- Type 2 diabetes is characterized by raised blood glucose levels, which can increase the risk of cardiovascular disease.
- A new study has found that people with type 2 diabetes who ingested ketones before exercise had increased cardiac output, stroke volume, and peripheral muscle oxygenation — all indicators of improved heart function.
- The researchers suggest that ketones may improve heart health but emphasize that research is ongoing.
Type 2 diabetes, which is affecting increasing numbers of people worldwide, occurs when the body stops responding to insulin, the hormone that controls blood glucose. When the insulin does not work correctly, glucose remains in the blood instead of being taken into cells to be used as energy.
If blood glucose is not controlled, this can lead to complications, which may include cardiovascular disease.
Treatments for type 2 diabetes aim to reduce blood glucose levels. One type — sodium-glucose cotransporter-2 inhibitors (SGLT2i) — also appears to protect the heart, possibly by inducing ketosis, a state where the body uses fats instead of carbohydrates as an energy source. The liver converts fats into ketones, which cells metabolize to release energy.
A previous study found that ketone supplements reduced postprandial blood glucose concentrations in people with type 2 diabetes and called for research into other possible benefits of the treatment.
To test whether ketosis is responsible for the heart benefits of SGLT2is, a team from Portsmouth University in the United Kingdom gave ketone monoesters (exogenous ketones) to a group of people with type 2 diabetes and then measured their heart function.
“People with type 2 diabetes reportedly find physical activity and exercise difficult. This is because their heart cannot use glucose, the most efficient body fuel, due to insulin resistance. In the current study, the hearts of all 13 of the participants were working more efficiently after the ketone drink at rest and during moderate intensity exercise, compared to the placebo drink. Hence, a ketone drink has the potential to be an adjunct treatment to improve cardiac function and quality of life in people with type 2 diabetes. However, larger and longer-term efficacy and safety trials are warranted.”
— Study author, Dr. Maria Perissiou from the University of Portsmouth’s School of Psychology, Sport and Health Sciences.
The work is published in the Journal of Applied Physiology.
Cheng-Han Chen, MD, board certified interventional cardiologist and medical director of the Structural Heart Program at MemorialCare Saddleback Medical Center in Laguna Hills, CA, told Medical News Today that this study forms a basis for further research:
“This was a very small study (with 13 patients) that reported significant differences in heart function and muscle oxygenation after a ketone monoester drink. […] It should be noted that their test method for determining cardiac function is not commonly used in the clinical setting for this purpose.”
Researchers enrolled 13 people (six men and seven women) with a mean age of 66 years in the trial. The participants had a mean body mass index of 31.3, with only 4 having a BMI in the healthy range (less than 25). All had type 2 diabetes but no other significant health conditions related to it.
All participants attended a screening session for blood tests, resting
At each of two experimental visits, researchers gave them either a ketone monoester (0.3ml/kg), or an identical placebo drink. Each participant had the ketone drink once and placebo once, but neither the researchers nor the participants knew who received which drink at each visit.
The participants then rested for 30 minutes before undertaking a step-incremental cycling test. The researchers measured heart function using
In all the participants, heart function was better after the ketone drink than after placebo, both when resting and when undertaking moderate exercise.
The researchers found that following ketone treatment, not only did circulating β-hydroxybutyrate (which carries energy from the liver to cells) increase but there was also an increase in both cardiac output and stroke volume.
Dr. Menka Gupta, Functional Medicine Doctor in Singapore, and founder of Nutranourish, explained why the treatment might have this effect, telling MNT:
“Exogenous ketones offer a highly efficient fuel source for the heart. They produce more ATP per molecule of oxygen than glucose metabolism and may reduce the production of reactive oxygen species, thereby lowering oxidative stress and inflammation. By reducing oxidative stress and inflammation, they could help protect cardiac tissue, which is particularly important for individuals with metabolic challenges.”
How ketones help the heart“It is thought that ketones (specifically beta-hydroxybutyrate) can improve cardiac function by serving as a supplemental energy source in addition to glucose and fatty acids. There is also thought they provide anti-inflammatory properties, as well as improve vascular function.”
— Cheng-Han Chen, MD
The effects were seen even with the low dose of ketones given to the participants. Perissiou explained why they used this low dose:
“While generally considered safe when taken in appropriate doses, ketone monoesters can pose risks including potential stomach upset, electrolyte imbalances, particularly for people with kidney issues, and may cause negative effects (like ketonaemia) in people with type 2 diabetes mellitus if consumed in large quantities due to their ability to significantly raise blood ketone levels.”
The authors acknowledge that their findings apply only to the experimental conditions of their study, so more research is needed to ascertain whether ketone supplementation might have longer-term benefits for people with type 2 diabetes or even for those without the condition.
Perissiou outlined the next steps in their research:
“We are currently exploring the dose-response relationship of a ketone drink and cardiovascular function in healthy individuals. In addition, we recently acquired further funding to explore the physiological mechanisms by which chronic ketones ingestion can mitigate the cardiovascular burden imposed in people with type 2 diabetes during heat waves.”
“Individuals with type 2 diabetes present with well-documented metabolic challenges, and lower oxidative stress and inflammation benefits their condition. It is possible that similar benefits might extend to those without the condition. That said, people with diabetes could experience more pronounced improvements due to their impaired metabolic flexibility. Future studies involving non-diabetic or pre-diabetic populations will help clarify whether the benefits of exogenous ketones are universal or more condition-specific.”
— Menka Gupta
