What we know – and don’t – about South Asians’ heart disease risk
March 22, 2019
This month, I attended the American College of Cardiology conference in New Orleans, where colleagues from around the world met to discuss research, present findings, and pool our knowledge to improve patient care.
A major theme that arose was one of personal and professional importance to me: People living in the U.S. of South Asian ancestry – from Bangladesh, India, Nepal, Pakistan, and Sri Lanka – have a higher risk of heart disease than the general population.
For the past few years, this concern has surfaced across a variety of health and media organizations. In 2018, the updated cholesterol guidelines listed South Asian ethnicity as a recognized risk factor for heart diseases.
Then, in March 2019, an article in The New York Times discussed the Mediators of Atherosclerosis in South Asians Living in America (MASALA) study, in which researchers followed a cohort of South Asians living in the U.S. (many of whom were first-generation immigrants) to assess their heart health. UT Southwestern doctors participated in some of the analyses for this study.
While MASALA data revealed many insights into the state of heart health among South Asians, the reason the risk is so high in this population has preventive cardiologists stumped. To find potential answers, we are pursuing several theories that are rooted in cultural traditions and modern medicine.
Related reading: How does Asian ancestry affect heart disease risk?
Key predictor of heart disease identified for South Asians
New results from a long-term heart study led by UT Southwestern cardiologists show that South Asians with a family history of heart disease are at three times higher risk for calcium buildup in their arteries – a strong indicator of higher risk for heart attacks and stroke.
Important findings from MASALA
MASALA researchers discovered that two subsets of participants had the greatest risk for heart disease: those who adhered to their cultural dietary and lifestyle traditions and those who actively embraced the Western diet and lifestyle.
Several statistics emerged from the data:
- South Asians develop heart disease approximately a decade earlier than people of other ethnicities.
- Approximately 44 percent of normal-weight South Asians in the study had two or more risk factors for heart disease compared with just 21 percent of normal-weight whites.
- South Asians develop Type 2 diabetes, high blood pressure, high triglycerides, and high cholesterol at lower body weights than the general population.
In light of these findings, researchers have several avenues to delve into the potential biological reasons for why this population has increased risk. In the interim, South Asians living in the U.S. – and their doctors – should be mindful of six important heart-health considerations to actively reduce their risk.
6 heart-health considerations for South Asians
1. The traditional South Asian diet might not be as healthy as you think.
The Western world often views a meatless diet as healthy. But there are plenty of vegetarian foods that are not conducive to a heart-healthy diet, including white rice, cream sauces, and other heavy dairy products that often are found in traditional South Asian cuisine. Add in processed Western snacks, and this supposedly healthy diet goes out the window. Rather than eating rich foods, focus on plant-based vegetarian options: nuts, legumes, fruits, and vegetables. For non-vegetarians, include lean meats, such as fish and white-meat poultry – similar to the Mediterranean Diet.
2. Exercise is crucial, even if your body weight is normal.
Visceral fat is the culprit behind the term “skinny fat.” Even if you are naturally trim, you might carry fat stores deep within the body that aren’t easily detected by standard exams. So, while your BMI or weight might be within normal range, exercise is crucial to help ensure that your heart is as healthy as it can be.
Related reading: How doctors squeeze in exercise, and how you can, too
3. Your risk is likely being underestimated by today’s standard testing.
Today’s heart disease risk tools and estimators were designed around data that was historically available, and much of that data was accumulated from white, African-American, and Hispanic patients. However, given the data MASALA has revealed, the tests we know are effective for these populations likely underestimate the risk for South Asians. Consider flagging this to your doctor so you can work together to reduce your personal risk.
4. Internal body fat distribution might be a factor in your heart disease risk.
Everyone has two types of fat: subcutaneous, which is under the skin and can be pinched and measured, and visceral, which lies deeper in the body, surrounding the organs. Visceral fat is associated with heart disease risk and is considered more unhealthy than subcutaneous fat. Doctors are researching whether South Asians acquire visceral fat differently or at a higher rate than other populations, putting them at greater risk for heart disease.
5. Family history and genetics are important.
Whether you were born here or born in a South Asian country, learn as much as you can about your family’s heart disease risk. Did your aunts, uncles, or grandparents have heart disease? How old were they when it developed, and how old were they when they were diagnosed? These factors can help your doctor better assess your personal risk for heart disease.
6. “South Asian” is a broad term that covers many genetically diverse people.
Researchers are studying whether, genetically, the bodies of South Asians react differently to certain diet and lifestyle choices than the bodies of whites, blacks, Hispanics, and other cultural groups.
When it comes to heart disease, there is no single explanation for why certain populations are more at risk than others. The best way to optimize your heart health is to work with a doctor who takes time to consider every risk factor and answer your questions.