Ask the random person off the street what they need to do to avoid heart disease and they will probably tell you to lower your cholesterol levels by avoiding saturated fat.
This is bad advice. Total cholesterol not a strong predictor of heart disease. Other markers, such as triglycerides insulin, or the number of VLDL particles you have are much better predictors of heart disease than total cholesterol. Additionally, cholesterol is an important molecule necessary for hormone synthesis and brain function. Studies show that higher cholesterol levels are associated with lower risk of dying from any cause (known as all-cause mortality) and lower risk of dementia, especially in the elderly.
A much better approach for preventing heart disease and protecting your health is to focus on managing your blood sugar and insulin. This article will explain why avoiding blood sugar problems is much more important than lowering your cholesterol to prevent heart disease and avoid dangerous health problems like diabetes and Alzheimer’s.
Let’s start with cholesterol. You probably know that there are two kinds of cholesterol in the body: HDL, which is typically considered “good” and LDL, which is known as “bad.” This is a simplistic approach and recent research clarifies the impact of LDL on cardiovascular health, showing that there are two kinds of LDL cholesterol:
small, dense VLDL particles that increase heart disease risk, and
large, fluffy LDL particles that are benign and not associated with elevated heart disease risk.
The small, dense VLDL particles can damage the walls of arteries and blood vessels, leading to inflammation and plaque buildup. In contrast, the large, fluffy LDL particles have no effect. Your LDL particles can be tested with an apolipoprotein B or LDL particle numbers test. If these values are elevated, it is a good chance that you have high levels of the inflammatory molecule C-reactive protein, which correlates with heart disease risk and cardiovascular inflammation. You can also test directly for C-reactive protein if you’re concerned about heart disease risk. The bottom line is that when it comes to cholesterol, the focus should be on achieving low levels of small, dense LDL particles rather than categorically lowering total cholesterol.
The cholesterol molecule is actually essential for human health because it is used to produce all your body’s steroid hormones, including testosterone, estrogen, and cortisol. Cholesterol also plays a primary role in immune function and brain health. Adequate cholesterol is especially important for the elderly who suffer from a compromised immune system and reduced hormone levels.
Studies consistently show that as people age, low cholesterol levels are associated with increased risk of dying. For example, a study from the Netherlands that followed 724 people who were over 85 years old for 10 years found that those with higher total cholesterol concentrations had greater longevity due to lower risk of dying from cancer or infection (1). Each 1 mmol/L increase in total cholesterol corresponded to a 15 percent decrease in mortality over the study period.
A second study from Finland that followed subjects over 6 years found that in people over age 75, those with the highest total cholesterol levels had the lowest risk of death (2). The inverse association remained clear and significant when adjusted for other diseases. Participants with an average cholesterol of 252 mg/dl had the lowest death rates. Public health organizations typically recommend total cholesterol levels be kept under 200 mg/dl.
The first large review on the association between total cholesterol and mortality was published in 2016 using more than 68,000 subjects (3). Results showed an inverse association between all-cause mortality and LDL cholesterol levels in people over age 60. The study authors question the recommendation to lower LDL cholesterol to prevent heart disease, writing that “since elderly people with high LDL-C live as long or longer than those with low LDL-C, our analysis provides reason to question the validity of the cholesterol hypothesis.” They theorize that low LDL cholesterol puts older people at increased risk of cancer and infection by microorganisms due to a compromised immune system.
In 2015, the medical journal Annals of Nutrition and Metabolism dedicated an entire edition to debunk the theory that cholesterol causes heart disease and provide evidence contrary to what they call the “cholesterol myth (4).” In the introduction, the authors write that the cholesterol theory is so ingrained in public consciousness that most medical and public health professionals “take the notion to be a simple irrefutable ‘fact’ and self-explanatory.” They suggest that more has not been done to challenge the cholesterol theory until now because “the amount of money (from cholesterol-lowering drugs) at stake is too much to lose the fight.”
If lowering total cholesterol is not the goal for a healthy heart, what is?
Mounting evidence suggests that two markers, insulin resistance and high triglycerides, are strong predictors of heart disease. The two are intimately related in the body, which is why they often go together. It’s also why some studies that have looked at whether triglycerides are an independent risk factor for heart disease have been inconclusive (5).
Here’s how triglycerides and insulin resistance interact to cause heart disease:
Triglycerides are fat molecules in the blood. It should be noted that triglycerides can be elevated in response to diet and inactivity or due to genetics. People with the genetic disorder that raises triglycerides don’t appear to have the same risk of heart disease as people whose levels are elevated due to diet and obesity.
