PQQ Supplement Boosts Mitochondria But Fails to Affect Weight or Metabolism in Mice

This controlled study investigated whether pyrroloquinoline quinone (PQQ) supplementation could prevent weight gain and improve energy metabolism by enhancing mitochondrial function. Researchers divided 64 male mice into four groups: normal diet, normal diet plus PQQ, high-fat diet, and high-fat diet plus PQQ, treating them for three months with 30 mg/L PQQ in drinking water.

The results revealed a disconnect between cellular and systemic effects. PQQ significantly increased mitochondrial DNA content (indicating more mitochondria) and enhanced antioxidant capacity in liver tissue of normal-diet mice. It also boosted autonomous activity, with PQQ-treated mice covering more distance and spending less time resting during behavioral tests.

However, these cellular improvements didn't translate to metabolic benefits. PQQ had no significant effect on body weight gain, food intake, oxygen consumption, heat production, or fat accumulation in either diet group. High-fat diet mice gained weight at 1.19g per week versus 0.68g for normal diet mice, but PQQ didn't alter these rates. Similarly, PQQ didn't improve insulin sensitivity or glucose metabolism in either group.

Interestingly, PQQ did alter expression of key metabolic genes including CPT1a (fat oxidation), SCD1 (fat synthesis), and hexokinases HK2 and HK3 (glucose metabolism), suggesting cellular metabolic changes were occurring. The authors conclude that while PQQ enhances mitochondrial biogenesis and antioxidant defenses at the cellular level, these changes are insufficient to meaningfully impact whole-body energy balance or prevent diet-induced obesity in healthy male mice.