Why South Asians Get Heart Disease Earlier, and at a Lower BMI

A 45-year-old man in Lahore, slim, no big belly to speak of, walks into a clinic with a tight chest he has ignored for a week. The ECG is abnormal. The angiogram shows two badly blocked arteries. He does not smoke much, his weight looks fine on the scale, and there is no obvious villain. His cardiologist is not surprised. This is what heart disease in South Asians looks like in real life: it arrives early, it hides behind a normal-looking body, and it is brutally common.

This is not bad luck for one man. It is a pattern across Pakistan, India, Bangladesh, and the diaspora. South Asians get heart disease younger, at lower body weights, and with worse outcomes than almost any other group on earth. The reasons are partly in our genes, partly on our plates, and partly in the fact that the tools doctors use to score risk were never built for our bodies. Let me walk through the biology, the numbers, and what you can actually do.

What heart disease actually is, in plain terms

Coronary heart disease is a plumbing problem. The arteries that feed the heart muscle get narrowed by deposits, and when blood flow drops too far, part of the heart starves. That is a heart attack.

Atherosclerosis: the slow clogging

The deposits are called plaque. They build up over decades inside the artery wall, not as grease smeared on the inside of a pipe but as something more like a boil growing within the wall itself. This process is atherosclerosis, and it starts quietly in your 20s and 30s. You feel nothing. Then one day a plaque cracks, a clot forms on the crack, and the artery closes in minutes.

The role of LDL and inflammation

The raw material for plaque is LDL cholesterol, the so-called bad cholesterol. LDL particles slip into the artery wall and get trapped. The immune system treats them like an invader and sends in cells to mop them up. Those cells get stuffed with cholesterol, die, and form the fatty core of the plaque. So heart disease is really a slow inflammatory wound that never heals. The higher your LDL, and the longer it stays high, the more plaque you build. According to the American Heart Association, lowering LDL is one of the most reliable ways to cut heart attack risk.

There is a useful way to picture it. Think of the artery wall as a road surface and LDL as the grit that keeps getting pressed into a crack. Over years the crack widens into a pothole. Inflammation is the road crew that keeps arriving, making a mess, and never quite fixing the hole. The body even lays down a thin cap of scar tissue over the plaque, which works until the cap tears. When it tears, blood meets the raw core, a clot forms, and that is the moment a slow disease becomes a sudden emergency. This is why a person can feel completely well right up to the day of a heart attack. The blockage was building in silence for twenty years.

Lipoprotein(a): the silent inherited risk

Here is the part most people have never heard of. There is a cousin of LDL called lipoprotein(a), written Lp(a). It is sticky, it promotes clotting, and it speeds up plaque. Your level is set almost entirely by your genes and barely moves with diet or exercise. A high Lp(a) is one of the strongest inherited reasons a young, lean, non-smoking person has a sudden heart attack. And South Asians carry high Lp(a) at unusually high rates. A 2023 review in PubMed Central noted that South Asians tend to have higher Lp(a) levels than many other populations, which helps explain the early disease. Most Pakistanis have never had it measured even once.

Heart disease in South Asians: how bad the numbers really are

Heart disease is not a Western import that we caught late. It is the leading cause of death across South Asia, and the burden here is among the heaviest anywhere.

Cardiovascular disease accounts for a large and rising share of deaths in Pakistan, and the World Health Organization ranks ischaemic heart disease as the world’s single biggest killer. The brutal twist for South Asia is timing. Research summarised in The Lancet on the global burden of disease has repeatedly shown that the region carries a heavy and early cardiovascular load, with disease striking working-age adults rather than the elderly.

A decade earlier than the textbook

Large international studies, including the INTERHEART work that looked at heart attack patients across dozens of countries, found that South Asians have their first heart attack on average several years earlier than people in many other regions, frequently in the 40s and early 50s. In a country where the median age is young, that means heart attacks are hitting breadwinners in their most productive years. The economic and family cost of that is hard to overstate. A heart attack at 48 does not just threaten one life. It can pull the floor out from under a whole household that depends on that income.

Worse outcomes after the event

It is not only that heart disease in South Asians comes early. Once it arrives, outcomes are often worse, partly because diabetes commonly travels alongside it, partly because care is reached late, and partly because the disease is more diffuse across multiple arteries. Work from Aga Khan University and other Pakistani cardiology centres has documented this pattern of premature, multi-vessel coronary disease in local patients.

Why a “normal” BMI lies to South Asians

This is the heart of the puzzle. A Pakistani man can have a body mass index that any chart calls healthy and still be metabolically in trouble. The scale is reassuring him while his arteries are not.

Thin on the outside, fat on the inside

The issue is where the fat sits. South Asians tend to store fat viscerally, wrapped around the liver, pancreas, and gut, rather than under the skin on the arms and legs. This visceral fat is metabolically nasty. It pumps out inflammatory signals and fatty acids straight into the liver. Two people can weigh the same and look the same, yet the South Asian one often carries more dangerous internal fat. This is sometimes called the thin-fat phenotype, and we cover it in depth in our piece on South Asian diabetes and the thin-fat body.

