heart disease, the rules are tighter. Talk to your doctor about what's right for you.
Coconut oil — the surprising one
Coconut oil is sold as "natural" and "plant-based" — but it can still raise your LDL.
Coconut oil contains no cholesterol — plants never do. But it's roughly 80–90% saturated fat. So even though the label says "cholesterol-free," coconut oil can still raise your LDL through the same mechanism as butter.
Olive oil, on the other hand, is mostly unsaturated fat. It does the opposite — it helps lower LDL when it replaces saturated fat. So while coconut oil and olive oil are both plant oils with no cholesterol, they have very different effects on your heart.
What to eat instead
The most useful advice isn't "avoid cholesterol" or "cut all fat." It's simpler than that.
Simple swaps that help lower LDL
Add more fibre
Foods like oats, barley, legumes, apples and pears are rich in soluble fibre. Soluble fibre binds to cholesterol in your gut and helps your body get rid of more of it. It's one of the simplest things you can add to your day to help lower LDL.
Common myths
"If a food has cholesterol, it must be bad for my LDL."
Not really. Cholesterol in food can raise LDL a little in some people, but the effect is usually small. Eggs and prawns are good examples — they contain cholesterol but they're low in saturated fat, and most people can eat them in normal amounts without much effect on their LDL.
"If a food has no cholesterol, it can't raise my LDL."
False. Coconut oil and palm oil contain no cholesterol but they're very high in saturated fat, and both raise LDL.
"All fat is bad."
False. Unsaturated fats — like olive oil, avocado, nuts, seeds and fish — are part of every heart-healthy diet. The goal isn't no fat. It's better fat.
"Plant-based always means healthy."
Not quite. Coconut oil and palm oil are plant-based but high in saturated fat. Sugar, white bread and many "vegan" snacks are plant-based too — and they're not necessarily good for your heart.
"Plant sterol margarine works like a statin."
No. Plant sterols help a little — about 8–10% off your LDL at typical use. Statins and other lipid-lowering medications are far more powerful, and they're the right choice when medication is needed.
What to remember
If you take only three things from this page, take these:
Concerned about your cholesterol?
Dr Reza Moazzeni is a consultant cardiologist in Westmead, Sydney, with a focus on cholesterol, prevention of heart disease, and familial high cholesterol. A GP referral is required.
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