Why do we get Coronary Artery Disease?

I know that this is a pretty broad question. Therefore, I would like to start by setting my boundaries. First, I would like to take the question from a big picture perspective because that approach helps to understand most of the recommended preventive efforts and treatments. Second, I want to be clear about the meaning of coronary artery disease. Three arteries ring the top of the heart like a crown, giving them the designation coronary, from corona. Any illness that affects these arteries is reasonably called coronary artery disease. But, let’s not ignore the elephant in the room. One disease will affect ⅓ to ½ of us in our lifetime, loves the arteries of the heart and, most importantly, causes heart attacks. The disease is atherosclerosis, a corrosive scarring of the arteries, and almost any time someone says coronary artery disease, that is what they mean.

Atherosclerosis is a disease in the sense that it causes illness and suffering. However, the source of the problem is, to a great extent, in how we are designed to process and store what we eat and maintain our arteries. As most of us make the morning navigation to work, we mull over thoughts of success that center on peace, serenity and financial security. Mother nature sees things from a different perspective than you and I. From the biological perspective, success is navigating our hostile world long enough to reproduce. That is the target of our design and the goal of the genes that help to make us who and what we are. The genes that have made us such a rousing success developed under much different circumstances than we face today. In a hostile world, with scarcely enough to eat, full of predators, large enough to eat us and too small to be seen, those genes carried primitive people through their twenties and thirties, long enough to be fruitful and multiply.

Generally speaking, people are made to survive frequent hardship, long walks looking for food and long times without it. Weather was to be endured, abundance enjoyed and water kept in convenient reach. These were the challenges to be overcome for success and we are well equipped. We have long legs, can eat almost anything and store energy with great efficiency. However, our most important advantage is not physical.

We have the ability to learn, individually and collectively. We can make tools, build houses and, most importantly, write everything down. This advantage brings plentiful food, treatment for infections and longer lives. Under these conditions, our biological design for self-preservation misfires in many forms of cardiovascular disease such as high blood pressure and coronary artery disease. In essence, our heart and arteries are designed to maintain themselves under a set of difficult conditions and last a lifetime. With all of the success born of cumulative learning, we have moved outside of the conditions that shaped us and changed the duration of a lifetime.

Modern society lets us survive long enough to suffer from atherosclerosis and modern technology lets us see it. At any given time, more than 15 million people in the US have symptomatic atherosclerosis. It affects the heart most famously, but can also cause stroke, loss of limb, damaged kidneys and dysfunctional intestines. Of the 1 million people who will have a heart attack this year, almost all are over 40, an age seen by a lucky few of our primitive ancestors.

Atherosclerosis is very much affected by the body’s energy metabolism. It strolls along happily with obesity and inactivity. Obese and inactive adolescent children may already have arteries that misbehave. Their arteries may not be diseased at that young age, but measurable misbehavior is believed to be one of the first steps toward disease. By the age of thirty, some people may have an abnormal appearance of the arteries on an angiogram. Most heart attacks occur much later in life, meaning that this disease starts early and may be present for a very long time before it starts to cause problems.

Atherosclerosis can remain silent for so long because it is alive. Unlike the debris in a clogged drainpipe, atherosclerosis is in constant negotiation with the walls of arteries, forcing them to adapt to its presence. Baudelaire said that the “finest trick of the devil is to persuade you that he does not exist”. Atherosclerosis has mastered this trick as well. Arteries accommodate disease in their walls by enlarging so that blood flows freely. Each step that may help atherosclerosis along does not exact immediate restitution, but lays claim much later, when the arteries can no longer accommodate. Fortunately for us, atherosclerosis is the rarest of all biological cats. By addressing the root cause of disease, we can put it back in the bag… at least part way.

The processes, actions and events leading up to a heart attack are partly determined by our inborn programming and partly by the life that we lead. The almost universal coexistence of plentiful food and heart attack lends credence to the misunderstanding that atherosclerosis is simply a penalty for each moment spent enjoying a cup of coffee and a donut. The truth is a bit more complicated. We each live within a design that dictates how we store energy from food, distribute salt and water, fight infection and function physically. Our design was shaped under different conditions from those that we presently encounter. As a result, many of us may encounter difficulty as we age because the lifestyle that has become normal combines with our design to steer a course that will end in decay of our arteries. For most of us, the inherited parts of our design that predispose to atherosclerosis and heart attack are not genetic errors. They are built-in safeguards for times of need. In a different setting, of environment or of food availability, these tendencies may be advantages for survival. In times of plenty, they are not.

Preventing or treating atherosclerosis requires realignment of modern lifestyle with our design. Alignment with design refers to all of us in a general sense as well as each of us specifically. We do not all share the same inheritance. Therefore, the prescription to align with our design will vary from person to person.

More on coronary artery disease can be found in the educational booklets for CAD and Heart Attack here.