New Delhi: South Asians in the US are eating better, cutting back on alcohol, and keeping their weight in check. Yet by their mid-40s, they are far more likely to have prediabetes, high blood pressure and eventually diabetes than several other ethnic groups.
These are the findings of a new study, led by Northwestern University Feinberg School of Medicine, published in the Journal of the American Heart Association Wednesday.
This mismatch between healthier lifestyle behaviour and clinical risk, the researchers say, is surprising.
“This paradox tells us we’re missing something fundamental about what is driving this elevated risk among South Asians,” senior author Dr Namratha Kandula, professor of general internal medicine and epidemiology at Northwestern University Feinberg School of Medicine, said in a communication Wednesday.
Kandula described the 40s as a “critical window”. She said that even though we have known for decades that South Asians develop heart disease at a younger age, we didn’t have data showing exactly when this risk begins.
“We’ve now identified a critical window in the 40s when risk is already high, but disease is still preventable,” she added.
As a person ages, fat, cholesterol and inflammation build up inside blood vessels over time, increasing the risk of heart attacks and strokes.
The study finds that for South Asians—people tracing their ancestry to India, Pakistan, Bangladesh, Sri Lanka, Nepal, Bhutan and the Maldives—this process appears to begin earlier and progress faster.
The research followed nearly 2,700 adults aged 45 to 55 over a decade, drawing data from two long-running cohort studies—MASALA (Mediators of Atherosclerosis in South Asians Living in America) and MESA (Multi-Ethnic Study of Atherosclerosis). Atherosclerosis is hardening of arteries over time due to buildup of plaque in them, increasing the risk of heart attacks and strokes.
The findings paint a stark picture. By age 45, nearly one in three South Asian men had prediabetes. Rates among white men of the same age were significantly lower, and the prevalence was also lower among black, Hispanic and Chinese men.
South Asian women showed a similar trend—almost one in five had prediabetes in their mid-40s, roughly double that seen in women from other ethnic groups.
By 55, South Asian men and women were at least twice as likely as white adults to develop diabetes. Hypertension, too, appeared earlier and more frequently.
“The study reinforces what Indian clinicians have long suspected—cardiovascular risk factors show up earlier in this population, including among the diaspora,” said Dr Ambuj Roy, cardiologist at the All India Institute of Medical Sciences (AIIMS), New Delhi, commenting on the findings.
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Childhood patterns & adult risk
If lifestyle at 45 does not fully explain the higher risk, the roots may lie much earlier. The study suggests that the risk of conditions like diabetes, high blood pressure and heart disease in South Asians may start building up much earlier in life, long before middle age.
Many participants in the MASALA study are immigrants, and their childhood and early adult environment—including diet quality, stress exposure and physical activity—may have been very different from what they report now.
“Early life nutrition, environment, stressors and activity patterns in childhood may increase cardiometabolic risks that show up by age 45,” Dr Kandula said.
Previous MASALA data shows that South Asians tend to carry more fat around their internal organs—even when their Body Mass Index (BMI), a measure of weight based on height, is in the normal or low range. This type of deep belly fat—seen even from childhood in many South Asians—is strongly linked to the body’s reduced ability to use sugar properly (insulin resistance) and a higher risk of heart disease.
South Asians make up about one-quarter of the world’s population but account for nearly 60% of heart disease patients. According to the study, in the US, where South Asians are among the fastest-growing demographic groups, they develop atherosclerosis nearly a decade earlier than the general population.
Early screening a key strategy
The study findings strongly support earlier and more proactive screening for South Asian adults.
“Clinicians should start looking for high blood sugar, high blood pressure and other risk-enhancing factors, such as lipoprotein A, before midlife,” Dr Kandula said.
The study emphasises that even with healthy habits, South Asians may face higher risks at younger ages and should speak to their doctors about early screening, as early detection and treatment can help prevent heart disease.
Dr Ambrish Mithal, Chairman and Head of Endocrinology and Diabetes at Max Healthcare, said: “We often assume that poor diet explains the higher risk in South Asians. But by 45, eating patterns actually seem to have improved, and from 45 to 55 there is even further lifestyle improvement. Yet the clinical risk factors remain high.”
“One hypothesis is that younger South Asians may have poorer lifestyles, because of which these risk factors develop earlier and are already established by 45. Even if they become more careful at that age, the clinical risks persist—and therefore the higher heart disease risk persists,” he added.
(Edited by Nida Fatima Siddiqui)
Also Read: Why are South Asians more prone to heart disease? MASALA could hold the answer
South Asians eat white sugar, white rice, refined wheat flour, samosa, jalebi, puri/ batura, vada, kachori, bonda, ghee, etc., to develop diabetes mellitus-2. Also, they guzzle cane juice, fruit juice with added sugar, and carbonated beverages.