You’ve heard of fitness, lifestyle and food habits affecting your heart, but did you know that ethnicity could play a vital role in cardiovascular health too? South Asians listen up! Increasingly studies are pointing towards a correlation between ethnic origin (no matter where you live), and risk of cardiovascular i.e heart disease.
How it All Adds Up
South Asians i.e., those from India, Pakistan, Bangladesh, Nepal, Bhutan, Maldives and Sri Lanka are at a whopping four times greater risk of heart disease vs. the rest of the population (1). With heart disease being the number 1 cause of death in the Indian subcontinent, it’s time individuals of South Asian descent pay attention to their cardiac health.
Dr Ramasami Nandakumar, Senior Interventional Cardiologist at Mount Elizabeth Hospital, Novena & Gleneagles Hospital says “Reports of increased heart disease risk and increased mortality due to heart disease first emerged in Singapore in the 1950’s(2). Further studies emerged from other countries with significant South Asian immigrants in Canada (3), UK (4) and USA (5) which mirrored the results from Singapore.
Heart disease occurs almost a decade earlier in South Asians and is much worse at angiography, heart attacks are larger, and outcomes are far worse (6,7). As the body of evidence continues to increase, strategies are evolving to deal with this epidemic in the South Asian population.”
Why is the Risk Higher for South Asians?
From a lower rate of consumption of fruit and vegetables to frequent use of partially hydrogenated vegetable oils with high trans-fat content and a greater consumption of fats, saturated fats, trans fats and processed fats; the relationship of heart disease with the South Asian diet is somewhat obvious.
But there’s more evidence and numbers are stacking up against lifestyle in general. In India for instance, the average blood pressure has increased in the past 2 decades (8), whereas in most Western nations it has declined. In the urban areas of India, the prevalence of diabetes has risen from 2 to 12% in the last 30 years! (9)
Dr Nandakumar elaborates “Compared with European populations, South Asians are likely to have the thin-fat syndrome where an otherwise thin person carries increased abdominal visceral fat (10). This also leads to greater insulin resistance at similar levels of BMI. Smoking too is highly prevalent in the South Asian population – and as they say, it all adds up!”
Immigrants – Where Does that Put You?
Lived your entire life abroad? If you are South Asian, that still puts you at risk! Also, called the thrifty gene hypothesis (11,12) suggesting a link between genetic predisposition and the environment you stay in; living away from your country of origin does not reduce the risk of cardiovascular disease for South Asians. In Britain for instance, Coronary Artery Disease accounts for 27% of all deaths in South Asian men as compared to 17% among Caucasian men (13).
Dr Nandakumar explains “Barker’s Hypothesis (which is under considerable debate) essentially states that a baby’s nourishment before birth and during infancy programs the development of risk factors for heart disease.
Current thinking suggests that the excess of heart disease in South Asians worldwide appears to be due to double jeopardy from both nature (genetic) and nurture (lifestyle factors). Exposure of South Asian immigrant population to the “obesogenic” environment in the West (mirrored by rapid urbanization in South Asia) has contributed to the current epidemic.
While traditional risk factors (i.e sedentary lifestyles, increased psycho-social stress and consumption of energy-dense food) undoubtedly play a large part, non-conventional risk factors such as lipoprotein(a), CRP, apoprotein B100/Apoprotein AI ratio, adiponectin, dysfunctional HDl and altered LDL particles etc, have emerged as additional risk factors in the South Asian population.
Therefore currently we tend to use a focused screening program specifically targeted at South Asians, to get a more comprehensive picture of the risk profile rather than just the traditional risk factors of lipids and sugar levels.”
Countering the Ethnic Disadvantage
We can’t change the way our bodies are built and our ethnic predisposition, but there are steps we can take to lower the risk of heart disease. Top of that list is awareness and acceptance that South Asians are at a greater risk of CVD (cardiovascular disease) and taking action such as lifestyle modification and going for heart screening.
