In a cohort of 43 children with drug‑resistant epilepsy, higher pre‑diet intake of n‑3 and n‑6 polyunsaturated fatty acids and fewer baseline deficiencies in phosphorus, magnesium, zinc, and vitamin E were associated with ≥70% seizure reduction after 3–6 months of ketogenic diet therapy.
Study and findings
The authors enrolled 43 children (mean age 5.4 ± 4.7 years) with drug‑resistant epilepsy and recorded their usual dietary intake using 24‑hour recalls and three‑day food records. Nutrient intakes were compared with Dietary Reference Intakes to identify insufficiencies. After initiating a classical ketogenic diet, seizure outcomes were classified as ≥70% reduction or <70% reduction at 3 and 6 months. At 3 months, the ≥70% reduction subgroup (n = 11) consumed a higher proportion of energy from n‑3 polyunsaturated fatty acids (2.23% vs. 0.78%, p = 0.021) and n‑6 polyunsaturated fatty acids (8.98% vs. 5.87%, p = 0.018), and none had phosphorus insufficiency compared with 31.3% in the lower‑response group (p = 0.043). At 6 months, the ≥70% reduction group (n = 17) showed lower rates of insufficient magnesium (47.1% vs. 86.7%, p = 0.019), zinc (11.8% vs. 53.3%, p = 0.021) and vitamin E (17.6% vs. 53.3%, p = 0.034).
Clinical interpretation
These observations suggest that children whose baseline diets provide adequate amounts of n‑3/n‑6 polyunsaturated fatty acids and meet recommended intakes for phosphorus, magnesium, zinc, and vitamin E are more likely to achieve a clinically meaningful seizure reduction when treated with a ketogenic diet. The findings are consistent with the notion that sufficient substrate for fatty‑acid oxidation and adequate micronutrient status may support the metabolic shift required for ketosis and its anticonvulsant effects. However, the study does not establish that correcting these deficiencies will improve outcomes, only that the deficiencies were less common among responders.
Limitations and open questions
The sample size is modest, and the analysis relies on dietary recall data, which are subject to reporting bias. The study design is observational; therefore, causality cannot be inferred. It remains unclear whether targeted supplementation of the identified nutrients would enhance ketogenic diet efficacy, or whether the associations reflect broader aspects of overall nutritional health. Larger, controlled trials are needed to determine if pre‑emptive correction of PUFA, phosphorus, magnesium, zinc, and vitamin E insufficiencies can increase the proportion of children achieving ≥70% seizure reduction.
Source
Chen YT, Lee LJ, Fan PC, Lee WT. Influence of baseline nutritional status on ketogenic diet efficacy in children with drug-resistant epilepsy. Pediatr Res. 2026. doi: 10.1038/s41390-026-05410-9. PMID: 42661052.