Why (and How) You Should Increase Your HDL Cholesterol
Studies show that having lots of HDL-cholesterol (high-density lipoprotein cholesterol, also referred to as “good” cholesterol) is strongly associated with lower risk of cardiovascular disease... even more than the LDL (low density lipoprotein) cholesterol we hear about more often. This could be because we have drugs that lower LDL, but none that raise HDL significantly.
What are HDL and LDL?
Cholesterol is fat-soluble and doesn’t dissolve in watery blood, so it’s wrapped up in a protein coating, called a lipoprotein. Think of it as a delivery envelope. Some lipoproteins are small and dense (HDL) and others are larger and fluffy (LDL).
LDL Cholesterol
LDL molecules are thought to carry cholesterol from the liver, where most is produced, to the parts of the body where it is needed. It's a misconception that you need to avoid cholesterol in your diet--if you don't eat it, your liver simply produces more of this essential molecule.
Your body uses cholesterol to strengthen and maintain cell walls and other structures in the body, to insulate nerves, to make hormones (including stress hormones, cortisol and adrenaline and the reproductive hormones estrogen, progesterone and testosterone), and to make vitamin D (actually a hormone). Your body works to maintain enough in your blood for all its essential functions.
Most health organizations currently recommend keeping LDL cholesterol levels low to reduce heart disease risk, but there is some controversy over this advice since heart attacks can still occur in those with low to normal cholesterol levels and having high levels doesn't necessarily mean you will have a heart attack. Other factors are important for heart disease risk, too... perhaps more important than your cholesterol.
Newer guidelines place less emphasis on LDL blood cholesterol and more on things like levels of inflammation in the body, and waist to hip measurement ratio (the waist measurement should be smaller than the hips: a ratio of 0.8 in women and 1.0 in men when the waist measurement is divided by the hip measurement). Because this measurement is associated with body fat distribution (with abdominal fat deposits indicating more danger to health than those elsewhere, such as on the hips), it’s considered more accurate for heart disease risk than the Body Mass Index (BMI) that has been used for many years.
The inherited metabolic disorder, Familial Hypercholesterolemia (FH), is associated with very high levels of LDL and those who inherit this condition often have elevated levels of cholesterol even in childhood. FH is associated with a definite increase in heart disease risk. It has been assumed by many researchers that this proves that high LDL cholesterol is dangerous for all. However, FH involves additional metabolic changes, not just increased LDL, including changes in the HDL receptor in the liver, changes in Apolipoproteins a and b, and markers of insulin resistance, that also contribute to heart disease risk. Some researchers now believe that, because so many with this disorder were included in cholesterol studies (with patients being selected for their high cholesterol levels), they may have influenced the results of early research.
HDL Cholesterol
HDL molecules, on the other hand, are believed to collect up excess cholesterol from the arteries and carry it back to the liver. Studies show that higher levels of HDL are more strongly associated with lower risk of heart disease than lowering LDL. Having at least ¼ of your blood cholesterol in the form of HDL (a ratio of 4 or less) is associated with less risk.
We have medications that effectively lower LDL cholesterol. The most commonly used ones also have anti-inflammatory, anti-clotting and antioxidant effects—all beneficial in reducing heart disease, especially in those with Familial Hypercholesterolemia (FH). But these drugs have little effect on HDL, which studies suggest may actually be more important than LDL.
However, the good news is that there are non-drug strategies that are known to raise your HDL. Here are 9 lifestyle and diet choices that can make a difference:
Consume olive oil—Olive oil is great straight up on salads, or for baking as it’s stable when heated. Although some experts are now questioning the advice to avoid animal fats due to their saturated fat content, vegetable oils lower HDL while animal fats raise it. Olive oil, an important part of the Mediterranean Diet, seems to be a happy medium that all experts can agree is a healthy all-round oil. High quality, extra virgin olive oil has more polyphenols, the substances in olive oil that are believed to best reduce heart disease risk.
Eat a low carbohydrate (or ketogenic) diet—Studies have found that even reducing carbs to less than 50 grams daily can boost HDL blood levels. Note that a weight-loss keto diet is more like 20 to 30 grams of carbohydrates. The same studies found that low fat, high carb diets decreased HDL cholesterol, and that saturated fats from animal sources increased HDL more than vegetable oils.
Exercise regularly—Many types of exercise are effective in increasing HDL levels, including strength training, high intensity, and aerobic exercises. The largest increases were with high intensity exercise, such as interval training where high and lower intensity exercises are alternated, as tolerated. As well as increasing HDL, study participants showed other health improvements, such as decreased insulin resistance and better artery function. Exercise has many health benefits!
