Increasing Dietary Fish Oil Reduces Adiposity and Mitigates Bone Deterioration in Growing C57BL/6 Mice Fed a High-Fat Diet. Issue 1 (11th September 2019)

• Record Type: Journal Article
• Authors: Cao, Jay J; Gregoire, Brian R; Michelsen, Kim G; Picklo, Matthew J
• Is Part Of: Journal of nutrition. Volume 150:Issue 1(2020)
• Page Start: 99
• Page End: 107
• Publication Date: 2019-09-11
• Subjects: fish oil -- long chain n–3 fatty acids -- bone -- obesity -- high-fat diet; Nutrition -- Periodicals; Diet -- Periodicals; 613.205
• DOI: 10.1093/jn/nxz215
• Languages: English
• ISSNs: 0022-3166

Abstract

ABSTRACT: Background: Intake of total fat is linked to obesity and inversely associated with bone density in humans. Epidemiologic and animal studies show that long-chain n–3 (ω-3) PUFAs supplied as fish oil (FO) are beneficial to skeletal health. Objective: This study tested the hypothesis that increasing dietary FO would decrease adiposity and improve bone-related outcomes in growing obese mice. Methods: Male C57BL/6 mice at 6 wk old were assigned to 6 treatment groups and fed either a normal-fat diet (3.85 kcal/g and 10% energy as fat) or a high-fat diet (HF; 4.73 kcal/g and 45% energy as fat) containing either 0%, 3%, or 9% energy as FO (0FO, 3FO, and 9FO, respectively) ad libitum for 6 mo. Bone structure, body composition, and serum bone-related cytokines were measured. Results: The HF diet increased the expression of the adipose tissue tumor necrosis factor α ( Tnfa ) and serum concentrations of leptin and tartrate-resistant acid phosphatase (TRAP), and decreased serum concentrations of osteocalcin and bone-specific alkaline phosphatase ( P < 0.05). FO decreased fat mass ( P < 0.05), serum TRAP ( P < 0.05), and adipose tissue Tnfa expression ( P < 0.01). Bone content of long-chain n–3 PUFAs was increased and n–6 PUFAs were decreased with the elevation in dietary FO content ( P < 0.01). Compared with mice fed 9FO, animals fed 3FO had higher femoral bone volume/total volume (25%), trabecular number (23%), connectivity density (82%), and bone mass of second lumbar vertebrae (12%) and lower femoral trabecular separation (−19%). Mice fed the 3FO HF diet had 42% higher bone mass than those fed the 0FO HF diet. Conclusions: These data indicate increasing dietary FO ≤3% energy can decrease adiposity and mitigate HF diet–induced bone deterioration in growing C57BL/6 mice possibly by reducing inflammation and bone resorption. FO at 9% diet energy had no further beneficial effects on bone of obese mice.