What is familial hypercholesterolemia and how to thrive if you have it
Familial hypercholesterolemia is an inherited condition which leads to very high cholesterol levels. If you take away the word “familial”, then hypercholesterolemia itself simply means high blood cholesterol. As discussed often on this blog, in normal adults, high cholesterol is almost 100% manageable via lifestyle alone (without the need for prescription drugs like statins.)
In familial hypercholesterolemia, the reason for the high cholesterol is primarily genetic. The picture above is from my (very large) family reunion. These are most of my immediate cousins from my dad’s family which had 13 brothers and sisters. In families like mine, the mother or father passes along a gene to the child that interferes with the body’s ability to take cholesterol into the cells. The type of cholesterol impacted is the Low Density Lipoprotein-cholesterol (LDL-cholesterol). This means that the ability to remove LDL-cholesterol efficiently from the bloodstream is reduced. The condition results in a higher level of LDL-C in the bloodstream. (We used to think this was a very bad situation, and sometimes even a death sentence, but read on to see how the science has changed.)
If the child receives the gene from only one parent, it is called heterozygous familial hypercholesterolemia. In rare cases, the child will receive the gene from both parents (homozygous familial hypercholesterolemia). Depending on the number of faulty genes received, a person with familial hypercholesterolemia will have double (hetero) and sometimes four times (homo) the LDL cholesterol of the general population.
The prevalence of familial hypercholesterolemia
The prevalence of familial hypercholesterolemia varies worldwide. This could be due to different tracking systems for the disease in each country, or potentially different ethnic predispositions to the condition. Populations vary in their estimates from between one in 500 to one in 200. It is estimated that between 14 and 34 million individuals worldwide have the condition, but fewer than 15% of these cases are diagnosed. This means that millions of people throughout the world remain undiagnosed and are unaware that their eating patterns could be creating a significant and potentially fatal disease risk (see below on what you can do to minimize your risk).
Here are some general estimates of the condition by country:
- USA: About 1 in 500 have the heterozygous form of FH (around 600,000 Americans)
- UK: At least 1 in 500 have this condition (roughly 120,000 in the UK)
- Holland: Around 1 in 200 to 1 in 300 are affected (roughly 84,000 in Holland)
The bodily mechanism behind familial hypercholesterolemia
Despite all the negative press, LDL particles are actually just transport vehicles for cholesterol particles. Cholesterol is an important fatty building block for our body, however it cannot circulate in our blood on its own. It needs an LDL particle to act as a taxi to take it to cells where it can be used.
LDL receptors are found on cell walls in our bodies. They allow LDL particles that circulate in our blood to “dock” much like a spaceship docks onto a space station. Once the cholesterol docks, it is taken out of the bloodstream and used in the cell. Someone with familial hypercholesterolemia often has fewer of these LDL receptors (typically half the normal amount). When we have less LDL receptors available, fewer LDL particles can dock with our cells and therefore more LDL particles must stay circulating in our bloodstream. The good news is that more LDL in our bloodstream does not have to be a big deal. But, if we don’t know it’s there and eat a poor diet, then it can be deadly. If we do know it’s there, and we eat a healthy diet, the extra cholesterol does not need to negatively impact us.
How do we avoid atherosclerosis or arterial plaque if we have familial hypercholesterolemia?
The reason why many of us are scared of high cholesterol is because cholesterol can be changed through chemical processes into arterial plaque. So the excess LDL cholesterol circulating in the bodies of those of us with familial hypercholesterolemia can become trapped in the walls of blood vessels, eventually forming plaques, which cause narrowing arteries and eventually heart attacks.