We get it. Being overweight is bad for you. Extra weight strains the heart, forcing it to work harder, consequently raising your blood pressure and increasing your risk of myocardial infarction, cardiomyopathies, and stroke. Spending your days on the couch binge-watching Grey’s Anatomy probably isn’t the best lifestyle choice, and a diet of salty, trans-fat-fried carbohydrates cannot possibly be good for you. You do need some exercise to strengthen your heart, and fruits and vegetables are a nutritional necessity, but that’s common knowledge; we all know that already. So, let’s discuss something different; let’s discuss the other extreme–severe emaciation, caloric restriction, and compulsive purging. Underweights are underrepresented by/in the cardiovascular health community, and thusly, I have taken it upon myself to educate you on this equally unhealthy lifestyle.
Bradycardia and hypotension are the two most common cardiac complications of anorexia. In an endeavor to conserve energy, the body begins to shut down, slowing the heart rate and consequently lowering the blood pressure; neither matter is helped by nutritional irregularities/deficiencies (such as B-12, iron, magnesium). Both bradycardia and hypotension are generally benign, but prolonged cases of each can result in confusion, dizziness, fainting, fatigue, heart failure, and tissue death. Many bradycardic and hypotensive patients notice spikes in their heart rate and blood pressure when they stand up; some even experience palpitations, lightheadedness, and collapse. And that’s just standing–imagine what exercise can do!
Exercise in and of itself cannot cause a heart attack, but it can trigger one. The stress on your heart can induce palpitations, arrhythmias, arterial spasms, sudden cardiac death, and, yes, a heart attack. This exercise, while it should strengthen your heart, ends up weakening it because of the atrophic nature of muscles during starvation; you break down the muscle without giving it the energy it needs to build up again. Do I really need to tell you how dangerous this is?
This brings me to the second half of my post, the nutritional component. When deprived of nutrients, the body starts to eat itself. Contrary to popular belief (read: diet industry propaganda), fat is not the first thing to go; on account of their nutritional density, muscles are devoured, and the heart, as one of the largest muscles, is a natural victim. You can literally eat your heart out.
This catastrophic self-consumption leads to many dire results, including mitral valve prolapse, the flopping of the mitral valve, where its flaps collapse and allow for valvular leakage and regurgitation, eventually leading to arrhythmias, left ventricular enlargement, strokes, and heart attacks. Self-consumption is premised by malnutrition, an incredibly harmful state in its own right. A caloric deficit is also a nutritional deficit, since calories are not just energy, but couriers, carrying vital vitamins and minerals, including essential electrolytes. Electrolytes are necessary for heart function, as the heart’s de- and repolarisation is facilitated by ionic channels. A severe shortage of electrolytes can have immediate results like life-threatening cardiac arrhythmias; these, including the frequently fatal ventricular fibrillation, can cause cardiac arrest and, in rare instances (represent!), a heart attack. Consequences can be lasting as well, with electrolyte deficiencies yielding permanent extrasystoles (both atrial and ventricular, including various varieties of geminy) and Long QT Syndrome, the latter of which predisposes one to chaotic heartbeats, and in turn, heart attacks and/or cardiac arrests. It is also worth noting that heart attacks do permanent damage to the myocardial muscle, creating eventual and incurable cardiomyopathies.
Additionally, many underweight individuals are susceptible to vicious binge/purge cycles. A binge’s rapid influx of calories can cause systemic shock, manifesting as cardiac arrest, and self-induced emesis can do the same, with dehydration and the abrupt loss of electrolytes rendering similar effects. The cardiac complications of anorexia can be fatal, and if you are lucky enough to escape them, you are still susceptible to recovery-occurrent ones such as refeeding syndrome, a type of systemic shock analogous to that of a binge. Sounds fun, right?
Please do not do this to yourself. Maintain a healthy weight, eat a balanced diet, and exercise in moderation! Your body will thank you.