Since the 1960s, doctors have begun to understand better some of the risks and causes of coronary heart disease in the original white population of Western countries. Some factors such as getting older, being male, and having a family history of heart disease are important but can't be changed. But we have also realised that other factors such as smoking, obesity, high cholesterol, high blood pressure and lack of exercise are relevant, and can be improved by medication or changes in lifestyle. Governments and other organisations have made efforts to reduce the risk through education and other public health measures. It is thought that these efforts are beginning to pay off, and rates of heart disease in the white population have started to fall.
Unfortunately, the same success has not been realised amongst the South Asian population, where heart disease continues to rise. We are now seeing friends and relatives affected with angina and heart attacks in their fifties, forties, and even thirties. Doctors have suggested all sorts of causes, for example the stress of moving to a new country or facing racism, a diet high in certain fats such as ghee (clarified butter), and a tendency to develop diabetes. I think it is fair to say that we simply don't know for sure why Asians seem more prone, and there probably isn’t a single reason. However, in the last few years we are beginning to develop more ideas as a result of new research.
One of the most promising theories to emerge is that South Asians are at risk because they have a greater tendency to put weight on around the middle (the belly and the chest), even though they might not be particularly heavy generally. This belly fat interferes with the functioning of insulin, a hormone that controls blood sugar. This increases the risk of developing diabetes and pre-diabetes (also called insulin-resistance) which can damage blood vessels and lead to heart disease.
In this book/blog I outline some of the causes and risks for coronary heart disease in South Asians and give you some practical advice on measures you can take to try to reduce your chances of developing heart problems in the future. The good news is that the same measures can also help to reduce the incidence of diabetes and stroke, bring down blood pressure and weight, and (perhaps surprisingly) slow the age-related decline in memory and potency, all contributing towards a longer, healthier life. I hope it will be of use and interest not only to readers of South Asian origin now living in the West, but also to people in the Indian Sub-continent.
Important information (disclaimer)
In this short text, I can only give general health information. I am unable to give any specific medical advice to individual readers, If you are ill, or suspect that you have any symptoms of heart disease such as chest pain, feeling faint, light-headed or short of breath, then you should consult your family doctor or emergency medical service. If you live in the UK, then NHS Direct is a very useful source of advice and information: visit www.nhsdirect.nhs.uk or telephone 0845 46 47.
What is coronary heart disease?
Our heart is a pump made of muscle, pushing blood constantly around the body. Like any other muscle, it needs a good supply of blood to function well. Blood is fed to the heart through blood vessels called the coronary arteries. With age, in practically everyone, the arteries become narrower and harder, and develop fat-filled bumps on the inside wall. These changes are commonly called ‘furring of the arteries’ and reduce blood flow to the heart.
Technically, the hardening process is called arteriosclerosis, and the formation of the bumps is called atherosclerosis. The medical term for the bump is plaque or atheroma.
Diagram of atherosclerosis
Angina and heart attack
Two common forms of coronary heart disease (CHD) are angina and heart attack (myocardial infarction or MI, or simply ‘coronary’). They are both caused by atherosclerosis (‘furring’) of the coronary arteries:
In angina, the narrowing of the arteries to the heart leads to a reduction in blood supply, particularly in situations where the heart needs more blood such as exercise or stress. The result is a sort of temporary cramp of the heart muscle, which is usually felt as chest pain or tightness, or as shortness of breath. The symptoms will usually pass by resting or by taking certain medications such as GTN (glyceryl trinitrate).
In a heart attack (more technically, a myocardial infarction) one of the plaques splits open. When the contents of the plaque come into contact with the blood, they cause the blood to clot, forming a plug that blocks the artery. This completely restricts the flow of blood to an area of the heart muscle and usually causes pain. This area of muscle will become permanently damaged if the clot does not move or dissolve quickly. The damaged muscle may prevent the heart from beating properly, which can result in an irregular heartbeat, breathlessness, heart failure or death.
In this book/blog, I will refer to coronary heart disease as CHD or simply 'heart disease'.
PREVALENCE, OR HOW BIG IS THE PROBLEM?
Traditionally in the rural areas of the Indian Sub-continent, rates of heart disease were relatively low. One explanation could be that other causes of ill health such as infection were more common.
In the last three decades there has been a huge increase in the rate of heart disease amongst South Asians, first noted in those moving to the West or to the cities of the Indian Sub-continent. The rate in rural areas in the Indian Sub-continent is half that of the cities, and a quarter that of South Asians living in the US.
Differences in prevalence and severity of heart disease
Depending on which study you look at CHD is 1 - 4 times as common in South Asians as it is in the White population. This obviously increases the risk of dying, but also results in more ill health and disability.
What is perhaps less obvious and well-known is that, statistically, a South Asian suffering a heart attack is more likely to die from it. South Asians undergoing ‘bypass operations’ (Coronary Artery Bypass Grafting, CABG) have twice the post-operative death rate of white people.
Also worrying is the fact that South Asians are affected by heart diesease prematurely, on average 5-10 years earlier than their White counterparts. One study calculated the average age of first heart attack in South Asians to be 50 as compared to 56 in a White European population.
Summary
Coronary heart disease has become more common in South Asians over the past three decades. The condition seems to strike earlier and more aggressively. In the next section I will discuss some of the possible explanations.
