The Surprising Link Between Blood Sugar and Heart Disease, According to Cardiologists

Emily Laurence
Updated ·5 min read
20

Here's why blood sugar levels are so important for heart health.

If prioritizing heart health is one of your wellness goals, you likely know the importance of keeping blood pressure and cholesterol levels in check. Consistent high levels of both significantly increase the risk for strokes and heart disease, the number one cause of death in the U.S.

But there’s something else that cardiologists emphasize that it’s important to be mindful of. Like blood pressure and cholesterol, having high blood sugar levels can also negatively affect the heart in major ways. People who have a family history of cardiovascular disease should be especially mindful of their blood sugar levels and take steps to lower them if it’s too high.

Related: Your Live-Well Guide to Maintaining Heart Health and Preventing Heart Disease

Why Having High Blood Sugar Levels Is Bad for Your Heart

Dr. Kaustubh Dabhadkar, MD, MPH, FACC, a cardiologist with Novant Health, says that there are several reasons why having high blood sugar levels can negatively affect the heart. “First and foremost, high blood sugar can raise the level of triglycerides in the blood. This can, in turn, lead to a high level of unhealthy cholesterol in the blood,” he says.

Second, Dr. Dabhadkar says that high blood sugar levels stimulate insulin secretion. When this happens, sugar is converted into fat, which leads to weight gain. Over time, this can contribute to obesity, which is another major risk factor for heart disease. Dr. Nilay Mehta, DO, a cardiologist with Memorial Hermann in Houston, Texas, says that insulin secretion stimulated by high blood sugar levels also damages blood vessels. “It causes inflammation, which causes some disruption in the blood vessels and this can lead to buildup and blockages to the heart,” he explains.

Related: This Is the #1 Way To Lower Blood Sugar Naturally, According To an Endocrinologist 

Yet another way that having high blood sugar is bad for heart health is that it can make the cells in the body resistant to insulin. “These cells cannot effectively use the excess sugar in the blood,” Dr. Dabhadkar says. Both doctors explain that this is what happens when someone has type 1 or type 2 diabetes. “Diabetes is often related to the inability of the body to effectively utilize the sugar present in the blood, also known as insulin resistance,” Dr. Dabhadkar says.

When this happens, he explains that it raises LDL cholesterol levels, which can then cause plaque buildup in arteries supplying blood to the heart. “The plaque, in turn, causes a reduction in blood supply to the heart. If the plaque breaks open, it leads to a heart attack,” he says. Both doctors say that this is why people with diabetes are at an increased risk for heart disease, whether diabetes was something they were born with or that has developed over time.

Related: The 6 Best Free Apps for Managing Diabetes and Blood Sugar

What Causes High Blood Sugar and What Is the Best Way To Lower It?

Dr. Mehta says that some people are born with high blood sugar or have a genetic predisposition to it. Both type 1 and type 2 diabetes runs in families. But this does not mean that someone with diabetes is automatically destined to have heart problems in the future. It just means that it’s extra important for them to look after their heart by adopting healthy eating and lifestyle habits. (If you have diabetes and smoke, consider this your firm warning to stop.)

A big cause of high blood sugar is eating foods high in sugar (makes sense, right?) and simple carbohydrates such as white bread, white rice, soda and fruit juices. Dr. Mehta explains that these foods are more quickly absorbed in the bloodstream than complex carbs. Since they’re absorbed more quickly, they raise blood sugar levels faster.

Because of this, both doctors say that the most effective way to lower blood sugar levels is to minimize simple carbohydrates and foods high in sugar. Instead, focus on eating nutrient-rich foods that are absorbed slower, such as non-starchy vegetables and foods high in protein or healthy fats. Dr. Dabhadkar emphasizes that it’s especially important to minimize soda and fruit juices that are high in added sugar.

Exercising regularly can also help lower blood sugar. Dr. Mehta explains that this is because, during exercise, the body uses sugar for energy, which then lowers blood sugar levels. Exercising is also a great way to manage stress, something else that Dr. Mehta says can contribute to high blood sugar levels. “When people are stressed, it causes the body to release more of the hormone cortisol, and that can raise blood sugar levels,” he explains.

Of course eating healthy, exercising regularly and managing stress aren’t only good for keeping blood sugar levels in check; all of these habits help keep blood pressure and cholesterol levels from rising too. Dr. Mehta says that healthy habits benefit the entire body; besides the heart, you’ll be supporting your brain and gut too.

What’s especially encouraging about the connection between blood sugar and heart health is that it can be managed. If you have high blood sugar levels, you can turn those numbers around. Your heart health is in your hands.

Next up, find out what the optimal blood glucose levels are and how to know your numbers.

Sources