Fish Oil Consumption: Its Effects on Bone and Blood Parameters of the Ovariectomized Rat Model of Osteopenia

Background/Objectives: The beneficial effects of ω-3 fatty acids on the cardiovascular system have been observed in many epidemiological studies; however, their effects on the skeleton and in particular on postmenopausal bone loss appear to vary. The present study's purpose was to investigate the effects of oral fish oil (rich in ω-3 fatty acids) consumption on bone, plasma, and inflammation parameters in the ovariectomized (Ovx) rat model of osteopenia. Methods: Four Groups of ten rats each were separated into Non-Ovx receiving fish oil (2.8 g/kg body weight) (Non-Ovx + FO), Non-Ovx receiving isocaloric corn oil (Non-Ovx + CO), Ovx receiving fish oil (Ovx + FO), and Ovx receiving corn oil (Ovx + CO) daily for 4 months. Results: Tibial bone mineral density percentage changes from baseline were +4.09% in Non-Ovx + FO rats versus -2.99% in Non-Ovx + CO rats (p NS), and -5.73% in Ovx + FO rats versus -14.12% in Ovx + CO rats (p = 0.070), indicating a tendency to protect from bone loss. Fish oil exerted a beneficial effect on bone strength, as shown by significantly increased femoral fracture stress in Ovx + FO, compared to Ovx + CO rats (p = 0.05). The plasma's total cholesterol was significantly reduced in both FO Groups versus the CO Groups (p < 0.001), while HDL-cholesterol decreased slightly in both FO Groups, significantly (p < 0.001) between Non-Ovx + FO versus Non-Ovx + CO. Interleukin 6 was reduced in both FO Groups, indicating the anti-inflammatory effect of fish oil consumption, which was highly significant (p < 0.001) between Non-Ovx + FO versus Non-Ovx + CO. Interleukin 10, TNF-α, and RANKL displayed non-significant changes. Conclusions: Among the skeletal and blood parameters studied, several, but not all, demonstrated a mild to significant beneficial effect of four-month fish oil consumption.