The Effects of the Ketogenic Diet and the Atkins Diet on Intractable Pediatric Epilepsy
By Erica Tennenhouse
Under normal conditions, our bodies use glucose as the primary and preferred energy source. When glucose is not available, the body metabolizes stored fat instead. Ketones are produced when fat is burned for energy in a process called ketosis (1). For reasons which are not completely understood, ketosis has been successful in preventing seizures in children with intractable epilepsy. Ketosis can be achieved through the ketogenic diet as well as the Atkins diet. The ketogenic diet has traditionally been applied to the treatment of epilepsy, while the Atkins diet has achieved popularity as a treatment for obesity. However, a recent study in Epilepsia reports that a modified Atkins diet is an effective therapy for intractable pediatric epilepsy, with the added advantage of not restricting calories, fluids, or protein, as the ketogenic diet does (2).
Ketogenic Diet
The ketogenic diet has been used for more than eight decades in the treatment of refractory epilepsy. According to Edwin Trevathan, M.D., M.P.H, director of the Comprehensive Epilepsy Program at the University of Kentucky, the ketogenic diet is "a rigidly calculated high-fat diet, with adequate protein and carbohydrates for growth, designed to maintain ketosis" (3). To maintain desired ketosis on this diet, the ratio of fat to carbohydrates and protein combined is supposed to be 4:1 (4). In order to assure that this ratio is achieved, all food and ingredients must be weighed on a gram scale before consumption (5). As well, the water content of a fasting body is lower than normal; therefore, since ketosis is meant to mimic the act of fasting, the ketogenic diet limits liquid intake in order to lower the body's water content (6).
This diet is usually used in children between the ages of one and eight. The ketogenic diet commences at the hospital where the child fasts for approximately one to two days, the point of which is to burn up all of the glucose in the blood so that the body can begin ketosis. Typical meals for individuals following this highly regimented diet may include small amounts of fruits and vegetables, which contain carbohydrates, small portions of meat or fish, which contain protein, and large servings of fatty foods such as eggs, butter, and cream (7). After two years, children are slowly weaned off of the diet; most improvements in seizure control that result from the diet will remain after the diet has ended (8).
Some parents find that their children cannot tolerate the ketogenic diet. These children may experience side effects ranging from hyperlipidemia to kidney stones (2). High cholesterol may also occur in children on this diet, but cholesterol tends to return to normal levels after the diet has been discontinued (9). One major drawback to this diet is its restrictiveness; children following this diet can never eat a cookie and must even make sure that their multivitamins are sugar-free. As well, the slightest deviation from the ketogenic diet after having started it can actually cause seizures.
Atkins Diet
The Atkins diet is a somewhat controversial diet for weight loss. The premise of the Atkins diet is as follows: Obesity is caused by "excessive release of insulin after eating" (10). When carbohydrates are consumed, body glucose levels increase. The body responds to this by releasing insulin. Insulin does lower glucose levels, but has the unfortunate side effect of increasing fat production and causing weight gain. In order to lose weight, one should cause their body to stop producing insulin by restricting consumption of carbohydrates. While carbohydrates are greatly reduced on this diet, consumption of fat and protein is encouraged (11).
One begins the Atkins diet with what is called the induction phase (12). This phase occurs in the first two weeks of the diet, during which time carbohydrates are severely restricted to about 20 g/day, and no fruit, bread, grains, or starchy vegetables are permitted (12). The goal of this phase is to cause the body to begin the process of ketosis. Following the induction phase the dieter gradually increases carbohydrate allowance until a point is reached where the dieter is able to maintain weight loss. A typical Atkins diet meal may consist of an omelet made with lots of butter and cheese, or pork chops and a small salad (10).
The Atkins diet is a relatively easy diet to maintain because it is not quantitative, meaning that foods need not be weighed before consumption. Although carbohydrates are limited to a set amount per day, calories, fluids, and protein can be eaten in unlimited amounts. As Dr. Atkins tells his dieter: "if you're hungry, eat!" (10).
Clinical Study on the Modified Atkins Diet
In the February 2006 issue of Epilepsia, a clinical study performed by researchers at The John Hopkins Medical Institutions reported that between 2003 and 2005, twenty children ages 3-18 years, who had at least three seizures per week received a modified Atkins diet for a 6-month period. The only modification to the Atkins diet mentioned in the article is that carbohydrates were restricted to 10 g/day for the entire duration of the diet, whereas in the classic Atkins diet carbohydrates are limited to 20 g/day during the induction phase and can be increased as the diet progresses (10). Researchers reported that the diet was "an effective and well-tolerated therapy for children with intractable epilepsy." 65% of the children enrolled experienced a >50% seizure reduction, and 35% enjoyed a >90% seizure reduction, with 4 patients becoming seizure-free at the end of the 6-month period. The five children with absence epilepsy who participated in the study responded particularly well to the diet. Few side effects
were reported, which the researchers note could be due to the small sample size of the study. The researchers suggest that the modified Atkins diet could also be useful for patients with newer-onset, less intractable epilepsies that are not typically treated with the ketogenic diet (2).
Conclusion
Although this study in Epilepsia provides evidence that the Atkins diet is a good alternative to the ketogenic diet, it, like many other studies that have approached this same question, is limited by the small number of patients that it enrolled. However, it is clear that there are more palatable ways to treat intractable pediatric epilepsy through diet than the highly restrictive ketogenic diet. There are some Canadian ketogenic diet programs that are already offering some form of modified Atkins diet as an alternative to the ketogenic diet. Reasearch in this area is ongoing; effectiveness of the modified Atkins diet in adults with intractable epilepsy is currently being studied at the John Hopkins Medical Institutions.
Sources
1. http://www.carbs-information.com/ketosis.htm.
2. Kossof, Eric H., et al. 'A Modified Atkins Diet Is Effective for the Treatment of Intractable Pediatric Epilepsy.' Epilepsia. 47(2002): 421-424.
3. http://w3.ouhsc.edu/neuro/division/cope/ketogen.htm.
4. Epilepsy: a Comprehensive Textbook. Lippincott-Raven Publishers: Philadelphia, 1997.
5. http://www.charliefoundation.org/noframes/diet/dietfaq.php.
6. Freeman, John M., Millicent T. Kelly and Jennifer B. Freeman. The Epilepsy Diet Treatment: an Introduction to the Ketogenic Diet. Page 6.
7. http://www.childrensmemorial.org/depts/neurocenter/epilepsy/ketogenic.asp.
8. Curtis, Rosalind M., FRCPC. 'Ketogenic diet: Old treatment, new therapy.' from Epilepsy Ontario's Resource Library.
9. http://www.hopkinschildrens.org/pages/news/archivedetails.cfm?newsid=148.
10. Atkins, Robert C, M.D. and Fran Gare, M.S. Dr. Atkins New Diet Cookbook. M. Evans and Company, Inc.: New York, 1994.
11. http://www.healthyweightforum.org/eng/diets/atkins_diet/.
12. http://www.atkins.com/articles/atkins-phases/phase-one/ phase-1-induction.