The BMI cut-offs are different for us

Because of this, the usual BMI thresholds underestimate South Asian risk. Health authorities now use lower cut-offs for people of South Asian origin. The NHS and other bodies recognise that South Asians face raised risk at a lower BMI, with overweight starting around 23 rather than 25 and obesity around 27.5 rather than 30. Waist size matters more than the scale. A waistline creeping past roughly 90 cm in men or 80 cm in women is a warning, and that often shows up well before any belly looks obviously large. If you want the mechanics of why mid-life weight settles around the middle, read why belly fat arrives after 45.

What the scale says	What is really happening
BMI 23, looks slim	May already carry high visceral fat
Normal weight, soft midriff	Insulin resistance can be building silently
No obvious belly	Liver fat and high triglycerides still possible
Weight stable for years	Muscle can be quietly replaced by fat

Diabetes and insulin resistance: the engine behind it

If visceral fat is the fuel, insulin resistance is the engine that turns it into heart disease. South Asians develop type 2 diabetes earlier and at lower body weights than almost any other group, and diabetes roughly doubles heart disease risk.

How insulin resistance damages arteries

When cells stop responding well to insulin, blood sugar and insulin both climb. High blood sugar damages the delicate inner lining of arteries. High insulin pushes the liver to make more triglycerides and small dense LDL particles, the kind that wedge most easily into artery walls. Blood pressure tends to rise too. So one underlying problem, insulin resistance, feeds several heart risks at once. This clustering is why a single slim-looking patient can carry high sugar, high triglycerides, low protective HDL, and high blood pressure together.

Why we get it younger

Part of this is the visceral-fat tendency. Part may trace back to early life: lower birth weights followed by rapid weight gain seem to prime the body for insulin resistance later. There is also a simple capacity issue. The pancreas can only make so much insulin, and South Asian bodies appear to hit that ceiling at a lower threshold, so blood sugar climbs sooner. The result is that a 35-year-old in Karachi can be pre-diabetic without a clue, because the only symptom is a number on a blood test nobody ordered. By the time the classic signs appear (thirst, frequent urination, fatigue), the damage to arteries has often had a head start of several years.

The plate, the chair, and the cigarette

Genes load the gun. Daily life pulls the trigger. Three everyday habits do most of the damage, and all three are deeply woven into how we live.

Refined carbs and the way we cook

The traditional festive plate leans heavily on refined carbohydrates: white rice, naan and roti from refined flour, sugary chai, and sweets. These spike blood sugar fast and, eaten daily, push insulin resistance along. The problem is rarely a single meal. It is the repetition, three times a day, year after year, that trains the body toward higher sugar and higher insulin. Then there is the oil. Frying in reused cooking oil, common in homes and especially in street food, generates harmful trans and oxidised compounds, and the sheer quantity of oil and ghee in everyday cooking adds up fast. A single plate of biryani or a few samosas can carry more cooking fat than a person realises. Salt is the other quiet problem, driving the blood pressure that strains the heart, and much of it hides in packaged snacks, pickles, and restaurant food rather than the salt shaker at home.

Sitting all day

Physical activity has collapsed as cities grow and work moves to desks and screens. The widely used target is at least 150 minutes of moderate activity a week, and a large share of South Asian adults fall short of it. Walking has been engineered out of daily life by cars, motorcycles, and lifts. Muscle is where blood sugar gets burned, so less movement means more insulin resistance and more plaque.

Tobacco, naswar, and the heart

Smoking is one of the most powerful heart-attack triggers there is, and rates among Pakistani men remain high. Smokeless tobacco like naswar and gutka, common in parts of the country, is not a safe alternative. It still raises blood pressure and damages arteries. Quitting tobacco is the single fastest way to cut your risk, and the benefit starts within weeks.

Risk factor	Typical Western pattern	South Asian pattern
Age at first heart attack	60s	40s to 50s
Body weight at diagnosis	Often overweight	Often normal BMI
Fat distribution	More under-skin	More visceral (around organs)
Lipoprotein(a)	Lower on average	Higher on average
Diabetes link	Common	More common, earlier onset
Diet driver	Processed food	Refined carbs, ghee, reused oil, salt

Why doctors miss it: the calculator problem

There is a structural blind spot. The risk scores many doctors use to decide who needs treatment were built mostly on white populations. The well-known Framingham risk score, and several others like it, tend to underestimate risk in South Asians. A patient who scores “low risk” on paper can still have arteries quietly filling with plaque.

Standard scores were not built for us

Because the equations were calibrated on other groups, they do not fully capture the drivers of heart disease in South Asians, namely the extra weight of visceral fat, early diabetes, and high Lp(a) we carry. Some newer tools add an ethnicity adjustment, but many clinics still use the old ones. The practical lesson: if you are South Asian, treat a “reassuring” risk score with healthy suspicion and ask about the factors the score may be missing.

