Rethinking prevention: Why heart health starts in the gut, brain, and mitochondria

Your heart beats about 100,000 times each day. On top of this, it pumps about 2000 gallons of blood each day, ensuring your body and its systems get the nutrients and cells they need to function optimally. This organ’s importance is undeniable. As many ancient civilizations noted, the heart is the center of life. Thus, taking care of it counts for a lot.

Yet, most of us think about heart health in terms of cholesterol numbers, blood pressure readings, and cardio workouts. We’ve been taught to focus on the obvious markers—the ones that show up in standard blood panels and annual checkups. 

While these markers are still important, this conventional approach misses the fact that your cardiovascular system doesn’t exist in isolation. Your heart health depends on a number of other systems and functions within your body. Surprisingly, your gut, brain, and mitochondria all play a role.

And by the time traditional risk factors appear on a blood test, underlying dysfunction has often been developing for years—or even decades. The real opportunity for prevention lies in understanding and supporting these systems upstream. And this has never been more important than in the modern age.

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Cardiovascular disease is currently the leading cause of death

Cardiovascular disease claims more lives than all forms of cancer combined. Every 34 seconds, someone in the United States has a heart attack. Every 60 seconds, someone dies from a heart disease-related event. These statistics impact millions of families, cut careers short, and leave dreams unfulfilled.

But the impact extends far beyond mortality statistics. 

For every person who dies from heart disease, many more live with its consequences—reduced quality of life, limited physical capacity, cognitive decline, and the constant management of medications and symptoms. 

Additionally, direct medical costs and lost productivity from cardiovascular disease exceed $400 billion annually in the U.S. alone. But despite decades of research and billions spent on treatments, rates of heart disease continue to climb, particularly among younger populations who are developing risk factors earlier than previous generations.

A fact that is especially troubling is that up to 80% of premature heart disease is preventable. However, the challenge isn’t just knowing what to prevent—it’s understanding where prevention actually begins. 

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Where heart health starts

True cardiovascular protection requires looking at the systems that influence heart health from the cellular level up. These interconnected networks—your gut microbiome, nervous system, and cellular energy production—create the conditions that either promote or prevent heart disease. In the following sections, we take a closer look.

How does the gut impact heart health?

Your gut microbiome—the trillions of bacteria living in your digestive tract—produces compounds that directly influence cardiovascular function. These microbial metabolites can either protect or damage your arteries, depending on the balance and diversity of your gut bacteria.

One of the most significant connections involves a compound called trimethylamine N-oxide (TMAO). When certain gut bacteria break down nutrients like choline and L-carnitine from foods, they produce trimethylamine, which the liver converts to TMAO. Elevated TMAO levels strongly correlate with increased risk of heart attacks, strokes, and death from cardiovascular disease. Studies further show that people with the highest TMAO levels have a significantly increased risk of major adverse cardiovascular events.

But the gut-heart connection goes beyond TMAO. 

Beneficial bacteria produce short-chain fatty acids (SCFAs), such as butyrate, which reduce inflammation throughout the body, including in blood vessels. These SCFAs help regulate blood pressure, improve cholesterol profiles, and protect the endothelial cells that line your arteries. 

When gut dysbiosis occurs—an imbalance between beneficial and harmful bacteria—SCFA production drops while inflammatory compounds increase, creating conditions that promote atherosclerosis.

Thus, supporting gut health through diverse, fiber-rich foods, fermented products, and targeted probiotics can shift the microbiome toward cardioprotective species. Specific strains, such as Lactobacillus reuteri, have even been shown to reduce cholesterol levels.

How does the brain affect heart health?

Your nervous system directly controls heart rate, blood pressure, and vascular tone through a complex network of neural pathways. Chronic stress, anxiety, and depression can actually lead to physiological changes that damage your cardiovascular system over time.

When your brain perceives stress, it activates the hypothalamic-pituitary-adrenal (HPA) axis, flooding your system with cortisol and adrenaline. While this response helps you handle immediate threats, chronic activation keeps your heart rate elevated, blood pressure high, and inflammatory markers circulating. In turn, this could put you at a higher risk of heart disease.

Depression and anxiety may also increase inflammatory cytokines, promote platelet aggregation (increasing clot risk), and dysregulate endothelial function, which maintains healthy blood vessels. On top of this, this relationship is bidirectional—heart disease increases depression risk, while depression accelerates cardiovascular decline.

However, the brain-derived neurotrophic factor (BDNF), a protein that supports neuron health, protects cardiovascular function. Low BDNF levels correlate with increased atherosclerosis, heart failure, and post-heart attack mortality. But activities that boost BDNF—like exercise, meditation, and quality sleep—support both brain and heart health. 

Additionally, relaxation exercises, such as meditation or deep breathing, can help alleviate anxiety and depression, ultimately contributing to improved heart and overall health.

Where do the mitochondria come in?

Pumping 2,000 gallons of blood through 60,000 miles of blood vessels requires an enormous amount of energy—more than any other organ relative to its weight. This energy comes from the mitochondria, and when these cellular powerhouses falter, your heart is often the first organ to suffer.

The heart contains more mitochondria per cell than almost any other tissue. They generate 95% of the ATP (cellular energy currency) your heart needs to maintain its constant rhythm. And this means that when mitochondrial function declines, the heart can’t maintain proper contraction strength, electrical conduction, or cellular repair processes.

In fact, age-related mitochondrial decline partially explains why cardiovascular risk increases over time. As mitochondria accumulate damage, they become less efficient at producing energy and more prone to triggering cell death pathways. This leads to loss of cardiac muscle cells, stiffening of blood vessels, and reduced capacity to handle metabolic demands.

Yet, there’s always something you can do. Several nutrients specifically support cardiac mitochondrial function. Coenzyme Q10 (CoQ10), which mitochondria require for energy production, becomes depleted with age and statin use. 

Lifestyle factors also considerably influence mitochondrial health. Exercise, for instance, has the power to increase both the number and efficiency of these organelles. Intermittent fasting triggers mitophagy—the removal of damaged mitochondria—while promoting the growth of healthy ones. Even cold exposure and certain breathing practices can improve mitochondrial function, translating directly to better cardiovascular health.

At the end of the day, heart health begins long before the first symptom appears, including in the brain, gut, and mitochondrial systems. Knowing this has the power to transform how we think about prevention. Instead of waiting for risk factors to develop and then trying to manage them, we can support the fundamental systems that determine cardiovascular health. 

At Welle, we help you focus on proactive prevention practices, ensuring your health stays in good shape for years to come. With comprehensive lab testing, biomarker monitoring, expert consultation, and customized action plans, we help give you clarity and a clear path forward. Begin changing your health today with Welle; don’t wait for heart disease to strike before making changes.

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