A high fat, low carb diet reversed heart failure in a mouse model of the condition and a 24-hour fast also led to improvements, mimicking the physiological effects of the diet.
In people with heart failure, the muscle on the right or left side of the heart — or on both sides — weakens. This impairment limits the organ’s ability to pump blood around the body, causing fatigue and shortness of breath, among other symptoms.
The leading causes are high blood pressure, diabetes, and ischemic heart disease, in which the heart muscle becomes starved of oxygen.
The National Heart, Lung, and Blood Institute estimate that about 5.7 million people in the United States have heart failure. There is currently no cure, but medications and lifestyle changes can improve people’s quality of life and increase their lifespan.
Healthy heart muscle can draw upon a variety of chemical energy sources, depending on the circumstances. One of these is a molecule called pyruvate, which the body generates during the breakdown of the sugar glucose.
However, conditions such as heart failure and diabetes reduce this flexibility, starving the muscle of the fuel it needs to function effectively.
Researchers have now traced this loss of flexibility to a transporter protein that shuttles pyruvate into mitochondria — the so-called power stations of cells.
Known as the mitochondrial pyruvate carrier (MPC) complex, it comprises two subunits: MPC1 and MPC2.
Researchers at the Saint Louis University School of Medicine in St. Louis, MO, led a team who discovered that the production of both subunits is reduced in failing human hearts.
The researchers compared heart tissue samples from people undergoing heart surgery with tissue samples from donor hearts that were healthy but unsuitable for transplant.
They then showed that mice that lack the gene for producing MPC2 steadily develop heart failure over time. Their hearts became outsized, or hypertrophied, and the organs’ ability to pump blood diminished. Crucially, the scientists found that they could reverse the damage to the animals’ heart muscle by simply feeding them a special diet for 3 weeks.
“Interestingly, this heart failure can be prevented or even reversed by providing a high fat, low carbohydrate ‘ketogenic’ diet,” explains Kyle S. McCommis, Ph.D., assistant professor of biochemistry and molecular biology at the university, who led the research.
