So I've Got High Cholesterol – Now What?

So you've had a blood test and found out you have high cholesterol. Don't panic — it's one of the most common findings in Australian adults, and in many cases it's very manageable. But it's also worth taking seriously, particularly as you get older or if you have other cardiovascular risk factors.

Cholesterol science has evolved a lot over the past decade. The old narrative of 'good' and 'bad' fats — and simple rules like 'avoid saturated fat' — has given way to a more nuanced picture. This article reflects that updated understanding.

What is cholesterol?

Cholesterol is an essential fatty substance carried in the blood. Your body needs it to build cell membranes, produce hormones (including sex hormones and vitamin D), form bile acids for fat digestion, and support neurological function including memory. About 75% of your cholesterol is made by your liver — the rest comes from food.

Cholesterol is transported through the body by lipoproteins. The key ones are:

• LDL (low-density lipoprotein) — carries cholesterol to cells. Elevated LDL, particularly small, dense LDL particles, is associated with a higher risk of arterial plaque buildup. But not all LDL is equal — large, buoyant LDL particles are far less atherogenic than small, dense ones. Total LDL alone can be misleading. A Lipoprotein Particle Test measures particle size and number directly, rather than inferring it from total LDL.
• HDL (high-density lipoprotein) — helps transport cholesterol away from the arteries back to the liver for processing. Higher HDL is generally associated with lower cardiovascular risk.
• VLDL (very low-density lipoprotein) — large particles associated with triglyceride transport. Elevated VLDL and triglycerides are linked to increased cardiovascular and metabolic risk.
• Triglycerides — the main storage form of fat in the body. High triglycerides, particularly combined with low HDL, are a significant cardiovascular risk marker, and are strongly influenced by refined carbohydrate and sugar intake, not just dietary fat.
• Lipoprotein(a) or Lp(a) — a genetically determined lipoprotein that is an independent and significant risk factor for heart disease. It's rarely tested by GPs but worth checking, especially with a family history of early heart disease — it's included in our Advanced Lipid Test.

A note on the 'good cholesterol / bad cholesterol' framing: this is a significant oversimplification. Whether cholesterol is harmful depends on the type of particle carrying it, the context of your overall lipid profile, your genetics, your metabolic health, and your broader cardiovascular risk picture. A standard cholesterol panel is a useful starting point — but it doesn't always tell the full story.

What cholesterol levels should I be aiming for?

Australian guidelines recommend total cholesterol below 5.5 mmol/L when no other cardiovascular risk factors are present. If you have risk factors — such as high blood pressure, smoking, diabetes, obesity, or a personal or family history of heart disease — a total cholesterol below 4.0 mmol/L is generally advised.

The National Vascular Disease Prevention Alliance's absolute cardiovascular risk calculator at cvdcheck.org.au is a useful tool that takes into account your full risk picture, not just cholesterol in isolation.

Increasingly, clinicians are moving beyond total cholesterol to look at ApoB (a measure of atherogenic particle number), LDL particle size, and the ApoB:ApoA1 ratio as more precise indicators of cardiovascular risk. You can test all three with our Apolipoprotein ApoB Test or the full Advanced Lipid Test.

Why is high cholesterol a problem?

When atherogenic lipoprotein particles (particularly small, dense LDL) are elevated over time, they can penetrate and accumulate in artery walls, contributing to the formation of plaques (atherosclerosis). This narrows and stiffens the arteries, increasing the risk of heart attack and stroke.

That said, cholesterol is rarely the whole story. Inflammation, insulin resistance, oxidative stress, blood pressure, genetics, and lifestyle factors all contribute to cardiovascular risk. A high total cholesterol reading in isolation, without considering particle type and other markers, doesn't determine your risk. Our Cardiovascular Health Test combines cholesterol, inflammation and metabolic markers in one panel for a fuller picture, and if insulin resistance or blood sugar is a concern alongside your cholesterol, see our Weight, Metabolism & Blood Sugar testing.

What role does diet play?

Diet affects cholesterol, but the relationship is more nuanced than older guidelines suggested. Here's what the current evidence supports:

Dietary cholesterol

For most people, dietary cholesterol (from eggs, shellfish, and organ meats) has only a modest effect on blood cholesterol levels. Eggs, for example, are no longer restricted in heart-health guidelines for most individuals.

