How Blood Sugar Impacts Cholesterol: The Hidden Connection

When you think about high cholesterol, your mind likely jumps to the usual suspects: fried foods, fatty meat and skipping that morning run. However, these factors are just one piece of a much larger, more complex puzzle. “Heart health goes beyond simply cutting fats; it’s also about how we manage our body’s response to everyday foods,” explains Whitney Stuart, M.S., RDN, CDCES. One major player in your metabolic health is your blood sugar—and it’s often overlooked in discussions about lipid panels.

It turns out that the glucose circulating in your bloodstream has a direct line of communication with your cholesterol levels. For millions of people managing prediabetes, diabetes or insulin resistance, understanding this connection is the key to unlocking better heart health. It is a metabolic double whammy; when blood sugar is unregulated, cholesterol often follows suit. But the reverse is also true; stabilizing your glucose can have profound effects on your lipid profile.

Here are some ways that blood sugar can impact cholesterol.

How High Blood Sugar Can Impact Cholesterol

The relationship between glucose and cholesterol is deeply intertwined, primarily driven by the hormone insulin. When this delicate balance is disrupted, it creates a domino effect that changes how your body processes fats.

Insulin Resistance Disrupts Lipid Metabolism

The most significant link between high blood sugar and cholesterol is insulin resistance. When you have chronically high blood sugar, your body pumps out more insulin to try to move that sugar into cells. “Over time, chronically high blood sugars can lead to insulin resistance, which disrupts how the body metabolizes cholesterol,” says Kiran Campbell, RDN. This doesn’t just “trap” sugar in the blood; it fundamentally changes how your liver handles fat.

The specific changes this causes are often referred to as diabetic dyslipidemia. Campbell notes, “Research shows insulin resistance lowers HDL (‘good’) cholesterol and raises LDL and apoB-containing lipoproteins.” This creates a hazardous combination where the protective cholesterol is suppressed while the potentially harmful cholesterol is ramped up.

Increased Intestinal Absorption

High blood sugar doesn’t just affect how your liver processes cholesterol; it can also change how much cholesterol your body absorbs from the food you eat. Under normal circumstances, your body is able to regulate how much cholesterol it takes in versus how much it makes. However, metabolic dysfunction throws this calibration off.

According to Campbell, insulin resistance drives this issue by increasing intestinal cholesterol absorption and altering bile acid metabolism. Essentially, the signals that tell your gut to slow down on absorbing dietary cholesterol get crossed. This means that even if you are eating the same diet as someone with healthy blood sugar, your body might be pulling more cholesterol into your bloodstream simply because of the high-insulin environment.

Production of Plaque-Forming Particles

Not all cholesterol particles are created equal. In an environment of high blood sugar, the body tends to produce a specific type of particle that is more atherogenic, meaning more likely to form plaque in the arteries. This often involves apolipoprotein B (apoB), a primary protein found in bad cholesterol.

“Chronically high blood sugar and insulin resistance make the body produce more LDL and other plaque-forming apoB particles,” explains Michelle Routhenstein, M.S., RD, CDCES, CDN. This overproduction may provide the exact building blocks needed to promote buildup in the bloodstream, increasing the risk of atherosclerosis and cardiovascular events more than if LDL levels were elevated alone without the presence of insulin resistance.

Does Managing Your Blood Sugar Improve Cholesterol?

The good news is that this biological connection works both ways. Just as unregulated blood sugar can impact a lipid panel, stabilizing glucose can help repair it. This offers a powerful tool for anyone feeling stuck with high cholesterol numbers despite dietary changes.

“One reason managing blood sugars can lower your cholesterol is through improved insulin sensitivity, which directly regulates cholesterol metabolism,” notes Campbell. 

“When insulin signaling is improved through better blood sugar control, cholesterol absorption decreases and LDL levels normalize, leading to a healthier lipid profile,” Campbell adds. This means that lowering your A1C or fasting glucose isn’t just a win for diabetes risk reduction and management, it is a direct investment in lowering your LDL and raising your HDL.

Tips to Improve Blood Sugar

Supporting healthy blood sugar (and by extension, your cholesterol) doesn’t require a strict, restrictive diet. Instead, try a well-rounded lifestyle approach that keeps your glucose levels steady throughout the day.

• Prioritize Fiber-Rich Carbohydrates: Instead of cutting carbs entirely, switch to complex carbohydrates like oats, quinoa, beans and lentils. Soluble fiber slows down the absorption of sugar into the bloodstream, preventing spikes, while simultaneously binding to cholesterol in the digestive tract to help remove it from the body.
• Move Your Body Regularly: You don’t need to run a marathon. Walking for 15 minutes after a meal can significantly blunt a blood sugar spike. Muscles use glucose for energy, pulling it out of the bloodstream without needing as much insulin.
• Combine Your Macros: Don’t eat a “naked” carb. If you are having an apple, pair it with a handful of almonds. If you are having toast, add avocado or an egg. Protein and healthy fats slow down digestion, leading to a more gradual rise in blood sugar rather than a sharp spike.
• Manage Stress and Sleep: Cortisol, the stress hormone, signals your liver to release stored glucose, raising blood sugar even if you haven’t eaten. Poor sleep induces a similar stress response. Prioritizing rest is a metabolic necessity.

As Hennis Tung, M.S. RD, summarizes: “High cholesterol can be caused by multiple factors, including genetics and lifestyle such as an imbalanced diet and inactivity. Therefore, looking at things like regular movement, stress management, sleep and keeping meals steady throughout the day can make a big difference for both blood sugar and cholesterol.”

30-Day Heart-Healthy, Diabetes-Friendly Dinner Plan

Our Expert Take

It’s time to stop viewing blood sugar and cholesterol as two completely separate health metrics. They are deeply interconnected indicators of your overall metabolic health. Focusing solely on restricting dietary cholesterol without addressing underlying blood sugar issues is often like trying to bail water out of a boat without plugging the hole.

If you are struggling with high cholesterol, ask your doctor to look at your fasting insulin or HbA1c levels. By broadening your approach to include blood sugar management through balanced meals, regular movement and stress reduction, you can tackle two major risk factors for heart disease simultaneously.