Fasting and Absence Epilepsy: Reassessing Both in 2013

Epilepsy News From: Tuesday, February 12, 2013

Two very interesting articles have come in this month worth mentioning on Keto News.

The first was published in Epilepsia by Arsov and collegues from Australia. In this study, the authors found that 7 of 55 (13%) with early-onset absence epilepsy (defined as onset younger than 4 years of age) were due to mutations in SLC2A1. This genetic mutation is the cause of Glut-1 deficiency, a condition for which the ketogenic diet is the treatment of first choice. Glut-1 is most commonly associated with severe epilepsy, movement disorders, and developmental delay ( However, this study and others by the Australian group have shown that early-onset absence epilepsy should be added to the Glut-1 "family" and perhaps screened for.

Unfortunately, few in this study and others by this group were then tried on the ketogenic diet, so how they would do is unknown. Our group at Johns Hopkins has found that children with absence (early or more classic age of onset) do well on ketogenic diets, so as a result of this study we are now screening more of our difficult-to-control absence epilepsy patients for Glut-1. These results are very interesting, but do NOT mean that all epilepsy patients should be screened for Glut-1 at this time.

The second article was published by our group in Epilepsy Research. Fasting, even before the ketogenic diet was created in 1921, was recognized as a therapy for epilepsy. The ketogenic diet was designed to mimic fasting, but research over the past few decades has shown that they are two different treatments. As a result of a randomized study by Bergqvist et al from 2005, it is well-accepted that fasting at the onset of the ketogenic diet is not necessary for long-term seizure control. However, fasting may make the diet work more quickly in some of our research in combination with the group from Chicago 3 years later.

Dr. Hartman from our group had found in mice that intermittent fasting mice seemed to be very distinct from the actual ketogenic diet in terms of effects on seizures. As a direct result of this work, the past few years we have tried intermittent fasting (typically skipping 2 meals a day for 2 days a week) in 6 children on the ketogenic diet who either lost seizure control or never had it. Four children had 50-99% reduction in seizures with the intermittent fasting approach, although it didn't last long in three of them. Several families found this approach difficult to do due to hunger.

What these results show is that fasting is indeed likely different than the ketogenic diet and may be a way to improve seizure control for children with epilepsy. Beyond using it in children already on the ketogenic diet, it would be interesting to try it with medical supervision in children not on dietary therapy but dealing with refractory epilepsy. Different ways to intermittently fast may also lead to future better results. Regardless, it is another good example of basic and clinical ketogenic diet scientists learning from each other to help children.


Demos publishing has just released "Fighting Back with Fat", written by Erin Whitmer and Jeanne Riether. This book is written by two mothers of children who were on dietary therapy for their epilepsy (ketogenic and modified Atkins diets, respectively). It is a candid, honest accounting of life on the ketogenic diet, especially during the initial few weeks. Full of practical tips and advice, it is a helpful guide for any family considering starting these treatments. $14.53 plus shipping at


Arsov T, Mullen SA, Damiano JA, Lawrence KM, Huh LL, Nolan M, Young H, Thouin A, Dahl HH, Berkovic SF, Crompton DE, Sadleir LG, Scheffer IE. Early onset absence epilepsy: 1 in 10 cases is caused by GLUT1 deficiency. Epilepsia. 2012 Dec;53(12):e204-e207

Hartman AL, Rubenstein JE, Kossoff EH. Intermittent fasting: A "new" historical strategy for controlling seizures? Epilepsy Res. 2012 Nov 30. doi:pii: S0920-1211(12)00322-1. 10.1016/j.eplepsyres.2012.10.011. [Epub ahead of print]

Bergqvist AG, Schall JI, Gallagher PR, Cnaan A, Stallings VA. Fasting versus gradual initiation of the ketogenic diet: a prospective, randomized clinical trial of efficacy. Epilepsia. 2005 Nov;46(11):1810-9.

Kossoff EH, Laux LC, Blackford R, Morrison PF, Pyzik PL, Hamdy RM, Turner Z, Nordli DR Jr.When do seizures usually improve with the ketogenic diet? Epilepsia. 2008 Feb;49(2):329-33

Hartman AL, Zheng X, Bergbower E, Kennedy M, Hardwick JM. Seizure tests distinguish intermittent fasting from the ketogenic diet. Epilepsia. 2010 Aug;51(8):1395-402.

Authored by

Eric Kossoff MD

Reviewed Date

Tuesday, March 18, 2014

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