Fish oil supplementation for two generations increases insulin sensitivity in rats

Area of Science:

• Nutritional Science
• Metabolic Health
• Molecular Biology

Background:

• Insulin resistance is a growing metabolic concern.
• Dietary interventions, like fish oil, are explored for metabolic benefits.
• Transgenerational effects of nutritional supplementation are not fully understood.

Purpose of the Study:

• To investigate the impact of two-generation fish oil supplementation on insulin sensitivity.
• To explore the molecular mechanisms underlying observed metabolic changes.
• To assess effects on glycemia, lipidemia, and insulin signaling pathways.

Main Methods:

• Female rats received fish oil or control diet for 3 months, then through gestation and lactation.
• Supplementation was continued for two subsequent generations (G1 and G2).
• Insulin sensitivity was assessed in male offspring (G1 and G2) using in vivo and in vitro methods; molecular analyses included kinase phosphorylation and DNA methylation.

Main Results:

• First-generation (G1) offspring showed no significant changes compared to controls.
• Second-generation (G2) offspring exhibited reduced blood glucose and lipids, with improved insulin sensitivity.
• Improvements in G2 were associated with increased p38 MAP kinase phosphorylation, a lower n-6/n-3 fatty acid ratio in skeletal muscle, and decreased global DNA methylation in the liver.

Conclusions:

• Two-generation fish oil supplementation can improve insulin sensitivity in offspring.
• The benefits appear in the second generation and are linked to specific molecular adaptations.
• Findings suggest potential for dietary strategies to influence metabolic health across generations.