Add coconut oil or MCT Oil to your diet—Although these oils contain saturated fat and were thought to be unhealthy, according to the “low fat” diet recommendations, research has found they increase HDL and reduce the HDL to LDL ratio, a positive marker for cardiovascular health. The ratio of HDL:LDL is recommended to be 4 or less, meaning that at least ¼ of a person’s blood cholesterol should be in the form of HDL. Consuming 2 tablespoonfuls of oil per day is recommended to achieve benefits, and this is best done by incorporating the oil into food preparation.
If you smoke, quit—Of course, there are many reasons to quit smoking (including fewer wrinkles as the years pass!) and one of them is to avoid the HDL suppression it causes. Just quitting smoking can double your HDL blood cholesterol levels, decreasing your heart disease risk. Quitting also improves HDL function, decreasing inflammation and providing other benefits to heart health.
If overweight, lose a few pounds—Losing just 1 to 3% of body weight can result in significant increases in HDL if you’re carrying some extra pounds. And it doesn’t matter how you do it, whether by reducing calories, cutting carbohydrates, intermittent fasting, surgery, or a combination of diet and exercise. Pick whatever is easiest for you and reap the health benefits!
Eat more purple/blue foods—Purple and blue foods like eggplant, red cabbage, blueberries, blackberries and black raspberries are rich in anthocyanins that are believed to help raise HDL levels and improve heart health.
Eat fatty fish several times a week—Fatty fish, such as salmon, herring, sardines, mackerel and anchovies, contain omega-3 fats that provide heart health benefits like decreased inflammation, improved function of the cells that line the arteries (arterial endothelial cells), and increased HDL. Research suggests that taking a fish oil supplement can give the same benefits.
Avoid artificial trans fats—Although promoted as “healthy” for many years, trans fats are now known to cause inflammation and increase the risk of heart and other diseases. They may also lower LDL cholesterol levels. Food manufacturers are now required to label food with trans fat content, so check the label of any prepared foods before buying.
So, although it may seem logical that too much fat in the blood will increase the risk of it sticking to the inside of blood vessels, causing plaque and increasing risk of heart disease, the development of heart disease is more complex than just that. The state of the blood vessel lining (inflamed or not), the balance of fat types, exercise, high blood insulin levels due to insulin resistance, and various dietary factors all have an influence.
As a pharmacist, you can imagine how surprised I was to discover that saturated fats like coconut and MCT oil are better at raising your “good” HDL cholesterol and lowering heart disease risk than the vegetable oils that have been promoted for so many years as healthful. As my sister (who reads a lot on this subject) likes to say: Fat doesn't make you fat, it satisfies your appetite. Some fats are necessary for good health. I guess it just shows how science advances. New scientific evidence means we need to change our ideas and beliefs, but it takes time for “official guidelines” to update.
Diet research is difficult to do properly because you simply can’t lock people up to control their diet for the years it takes to complete a study. And heart disease is affected by many factors, not just diet, although it appears to be important. Several assumptions were made back in the 50s when these food recommendations and guidelines were developed, that are being questioned. There is a definite controversy right now about whether dietary fat or added sugar is the bigger problem.
One thing chefs know, though, is that restricting fats can easily result in dry, tasteless food! It’s also easier to miss out on some nutrients, especially fat-soluble vitamins like vitamins A, D, E and K, when most fats are severely limited, especially important in children (note that additional vitamins were given in studies of the low fat diet in children). You should assume that, if a processed food is labelled as low fat, it’s quite likely it has added sugars to give it some taste.
But one factor is indisputable... since the official diet recommendations to eat a diet based on whole grains, bread, cereal and rice (all high carbohydrate foods) while limiting as much fat possible, as recommended in the “food pyramid”, the average body weight of North Americans has steadily increased to the point where over 40% of adults are now considered overweight or obese, and rates of heart disease have not improved. Even more alarming, growing numbers of children are also being affected, a factor that could influence their future health. While multiple factors could be at play, it certainly seems that our current typical diet isn’t helping.
So, that’s what I’ve been reading this week--food for thought and some of the reasons I've been changing my diet! What about you? Have you changed your eating pattern in recent years? Let me know your thoughts and what you've been reading...
References and additional reading:
9 Ways to Increase Your HDL Cholesterol Levels—Medical News Today
Cholesterol, The Nutrition Source—Harvard School of Public Health
Why some cholesterol does your body good—Verywell Health
Obesity in the United States—Wikipedia
Waist to Hip Ratio—Wikipedia
The Big Fat Surprise—Nina Teicholz
Food Pyramid--Wikipedia
Who invented the food pyramid?(a fun history of the food pyramid)—Today I Found Out
Lipoprotein metabolism in Familial Hypercholesterolemia--Journal of Lipid Research
