Understanding Remnant Cholesterol: A New Perspective on Heart Health
For many years, heart health has been simplified into a struggle between two types of cholesterol. On one side, we have HDL (high-density lipoprotein), often dubbed the ‘good’ cholesterol that assists in clearing arteries. On the flip side is LDL (low-density lipoprotein), the so-called ‘bad’ cholesterol that can accumulate in blood vessels and heightens the risk of heart disease.
This narrative has led to a straightforward directive from healthcare professionals: maintain low LDL levels to ensure heart health. But there’s a catch. Recently, it’s come to light that a lesser-known type of cholesterol plays a significant role. This type, known as remnant cholesterol, comprises about a third of your total cholesterol levels and appears to be more challenging to manage, even for the most common cholesterol-lowering medications, statins.
“I used to categorize them as the good, the bad, and the ugly,” says Børge Nordestgaard, a clinical professor at the University of Copenhagen and an authority on cholesterol. “While LDL is the villain, remnant cholesterol appears to be an even bigger threat.” He notes that remnant cholesterol has frequently gone overlooked by many medical professionals, which is a concern.
The Introduction of a Third Player
To grasp the concept of remnant cholesterol fully, it helps to debunk a prevalent myth: cholesterol itself isn’t fundamentally good or bad. It’s a fatty substance your body uses for various functions, such as building cells and producing hormones. While excess cholesterol can lead to clogged arteries, it’s a necessary component of your body.
The classifications of ‘good’ and ‘bad’ aren’t solely about cholesterol but rather the particles that carry it. Cholesterol is difficult to dissolve in blood, prompting your body to package it for transport. Imagine cholesterol as a parcel that requires a delivery vehicle. Some particles, like LDL, deliver cholesterol to tissues and arteries, while others, such as HDL, recycle it back to the liver.
So what are the ‘ugly’ cholesterol particles? They belong to a different category entirely. Chylomicrons and very low-density lipoproteins (VLDLs) are significantly larger than LDLs—up to 50 times wider—and mostly transport triglycerides, the body’s energy source, rather than cholesterol itself.
Despite cholesterol making up merely 1-3% of these ‘lorry’ particles, their size means this small percentage can amount to a substantial quantity—potentially up to 40 times more cholesterol than LDLs. While loaded with triglycerides, these large particles are generally harmless as they can’t dig into artery walls. However, as they navigate through your bloodstream and lose their triglyceride load, they become cholesterol-rich remnants.
In a healthy individual, these remnants are usually cleared out by the liver. However, if your body generates an excess of them—due to poor diet, weight gain, or genetics—the liver may struggle to keep pace. Consequently, the remnants can linger in the bloodstream, eventually embedding themselves in arterial walls.
Once lodged, these remnants spark a significant immune response. White blood cells rush in to consume the cholesterol but can’t process it, leading to their death and forming fatty plaques that narrow arteries over time. This accumulation can lead to severe complications like heart attacks or strokes.
The Danger Zone
Research indicates that individuals with elevated remnant cholesterol and triglyceride levels face twice the risk of cardiovascular diseases compared to those with lower levels. Yet, the focus in cholesterol discussions often remains on LDL. While that’s understandable—many people have elevated LDL levels—this emphasis could overlook the risks associated with remnant cholesterol.
In one study, nearly 12% of patients with cardiovascular diseases had elevated remnant cholesterol despite managing their LDL levels. This suggests that conventional tests could miss potential risks. In another study involving over 113,000 participants, individuals with low LDL but high remnant cholesterol had a 15% increased risk of stroke.
A major part of the issue is the rarity of measuring remnant cholesterol. Comprehensive blood tests typically report LDL, HDL, triglycerides, and total cholesterol, but remnant cholesterol usually isn’t highlighted. If you have LDL and HDL figures, you can estimate your remnant cholesterol by subtracting these from your total cholesterol. If not, high triglyceride levels may indicate elevated remnant cholesterol.
- Up to 150 mg/dL is considered healthy
- 150–199 mg/dL is mildly elevated
- 200–499 mg/dL is moderately high
- Above 500 mg/dL is very high
Taking Action
If you suspect high remnant cholesterol due to elevated triglycerides, what can you do? Statins have been the go-to solution for managing cholesterol for decades, but they’re not as effective against remnant cholesterol. Studies suggest that statins might reduce LDL by 20%, but only about 10% for remnants, which poses a risk potentially double that of LDL.
There’s hopeful news, however. New medications are emerging that could significantly lower remnant cholesterol levels, with reductions of 50-80% reported in recent treatments. Yet these are not widely available yet and will likely be most effective when combined with lifestyle adjustments.
Both LDL and remnant cholesterol are influenced by genetics, but remnant levels are especially affected by diet, physical activity, and weight—areas most people can control.
Your first step should be consulting a healthcare provider, who can recommend a lipid profile blood test and discuss possible actions based on results. Medications can be beneficial, but lifestyle changes are crucial for lowering these levels and preventing future buildup.
1. Dietary Changes
Your diet plays a significant role in managing cholesterol levels, including remnant cholesterol. Cutting back on sugar and refined carbohydrates—like sodas and white bread—is an effective strategy. It’s not so much that these foods contain cholesterol; it’s the sugar they carry that’s concerning.
Excess sugar is processed by your liver into triglycerides, culminating in more of those large lorry-like particles. Thus, the more sugar you consume, the greater the production of triglycerides and remnant cholesterol. Saturated fats have a similar effect, which is why many doctors suggest swapping butter and red meats for healthier Mediterranean fats like olive oil and avocados.
Dr. Zoe Astroulakis from New Victoria Hospital emphasizes filling your plate with pulses, legumes, fruits, vegetables, and proteins instead of carbs. She recommends overnight oats soaked in milk or water, as they release a fiber called beta-glucan that helps absorb cholesterol and lower overall levels.
2. Moderation with Alcohol
Alcohol can also elevate triglyceride levels, which is a contributing factor. The liver produces more triglycerides when alcohol is consumed, thereby increasing the number of those large cholesterol-carrying particles. Recent dietary guidelines advise drinking less for better health, and some experts argue there may not be any safe level of consumption.
Dr. Astroulakis states, “There’s no safer level than zero.”
3. Maintain a Healthy Weight
Excess weight can adversely affect heart health and contribute to higher levels of remnant cholesterol. Increased fat cells lead to additional triglycerides entering the bloodstream, and the liver compensates by producing more chylomicrons and VLDLs. This cycle results in even more remnants.
Moreover, excess weight is tied to insulin resistance, which slows down the elimination of remnants. Dr. Riyaz Patel from University College London points out that individuals who are obese often have significantly higher levels of remnant cholesterol, but losing weight through various methods tends to lower these levels.
It’s important to note that just having a ‘normal’ BMI doesn’t mean you’re in the clear. One can still have a high level of visceral fat, which is closely associated with elevated remnant cholesterol. Sometimes, only a blood test can reveal this hidden risk.
