Influence of high-fat diet from differential dietary sources on bone mineral density, bone strength, and bone fatty acid composition in rats

• Published in: Applied physiology, nutrition, and metabolism Vol. 35; no. 5; pp. 598 - 606
• Main Authors: Lau, Beatrice Y, Fajardo, Val Andrew, McMeekin, Lauren, Sacco, Sandra M, Ward, Wendy E, Roy, Brian D, Peters, Sandra J, LeBlanc, Paul J
• Format: Journal Article
• Language: English
• Published: Ottawa Presses scientifiques du CNRC 01.10.2010; NRC Research Press; Canadian Science Publishing NRC Research Press
• Subjects: acide linoléique; acide α-linolénique; Adipose tissues; Age; alpha-Linolenic Acid - metabolism; alpha-Linolenic Acid - pharmacology; Animal Feed; Animal subjects; Animals; Biological and medical sciences; Biomechanical Phenomena; Body weight; Bone composition; Bone density; Bone Density - physiology; bone mechanical strength; Bone mineral density; Bone strength; Bones; Calcium; Cholesterol; Coconut Oil; composition lipidique du fémur; Density; densité minérale osseuse; Development; Diet; Diet (effects); Diet (weight control); Dietary Fats - pharmacology; Fatty acid composition; Fatty acids; Femur; Femur - physiology; femur lipid composition; Folic acid; force osseuse; Fundamental and applied biological sciences. Psychology; Health aspects; High fat diet; Ketogenic diet; linoleic acid; Linoleic Acid - metabolism; Linoleic Acid - pharmacology; Linseed Oil - pharmacology; Lipids; Male; Measurement; Oil; Physiological aspects; Plant Oils - pharmacology; Polyunsaturated fatty acids; Rats; Rats, Sprague-Dawley; Rodents; régime riche en gras; Safflower Oil - pharmacology; Strength; Studies; Sucrose; Vertebrates: body movement. Posture. Locomotion. Flight. Swimming. Physical exercise. Rest. Sports; Weight-Bearing - physiology; α-linolenic acid; Canada; Human; Femur; Rat; Force; Rodentia; Lipids; Fatty acids; Feeding; Linoleic acid; Osteoarticular system; Vertebrata; Mammalia; Linolenic acid; Diet; Fat; Essential fatty acid; Bone mineral density; Bone
• ISSN: 1715-5312; 1715-5320
• DOI: 10.1139/H10-052

Previous studies have suggested that high-fat diets adversely affect bone development. However, these studies included other dietary manipulations, including low calcium, folic acid, and fibre, and (or) high sucrose or cholesterol, and did not directly compare several common sources of dietary fat. Thus, the overall objective of this study was to investigate the effect of high-fat diets that differ in fat quality, representing diets high in saturated fatty acids (SFA), n-3 polyunsaturated fatty acids (PUFA), or n-6 PUFA, on femur bone mineral density (BMD), strength, and fatty acid composition. Forty-day-old male Sprague-Dawley rats were maintained for 65 days on high-fat diets (20% by weight), containing coconut oil (SFA;; n = 10), flaxseed oil (n-3 PUFA;; n = 10), or safflower oil (n-6 PUFA;; n = 11). Chow-fed rats (n = 10), at 105 days of age, were included to represent animals on a control diet. Rats fed high-fat diets had higher body weights than the chow-fed rats (p < 0.001). Among all high-fat groups, there were no differences in femur BMD (p > 0.05) or biomechanical strength properties (p > 0.05). Femurs of groups fed either the high n-3 or high n-6 PUFA diets were stronger (as measured by peak load) than those of the chow-fed group, after adjustment for significant differences in body weight (p = 0.001). As expected, the femur fatty acid profile reflected the fatty acid composition of the diet consumed. These results suggest that high-fat diets, containing high levels of PUFA in the form of flaxseed or safflower oil, have a positive effect on bone strength when fed to male rats 6 to 15 weeks of age.