The human body is an enormous question mark. It needs many things to function, often in a particular proportion, lest its systems go awry. Cholesterol is one of these, and it's often misunderstood. There are many cholesterol myths out there, but before we can debunk them, we need to answer a basic question: What is cholesterol?
Cholesterol is a waxy substance that resembles fat and lives in all the body's cells. Lipoproteins, lipids (which are fat) wrapped in proteins, circulate it through the bloodstream. There are two types of lipoproteins: high-density lipoproteins (HDL) and low-density lipoproteins (LDL); the latter is what we talk about when we talk about bad cholesterol, but people need both to function properly.
Which is to say that not all cholesterol is bad. Cholesterol plays a critical role in digestion as well as the production of hormones and vitamin D, but the body makes all the cholesterol a person needs. When we eat too many animal products and foods rich in trans fats, the liver makes excessive amounts of cholesterol, which can lead to plaque build-up in the arteries — atherosclerosis — which in turn can lead to blockages, blood clots, heart disease, heart attacks or stroke.
LDL is the cholesterol that accumulates in arteries; HDL, typically considered the good cholesterol, helps clear them of LDL deposits, so having too little of it is also dangerous.
But too much good cholesterol could be harmful. A study published in Science magazine on Friday suggested that naturally high levels of HDL, the result of a genetic mutation, may predispose a person to coronary heart disease. But high levels of LDL can also be genetic, meaning certain individuals are at greater risk for heart attack from birth. Even the relatively youthful — looking at you, millennials — should get their cholesterol levels tested.
None of this means we should stop eating eggs, though. So brunch can proceed as usual. Eggs have often been targeted as a cholesterol-elevating food, because they pack a lot of the substance. But the federal dietary guidelines committee has removed its caution on eggs and shellfish consumption because these high-cholesterol foods don't seem to do much to up the amount of cholesterol in a person's bloodstream. Indeed, eggs boast a nutritional profile that might reduce the risk of heart disease, so long as the person eating them doesn't have diabetes.
It does mean that nutrition labels should be scrutinized. Even if a label says the product contains no cholesterol, if it contains trans fats, beware: These can contribute to high levels of LDL and thus increases the odds of atherosclerosis.