Researchers reviewed how a special type of diet that produces ketones—molecules your body makes when eating very few carbohydrates—might help hearts function better. Studies show that when ketone levels go up in your blood, your heart can pump more efficiently and get better blood flow, especially in people with heart disease. These improvements happen quickly and can last for about two weeks. However, scientists still need to do longer studies to understand if these benefits continue over months or years, and to figure out the safest way to use this approach for heart health.

The Quick Take

  • What they studied: Whether eating in a way that produces ketones (a special fuel your body makes) can improve how well the heart works and help people with heart disease
  • Who participated: This was a review article that looked at existing research rather than testing new people. It examined studies involving both healthy people and those with heart problems
  • Key finding: When ketone levels in the blood increase, the heart appears to pump more effectively and get better blood supply. This effect happens quickly—within days—and seems to last about two weeks, with stronger effects at higher ketone levels
  • What it means for you: This research suggests ketone-based approaches might help heart function, but it’s still early-stage research. Don’t make major diet changes without talking to your doctor first, especially if you have heart disease or take medications

The Research Details

This was a review article, meaning researchers looked at and summarized what other scientists have already discovered about ketones and heart health. They examined how the heart uses different fuels for energy, how ketones work in the body, different ways people can produce ketones (like special diets), and what effects these have on heart function in both healthy people and those with heart disease.

The researchers organized information about how ketones affect the heart’s ability to pump blood, how much blood reaches the heart muscle, and how these effects change depending on how many ketones are in the blood. They also discussed different methods people can use to raise their ketone levels and looked at what scientists still need to study.

This type of research is useful for understanding the “big picture” of what we know so far, but it doesn’t involve testing new people or doing new experiments.

Review articles are important because they help doctors and patients understand what the current evidence shows before expensive and time-consuming new studies are done. By organizing existing research, scientists can identify patterns, spot gaps in knowledge, and suggest the best directions for future research. This helps make sure new studies focus on the most promising and practical approaches.

This is a review article published in a respected medical journal, which means it was checked by other experts. However, because it reviews existing studies rather than conducting new research, its strength depends on the quality of the studies it examined. The authors note that long-term studies haven’t been done yet, which is an important limitation. The findings are based on short-term observations (up to 14 days), so we don’t know if benefits continue longer.

What the Results Show

The main finding is that when people enter nutritional ketosis—a state where the body produces and uses ketones for fuel—their heart function improves quickly and noticeably. Specifically, the heart pumps more blood with each beat (cardiac output increases) and the heart muscle receives better blood flow. These improvements appear within days of starting ketone-producing approaches.

Importantly, the benefits seem to depend on how high the ketone levels are in the blood. Higher ketone levels appear to create better heart improvements, suggesting a dose-dependent relationship. This means it’s not just about producing some ketones—the amount matters.

The improvements observed lasted for up to 14 days in the studies reviewed. This suggests the benefits aren’t just a one-time spike but can continue for at least a couple of weeks. The researchers found these effects in both healthy people and those already dealing with heart disease, though the studies reviewed were relatively short-term.

The review discusses multiple ways people can achieve nutritional ketosis, including very low-carbohydrate diets, fasting, and other dietary approaches. Different methods may produce different ketone levels and may be easier or harder for different people to maintain. The researchers suggest that understanding which methods work best for reaching and maintaining higher ketone levels is important for practical use. They also note that the heart’s response to ketones appears to be rapid and consistent, which is encouraging for potential therapeutic use.

This research builds on growing interest in ketone metabolism and heart health. Previous research has shown that the heart can use ketones as fuel, but this review emphasizes that ketones may do more than just provide energy—they appear to actively improve heart function. The findings align with emerging research suggesting ketones have special benefits beyond simple fuel provision, though the field is still relatively new and many questions remain unanswered.

The biggest limitation is that all the studies reviewed looked at short-term effects—mostly days to two weeks. We don’t know if these benefits continue for months or years. The review doesn’t include long-term safety data, so potential risks from sustained ketosis aren’t well understood. Additionally, the sample sizes and specific populations studied in the reviewed research aren’t detailed in this overview. The researchers themselves note that more rigorous, longer-term studies are needed before making strong recommendations. Finally, this review doesn’t provide information about whether these benefits work equally well for all types of heart disease or all people.

The Bottom Line

Based on current evidence, ketone-based approaches show promise for heart function, but the evidence is still preliminary (moderate confidence level). If you’re interested in exploring this approach, work with your doctor or a registered dietitian to determine if it’s appropriate for your situation. Don’t stop taking heart medications or make major diet changes without medical guidance. For people with heart disease, diabetes, or those taking medications, medical supervision is especially important.

This research is most relevant to people with heart disease or cardiovascular risk factors who are looking for additional ways to support heart health. It may also interest people exploring ketogenic diets for other health reasons who want to understand potential heart benefits. However, people with certain conditions (like type 1 diabetes, severe kidney disease, or those taking specific medications) should be cautious and consult healthcare providers. Healthy people without heart concerns don’t need to make diet changes based on this research alone.

Based on the studies reviewed, improvements in heart function appear within days of entering ketosis and can be observed within 1-2 weeks. However, we don’t know if these benefits continue beyond two weeks or if they increase over longer periods. Realistic expectations should be measured in weeks, not months, based on current evidence. Long-term benefits and optimal duration of use remain unknown.

Want to Apply This Research?

  • Track daily ketone levels (if using a ketone meter) alongside heart-related metrics like resting heart rate and perceived energy levels. Record these daily to see if higher ketone levels correlate with improvements in how you feel and your heart rate patterns over 2-4 weeks
  • If working with a healthcare provider on a ketogenic approach, use the app to log meals and monitor carbohydrate intake to maintain consistent ketone production. Track which foods and meal timing help you maintain target ketone levels most easily and sustainably
  • Establish a baseline of your current heart rate and energy levels, then monitor weekly changes as you adjust ketone levels. Create alerts to check in with your healthcare provider monthly to discuss any changes in symptoms, medications, or how you’re feeling. Track adherence to your chosen ketone-producing method to understand what’s sustainable for you long-term

This research is a review of existing studies and does not represent new clinical evidence. The findings are based on short-term studies (up to 14 days), and long-term safety and effectiveness have not been established. If you have heart disease, take heart medications, have diabetes, or have any chronic health condition, consult your doctor or cardiologist before making significant dietary changes or attempting nutritional ketosis. Do not stop taking prescribed medications based on this information. This content is for educational purposes only and should not replace professional medical advice. Individual responses to ketogenic approaches vary, and what works for one person may not work for another.