Adverse Effects of Omega-3’s

CORK, Ireland—Omega-3 essential fatty acids (EFAs) unfavorably altered bone turnover markers in young overweight adults in a recent study at the University College Cork, Ireland (Am J Clin Nutr. 2008;87(4):1045-52). While following a strict hypoenergetic diet for eight weeks, 276 overweight men and women, 20 to 40 years old, with a body mass index (BMI) between 27.5 and 32.5, were randomly assigned to one of four dietary groups: 3 g/d of sunflower oil capsules (control); 150 g, three times a week, of cod; 150 g, three times a week, of salmon; and 3 g/d of fish oil capsules. During the eight weeks, the mean weight loss was 5.14 +/- 3.0 kg in the four dietary groups combined. Urinary N-telopeptides of type I collagen and serum C-terminal telopeptide of type I collagen increased (P<0.05), whereas serum osteocalcin, but not bone-specific alkaline phosphatase, decreased (P<0.05) from baseline to endpoint. Increased fish or fish oil consumption had no effect (P>0.1) on the changes in bone markers induced by weight loss; however, increased salmon consumption increased serum 25-hydroxyvitamin D (P<0.01).