Ketogenic diet
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The ketogenic diet is a treatment for epilepsy that relies on inducing a state of ketosis. The diet prescribes foods high in fat, and heavily restricts carbohydrate intake. As fats become the body's primary source of metabolic energy, ketones accumulate in the brain, which can alleviate epileptic symptoms. The diet is more effective in children than adults, particularly when anticonvulsant drug therapy is ineffective (20%-30% of patients) or contraindicated.
The diet provides 3-4 grams of fat for every 1 gram of carbohydrate, calling for such foods as high-triglyceride dairy products (butter, cream, mayonnaise) and peanut butter. Carbohydrates, found in breads and starches, are eliminated from the diet, and liquid intake is often restricted as well in order to aid ketone accumulation. Though superficially similar, this is not the same as the Atkins diet. Possible long-term side effects of the diet include:
- kidney stones
- abnormal liver function
- high cholesterol
- weight gain
- dehydration
- bone thinning
The diet is typically supplemented with calcium, vitamin D, iron, and folic acid.
Among the possible reasons the diet was not widely adopted by doctors:
- Lack of double blind studies. (see below)
- Concerns about patient compliance with diet
- Concerns about potential nutritional deficiency
- It is possible that early anti-convulsants were statistically more effective than diets as treatment for new patients but that they worked on separate population groups.
The TV movie First Do No Harm (http://www.imdb.com/title/tt0118526/) increased awareness of the Ketogenic diet, though a curative link between fasting and epilepsy was even mentioned in the Bible.
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Scientific Studies
A study conducted by Johns Hopkins (http://www.hopkinsmedicine.org/press/1998/DECEMBER/981207.HTM) reported that 50% of those patients starting the ketogenic diet reported a decrease in seizures of 50% or more, with 29% of patients reporting a 90% reduction in symptoms; these patients had previously tried an average of six anticonvulsant drugs. The success rate on patients who responded to anticonvulsants was not measured in that study (and appears to be lacking in other recent studies as well - there appears to be reluctance to try the diet on subjects except as a last resort). The success rate of the diet on those who are successfully treated with anti-convulsants may be higher, lower, or the same as those who do not respond. It may be that the diet and anti-convulsants are effective on different segments of the population.
The ketogenic diet has been reported to work in cases where multiple epilepsy drugs have failed. There may also be cases where the ketogenic diet has failed and epilepsy drugs succeeded. When one epilepsy drug fails, there is a high likelihood that other drugs will also fail. When the diet works, the response is often rapid and dramatic.
Double Blind Studies
Lack of double blind studies is an issue preventing wider acceptance by the medical profession. Reliance on proper studies rather than anecdotal evidence or flawed studies is important. Double blind studies help eliminate:
- Placebo effect
- Spontaneous remission
- Researchers expectations may prejudice their observations
- Researchers inadvertently prejudicing patients through body language, tone of voice, etc.
A double blind study of the Ketogenic Diet (http://www.clinicaltrials.gov/ct/gui/c/a1r/show/NCT00004729?order=5&JServSessionIdzone_ct=blet58c3r1) is underway.
External links
- Epilepsy Action: The Ketogenic Diet (http://www.epilepsy.org.uk/info/ketogenic.html)
- Johns Hopkins (http://www.neuro.jhmi.edu/Epilepsy/keto.html)
- NICUS: Ketogenic Diet: Fact or Fiction? (http://webhost.sun.ac.za/nicus/Factsheets/ketogenic.htm)
Studies
- Abstract: Clinical efficacy of the ketogenic diet. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10584968&dopt=Abstract)
- Abstract: The ketogenic diet in children, adolescents and young adults with refractory epilepsy: an Italian multicentric experience. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11904241&dopt=Abstract)