Sarah Rice BSc. (Hons), MCOptom (UK), MHP, NNP
Heart failure is a condition where the heart is unable to effectively pump blood to meet physiological needs, resulting in symptoms like fatigue, breathlessness, and fluid retention. This condition represents a significant public health burden that has a poor prognosis and a high 5-year mortality rate (1). A recent state-of-the-art review looks into the potential of therapeutic ketosis for heart failure (1).
Causes
The primary causes of heart failure are ischaemic heart disease, caused by disease of the coronary arteries, and high blood pressure. Other contributors include diabetes and metabolic disorders, chronic obstructive pulmonary disease, structural problems with the heart, and inflammation. We know that therapeutic carbohydrate reduction improves many of these conditions, so there is a role for prevention as well as being supportive after diagnosis.
The role of ketone bodies
Even in a healthy individual, fatty acid oxidation meets 60–90% of the energy demands of the heart, and ketones are used as fuel in proportion to circulating availability. In this healthy state, the heart is metabolically flexible and is able to use several fuel sources (1). In the failing heart, this flexibility is lost, and the heart becomes more dependent on fatty acid oxidation and circulating ketone bodies to meet energy needs (1, 2). This metabolic shift compensates for energy deficit and studies suggest it is an adaptive and cardioprotective process (1)
Emerging evidence suggests that nutritional ketosis, defined by a blood ketone level ≥0.5 mmol/L, may provide additional energy to support heart function in the failing heart. In this context, elevating circulating ketones via nutritional ketosis or exogenous means has become a therapeutic target of interest (2). In addition to the provision of an auxiliary energy source, ketone body metabolism may also reduce oxidative stress and inflammation, prevent microvascular thinning and loss, and promote vasodilation. All these factors can contribute to reducing cardiac demand, increasing cardiac output, and possibly preventing maladaptive cardiac remodelling (1).
Therapeutic ketosis
It is well understood in this community that therapeutic ketosis (beneficial) is not the same as ketoacidosis (pathological), a state where metabolic regulation fails (normally a feature of type 1 diabetes complications) and ketones rise with accompanying hyperglycaemia and metabolic acidosis. Occasionally medications can induce ketoacidosis without hyperglycaemia, and one such medication is the SGLT2 inhibitor. SGLT2 inhibitors may be used in patients with heart failure, and there could be synergistic effects (SGLT2 inhibitors cause a low level of ketosis), so caution and close monitoring are required in this setting if a ketogenic intervention is being considered (1).
A phase 1 clinical trial has demonstrated combined interventions are possible (3). This situation requires expert management by a medical team. It is important to note that when heart failure is not a consideration, SGLT2 inhibitors are often discontinued at the initiation of a reduced carbohydrate approach under the supervision of a medical professional (4).
A study using a ketogenic diet for patients with obesity and heart failure has shown it to be safe and effective with a reduction in the rate of heart failure hospitalisation (5), and studies using exogenous ketones have produced improved cardiac function and myocardial blood flow in healthy adults, as well as those with heart failure (2)(6).
Conclusion
While early data are promising, more research is needed before these interventions can be routinely recommended. However, we can be encouraged that this latest review acknowledges that more patients are pursuing ketogenic interventions necessitating clinician awareness of management practices.
Finally, we know that ketogenic interventions have robustly demonstrated the ability to improve or reverse many of the contributing factors that can culminate in heart failure. We can be hopeful that as ketogenic applications become more widely studied, more and more practitioners will become confident in offering these options to their patients.
References
1. Kodur, N., Nguyen, C. and Tang, W.H.W. (2025) ‘Therapeutic Ketosis for Heart Failure: A State-of-the-Art-Review’, Journal of Cardiac Failure, 0(0). Available at: https://doi.org/10.1016/j.cardfail.2025.01.028. PDF
2. Crabtree, C.D. et al. (2025) ‘A ketogenic‐promoting beverage acutely elevates cardiac function and myocardial blood flow compared to placebo in adults: A cardiac MRI investigation’, Physiological Reports, 13(6), p. e70208. Available at: https://doi.org/10.14814/phy2.70208.
3. Selvaraj, S. et al. (2024) ‘Abstract 4116177: Metabolic and Pharmacokinetic Profiling of Ketone Ester by Background SGLT2 Inhibitor Therapy in Heart Failure with Reduced Ejection: A Phase I Clinical Trial’, Circulation, 150. Available at: https://doi.org/10.1161/circ.150.suppl_1.4116177.
4. Cucuzzella, M., Riley, K. and Isaacs, D. (2021) ‘Adapting Medication for Type 2 Diabetes to a Low Carbohydrate Diet’, Frontiers in Nutrition, 0. Available at: https://doi.org/10.3389/fnut.2021.688540.
5. Moseley, G. et al. (2024) ‘Abstract 4139384: Retrospective Review of the Safety and Effectiveness of a Low Carbohydrate Ketogenic Diet in Overweight or Obese Patients with Heart Failure’, Circulation, 150(Suppl_1). Available at: https://doi.org/10.1161/circ.150.suppl_1.4139384.
6. Berg-Hansen, K. et al. (2024) ‘Cardiovascular Effects of Oral Ketone Ester Treatment in Patients With Heart Failure With Reduced Ejection Fraction: A Randomized, Controlled, Double-Blind Trial’, Circulation, 149(19), pp. 1474–1489. Available at: https://doi.org/10.1161/CIRCULATIONAHA.123.067971.