The body’s metabolism of triglycerides is closely linked with that of cholesterol. As triglycerides in the blood go up, levels of the harmful small, dense LDL particles increase. These particles are more susceptible to oxidation, or damage, which increases the chance that they will harm blood vessels and result in the deposition of plaques that lead to atherosclerosis (heart disease). Another problem with high triglycerides, especially when combined with insulin resistance is that HDL cholesterol go down. HDL particles scavenge the small LDL particles from the blood transporting them to the liver to be metabolized.
What makes triglycerides go up?
Triglycerides are elevated when cells become resistant to insulin. Remember that the role of insulin is to regulate the amount of nutrients circulating in the bloodstream. When you eat a meal, the amount of sugar (glucose) in your blood stream increases. Insulin binds with your cells to store the glucose either in muscle as glycogen (the energy source for the muscle) or as fat.
The body will replenish glycogen first, only storing excess glucose as fat if glycogen stores are topped off. For people who are sedentary or overeat calories, there is often an excess of glucose on high-carb diets, leading to fat gain. In this situation, the cells can become resistant to insulin, which means they aren’t readily binding to it. When this happens, the body will pump out more insulin to bring blood sugar levels down.
Over time, cells become more and more resistant to insulin. In fat tissue, insulin no longer inhibits free fatty acid release, which might seem like a good thing, but is not because it means you will have fat circulating in your blood that has nowhere to go. Instead of being burned for energy, in an insulin resistant state, the free fatty acids in the blood go to the which releases triglycerides into the blood that cause inflammation in tissues (muscle, liver, endothelial cells), increasing risk of diabetes, heart disease, and high blood pressure.
This is why counterintuitively, one of the biggest factors that increases triglycerides is diets higher in carbohydrates and lower in fat (6). Diets higher in carbohydrates, especially refined carbs such as those that make up the majority of the typical American diet, trigger larger peaks and valleys in insulin and blood sugar. For example, in a meta-analysis of 19 studies published by the Institute of Medicine, for every 5 percent increase in carbohydrate intake, triglyceride levels were predicted to increase by 6 percent and HDL cholesterol to decrease by 2.2 percent (6).
High insulin and blood sugar problems have several other negative effects on health. High blood sugar causes damage to organs, can induce a coma, or potentially lead to death if untreated. High insulin leads to the body to deposit fat in the abdominal cavity, which is a type of fat that is metabolically active, releasing inflammatory markers into the blood. These inflammatory molecules circulate, leading to a hardening of arteries and the development of plaque that leads to heart disease.
What Can You Do About It?
The first step is to get some data so that you know where you’re starting from. Hopefully, you are working with your doctor to monitor your glucose, cholesterol, and triglyceride levels.
Normal fasting glucose values are between 70 to 100 mg/dl, however, it’s recommended that you achieve a value between 70 to 90 mg/dl, with a goal of below 85 mg/dl to stay on the safe side. Additionally, you may want to have your doctor test your fasting insulin because this has been shown to be a strong predictor of diabetes and heart disease risk.
The typical public health recommendation is that triglycerides should be below 150 mg/dl, however, functional medicine practitioners recommend staying below 100 mg/dl for optimal health. One way to assess your heart disease risk is to determine your triglycerides-to-HDL ratio. A ratio of less than 2 is recommended and is indicative of having your LDL be made up of predominantly large, fluffy benign LDL particles. If your triglyceride-to-HDL ratio is greater than 4, you probably have a lot of small dense particles that can accelerate development of plaques in the arteries.
The second step is to get a home glucose monitor so that you can keep an eye on your blood sugar day-to-day. Easily purchased for less than $25 at a drug store, a glucose monitor allows you to measure your glucose with a finger prick before and after a meal.
One hour after eating, blood glucose should be below 130 mg/dl. With a home monitor, you can get a baseline understanding of your metabolic health and then assess which factors may be negatively impacting your levels. A few factors have been shown to consistently help improve blood sugar and insulin include the following:
Improve your diet by eating whole foods and planning meals around high-quality protein, healthy fat, and leafy green vegetables.
Work out with weights and perform regular conditioning sessions, either doing intervals or aerobic cardio.
Consider ways to improve lifestyle factors such as sleep, physical activity, and stress.
For a more in-depth list of ways to combat insulin resistance and protect your heart, read this article.
With this data, you can trouble shoot problem areas and protect yourself from one of the biggest health problems affecting people today.