Confused by Cholesterol? Here’s What Really Matters

If you’ve ever been told your cholesterol is “a bit high”, you are not alone. Many of my clients leave the GP surgery with a print-out of numbers and very little explanation of what they actually mean, or what is worth focusing on first. This can be quite worrying, particularly if you have a family history of heart disease. 

This blog will walk you through the basics in a practical way. We will take a look at what cholesterol actually is, how to interpret the key markers on a standard lipid panel (cholesterol report), and look at why two additional tests, lipoprotein(a) (Lp(a)) and apolipoprotein B (ApoB), can add some important context. And then we’ll look beyond cholesterol, because heart health is about far more than just a single number.

Cholesterol: friend, not foe

Cholesterol is a waxy, fat-like substance that your body uses to build cell membranes, make vitamin D, and produce hormones and bile acids. It is super important for your wellbeing! Your liver makes most of the cholesterol you need, and you also get a small amount from food.

Cholesterol only becomes a problem when cholesterol-containing particles build up in artery walls over time, contributing to atherosclerosis (narrowing and hardening of the arteries). This process is influenced by many things - including blood pressure, blood sugar balance, inflammation, smoking, genetics, menopause, stress, sleep and how much exercise you do.

What is a lipid profile actually measuring?

A standard lipid profile usually includes:

Total cholesterol

This is the overall amount of cholesterol in your blood. It is a broad measure and does not tell you how cholesterol is being carried.

LDL cholesterol (often called “bad cholesterol”)

LDL stands for low-density lipoprotein. LDL particles carry cholesterol from the liver out to tissues. When LDL particles are present in higher numbers, or are circulating for longer, the risk of cholesterol being deposited in artery walls may be increased.

HDL cholesterol (often called “good cholesterol”)

HDL stands for high-density lipoprotein. HDL particles are involved in reverse cholesterol transport, moving cholesterol away from tissues back towards the liver – they are like the rubbish truck coming and taking away the waste. HDL is not a simple “the higher the better” marker, but in general, low HDL can be a sign of metabolic risk.

Triglycerides

Triglycerides are a type of fat used for energy storage. They often rise with insulin resistance (when blood sugar isn’t under control), excess alcohol intake, high intakes of ultra-processed foods, and low activity levels. They can also rise if the blood test is taken soon after eating, which is why your GP may request a fasting test.

Non-HDL cholesterol

This is not always reported, but it is easy to calculate: total cholesterol minus HDL cholesterol. It represents the cholesterol carried by all potentially atherogenic particles (not just LDL), ie the particles that are linked to potential heart disease. In UK practice, non-HDL cholesterol is often used in risk assessment and monitoring. 

Why “LDL cholesterol” is not the whole story

LDL cholesterol tells you how much cholesterol is being carried inside LDL particles. But it does not tell you how many particles are carrying it.

This matters because atherosclerosis is driven by the number of atherogenic particles entering the artery wall. Two people can have the same LDL cholesterol but a very different number of LDL particles. This is one reason why measuring something called ApoB can actually be more helpful in ascertaining your risk of heart disease.

ApoB: the marker many people have never heard of

Apolipoprotein B (ApoB) is a protein found on the surface of atherogenic lipoproteins (including LDL, VLDL and remnants), ie the cholesterol carriers that may lead to heart disease. Each particle carries one ApoB, so ApoB is effectively a count of the number of “risk-carrying” particles.

Recent expert discussions and guideline conversations increasingly highlight ApoB as a strong predictor of cardiovascular risk, particularly when LDL cholesterol alone may underestimate risk (for example, in insulin resistance or higher triglycerides). 

When might ApoB testing be useful?

ApoB is not essential for everyone, but it is worth discussing with your GP (or clinician) if any of these apply:

• A family history of early heart disease
• Type 2 diabetes, prediabetes, PCOS, fatty liver, or metabolic syndrome
• Higher triglycerides
• “Normal” LDL cholesterol but ongoing concern about risk, especially if other markers or symptoms suggest metabolic strain

This is something you can request from your GP, or there are many private labs that offer this measurement. If this is something that you’d like to look at, please do get in touch as this is something that I can potentially help with.

Lp(a): a genetic risk factor worth knowing about

Lipoprotein(a), written as Lp(a), is an LDL-like particle with an additional protein attached (apolipoprotein(a)). Lp(a) is largely genetic and remains fairly stable across your lifetime.

However, elevated Lp(a) is now recognised as an independent risk factor for cardiovascular disease. It can contribute to risk even when other cholesterol markers look “fine”. European guidance and consensus documents support measuring Lp(a), often at least once in adulthood, to identify inherited elevation and refine risk assessment. 

