Ketogenic diets reportedly help with weight loss and other conditions and have become popular again in recent years, but there is conflicting information on their safety and long term benefits. Ketogenic diets typically provide 75-90% of calories from fat. Waste products of fat metabolism called ketones are produced. By drastically reducing carbohydrates in the diet, the body turns to fat as a source of fuel.
Since the early 1900s, a ketogenic diet has been used to treat epilepsy in children who have not responded to multiple seizure medicines. In the 1920s, before the discovery of insulin, patients with diabetes were prescribed high-fat, low-carbohydrate diets to help control blood sugar. This was probably more effective for patients with type 2 diabetes, but likely did little to prolong life in patients with type 1 diabetes, who need insulin to survive.
Recent studies have shed more light on the potential risks and benefits of a ketogenic diet.
The good news:
- Epilepsy patients on a ketogenic diet after failing treatment with 2 or more medications experienced seizure reduction rates of up to 85%.
- Multiple studies have shown better blood sugar control, weight loss, and a reduced need for medications in patients with type 2 diabetes.
- The Warburg effect describes how cancer cells use glucose for growth and proliferation. A ketogenic diet may help to starve tumors, but studies so far are inconclusive.
- Some neurological conditions such as Alzheimer’s disease, Parkinson’s disease and autism have shown improvement with a ketogenic diet. More research is needed to clarify the effects for these conditions.
The bad news:
- Children on a ketogenic diet for epilepsy may accrue bone mass at a slower rate, and are at risk of developing kidney stones
- Diabetes patients on a ketogenic diet who are taking certain medications (insulin, sulfonylureas) are at risk of developing hypoglycemia.
- Diabetes patients taking SGLT2 inhibitors are at risk of developing diabetic ketoacidosis with a ketogenic diet.
- Long term ketogenic diets may lead to glucose intolerance due to loss of pancreatic alpha and beta cells.
- Some studies have shown an increased risk of heart disease and death linked to low carbohydrate consumption.
When choosing a diet, it is also important to consider the quality of nutrients. We know there are healthy fats (avocado, nuts, olive oil, and fish oil) and unhealthy fats like animal fats that can have effects far beyond the formation of ketones.
This is just as true for carbohydrates. An apple does not equal a cupcake, after all.