by Brian Shilhavy
Editor, Health Impact News

A review published in August 2018, in the Journal Brain Sciences looked at the effectiveness of the ketogenic diet to treat adult epilepsy, adult malignant glioma (brain tumors), and Alzheimer’s disease.

It was written by Tanya J. W. McDonald and Mackenzie C. Cervenka from the Department of Neurology, Johns Hopkins University School of Medicine.

The high-fat low-carb ketogenic diet was first developed at Johns Hopkins back in the 1920s, but the authors state that the origin of the therapeutic diet dates back even further:

The ketogenic diet (KD) was formally introduced into practice in the 1920s although the origins of ketogenic medicine may date back to ancient Greece.

This high-fat, low-carbohydrate diet induces ketone body production in the liver through fat metabolism with the goal of mimicking a starvation state without depriving the body of necessary calories to sustain growth and development.

The authors describe the effects of the ketogenic diet, and then give a brief summary of some of the current variations of the diet:

The ketone bodies acetoacetate and β-hydroxybutyrate then enter the bloodstream and are taken up by organs including the brain where they are further metabolized in mitochondria to generate energy for cells within the nervous system. The ketone body acetone, produced by spontaneous decarboxylation of acetoacetate, is rapidly eliminated through the lungs and urine.

The classic KD is typically composed of a macronutrient ratio of 4:1 (4 g of fat to every 1 g of protein plus carbohydrates combined), thus shifting the predominant caloric source from carbohydrate to fat.

Lower ratios of 3:1, 2:1, or 1:1 (referred to as a modified ketogenic diet) can be used depending on age, individual tolerability, level of ketosis and protein requirements.

To increase flexibility and palatability, more ‘relaxed’ variants have been developed, including the modified Atkins diet (MAD), the low glycemic index treatment (LGIT) and the ketogenic diet combined with medium chain triglyceride oil (MCT).

Introduced in 2003, the MAD typically employs a net 10–20 g/day carbohydrate limit which is roughly equivalent to a ratio of 1–2:1 of fat to protein plus carbohydrates.

The LGIT recommends 40–60 g daily of carbohydrates with the selection of foods with glycemic indices <50 and ~60% of dietary energy derived from fat and 20–30% from protein.

The MCT variant KD uses medium-chain fatty acids provided in coconut and/or palm kernel oil as a diet supplement and allows for greater carbohydrate and protein intake than even a lower-ratio classic KD, which can improve compliance.

They then state the purpose of their review, which is titled “The Expanding Role of Ketogenic Diets in Adult Neurological Disorders.”

The aim of the current review is to describe the evidence, preclinical and clinical, supporting KD use in the management of adult epilepsy, adult malignant gliomas and Alzheimer’s disease.

Several randomized controlled trials support the use of KDs for the treatment of drug-resistant epilepsy and there is emerging evidence that these diets may also be effective in treating refractory status epilepticus, malignant glioma and Alzheimer’s disease in adults.

The review is impressive, with 130 footnotes referencing peer-reviewed studies, some of which we have published previously here at Health Impact News.

With such impressive results from the long history of this diet that has been around at Johns Hopkins since the 1920s, why did the diet stop being utilized for so long until just recently?

The authors give one explanation:

Despite being first recognized as an effective tool in the treatment of epilepsy in the 1920s, interest in diet therapy subsequently waned following the introduction of anti-epileptic drugs (AEDs)…

But drugs are not always effective in treating epilepsy, and interest in the ketogenic diet was renewed in the 1990s for “drug-resistant” epilepsy.

The other reason the diet fell out of favor, as we have written about extensively over the years, was due to the demonization of saturated fats, a political decision made in the 1970s through the McGovern Report, and then adopted as official dietary policy by the USDA.

This has led to decades of promoting a low-fat diet around a failed theory of heart disease, the lipid theory, which has had disastrous results with Americans’ health.

It is good to see some researchers at Johns Hopkins giving attention to studying the ketogenic diet and summarizing the multitude of studies now published on its therapeutic effects.

Read the full study here.