Differential effects of fish oil and folic acid supplementation during pregnancy in rats on cognitive performance and serum glucose in their offspring

Objective We studied the effect of folic acid and polyunsaturated fatty acid supplementation during pregnancy in Wistar albino rats on cognitive performance and serum glucose concentrations in their pups. Methods Pregnant female rats from four groups (n = 6/group) were fed casein diets with 18% protein and 2 mg of folic acid/kg of diet (group I), 12% protein and no folic acid (group II), 12% protein and 8 mg of folic acid/kg of diet (group III), or 12% protein and 70 g of cod liver oil/kg of diet (group IV). All pups were weaned on standard control diet with 18% protein. Cognitive performance, brain fatty acid profile, and serum glucose concentrations were studied in offspring at age 6 mo. Results There was no significant difference in length of gestation or litter size, but the litter weight for group IV was lower (P = 0.047) than that for group I. After weaning, males in group II had lower (P < 0.05) body weights, but those in group III had weights comparable to those in group I for both sexes. In group IV, body weights were lower beyond 15 wk (P < 0.05). Relative brain weight and cognitive performance were significantly higher (P < 0.05) in group IV males and showed higher levels of brain γ-linolenic acid. Further, these animals had serum glucose levels comparable to those of control animals at age 6 mo, whereas serum glucose levels were higher in males from groups II (P = 0.01) and III (P = 0.01). Conclusion Fish oil supplementation during pregnancy improved cognitive performance and maintained glucose levels into adulthood, unlike folic acid supplementation, which supported only fetal growth and did not maintain glucose levels.