Disease Risk Reduction and Lcn3-Rich Rainbow Trout
Project Number: 3062-51000-048-05
Interagency Reimbursable Agreement
Start Date: Feb 15, 2014
End Date: Feb 14, 2019
Consumption of the long chain n-3 fatty acids (LCn3) eicosapentaenoic acid (20:5 n3) and docosahexaenoic acid (22:6 n3) is associated with prevention of inflammation and reduction of cardiovascular disease (CVD) risk. Inflammatory diseases and CVD are major negative outcomes of obesity and cost > $100 billion annually in the United States alone. While marine fish such as farmed Atlantic salmon (Salmo salar) are recognized as excellent sources of LCn3, there is a need to develop alternative food sources of LCn3.
Farmed, fresh water rainbow trout (Oncorhynchus mykiss) has the potential to become an attractive, alternative source of LCn3 and its land-based production is viewed as environmentally sustainable. Rainbow trout contain significant amounts of LCn3. However, there is a need to identify the production practices that increase LCn3 content in rainbow trout. The US trout industry raises primarily diploid (2N) trout; however, there is a demand for triploids (3N) for their larger fillets. Triploids fail to sexually mature therefore avoiding the negative effects of maturation on fillet quality in larger fish.
Our initial data indicate that female 3N rainbow trout have levels of LCn3 comparable to that of farmed Atlantic salmon. While we have shown that consumption of farmed Atlantic salmon significantly elevates LCn3 status in humans, the consumption of 3N rainbow trout may represent a new choice for American consumers to achieve optimal LCn3 levels and reduce the risk of disease.
Hypothesis: We hypothesize that consumption of LCn3 rich rainbow trout will reduce markers of inflammatory disease and CVD risk in obese individuals.
Objectives: This hypothesis will be tested by completion of the following objectives: (1) Evaluate the effects of feeding practices and age on LCn3 content in 2N and 3N rainbow trout; (2) Determine in a human trial the extent to which consumption of 3N rainbow trout increases LCn3 status and reduces indices of inflammation and CVD risk.
This work is the collaboration between the USDA-ARS Grand Forks Human Nutrition Research Center (GFHNRC; Grand Forks, ND) and the USDA-ARS National Center for Cool and Cold Water Aquaculture (NCCCWA; Leetown, WV). Our collaboration capitalizes on the combined expertise of these Centers in the study of improving trout production practices, the successful execution of human studies, the analysis of LCn3 metabolism, and the analysis of inflammatory and cardiovascular endpoints. Studies to improve LCn3 content in rainbow trout will be performed at the NCCCWA. These studies will establish the effect of feeding regime and optimal age on LCn3 content in fillets from 2N and 3N trout that will be the basis for rearing fish in support of a human disease risk study. Determination of human disease risk markers and LCn3 status will be performed at the GFHNRC. This work will include a randomized, cross-over-designed, feeding study. Inflammatory outcomes (TNFa, hsCRP), CVD risk measures (platelet reactivity, vascular responsiveness), and LCn3 status (plasma phospholipids and platelets) will be assessed at baseline and after 6 weeks of biweekly consumption of 2N or 3N trout. We will recruit obese, adult volunteers with metabolic syndrome (MetS, encompassing > 25% of the US population) for this study. Inflammation and cardiovascular dysfunction are hallmarks of MetS and make this population ideal for this study.