HDL (high-density lipoprotein) is often referred to as the “good” cholesterol because it helps to remove the “bad” cholesterol from the body and is required for many vital processes within the body. Having high levels of HDL cholesterol has been shown to decrease your risk for heart disease. Read on to learn how you can increase HDL levels naturally.
People go to their doctor to get their HDL cholesterol tested as part of a standard lipid panel. Almost always, the results are not scrutinized, even though we know that you can be healthier and live longer when your results lie within optimal ranges. When I used to go to doctors and tried to discuss my results, they had no clue what these meant from a health perspective. All they cared about was whether they could diagnose me with some disease. If I complained a lot, then they simply brushed me off as depressed so they could give me a pill.
What is HDL Cholesterol?
High-density lipoprotein (HDL) is a particle that transports fat molecules (lipids) through the body. HDL is often referred to as “good” cholesterol because it carries the “bad” cholesterol, or LDL cholesterol (low-density lipoprotein), away from the heart for degradation. It’s referred to as high-density because it contains the highest proportion of protein to lipids, making it denser than other types of cholesterol molecules such as LDL [R].
HDL is made in the liver and small intestine travels through the blood picking up cholesterol particles and returns the cholesterol back to the liver to be broken down. Because of this, higher HDL levels (> 40 mg/dL for men and >50 mg/dL for women) has been associated with decreased risk for cardiovascular disease. HDL levels are easily tested via blood tests [R, R, R].
Types of Cholesterol and Lipids
HDL is one of the types of lipids, or fat molecules, found in the blood. The other lipids that circulate the blood are low-density lipoprotein (LDL), very-low-density lipoprotein (VLDL), and triglycerides [R, R].
LDL transports cholesterol around the body for use in various organs, while HDL picks up unused cholesterol and returns it to the liver. VLDL is made in the liver and converted to LDL in the bloodstream [R, R].
HDL Blood Tests
HDL cholesterol is made up of particles of different sizes. Having higher levels of large HDL particles is strongly associated with a lower risk for heart disease while having higher levels of small HDL particles is less protective. Simple blood tests can determine the sizes that make up the HDL cholesterol in your body [R, R].
HDL Normal Range
High levels of HDL cholesterol has repeatedly been shown to protect against cardiovascular disease, so low levels of HDL will increase your risk. Low levels of HDL may also contribute to inflammation and metabolic syndromes such as type 2 diabetes [R, R, R, R].
In certain disease states, such as diabetes and sickle cell anemia, the HDL molecule can be dysfunctional and promote inflammation. In these cases, extremely high HDL levels could be detrimental rather than beneficial [R].
A study in 767 non-diabetic patients who had recently suffered a heart attack found that patients with high levels of HDL, in addition to a high level of the inflammatory protein, C-reactive protein, were actually at a higher risk for heart disease [R].
What Decreases HDL Levels?
1) Genetic Conditions
Apolipoprotein A1 (ApoA-1) is the main protein in HDL particles. People with mutations in the gene that codes for ApoA-1 have extremely low HDL levels and also early onset cardiovascular disease [R].
ATP-binding cassette transporter (ABCA1), also known as the cholesterol efflux regulatory protein (CERP), is a protein that regulates the movement of cholesterol throughout the body. Mutations in the ABCA1 gene are found in 5-21.4% of individuals with low HDL cholesterol [R].
Lecithin cholesterol acyltransferase (LCAT) is a protein that plays a role in the formation of lipoproteins such as HDL and LDL. Severe mutations in LCAT cause familial LCAT deficiency (FLD). A 70-80% decrease in HDL levels is observed in patients with familial LCAT deficiency. Many studies of various ethnic groups have been conducted and found between 2-25% of people with low HDL have a mutation in the LCAT gene [R, R].
2) Consuming Artificial Trans Fats
Artificial trans fats, found in margarine and many processed foods, cause inflammation and are detrimental to many aspects of health. A study in 27 young women found that consuming partially hydrogenated soybean oil resulted in a 10% decrease in HDL cholesterol compared to consuming palm oil [R].
A study on 40 healthy adults comparing the effect of consuming monounsaturated trans fatty acids (TFAs) from natural sources versus industrially produced found that HDL levels in women consuming industrially produced TFAs were lower [R].
