High cholesterol isn’t just about one number: Cardiologist explains LDL, ApoB, Lp(a) and how to lower your real heart attack risk

For years, cholesterol has been painted as the enemy. A single number on a blood test often decides whether someone feels relieved or alarmed. But the truth is more layered.
As Dr Sagar Shah, Consultant Cardiologist at Apollo Hospitals, Sheshadripuram, Bangalore, puts it, “For a long time, the message about cholesterol and lipids has been clear: it is bad. Whenever we see our blood reports, we are worried about cholesterol. But once you research more you find out that there is more to this than just a number, and it is quite interesting.”
Cholesterol is not simply “good” or “bad.” It is essential for life. The real danger lies in how it travels in the body, how many particles circulate in the blood, and how long they stay there.

Cholesterol exists in every cell. It forms part of the cell membrane and keeps it stable. Dr Shah explains, “Cholesterol is a basic building block of the cell, and not just a waste product or a villain which just clogs our arteries.”

Each cell can produce its own cholesterol. It acts like mortar between bricks, giving strength while allowing flexibility. It also serves as the raw material for hormones such as cortisol, estrogen, and testosterone. Even bile acids, which help absorb vitamins A, D, E, and K, come from cholesterol.

Without cholesterol, life would not function.

Cholesterol cannot float freely in blood. Blood is mostly water, and cholesterol is fat. So it needs a carrier. One of the main carriers is LDL, or low-density lipoprotein.

Dr Shah describes it simply, “The issue is usually about transportation… To move around it needs a ride, the most common ride is called the LDL.”

When LDL particles are too many, they begin to penetrate artery walls. The immune system reacts. Inflammation follows. Over time, fatty streaks turn into plaque. If that plaque ruptures, a clot forms. That clot can block blood flow and cause a heart attack.

This process is known as atherosclerosis. The NIH has reported that cardiovascular disease accounts for nearly 28 percent of all deaths in India, with high LDL being a major contributor.

Lower LDL levels consistently reduce heart attack risk. This is supported globally by long-term research from bodies such as the World Health Organization.

HDL, or high-density lipoprotein, is often called “good cholesterol.” It helps carry excess cholesterol back to the liver for disposal.

But modern science shows that simply having high HDL does not cancel out high LDL. The balance and the total particle count matter more.

In short, HDL helps. But it does not grant immunity.

Standard lipid tests measure cholesterol in milligrams per decilitre. That shows the weight of cholesterol. But risk depends more on the number of particles.

Each LDL particle carries one ApoB protein. So measuring ApoB tells doctors how many atherogenic particles are present.

Think of traffic. A traffic jam depends on the number of cars, not their combined weight.

For Indians, this matters greatly. Many people have “normal” LDL levels but high ApoB due to insulin resistance or abdominal obesity. The Ministry of Health and Family Welfare has repeatedly highlighted rising metabolic syndrome rates in urban India, which increase hidden cardiovascular risk.

ApoB testing often uncovers danger earlier than a routine lipid panel.

Lipoprotein(a), or Lp(a), is a genetically determined particle. It behaves like LDL but is stickier and more inflammatory.

Dr Shah calls it a serious concern. It promotes plaque formation and increases clot risk. About 20 percent of people globally have elevated Lp(a). Diet and exercise barely change it.

International guidelines now advise that every adult should check Lp(a) at least once in their lifetime. If it is high, doctors usually aim for stricter LDL reduction to offset that genetic risk.

The brain contains a large amount of the body’s cholesterol. It needs it for nerve insulation and signalling.

​Research suggests that high cholesterol in midlife increases the risk of dementia decades later. The National Institute on Aging has reported associations between elevated midlife cholesterol and later cognitive decline.

Protecting arteries in the 40s and 50s may protect memory in the 70s and 80s.

Lowering cholesterol is not about eliminating fat from life. It is about reducing harmful particles and inflammation.

Evidence-based strategies include:

Reducing saturated fat and eliminating trans fats
Increasing fibre intake to 25-40 grams daily
Exercising at least 150 minutes per week
Controlling diabetes and blood pressure
Stopping tobacco use completely
Taking statins or other prescribed medications when indicated

The World Health Organization confirms that lifestyle changes combined with medical therapy can significantly reduce cardiovascular mortality.

For people with high ApoB or Lp(a), doctors often recommend earlier and more aggressive LDL reduction.



Medical experts consulted
​
This article includes expert inputs shared with TOI Health by:
Dr Sagar Shah, Consultant Cardiologist at Apollo Hospitals, Sheshadripuram, Bangalore.
Inputs were used to explain how cholesterol works in the body and what one can do to reduce the risk of heart-related issues.