In the late 1800s, the medical community first noted the health benefits of low-to-very-low carbohydrate (ketogenic) diets, which allowed unlimited consumption of fats and proteins with unrestricted calorie intake. Despite initial enthusiasm, the American Medical Association’s Council on Foods and Nutrition raised concerns about potential adverse effects on cardiovascular health due to limited scientific evidence.
A recent study published in Nutrients has highlighted the positive impact of ketogenic diets on cardiovascular health, including improvements in blood lipids, strong anti-inflammatory effects, cardioprotective benefits, promotion of weight loss, favorable impacts on blood pressure and other cardiovascular disease risk factors. Additionally it provides “rescue fuel” for diseased hearts through metabolic effects and enhanced function of blood vessel linings, potentially delaying ageing.
By the early 2000s, randomized controlled trials revealed that participants on keto diets experienced greater weight loss and improvements in some coronary heart disease risk factors compared to those on higher carbohydrate diets, prompting further scientific investigation.
Consuming 20 to 50 grams of carbohydrates per day results in the production of ketones, acids formed when the body uses fats instead of glucose for energy, defining very low-carbohydrate, ketogenic diets. Diets with 50 to 150 grams of carbohydrates per day are still considered low-carb but may not produce the same metabolic changes.
Carbohydrate-restricted diets induce metabolic changes similar to those seen in starvation, affecting plasma levels of free fatty acids, insulin, glucose, and ketone bodies. Evaluating these diets involves considering their low carbohydrate content and their high fat and protein content.
Long-term studies indicate that low or very low-carbohydrate diets result in weight loss comparable to diets with higher carbohydrate content. However, randomized controlled trials show that low-carbohydrate ketogenic diets effectively reduce cardiovascular risk factors, particularly in individuals with overweight, obesity, and Type 2 diabetes.
Ketogenic diets have also been shown to significantly reduce body weight and fat mass in cancer patients. There is growing interest in their potential effects on schizophrenia, mood disorders, cognitive function, Alzheimer’s disease, and other dementias.