Dr Nandakumar comments “Early detection is key to countering heart disease! Regular cardiac screening should start around the age of 35, whilst an annual check-up is necessary if you have risk factors such as diabetes, high blood pressure or known heart disease. Heart screenings take time but will comprise of a full history, examination, blood tests and scans – sort of like a circuit run! Yes, it takes about half a day, but I promise you it is time well spent!”
Screening needs to be accompanied by lifestyle changes and an effort to put your risk at bay. Not smoking or consuming tobacco and an increased effort towards upping your physical activity, for starters. This teamed with healthy food habits and keeping that middle girth in control, will help bring down your risk levels too.
“The Indian or rather, South Asian diet is undergoing a rapid transition with excess consumption of calories, trans and saturated fats, simple sugars, salt and low intake of fiber. Though in general, Asian Indians tend to be vegetarians there is high use of clarified butter, sweets, high saturated fat dairy products and high trans fat fried foods which lead to ‘contaminated vegetarianism’ with the typical high risk picture of high triglycerides and low HDL.
However, less intake of energy dense foods and carbohydrates, increased intake of fresh fruits and vegetables, mono and polyunsaturated fats with less use of trans and saturated fats, and avoiding deep frying are changes that can be incorporated for a healthier heart ” says Dr Nandakumar. So, there you have it, your ethnicity does put you at a disadvantage but there’s plenty you can do to keep on top of your heart health. Take the right steps towards acknowledging this risk, and get started on a healthy heart journey right away!
- Ethnic group differences in coronary heart disease in Singapore: an analysis of necropsy records. Danaraj TJ, Acker MS, et al, Am Heart J. 1959 Oct; 58():516-26
- Cardiovascular and cancer mortality among Canadians of European, south Asian and Chinese origin from 1979 to 1993: an analysis of 1.2 million deaths, Sheth T, Nair C, Nargundkar M, Anand S, Yusuf S, CMAJ. 1999 Jul 27; 161(2):132-8.
- Coronary heart disease in south Asians overseas: a review, McKeigue PM, Miller GJ, Marmot MGJ Clin Epidemiol. 1989; 42(7):597-609
- Enas EA, Garg A, Davidson MA, Nair VM, Huet BA, Yusuf S. Coronary heart disease and its risk factors in first-generation immigrant Asian Indians to the United States of America. Indian heart journal. Jul-Aug 1996;48(4):343-353
- Risk factors, hospital management and outcomes after acute myocardial infarction in South Asian Canadians and matched control subjects. Gupta M, Doobay AV, Singh N, Anand SS, Raja F, Mawji F, Kho J, Karavetian A, Yi Q, Yusuf S, CMAJ. 2002 Mar 19; 166(6):717-22
- Gupta M, Singh N, Warsi M, Reiter M, Ali K. Canadian South Asians have more severe angiographic coronary disease than European Canadians despite having fewer risk factors. Can J Cardiol. 2001;17(Suppl C):226C.
- Prevalence and incidence of hypertension: Results from a representative cohort of 16000 adults in three cities of south Asia. D. Prabhakaran et al. / Indian Heart Journal 69 (2017) 434–441,
- V. Mohan, P. Mathur, R. Deepa, et al. Urban rural differences in prevalence of self reported diabetes in India-The WHO-ICMR Indian NCD risk factor surveillance, Diabetes Res Clin Pract, 80 (2008), pp. 159-168
- Deepa R, Sandeep S, Mohan V. Abdominal obesity, viceral fat, and type 2 diabetes- “Asian Indian Phenotype”. In: Mohan V, Gundu Rao, eds.Type 2 diabetes in South Asians; Epidemiology , Risk factors and Prevention ; 2006:138-152.
- Barker DJ, Hales CN, Fall CH, Osmond C, Phipps K, Clark PM. Type 2 (non-insulin-dependent) diabetes mellitus, hypertension and hyperlipidaemia (syndrome X): relation to reduced fetal growth. Diabetologia. 1993;36(1):62–67.
- Hales CN, Barker DJ. Type 2 (non-insulin-dependent) diabetes mellitus: the thrifty phenotype hypothesis. Diabetologia. 1992; 35(7):595–601
- www.heartstats.org. CHD statistics. Mortality 2011.