Research shows that high Lp(a) increases heart disease risk by acting like "sticky" LDL cholesterol, promoting plaque buildup (atherosclerosis) and blood clots in arteries, potentially leading to heart attacks and strokes, even with normal cholesterol. This is because its unique protein (Apo(a)) hinders plaque breakdown and encourages clot formation. This genetic factor causes more aggressive plaque, calcification, and inflammation, independently raising cardiovascular danger, especially with other risk factors present. 

Levels are largely determined by genetics (inherited from your parents), explaining why some people develop severe heart disease early without typical risk factors. It's often overlooked in routine checks but is a major contributor to premature cardiovascular disease, according to UK experts like the British Cardiovascular Society. Your level of Lp(a) is believed to be the same from the age of 5 onwards and can’t be massively changed by diet and lifestyle. That’s why it’s worth getting it checked at least once in your lifetime to help determine your risk. 

A note on numbers and units

Lp(a) can be reported in mg/dL or nmol/L. You cannot reliably convert between the two because the particles vary in size between individuals.

A commonly used threshold for increased risk is around 50 mg/dL or 125 nmol/L, but your full clinical picture matters too. 

Can you lower Lp(a) with diet?

Because Lp(a) is genetic, lifestyle changes tend not to shift the number very much. The focus is usually on lowering overall risk by improving other modifiable factors (LDL cholesterol, blood pressure, blood sugar, inflammation, smoking status, fitness, sleep). 

Specialist medications specifically targeting Lp(a) are under investigation, but lifestyle still matters because it reduces the total risk burden. 

How can you test ApoB and Lp(a) in the UK?

Both tests are simple blood tests. They are not always included in routine NHS lipid panels, so you may need to request them.

A practical approach is:

1. Ask your GP whether ApoB and/or Lp(a) are appropriate for you, based on your family history and overall risk.
2. If they are not available locally, a private blood test may be an option, and this is something I can organise for you if you are interested.

If you have a known high Lp(a), it is also worth telling close relatives, as this can run strongly in families and testing can be helpful for them too. 

Cholesterol is one piece of heart health. Blood pressure is another

High blood pressure increases strain on artery walls and is a major driver of cardiovascular risk. Nutrition and lifestyle changes can make a meaningful difference.  A large meta-analysis of randomised trials found the DASH dietary pattern reduces blood pressure in adults with and without hypertension. 

Separately, a dose response meta-analysis of clinical trials shows that reducing sodium intake lowers blood pressure, with stronger effects in those with higher starting blood pressure. 

As we age, keeping an eye on your blood pressure can be very useful. Blood pressure increases with age largely because arteries naturally become stiffer, thicker, and less flexible due to biological aging and wear-and-tear, forcing the heart to work harder to pump blood through them. This stiffening, known as arteriosclerosis, means blood vessels can't expand as well as they once did, leading to higher pressure against artery walls, even with healthy habits. Other contributing factors include lifestyle changes, genetics, and other medical conditions, but the vascular stiffening is the main physiological driver.  Using a home blood pressure kit can be helpful but make sure to test your blood pressure three times in a row – taking an average of the three – and try to take it at the same time of day each time. Take these results to your GP to discuss.

What actually helps in real life? Evidence-based priorities

Cardiovascular disease affects more than 7 million people in the UK alone, causing about a quarter of all deaths and 1 in 4 premature deaths. So, it’s super important to keep an eye on our heart health! There are number of changes that we can make to our diet and lifestyle to help improve our odds. If you are trying to support cholesterol, blood pressure and overall cardiovascular risk, these are the foundations I prioritise with my clients.

• Build meals around a heart-supportive pattern

A Mediterranean-style dietary pattern has consistently been associated with improved cardiovascular outcomes across multiple high-quality reviews. 

In practice, this looks like:
Plenty of vegetables, beans and lentils, fruit, extra virgin olive oil, nuts and seeds, wholegrains where tolerated, and regular fish, alongside much less ultra-processed food.

• Focus on the fats that genuinely move the needle

The strongest nutrition evidence is not about “low fat” diets. It is about the type of fat.

When we talk about fats and heart health, the conversation often becomes overly simplistic. Saturated fat is frequently grouped together as something to avoid, but the evidence does not support treating all saturated fats as equal.

Whole-food fats such as butter, ghee and coconut oil have been part of traditional diets for generations and are chemically stable, particularly at higher cooking temperatures. In contrast, the strongest evidence of harm relates to industrial trans fats and highly processed sources of saturated fat, such as those found in commercially baked goods, pastries, deep-fried foods and processed meats.