Cigarette smoking has been undeniably proven to be a preventable risk factor for heart disease. Cigarette smoking is associated with low HDL levels and cigarette smoke can directly damage the HDL molecule resulting in a dysfunctional HDL molecule that has lost its heart-protective properties [R].
4) Health Conditions
Several health conditions that fall under the category of metabolic disorders are associated with low levels of HDL cholesterol, as well as dysfunctional HDL molecules. These include type 2 diabetes, insulin resistance, central obesity (excess fat around the stomach), high blood pressure, and hypertriglyceridemia (high triglyceride levels) [R, R].
Ways to Increase HDL Levels
1) Use Olive Oil
Saturated fat, found in dairy and fatty cuts of meat, increases both LDL and HDL. Replacing saturated fat with “healthy fats” (polyunsaturated or monounsaturated fat found in nuts, seeds, avocados, vegetable oils) has been shown to lower both LDL and HDL cholesterol [R].
Numerous studies have shown that supplementing your diet with olive oil can help to lower total cholesterol and raise HDL cholesterol. Olive oil contains antioxidants called polyphenols that are responsible for its heart-protective properties [R, R, R, R].
Olive oil also improves cholesterol profiles by improving HDL’s ability to mediate proper cholesterol transport. A study in 26 healthy human volunteers suggests that olive oil (25 mL/day) improves cholesterol profiles by increasing the production of the proteins ABCA1 and ABCG1 which transport fats across cell membranes [R, R, R, R].
Olive oil also helps to increase the anti-inflammatory properties of HDL. A study performed in 20 healthy adults consuming extra virgin olive oil (25 mL/day) for 12 weeks had increased levels of a protein associated with HDL (paraoxonase 1, PON1) that helps to mediate HDL’s anti-inflammatory properties [R].
2) Eat Eggs
A study of 28 overweight men on a low carbohydrate diet found that eating 3 eggs/day resulted in a 25% increase in HDL cholesterol. Eating eggs also improved risk factors associated with metabolic syndrome. This effect was more pronounced in obese individuals. In a study of 15 obese men given 3 eggs/day HDL cholesterol increase 52% from baseline. However, this second study was funded by the American Egg Board [R, R].
A crossover study of 42 elderly men and women found that consuming 3 eggs/day increased HDL cholesterol by 23% [R].
In older adults taking statins, consuming 4 egg yolks/day for 5 weeks resulted in increased HDL cholesterol (5%) without an increase in LDL [R].
3) Follow a Low Carb or Ketogenic Diet
Numerous studies show that lowering carbohydrate intake and increasing intake of healthy fats can have many health benefits including lowered blood sugar, weight loss, and improved insulin sensitivity. Another great benefit is an increase in HDL cholesterol [R, R, R, R].
In a randomized controlled trial of 115 obese adults with type 2 diabetes, consuming less than 50 g of carbs/day resulted in weight loss and also an increase in HDL cholesterol nearly twice as high as those consuming a high carb diet [R].
Overweight, diabetic patients (n=194) that followed a low-carb Mediterranean-based diet for 12 months in a randomized intervention study experienced an increase in HDL that was not observed in those eating a traditional Mediterranean diet [R].
In a prospective study of 22 obese adults with metabolic syndrome, following the “Spanish Mediterranean Ketogenic Diet” for 12 weeks increase HDL cholesterol and cured them of metabolic syndrome completely [R].
4) Eat Foods High in Anthocyanins
Blueberries, blackberries, pomegranate, eggplant, red cabbage, and other purple fruits and vegetables are high in anthocyanins, which are potent antioxidants that may help to increase HDL cholesterol [R, R].
Diabetic patients given 160 mg, 2x/day anthocyanin extract for 24 weeks experienced a nearly 20% increase in HDL cholesterol [R].
Another study of 120 patients with high cholesterol saw a nearly 14% increase in HDL cholesterol after 12 weeks of anthocyanin supplementation (160 mg, 2 times per day anthocyanins) [R].
A study of 18 overweight men and women subjected to 12 weeks of regular endurance training found an increase in HDL levels in the men and a favorable shift in HDL sub-fraction in women, without any change in diet [R].
A study (prospective observational) of 200 men found that the increase in HDL with regular endurance training is most significant in patients that also have high levels of triglycerides and excessive abdominal fat [R].
