According to the WHO, cardiovascular disease (CVD) accounts for 17 million deaths worldwide. Coronary arterial disease (CAD) is the most common form of CVD, and the leading cause of death in both men and women in the United States. CAD is defined by the buildup of a waxy substance called plaque in the vessels that supply the heart with blood carrying oxygen.
As the plaque builds up, it hardens or sometimes ruptures. Hardened plaque narrows the blood vessels and reduces the flow of blood to the heart downstream. When a plaque ruptures, it can become lodged in a narrow part of the vessel, which can partially or completely block the flow of blood to that part of the heart muscle. What we call a heart attack (or myocardial infarction) is the usually the result of a blocked (occluded) coronary artery.
Indians have some of the highest mortality rates from CAD. And clinically significant CAD tends to develop it 10 to 15 years earlier than it does in most other ethnic groups in the US. Indians also develop CAD at lower body weights compared to other ethnicities based on studies on Indian immigrants in the UK and Canada.
Our relatively high risk for developing cardiometabolic diseases is due to a combination of genetics, lifestyle, and diet. Though traditional risk factors—high cholesterol, high blood pressure, smoking, and obesity—play an important role in heart disease, these risk factors alone don’t explain the unusually high prevalence of CAD in the Indian community.
Hyperinsulinemia (or abnormally high levels of insulin in the blood) caused by insulin resistance is very common in South Asians and could explain some of the increased risk we see for these diseases among our community.
Further, genetic factors that lead to both increased fat storage around internal organs in the abdomen (which is called visceral fat) and increased production of molecules carrying cholesterol in the bloodstream (called lipoproteins) are probably additional underlying mechanisms related to the high rates of these diseases.
South Asians tend to have central obesity (characterized by a large waist-to-hip ratio) due to excess visceral fat. This is due to genetics in part, something out of our control. But we can control our lifestyle and our diet, which also contribute to visceral fat. We can increase our physical activity, quit smoking, and deal with stress and anxiety better. As we will discuss in this book, we can make small changes to what we eat.