Low-density lipoprotein (LDL) cholesterol, or “bad” cholesterol, collects in the walls of the blood vessels, causing them to narrow. High-density lipoprotein (HDL), or “good” cholesterol, moves LDL cholesterol out of the bloodstream.
The two main types of cholesterol are high-density lipoprotein (HDL) or “good” cholesterol, and low-density lipoprotein (LDL) or “bad” cholesterol. Some cholesterol is needed in the body, but high levels can be dangerous.
Along with smoking and high blood pressure, raised blood cholesterol is one of the
In this article, we look at HDL and LDL in detail, including what makes one good and the other bad, as well as what a person can do to keep levels in check.
LDL cholesterol is often called bad cholesterol. If there is too much LDL cholesterol in the blood, it builds up in the walls of the blood vessels, causing them to narrow and stiffen.
HDL or good cholesterol can move LDL cholesterol from the blood to the liver, which breaks it down for disposal as waste. HDL cholesterol is referred to as good cholesterol because it reduces the level of cholesterol in the blood.
In the United States, cholesterol is measured in milligrams per deciliter (mg/dL). The
- total cholesterol below 200 mg/dL
- LDL cholesterol less than 100 mg/dL
- HDL cholesterol above 40 mg/dL for men and above 50 mg/dL for women
Different regions and countries may have varying guidelines, so it is wise to speak to a doctor about the most accurate and up-to-date ranges.
The total cholesterol to HDL cholesterol ratio is way to calculate cardiovascular risk. A high total cholesterol to HDL ratio indicates a higher risk for heart disease. It can be measured by dividing the total cholesterol by the HDL level.
Total cholesterol does fluctuate, so more than one blood test might be required for an accurate assessment. Levels can change following a meal, so sometimes a blood test will be taken first thing in the morning before a person has breakfast.
Studies suggest that the total cholesterol to HDL ratio is a better marker of the risk of heart disease than LDL cholesterol levels alone.
Another method of assessing cholesterol levels is calculating a non-HDL cholesterol level. This is measured by subtracting HDL cholesterol from the total cholesterol.
This method is
Similarly to LDL cholesterol, VLDL cholesterol can also build up inside the walls of blood vessels, which is undesirable.
Ideally, a non-HDL cholesterol level should be less than 130 mg/dL. A higher value than that increases the risk for heart disease.
Causes of high LDL cholesterol include:
- Eating a diet high in saturated fat: Diets high in saturated fats
can increaseLDL cholesterol levels.
- Inactivity: Not getting enough exercise can lead to weight gain, which is
linkedto increased cholesterol levels.
- Obesity: People who are overweight have an
increased riskof high cholesterol levels.
- Medical conditions: Some of these
that can affect LDL cholesterol levelsinclude type 2 diabetes, underactive thyroid, liver conditions, and alcohol addiction.
- Menopause: For some women, cholesterol levels
can riseafter menopause.
Familial hypercholesterolemia (FH)is an inherited form of high cholesterol that puts people at risk of early heart disease.
The following lifestyle changes
- maintaining a healthy weight
- exercising regularly
- quitting smoking
- using statin therapy when prescribed
People trying to lower their LDL cholesterol should also avoid eating saturated and trans fats. (Note: trans fats have been banned in the United states
- poultry, especially with skin
- beef fat (tallow)
- lard and cream
- ice cream
- palm oil
- palm kernel oil
- some baked and fried foods
Other diet tips to prevent LDL levels creeping up include:
- Switch fat sources: Swap saturated fats for nut and seed oils or monounsaturated fats from olive, avocado, and canola oil.
- Increase fiber intake: A diet high in fiber is believed to be good for total blood cholesterol levels.
Soluble fiberfound in fruits, vegetables, and oats is particularly beneficial.
A variety of things can improve HDL cholesterol levels, including:
- Omega-3 fatty acids: Omega-3 fatty acids can lower blood cholesterol when consumed as part of a balanced diet. The highest levels of omega-3 fatty acids are in oily fish, such as mackerel, trout, herring, sardines, fresh tuna, salmon, and halibut.
The American Heart Association recommendseating 2 servings of fish (particularly fatty fish) per week.
- Regular exercise:
Researchshows that exercise and physical activity can raise HDL levels.
High LDL cholesterol is a risk factor for heart disease, but it can often occur without any symptoms.
It is recommended that people over 40 years of age arrange a blood test to check their cholesterol levels and total cholesterol to HDL ratio.
Dietary and lifestyle changes can make a big difference to HDL and LDL levels. If they do not improve with these changes, a doctor may recommend medications.