6) Lose Weight
Many studies have shown that losing weight, regardless of which diet you follow, can result in a sustained increase in HDL cholesterol. A cohort study of 3,480 Japanese adults found that losing at least 3 kg (6.6 lbs) resulted in an average of 4 mg/dL increase in HDL cholesterol [R, R, R, R, R, R].
7) Consume Moderate Amounts of Alcohol
A link between light to moderate alcohol consumption (1 drink/day for women and 1-2 drinks/day for men) and lower risk of heart disease has been observed in many studies. Heavy alcohol consumption is not only associated with increased risk for heart disease but also increases your risk for many other diseases such as diabetes or stroke [R, R].
A study of 2473 men and 1530 women found that participants that reported alcohol intake had higher levels of HDL cholesterol [R].
Another study found moderate alcohol consumption was associated with increased HDL cholesterol levels. The type of alcohol consumed did not affect the increase in HDL and there was no association found between dietary fat and HDL cholesterol levels [R].
8) Cook With Coconut Oil
Several studies have found that consuming coconut oil (generally about 2 tablespoons/day used for cooking) can raise HDL levels more than other types of fat. Coconut oil also helps to lower the LDL to HDL ratio, which reduces the risk for heart disease [R, R, R, R].
9) Eat Fatty Fish
There are contradictory reports about the effect of consuming fatty fish or supplementing with fish oil on HDL cholesterol levels. Some studies have observed an increase in HDL cholesterol when participants consumed large amounts of fish, but the effects were minimal and other studies have found no increase in HDL in response to increasing dietary fish intake or supplementation [R, R, R, R, R, R, R].
Drugs That Increase HDL
Disclaimer: By writing this section, we are not recommending these drugs. We are simply providing information that is available in the scientific literature. Please discuss your medications with your doctor.
Statins can lower LDL cholesterol and raise HDL cholesterol in patients. However, whether or not this has a meaningful impact on risk for cardiovascular disease is still unclear. A meta-analysis of 12 studies including more than 26,000 patients found that “pharmacologically manipulating cholesterol” to optimal levels does not actually have a beneficial outcome as people are still at high risk for heart disease [R, R, R, R].
Fibrates (PPAR Alpha Agonists) or Thiazolidinediones
Fibrates and thiazolidinediones (TZD) are two classes of compounds that activate a protein (PPARα) that increases the breakdown of fat in the liver and other parts of the body. These compounds are sometimes used in patients that do not tolerate statins well to lower LDL and raise HDL. Paradoxically, in some rare cases, they can actually cause a dramatic decrease in HDL, so it’s important to work with your doctor when taking either of these medications [R].
Health Dangers of Abnormal HDL Levels
The largest risk of low HDL cholesterol is developing heart disease. There is a large body of data suggesting that HDL cholesterol has a heart-protective effect and up to 1/3 of patients with heart disease have “normal” total cholesterol but low HDL levels, highlighting the important role this molecule plays in protecting the heart [R, R, R].
HDL also plays an important role in immune function. A large prospective population study of 20,000 adults found that participants with very low HDL had a 75% higher risk of infection. Interestingly, very high levels of HDL can also be problematic, as those with very high HDL cholesterol had a 43% higher risk for infectious disease than those with “normal” levels. Very high HDL may be correlated with heart disease as well [R, R, R].
- APOA1 – the gene that codes for the main protein component in HDL particles
- ABCA1 – the gene that codes for cholesterol efflux regulatory protein
- LCAT – the gene that codes for the protein lecithin cholesterol acyltransferase that regulates the formation of HDL
Limitations and Caveats
A major issue with interpreting the results of studies on HDL is that it’s hard to determine how large a role other factors might play. For example, if there is an association between young males that eat low-fat diets and also have high HDL cholesterol, it’s also possible that those same men are non-smokers who exercise regularly. Additionally, many of these studies are self-reporting and participants do not always respond truthfully [R].
It’s commonly assumed that increasing dietary cholesterol will consequently raise blood cholesterol levels and over time, lead to heart disease. While this is partially true, it’s important to note that only 25% of blood cholesterol is from the diet. The other 75% of cholesterol found in the blood is synthesized by the body, and this is largely controlled by genetics [R, R].
In many of the egg studies, increases in HDL are generally accompanied by increases in LDL cholesterol. This means the ratio of LDL to HDL, and the risk of cardiovascular disease is mostly unchanged as well [R, R, R, R].
Irregular HDL Cholesterol Levels?
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