Written by Angeline Ajit
Graphic by @vyvy.le_ on Instagram
With heart disease, the first noticeable symptom is often fatal. Illness reaches into your body and disconnects it from its relentless mechanism of existing. At any point, you are one blocked artery away from confronting the fragile nature of the human heart.
For people that share my ancestry, this possibility is even more daunting. Nearly one in three South Asians will die from heart disease before the age of 65. Despite only being 25% of the world’s population, South Asians make up 60% of global cardiovascular patients. Not only is this population more susceptible to heart disease across several metrics, but these conditions are deadlier, happen 10 years earlier, and occur at lower body weights compared to other ethnic groups.
In South Asia, Cardiovascular disease is the leading cause of mortality, with rates of type 2 diabetes, hyperlipidemia, and hypertension continuing to increase rapidly over the 21st century. In fact, type 2 diabetes is over seven times more prevalent in Indians than in white Americans, despite ample representation in the physician workforce and lower rates of cigarette smoking and obesity.
In a 2017 study, 44% of healthy-weight South Asians had two or more metabolic abnormalities, like high blood sugar, high triglycerides, hypertension, or low HDL cholesterol, compared to just 21 percent of healthy-weight Caucasians. Even among young, healthy Asian Indians, higher levels of inflammatory markers, lower β-cell function, and lower adiponectin levels (associated with insulin resistance) may predispose them to a pro-inflammatory state that increases their risk of developing such conditions. Until recently, a BMI of 25 or greater was the standard cutoff point to screen for diabetes, which led to health professionals missing important predictive factors unique to South Asians and thus inaccurately estimating CVD progression. Since diabetes is a silent condition, a diagnosis too late after onset often means that blood glucose levels have already been unstable for long enough to cause bodily harm.
The threats to South Asians' cardiovascular health have been further obscured because, historically, researchers viewed Asian Americans as a monolithic group and major federal surveys did not classify Asian Americans into subgroups.
While a constellation of risk factors has been suggested to explain this phenomenon, it fails to fully explain the striking health disparity. Many may find it easy to dismiss this issue by blaming the affected community and their religious and cultural customs. South Asian cuisine often includes carbohydrates (rice, lentils, chapati, naan) and saturated fats (ghee, butter) with a conspicuous absence of lean meats. However, while dietary habits do tremendously impact the incidence of cardiovascular disease, they only add to the inherent predisposition to insulin resistance that many South Asians face.
One possible theory suggests that British Raj-induced famines could be to blame for this genetic susceptibility. Exposure to even one famine has a multi-generational effect of causing metabolic disorders. Under colonialism, the Indian subcontinent was exposed to 31 famines across 120 years. These famines originated from uneven rainfall but were worsened by exploitative, apathetic British economic and administrative policies like inequitable food distribution and tax raises on the native population. For instance, during the 1943 famine in Bengal, Britain’s wartime leader Winston Churchill suggested that any aid sent would be insufficient due to "Indians breeding like rabbits." While millions of people were dying from starvation, his cabinet continued to excessively export Indian grains to other parts of the empire for the war effort.
As an evolutionary response to food deprivation, South Asians may have developed an increased capacity for fat and nutrient storage through “thrifty genes.” In today’s era of food abundance, the populations who adapted to carry these genes are at higher risk of developing heart disease.
There is a need for culturally appropriate healthcare and comprehensive epigenetic data to better understand the metabolic profiles of South Asians. The health needs of this racial minority group need to be critically examined to create new strategies to improve cardiovascular health, start early intervention within the high-risk youth population, and successfully direct current and future clinical research.