Many friends who already have cardiovascular disease problems or are at higher risk of cardiovascular disease know the importance of blood lipid control. Dyslipidemia , especially the increase in total cholesterol and low-density lipoprotein cholesterol , is the basic risk factor for atherosclerosis and plaque formation. In terms of preventing cardiovascular disease, active control of blood lipids Levels, especially levels of the "bad cholesterol" LDL cholesterol, are particularly important.
In the new version of the dyslipidemia guidelines jointly launched by the European Society of Cardiology and the European Atherosclerosis Society published in 2019, one of the more subversive information given in the guidelines is that for the prevention of cardiovascular disease, low-density lipoprotein There is no lower limit for cholesterol control. That is to say, the guideline concludes based on relevant clinical evidence that the lower the LDL cholesterol is lowered, the lower the risk of cardiovascular disease.
With such foreign guideline recommendations, many friends believe that this statement is correct, but for low-density lipoprotein cholesterol, is it really that the lower it is, the better? In today’s popular science article, I will discuss with you some views and content that are different from those recommended in the guide.
"Bad cholesterol" is just a relative term
Many friends believe that cholesterol is a "bad thing". In fact, without cholesterol, life would not exist at all. Lipid nutrition is one of the three essential nutrients for the human body. The formation of cell membranes of cholesterol cell division and the synthesis of hormones are inseparable from cholesterol. The low-density lipoprotein in the blood carries cholesterol in the blood (actually It is combined with cholesterol) and is an important protein that transports cholesterol nutrients to various tissues and organs of the body and cell division. When low-density lipoprotein cholesterol is within the normal range, these cholesterols maintain the normal cell division and reproduction of our body, synthesize hormones, and form cholic acid and other aspects play an important role.
When there are risk factors for cardiovascular disease, or people with existing cardiovascular disease, and the level of low-density lipoprotein cholesterol exceeds the normal range, these excess "cholesterol" will gradually deposit under the endothelium of the blood vessel wall, Accelerate the progression of atherosclerosis and increase the risk of cardiovascular and cerebrovascular diseases . In this case, actively controlling the level of low-density lipoprotein cholesterol is an important control target to reduce the risk of cardiovascular and cerebrovascular diseases. .
How much blood lipid control is safe?
For healthy people with medium and low risk of cardiovascular and cerebrovascular diseases, the normal low-density lipoprotein cholesterol level in the blood is below 3.4mmol/L, while for people with high risk of cardiovascular disease, the low-density lipoprotein cholesterol level in the blood If it can be controlled below 2.6mmol/L, it can help reduce the chance of cardiovascular disease; for friends who already have cardiovascular disease problems, such as those who have had myocardial infarction, cerebral infarction and other major cardiovascular and cerebrovascular events For the general population, low-density lipoprotein cholesterol should be controlled below 1.8mmol/L.
If we can control LDL cholesterol to less than 1.8mmol/L, do we still need to lower it further? Is lower really better? In fact, those who put forward this view have ignored an important issue, that is, cholesterol is not a useless waste, but an important nutrient necessary for the human body. Judging from the data of some large-scale clinical studies, keeping cholesterol at an extremely low level does seem to further reduce the risk of myocardial infarction, cerebral infarction and other problems. However, this extremely low level of low-density lipoprotein cholesterol level comes from another aspect. From this perspective, it may lead to nutritional imbalance in the body, which may lead to other health risks.
Blood lipids will be too low, which may bring about two major health risks.
There are studies that there is no risk no matter how low the LDL cholesterol is. There are also studies on how low the LDL cholesterol is, which will bring health risks. . Below we will briefly share two related studies conducted on Chinese people to share with you the possible harm caused by lowering blood lipids.
In 2020, a study from Ruijin Hospital Affiliated to Shanghai Jiao Tong University included 137,800 subjects in the Chinese Cardiometabolic Disease and Cancer Cohort Study. For the blood lipids of the subjects , blood sugar levels, and the relationship with cancer risk were studied, and the results showed that compared with people with LDL cholesterol higher than 3.4mmol/L, people with LDL cholesterol less than 1.8mmol/L The risk of cancer increased by 48%, and especially for people with diabetes problems, poor blood sugar control, and low blood lipid levels, the risk of cancer increased the most.
In a 2019 study published in the journal "Nature Medcine" Peking University and the China Food and Drug Safety Risk Assessment Center, a total of more than 500,000 Chinese samples were analyzed to analyze the blood lipid control levels of Chinese adults, and The causal relationship between cerebral infarction, and cerebral hemorrhage , according to the follow-up data of the past 10 years, shows that if low-density lipoprotein cholesterol does not decrease by 1mmol/L, the risk of cerebral infarction is reduced by 20%, but the risk of hemorrhagic stroke is But it increased by 17%.
Like those large-scale clinical studies that suggest that the lower the LDL cholesterol, the better. Of course, such studies may have flaws of one kind or another, and cannot be used as a reference for everyone. However, such studies also remind us that low-density lipoprotein cholesterol The lower the density lipoprotein cholesterol is, the better. The health risks it may bring are also worthy of attention.
2 people should avoid lowering their blood lipids too low.
In terms of controlling the risk of cardiovascular disease, it is an uncontroversial fact to strictly control blood lipids. But how should blood lipids be controlled? How much control is enough? We should still make individualized analysis and judgment based on the actual situation. Whether it is guidelines or large-scale clinical studies, the data and probabilities given are all conclusions drawn through big data statistical analysis. As an independent individual, everyone's situation may vary greatly. If you set overly strict blood lipid control goals for yourself because you follow a certain study or a certain guideline without evaluating your actual situation, it may not necessarily be the best choice.
Based on the above two studies, it is recommended that friends with the following two types of situations should not lower their blood lipids too low.
The first type is people with diabetes and poor blood sugar control, as well as high risk factors for digestive tract cancer. For example, if you have a family history of cancer or have related precancerous lesions, you should pay more attention to reasonable control of blood lipid levels and try to avoid lowering LDL cholesterol too low. On the one hand, this group of people should further find ways to actively control blood sugar levels, and on the premise of ensuring safety, control the glycosylated hemoglobin level below 7.0%. At the same time, they should also pay attention to the reasonable control of low-density lipoprotein cholesterol. For example, patients with existing cardiovascular disease can control their LDL cholesterol to about 1.8mmol/L, and there is no need to lower it too low.
The second type is people with a higher risk of cerebral hemorrhage. Cerebral infarction and cerebral hemorrhage are closely related to the progression of atherosclerosis, but there are certain contradictions in controlling the risk. On the basis of controlling low-density lipoprotein cholesterol to 1.8mmol/L, blood lipid levels can be further reduced. , the risk of cerebral infarction can be reduced, but the risk of cerebral hemorrhage will further increase. If there are people with poor control of , hypertension, , or people at high risk of cerebral hemorrhage with cerebral arterial amyloidosis, it is still recommended to set a control target of about 1.8mmol/L, and there is no need to lower it too low.
In short, when we set blood lipid control goals, we should not only consider the requirements of the guidelines, but also make rational and personalized assessments and judgments based on our own actual situation.If other chronic disease factors can be actively controlled, and the risk of cancer, cerebral hemorrhage, etc. is low, and the risk of myocardial infarction and cerebral infarction is high, the LDL cholesterol can be controlled to a lower level, of course it can be considered; but if The risk of developing thrombosis and is not high, but for people who are at certain risk of cerebral hemorrhage and cancer, lowering their blood lipids too low may bring certain risks, and the gain outweighs the loss.