Dietary fat — it's about quality and context

The old 'saturated fat is bad, unsaturated fat is good' rule has been significantly revised. The current evidence points to food quality and overall dietary pattern mattering far more than any single nutrient:

• Whole-food sources of saturated fat — such as full-fat dairy, eggs, and unprocessed meat — behave differently in the body than saturated fats from highly processed foods. The food matrix matters.
• The type of LDL particles produced matters more than total LDL. High-carbohydrate, high-sugar diets tend to drive up small, dense LDL and triglycerides — the more atherogenic pattern. Some people on lower-carbohydrate, higher-fat diets see a shift toward larger, less atherogenic LDL particles despite a rise in total LDL.
• Highly processed seed oils (sunflower, soybean, corn, canola) are high in omega-6 polyunsaturated fats, which are prone to oxidation at high temperatures. The quality and processing method of oils matters. Cold-pressed, minimally processed oils used appropriately are different from refined seed oils used in deep-frying and ultra-processed foods.
• Omega-3 fatty acids (from oily fish, flaxseed, walnuts) support cardiovascular health by reducing triglycerides and inflammation. The balance between omega-3 and omega-6 intake is relevant, primarily because most Australians don't eat enough omega-3. You can check your own balance with an Omega 3 Index or the Essential Fatty Acids Test.
• Trans fats — found in older hydrogenated margarines and many ultra-processed foods — are clearly harmful and should be minimised. Most modern soft margarines have removed trans fats, but checking labels is worthwhile.

What a heart-healthy diet actually looks like

Rather than focusing on individual nutrients to restrict, focus on overall dietary quality:

• Eat mostly whole, minimally processed foods
• Prioritise vegetables, legumes, fruit, wholegrains, nuts, and seeds
• Include oily fish 2–3 times per week (salmon, sardines, mackerel)
• Choose quality protein sources — eggs, fish, lean meat, legumes
• Use extra-virgin olive oil as your primary cooking fat
• Minimise ultra-processed foods, fast food, refined carbohydrates, and added sugars
• Limit processed meats (sausages, deli meats, salami)
• Moderate alcohol — no more than 1–2 standard drinks per day

Foods that actively support cholesterol management include oats and oat bran (beta-glucan), legumes, psyllium, flaxseed, plant sterols (found naturally in nuts, seeds, and legumes, and added to some fortified foods), garlic, and green tea. If you'd like to check your broader nutrient status alongside your cholesterol, see our Nutrition & Micronutrients testing.

What else can I do?

• Exercise regularly — at least 150 minutes of moderate activity per week. Aerobic exercise raises HDL, lowers triglycerides, and improves insulin sensitivity.
• Maintain a healthy body weight — excess visceral fat drives insulin resistance, which worsens the lipid profile (higher triglycerides, lower HDL, more small dense LDL).
• Manage blood sugar — insulin resistance and high blood glucose significantly affect lipid profiles even before a diabetes diagnosis.
• Don't smoke — smoking damages artery walls and accelerates atherosclerosis independent of cholesterol levels.
• Manage stress — chronic stress raises cortisol, which can elevate blood glucose and drive unfavourable lipid changes over time.

What about genetics?

Genetics play a significant role in how your body manages cholesterol. Familial hypercholesterolaemia (FH) is a common inherited condition that causes persistently elevated LDL regardless of diet. The ApoE gene also influences how your body processes fat and cholesterol — ApoE4 carriers, for example, tend to have a stronger LDL response to saturated fat intake and higher overall cardiovascular and cognitive risk. You can check your variant with our APOE Genotype Test.

If you have a strong family history of high cholesterol or early heart disease, genetic testing can provide valuable context for understanding your individual risk and tailoring your approach to diet and prevention — see our full Genetic Health & DNA testing range.

When should I consider medication?

If diet and lifestyle changes don't bring your levels into a healthy range — particularly if your total cholesterol remains above 6.5 mmol/L or your calculated cardiovascular risk is high — your GP may recommend medication. Statins are the most commonly prescribed, and for people at high cardiovascular risk they have a well-established evidence base. Your GP is best placed to assess whether medication is appropriate for your individual situation.

If you can measure it, you can manage it

A standard lipid panel is a useful starting point, but for a complete picture of your cardiovascular risk, more detailed testing is available. i-screen offers:

• Cholesterol Test — $45 — total cholesterol, LDL, HDL, VLDL, triglycerides. A simple, affordable heart-health starting point.
• Advanced Lipid Test — $295 — includes LDL particle size and subfractions, ApoB, ApoA1, ApoB:ApoA1 ratio, and Lp(a). This gives a far more precise cardiovascular risk picture than standard cholesterol alone.
• Apolipoprotein ApoB Test — $69 — ApoB and the ApoA1 ratio, a superior predictor of cardiovascular risk compared to standard cholesterol.
• Lipoprotein Particle Test — $249 — LDL particle number and size.
• APOE Genotype Test — $230 — identifies your ApoE variant to help personalise dietary and preventive recommendations.
• Omega 3 Index — $99 — measures your omega-3 status and omega-6:omega-3 ratio.
• Cardiovascular Health Test — $199 — a multi-marker panel including CRP (inflammation), homocysteine, and metabolic markers alongside cholesterol.

Monitoring changes over time is more informative than a single result. Regular testing lets you track how diet, lifestyle changes, or medication are actually affecting your numbers. For the full range of heart and cardiovascular tests, including coronary calcium scoring and our most comprehensive cardiac panel, visit Heart & Cardiovascular Health testing.

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This article is intended for general educational purposes and does not constitute medical advice. Always consult your GP or a qualified health professional regarding your individual health circumstances. i-screen provides wellness and educational services only.