Abstract
Being overweight increases the risk of the development of metabolic conditions such as non-alcoholic fatty liver disease (NAFLD), which is itself an independent predictor of cardiovascular disease. Omega-3 polyunsaturated fatty acid (PUFA) supplementation is recommended for prevention of chronic disease, and is thought to reduce raised liver fat, yet there have been few randomized controlled trials with accurate measurement of liver fat. We assessed the effect of 12 weeks of supplementation with omega-3 PUFA from fish oil versus placebo on quantified liver fat, liver tests, and body composition including visceral adipose tissue (VAT) in a double-blind randomized controlled trial. Fifty apparently healthy overweight men (BMI 25.0–29.9 kg/m2; waist > 94 cm) were randomly allocated to consume fish oil (total daily dose: 1728 mg marine triglycerides, of which 588 mg EPA and 412 mg DHA, combined with 200 mg antioxidant, coenzyme Q10) or placebo (olive oil capsules) daily for 12 weeks. Liver fat was assessed using proton magnetic resonance spectroscopy. All outcomes were assessed at baseline and following 6 and 12 weeks of supplementation. Baseline liver fat was 4.6 ± 0.5% (range: 0.6 to 18.2%); 16 (32%) participants met the criteria for NAFLD (>5.5% liver fat). Repeated measures ANOVA revealed no significant time or group × time effect for fish oil versus placebo for liver fat, liver enzymes, anthropometry, or body composition including VAT (p > 0.05 for all), with similar finding for sub-analysis of participants with NAFLD. Omega-3 PUFA did not appear to be an effective agent for reducing liver fat in overweight men. The factors determining the health benefits of omega-3 PUFA supplementation on an individual level need to be clarified.
Highlights
Despite the well-recognized health consequences of excess body fat, epidemiological data show that the worldwide prevalence of overweight/obesity is continuing to increase [1]
In this study, using gold-standard non-invasive techniques for the assessment of intrahepatic lipid (IHL) concentration and composition, and an omega-3 dose that has previously been shown to result in reductions in liver fat [18], we failed to observe a hepatic benefit
The finding of no effect of fish oil on hepatic steatosis is opposite to the results of the majority of available trials [18]
Summary
Despite the well-recognized health consequences of excess body fat, epidemiological data show that the worldwide prevalence of overweight/obesity is continuing to increase [1]. Non-alcoholic fatty disease (NAFLD), an independent risk factor for cardiovascular disease (CVD) [3], is positively associated with increased adiposity, being present in around 20–40% of the general population, and up to 90% of obese individuals [4]. Diet-induced weight loss of as little as 3% is effective in reducing both visceral and hepatic adipose tissue [7], and such changes are associated with a reduction in traditional cardiovascular risk factors [7,8]. In the absence of other suitable therapies, weight loss by energy restriction and exercise remains the first line of treatment for reducing visceral obesity and hepatic steatosis [6]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
