Researchers studied how intense exercise and a natural body chemical called NAD+ protect the heart from damage caused by high cholesterol. Using mice with high cholesterol, they found that both high-intensity exercise and NAD+ supplements reduced harmful stress in heart cells, decreased inflammation, and prevented excessive cell breakdown. The study suggests that NAD+ could become a helpful treatment for people with high cholesterol who are at risk for heart disease. These findings offer hope for new ways to protect heart health beyond traditional medications.

The Quick Take

  • What they studied: Whether intense exercise and a natural body chemical called NAD+ can protect heart cells from damage caused by high cholesterol
  • Who participated: Two groups of mice with high cholesterol: one group did different types of exercise for 12 weeks, and another group received either NAD+ supplements or a regular diet for 16 weeks
  • Key finding: Both high-intensity exercise and NAD+ supplements reduced harmful stress in heart cells, decreased inflammation, and helped prevent excessive cell death in mice with high cholesterol
  • What it means for you: These findings suggest that NAD+ supplements or intense exercise may help protect hearts in people with high cholesterol, though human studies are still needed to confirm these benefits

The Research Details

Scientists used two separate experiments with mice that had high cholesterol (similar to humans with this condition). In the first experiment, some mice did moderate-intensity exercise while others did high-intensity interval training (short bursts of hard exercise) for 12 weeks. In the second experiment, mice were divided into four groups: some ate a normal diet, some ate a normal diet with NAD+ supplements, some ate a high-fat diet (to create high cholesterol), and some ate a high-fat diet with NAD+ supplements for 16 weeks.

The researchers then examined the mice’s hearts using several methods: they looked at heart tissue under a microscope, measured specific proteins in heart cells, and checked for signs of cell damage and death. They measured NAD+ levels, cholesterol levels, and markers of inflammation and stress in the heart tissue.

This research approach is important because it allows scientists to understand the exact mechanisms (how things work) inside heart cells when exposed to high cholesterol. By testing both exercise and NAD+ separately, researchers could see which approach works best and how they protect the heart. Using mice allows for controlled experiments that would be difficult or impossible to do in humans.

This study was published in a peer-reviewed scientific journal, meaning other experts reviewed the work before publication. The researchers used multiple methods to measure results, which strengthens their findings. However, because this was done in mice, the results may not directly apply to humans. The study was well-designed with clear control groups for comparison, which increases reliability.

What the Results Show

The study found that high-intensity exercise significantly increased NAD+ levels in the hearts of mice with high cholesterol. This increase in NAD+ activated protective pathways in heart cells, reducing oxidative stress (harmful chemical reactions) and inflammation. The exercise-trained mice showed less heart tissue damage and fewer signs of cell death compared to mice that didn’t exercise.

When NAD+ was given as a supplement directly, it produced similar protective effects even without exercise. The supplemented mice had lower cholesterol levels, less inflammation, and reduced signs of heart cell damage. Both approaches appeared to work by activating a protein called SIRT1, which acts like a protective switch in heart cells.

The researchers also found that both exercise and NAD+ supplements improved the heart’s ability to clean up damaged cellular components through a process called autophagy. This cellular cleanup process is important for maintaining healthy heart function. The mice receiving NAD+ supplements or doing intense exercise showed better markers of this cleanup process compared to control mice.

Additional findings showed that NAD+ supplementation reduced fibrosis (scarring) in heart tissue, which is important because excessive scarring can lead to heart failure. The study also found that both interventions reduced apoptosis (programmed cell death) in heart cells, meaning fewer heart cells were dying from stress. The protective effects were achieved by activating multiple cellular pathways that work together to defend heart cells from damage.

This research builds on previous studies showing that exercise improves heart health. The novel contribution is demonstrating that NAD+ is a key mechanism explaining why exercise protects the heart. Previous research suggested NAD+ was important for heart health, but this study shows specifically how it works in the context of high cholesterol. The findings align with growing evidence that NAD+ levels naturally decrease with age and in disease states, making NAD+ supplementation an emerging area of interest.

The most important limitation is that this study was conducted in mice, not humans. Mice have different body sizes, metabolisms, and lifespans than humans, so results may not directly translate. The study used genetically modified mice (lacking a specific gene), which doesn’t perfectly represent all people with high cholesterol. The exercise protocol and NAD+ doses used in mice may not correspond to practical recommendations for humans. Additionally, the study didn’t examine long-term effects beyond 16 weeks, so we don’t know if benefits persist over years. The study also didn’t compare NAD+ supplementation to standard cholesterol medications.

The Bottom Line

Based on this research, high-intensity exercise appears to be a beneficial approach for people with high cholesterol concerned about heart health (moderate confidence, as human studies are needed). NAD+ supplementation shows promise but should not replace standard medical treatments for high cholesterol (low confidence for human use, as this is preliminary research). Anyone with high cholesterol should consult their doctor before starting new supplements or exercise programs, especially if they have existing heart conditions.

People with high cholesterol or family history of heart disease may find this research relevant. Those interested in exercise as a preventive health strategy should note that high-intensity exercise appears particularly beneficial. People considering NAD+ supplements should discuss this with their healthcare provider, as the research is still in early stages. This research is less immediately relevant to people with normal cholesterol levels, though maintaining healthy cholesterol is important for everyone.

In the mouse studies, protective effects appeared within 12-16 weeks of intervention. For humans, benefits from exercise typically appear within 4-8 weeks, though more substantial improvements may take 12 weeks or longer. NAD+ supplementation effects in humans are unknown and would require clinical trials to determine. Cholesterol level improvements may take several weeks to become apparent.

Want to Apply This Research?

  • Track weekly high-intensity exercise sessions (aim for 2-3 sessions per week) and monitor resting heart rate monthly as an indicator of cardiovascular improvement. Users could also log energy levels and exercise recovery time to assess overall cardiac function.
  • Users could set a goal to incorporate high-intensity interval training into their weekly routine, such as 20-30 minute sessions of alternating intense effort with recovery periods. The app could provide guided high-intensity workouts and track completion rates to maintain motivation.
  • Establish a baseline of current exercise habits and cardiovascular markers (if available from medical records). Track exercise consistency monthly, monitor subjective measures like energy and endurance improvements, and encourage users to get cholesterol levels checked every 3-6 months with their doctor to see if lifestyle changes are having measurable effects.

This research was conducted in mice and has not yet been tested in humans. NAD+ supplementation is not an approved medical treatment and should not replace prescribed cholesterol medications or medical advice from your doctor. Before starting any new exercise program, especially high-intensity training, or taking supplements like NAD+, consult with your healthcare provider, particularly if you have existing heart conditions, high cholesterol, or are taking medications. This article is for educational purposes only and should not be considered medical advice. Always discuss new health interventions with a qualified healthcare professional.