A risk calculator that says you are fine was probably never tested on a body like yours. Trust your numbers, not the average.

Chronic stress adds to the load

Long hours, financial pressure, and poor sleep keep stress hormones elevated, and chronically high cortisol nudges up blood pressure, blood sugar, and belly fat. Stress alone does not cause heart attacks, but it stacks neatly on top of every other risk here. Our explainer on cortisol and chronic stress digs into the mechanism.

What you can actually do, tailored to life here

None of this is hopeless. Most heart disease in South Asians is largely preventable, and the levers are practical. The point is to start earlier than the West tells you to, because your clock runs faster.

Get screened earlier than the books say

Do not wait for your 50s. A reasonable approach for a healthy South Asian adult is to know your numbers from your 30s: blood pressure, fasting blood sugar or HbA1c, and a full lipid panel. And once in your life, ask for a lipoprotein(a) test. It is a one-time check because the level barely changes, and a high result tells you to be far more aggressive about everything else.

What to test	From what age	How often
Blood pressure	30s	Yearly, or more if high
Fasting sugar or HbA1c	30s	Every 1 to 3 years
Full lipid panel (LDL, HDL, triglycerides)	30s	Every 1 to 3 years
Lipoprotein(a)	Once as an adult	Once in a lifetime
Waist measurement	30s	A few times a year

Know your Lp(a) once, then act on it

If your Lp(a) comes back high, you cannot lower it much directly with current standard treatment, but you can attack everything else harder: drive LDL lower, control blood pressure tightly, keep sugar in range, and never smoke. Knowing the number changes the urgency.

Shift the plate without losing the culture

You do not have to abandon daal, roti, and sabzi. The shifts that matter:

• Swap some white rice for brown, or simply cut the portion and fill the plate with vegetables and fibre.
• Move from refined flour roti toward whole-wheat (atta with more bran).
• Stop reusing frying oil, and cut the total quantity of oil and ghee.
• Cook with less salt and taste before reaching for the shaker.
• Treat sweets and sugary chai as occasional, not daily.

Walk, every single day

The cheapest cardiac drug is a 30-minute daily walk. It improves insulin sensitivity, lowers blood pressure, and burns the visceral fat that scans cannot easily see. If 30 minutes at once is hard, three 10-minute walks after meals work and may blunt the post-meal sugar spike better.

Quit tobacco, including the smokeless kind

There is no safe form. If you use naswar, gutka, or cigarettes, stopping does more for your heart than any single pill. Help exists, and even quitting in your 40s adds years.

Frequently asked questions

Why do South Asians get heart disease at a normal weight?

Because where fat sits matters more than total weight. South Asians tend to store fat viscerally, around the liver and gut, rather than under the skin. This visceral fat drives insulin resistance and inflammation even when the scale and BMI look healthy. That is why a slim Pakistani man can already have dangerous arteries while a heavier person of another background may not.

What is lipoprotein(a) and should I get tested?

Lipoprotein(a), or Lp(a), is an inherited cholesterol-like particle that promotes clotting and speeds artery blockage. South Asians often carry high levels, and it explains many early heart attacks in lean non-smokers. Because the level is set by genes and barely changes, you only need to test it once in your life. A high result means you should control every other risk factor far more aggressively.

At what age should South Asians start heart screening?

Earlier than Western guidelines suggest. A sensible approach is to know your blood pressure, fasting sugar or HbA1c, and a full lipid panel from your 30s, with a once-in-a-lifetime Lp(a) test. Because disease here can strike in the 40s, waiting until your 50s means catching it after plaque has already built up for years.

Does diabetes really double heart risk?

Roughly, yes. Diabetes damages artery linings through high blood sugar and pushes the liver to make more harmful cholesterol particles and triglycerides. South Asians develop type 2 diabetes younger and at lower weights, so the heart risk it carries lands earlier too. Controlling blood sugar is one of the most direct ways to protect your heart over the long run.

Is naswar safer than cigarettes for the heart?

No. Smokeless tobacco like naswar and gutka still delivers nicotine and other harmful compounds that raise blood pressure and damage arteries. It carries real cardiovascular risk and is not a safe substitute for quitting. For your heart, the only good option is to stop tobacco in every form, and the benefit begins within weeks of stopping.

Why do standard risk calculators underestimate my risk?

Tools like the Framingham score were built mainly on white populations and were not calibrated for South Asian biology. They miss the extra burden of visceral fat, early diabetes, and high Lp(a) that many South Asians carry. So a score can read “low risk” while your arteries tell a different story. Treat a reassuring score with caution and discuss the missing factors with your doctor.

Can changing diet and walking really reverse the trend?

They can dramatically lower your risk, even if genetics like high Lp(a) cannot be erased. Daily walking, more fibre, less refined carbohydrate and reused oil, controlled salt, and no tobacco improve nearly every measure that drives heart disease. Started early and kept up, these habits prevent or delay the disease far more powerfully than any single late intervention.