Keto diet could be good for heart failure patients, but many questions remain
Following a ketogenic diet could potentially benefit certain heart failure patients, according to a new commentary published in JACC: Heart Failure.[1] However, additional research on this topic is still needed.
A team of researchers from Cleveland Clinic explored the science behind ketogenic and keto-like diets, which prioritize fats and restrict carbohydrates to help induce ketosis. While the ketogenic diet was originally developed to treat epilepsy, it is now more often associated with helping individuals lose weight.
The commentary’s authors noted that more and more people are now starting to investigate if these diets could help with the management and prevention of HF.
“The failing heart increases oxidation of ketone bodies to meet its energy demands, so it is conceivable that the ketogenic diet could aid the failing heart by boosting the supply of ketone bodies,” wrote contributing author Wai Hong Tang, MD, a cardiologist with Cleveland Clinic and professor of medicine with the Cleveland Clinic Lerner College of Medicine, and colleagues. “Moreover, the ketogenic diet could ameliorate HF by improving overall metabolic health, including body weight, lipid profile, glycemic control, and blood pressure.”
Ketogenic diets linked to key benefits—and possible risks
While some early animal studies focused on the ketogenic diet have led to “promising findings,” others have concluded that following such a diet could actually be bad for the heart. One four-week study, for example, found that a ketogenic diet worsened cardiac remodeling in hypertensive rats.
“These discrepant findings warrant further investigation into the myocardial effects of the ketogenic diet in HF,” the authors wrote.
The ketogenic diet has been studied countless times, of course—and a prevalent theme is that it can improve a person’s overall metabolic health—but concerns still remain, including the fact that it has been associated with heightened levels of LDL cholesterol. The authors did emphasize that this can be addressed by following a ketogenic diet low on saturated fats and red meats, which can provide benefits without automatically lead to increased LDL levels.
Another key question related to following a ketogenic diet is whether or not it impacts long-term survival.
“It has also been suggested that the ketogenic diet might increase the risk of mortality, given that low carbohydrate intake has been associated with a higher risk of mortality,” the authors added. “However, these findings are based on observational data, so a causal conclusion cannot be drawn. Perhaps more important, low-carbohydrate diets may be associated with higher risk of mortality only when carbohydrates are replaced with animal-derived fat and protein, but not when replaced with plant-based fat and protein. Indeed, low-carbohydrate diets consisting predominantly of plant-based fat and protein are associated with lower risk of mortality.”
Things to know if a heart failure patient is considering a ketogenic diet
Tang et al. noted that a ketogenic diet could possibly improve the metabolic health of patients with HF, but it’s still too early to fully endorse such a recommendation. More research is still required, including clinical trials that examine its impact on patients with different kinds of HF and studies that compared it to other eating pattern, such as intermittent fasting and time-restricted feeding.
For now, the group said physicians should rely on “their best judgement” when fielding questions related to keto diets. If a patient is going to follow such a diet, it is recommended that the dosage of any other medications they take be adjusted as needed to prevent “dehydration and hypoglycemic episodes.”
“Counseling with a nutritionist is recommended to ensure that patients consume high-quality foods and receive adequate nutrition, especially micronutrients,” the authors wrote. “Overall, clinicians should customize their recommendations based on each patient’s health history, personal preferences, and health goals.”
There are other factors to consider if a patient plans on beginning a ketogenic or keto-like diet. For example, highly processed foods marketed as being “keto-friendly” should be limited, because they typically contain high levels of artificial sweeteners. Instead, patients should borrow heavily from the Mediterranean diet, which is focused on plant-based foods and unsaturated fats, though they will still need to keep carbohydrates to a minimum.
The authors also noted that certain side effects—including fatigue, headaches, constipation and muscle cramps—are often seen when patients first start following such a diet. This “keto flu” can last as long as a few weeks, so the patient will need to be warned in advance.
In addition, patients with type 2 diabetes who face a high risk of ketoacidosis may want to skip the keto diet altogether due to the possibility that they develop a rare, potentially fatal condition known as euglycemic ketoacidosis.
“A ketogenic diet that adheres to the principles of the Mediterranean diet and limits intake of saturated fat and red meat could be a promising therapeutic intervention for patients with HF,” the authors concluded. “However, given the mixed findings in animal studies, lack of clinical trials, and broad adoption of SGLT2 inhibitors across the spectrum of HF, more research is needed to demonstrate the safety and incremental clinical benefits of the ketogenic diet—and this will hopefully settle the debate of whether adopting the ketogenic diet to ameliorate HF is fact or fiction.”
Read the full study in JACC: Heart Failure here.
Michael has more than 18 years of experience as a professional writer and editor. He has written at length about cardiology, radiology, artificial intelligence and other key healthcare topics.