Many people believe that cholesterol should be as low as possible. After all, high cholesterol is a well-documented risk factor for heart disease. Indeed, a high cholesterol level increases the risk of heart disease and stroke, adding that about 38% of Europeans have a high total cholesterol level, ie 200 mg/dL or more.
However, cholesterol levels are more complicated than that, as different types have different impacts. High-density lipoprotein (HDL) cholesterol, often referred to as “good” cholesterol, helps remove “bad” low-density lipoprotein (LDL) cholesterol from the body. For this reason, doctors consider it beneficial. However, there is still much to discover, and researchers are still learning how HDL and other types of cholesterol work. In this article, we look at whether or not HDL cholesterol may be too high. We’ll also look at what healthy levels are and what can happen to people whose HDL falls outside of that range.
When high cholesterol is good
There are two main types of cholesterol in the body, and only one is generally considered a heart health risk. LDL cholesterol contributes to the buildup of fat that can clog a person’s arteries. When this buildup clogs or narrows the arteries, a heart attack or stroke is more likely to occur. In the case of LDL cholesterol, it is better to have a lower level. HDL cholesterol helps remove LDL cholesterol from the blood and transport it to the liver to be processed and eliminated. A high HDL level is desirable because it generally indicates a lower risk of heart disease. Some experts also believe that HDL may have anti-inflammatory, anticoagulant, antioxidant and other properties that may provide additional protection against cardiovascular disease. Lifestyle recommendations for managing cholesterol aim to balance cholesterol types by increasing HDL levels and decreasing LDL levels.
HDL: is a higher rate always better?
You should try to aim for an HDL level equal to or greater than 60 mg/dL. It is the only cholesterol test measurement that has a lower rather than an upper limit. Total cholesterol should be below 200 mg/dL and LDL should be below 100 mg/dL.
Previous research suggests that the higher the HDL levels, the more a person is protected against heart disease. However, new evidence is emerging that could challenge this assumption. Some experts now speak of a U-shaped relationship, in which very low and very high HDL levels can be harmful. Some scientists now believe that genetic, environmental and lifestyle factors can influence how HDL builds up in the body and how it behaves, and that some of these effects could be harmful for some people. However, it is still unclear if this happens and, if so, who it affects and why. In 2010, researchers found that people who had recently had a heart attack and had high levels of HDL and a substance called C-reactive protein had a higher risk of having another heart attack. The liver produces C-reactive protein when inflammation occurs in the body.
Some experts believe that under certain conditions HDL particles may take on inflammatory properties rather than protecting a person from inflammation. The authors of a 2019 review note that the protective characteristics of HDL depend not only on the amount of HDL present, but also on how it behaves in the body. A 2018 study with the same lead author suggested that functionality (how HDL works) may be even more important than circulating HDL levels.
A 2016 research paper discusses a rare genetic change that can lead to unusually high HDL levels. It occurs in a molecule known as SR-BI. The change affects how HDL works in the body, and it can lead to high HDL levels and an increased risk of heart disease. The authors note that some participants had HDL levels above 95 mg/dL, which is unusual. Some participants with these high levels had this rare genetic characteristic.
Meanwhile, a 2017 review suggests that the balance between HDL and LDL may play a role. In one of the two large studies reviewed, people with “extreme” high or low HDL levels had a higher risk of death than those with more moderate levels. The authors proposed that the optimal levels might be 73 mg/dL in men and 93 mg/dL in women.
Although researchers are continuing their research in this area, experts still recommend focusing on managing known risks of cardiovascular disease, including reducing LDL levels.
Find the right balance
The first step to achieving healthy cholesterol levels is to take a test and discuss the results with a doctor, who will also consider individual risk factors. For most adults it is best to have a cholesterol test every 4-6 years, but more often if they have diabetes, heart disease or a family history of high cholesterol. Cholesterol tests measure the amount of different cholesterols in mg/dL. Most tests show HDL, LDL, and total (serum) cholesterol levels. To get a total cholesterol score, the doctor adds together a person’s HDL and LDL cholesterol levels and 20% of their triglyceride levels.
Desirable levels are:
Total cholesterol less than 200 mg/dL
“Good” HDL cholesterol 60 mg/dL or more
“Bad” LDL cholesterol Less than 100 mg/dL
Triglycerides below 150 mg/dL.
However, various factors affect what is healthy for each person.
Healthy Ways to Achieve High HDL
For most people, current guidelines recommend maximizing HDL levels, preferably by adopting a healthy lifestyle. To achieve and maintain moderate levels, experts recommend:
– do regular cholesterol tests
– to have a balanced diet, rich in fruits, vegetables, whole grains and lean proteins
– limit the consumption of saturated and trans fats, processed foods, salt and added sugars
– exercise regularly
– maintain a moderate weight
– avoid or quit smoking
– limit alcohol consumption
– manage stress, as much as possible
– sleep 7 to 9 hours at bedtime.
If a person’s HDL level is abnormally high, the doctor may recommend genetic or other testing to assess the risk of heart disease. Specific medications can treat high cholesterol levels due to inherited genetic changes. If a doctor prescribes a drug, the person should take it as directed. If she wants to stop taking the medicine, she should talk to a doctor first. The person may also need support for other health issues, such as diabetes or high blood pressure.
Cholesterol is an important indicator of heart disease risk. Doctors recommend aiming for high HDL cholesterol and low LDL cholesterol. HDL cholesterol is beneficial because it helps eliminate LDL cholesterol from the body. In some cases, however, HDL cholesterol levels can be very high or behave in non-beneficial ways. Scientists are currently studying how and why this can happen. In the meantime, experts continue to recommend focusing on lowering LDL and raising HDL, preferably through lifestyle measures, but also through medication, if needed.
Kosmas, CE, et al. (2018). High-density lipoprotein (HDL) functionality and its relevance to atherosclerotic cardiovascular disease.
Madsen, CM, et al. (2017). Extreme high high-density lipoprotein cholesterol is paradoxically associated with high mortality in men and women: two prospective cohort studies [Abstract].