Cholesterol “Good” Is Not So Good

2021-02-26   |   by CusiGO

All that glitters is not gold. Neither the life factors in instagram nor the abundance of HDL in human tissues. These particles, called high-density lipoprotein (HDL), are carriers of cholesterol, a fatty substance needed for life, but if it accumulates too much in the arteries, it is dangerous. However, HDL has a good reputation, in fact, they are also called good cholesterol because, unlike LDL or bad cholesterol, they capture fatty matter deposited in the arteries and transfer it to the liver, where it is removed. Thus, high HDL is a signal of cardiac protection, and high LDL levels mean an increased risk of heart problems – these lipoproteins transport cholesterol to cells, but not to the liver for clearance. However, a study by the Hospital del Mar de Barcelona shakes the benefits of high-density lipoprotein (HDL) and concludes that good cholesterol is not so good. Or at least not all: only one subgroup, small HDL particles, is associated with reduced cardiovascular risk. The big particles of HDL are not.

“We have a lot of studies that show the risk of coronary heart disease: high HDL levels reduce the risk, and high LDL levels increase the risk. As for prevention, in fact, we have several drug families to reduce LDL, and lowering these levels can reduce the risk of cardiovascular disease, “explains Roberto elosua, a researcher at marim hospital. The key is that LDL cannot reach the liver. “It doesn’t bind to liver receptors, it doesn’t bind to them, it doesn’t release cholesterol from the liver to eliminate it,” experts said. Cholesterol deposits on the walls of arteries can lead to atherosclerosis: it accumulates in the blood vessels, forming a plaque that narrows the arteries and limits blood flow.

For researchers, the Holy Grail, as elosuya says, is to find drugs that raise cholesterol levels. “Drugs made in 2000 almost tripled HDL levels, but they didn’t reduce the risk of cardiovascular disease, they increased it. As a result, they are not authorized to use them, and they are not in pharmacies, “elosuya said. But the failure of these drugs was the starting point of researchers at Delma hospital: they began to question whether there was a real causal relationship between HDL levels and coronary heart disease.

“We did genetic analysis to see if this relationship was causal. We knew some genetic features, changes in the position of certain letters in the genome sequence, which made some people have more HDL. We think: if I have genetic characteristics that make me have more HDL than you, I should also have more cardiovascular protection, “he explained. But this premise has not been met: “high density lipoprotein does not reduce the risk of heart attack.”

However, the key they found was the subgroup of HDL, the smaller or larger particles. Experts have found that the genetic characteristics associated with the production of large grains of good cholesterol are less favorable. In fact, they are directly related to the greater risk of stroke. However, genetic characteristics associated with small granule cholesterol are associated with a lower risk of stroke. “Small particles of HDL play a more important role in the reverse transport of cholesterol, that is, cholesterol is transferred to the liver and excreted through feces,” elosua concluded.

This finding has not had a significant impact on clinical practice, but it opens a window of opportunity. First, research new drugs. “If we can use drugs to regulate the activity of these genes that are associated with the production of small particles of HDL, we can increase their levels in the body,” elosua said, adding to cardiovascular protection. The researcher published his research in the Journal of clinical and experimental metabolism, and he did not rule out the routine assessment of HDL based on particle subgroup in traditional blood analysis to better adjust the actual cardiovascular risk.

Soon, in the absence of drugs and more thorough control of really good cholesterol, elosua revealed two factors that could help raise good cholesterol levels: “Mediterranean diet and physical exercise.”. That’s right.

You can follow topics on Facebook, twitter, instagram, or subscribe to our newsletters here