Results of the study are published in the August 20 issue of the Journal of the American Medical Association. After following the diet for six months, only one in six children in the study group had either a cholesterol or triglyceride level considered acceptable for children.
Despite the elevated lipids, the researchers believe the diet should remain in the treatment arsenal because children remain on the ketogenic diet temporarily – only one to two years. "These high cholesterol and triglyceride levels are unlikely to be associated with a long-term increase in risk for cardiovascular disease in adulthood," said the study's lead author, Peter O. Kwiterovich, Jr., M.D., director of the Division of Lipid Research and Atherosclerosis at the Children's Center.
"Although we know that, in adults, high cholesterol and triglyceride levels may increase one's risk for heart disease, we believe that children following the ketogenic diet do not stay on it long enough for these high levels to become a problem," he added. "Typically, when the children resume a normal diet, these levels return to normal."
Kwiterovich said parents may want to have their own and their child's cholesterol and lipid profiles tested before putting their child on the ketogenic diet. "Children with even one parent with high cholesterol, or a family history of heart disease, may be more prone to extremely high cholesterol and triglyceride levels when following the diet," he said.
Refined in the Pediatric Epilepsy Center at the Johns Hopkins Children's Center, the ketogenic diet is designed to maintain a child's normal growth and development and is not used for weight reduction. The diet mimics some of the effects of starvation, in which the body first uses up glucose and glycogen before burning stored body fat. In the absence of glucose, the body produces ketones, a chemical byproduct of fat that can inhibit seizures. Children who remain seizure-free for two years on the ketogenic diet can resume normal eating. Generally, their seizures don't return.
For the current study, the Hopkins team tracked 141 children between the ages of four months and 20 years who had been diagnosed with difficult-to-treat seizures and were part of a larger group of patients accepted into the Johns Hopkins ketogenic diet program between 1994 and 2001. After following the diet for six months, researchers measured the children's triglyceride and total cholesterol levels, including high-density lipoproteins (HDL, or "good" cholesterol), low-density lipoproteins (LDL, or "bad" cholesterol), and very low-density lipoproteins. A subset of the study group was followed up after 12 and 24 months.
After six months on the diet, the children's average total cholesterol rose significantly to 232 milligrams per deciliter, well above the 200 mg/dL level the medical community considers too high for children. Average LDL cholesterol also increased to levels almost 20 mg/dL above what is considered to be too high. Triglyceride levels averaged 154 mg/dL, which also exceeds normal levels for children.
For the subgroup that was followed after 12 and 24 months, total cholesterol levels were lower than they were after six months, but still remained above 200 mg/dL.
Kwiterovich cautioned that the results of this study do not predict how all children will respond to a high-fat, low-carbohydrate diet like the ketogenic diet. "Many of these children were on a number of medications for seizure control so diverse that it was not possible to determine the influence of each drug and dosage combination on lipid and cholesterol levels," he said.
Co-authors of the study were Eileen P.G. Vining, M.D.; Paula Pyzik, B.A.; Richard Skolasky, Jr., M.A.; and John M. Freeman, M.D. of the Pediatric Epilepsy Center of the Johns Hopkins Children's Center. The research was supported by grants from the National Institutes of Health, the Johns Hopkins University School of Medicine General Clinical Research Center, the Roxanne Fellowship Funds, and the Vaswani Family.
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