Scientific Alert Note

Fish diets promote health benefits: results of European randomized intervention trial

Eating 150 g of fish, such as salmon or cod three times a week, or taking fish liver oil daily, can improve health variables, like body weight, blood lipids, inflammation and oxidative status. Omega 3 fatty acid levels in membranes present a good correlation with diet, showing that consumption of either lean or fatty fish species, might have an important role in the prevention of cardiovascular disease. A novel finding is that a moderately calorie-restricted cod-based diet was found to facilitate weight loss, while also helping improving on oxidative stress markers. Seafood does not seem to decrease bone loss, which is generally found in weight loss processes.



Authors: Narcisa M. Bandarra1, J. Alfredo Martinéz2, Mairead Kiely3, Gertjan Schaafsmaand Inga Thorsdottir5


1The National Research Institute on Agriculture and Fisheries Research, Lisbon, Portugal
The Department of Physiology and Nutrition, University of Navarra, Navarra, Spain 
3Department of Food and Nutritional Sciences, University College Cork, Cork, Ireland
4TNO Nutrition and Food Research, the Netherlands & Wageningen University, the Netherlands
Unit for Nutrition Research, Landspitali-University Hospital & Department of Food Science and Human Nutrition, University of Iceland, Reykjavik, Iceland (project leader)




The SEAFOODplus project YOUNG was a cross European randomized dietary intervention study which investigated the effects of regular seafood consumption in young overweight and obese adults. It aimed to study the effects of seafood in energy restricted weight-loss-diets on weight loss, blood lipids, antioxidant status, inflammation and bone status.


In this controlled intervention study subjects were randomized to one of 4 groups, i.e., (1) control (no seafood, capsules w/sunflower oil enriched with oleic acid), (2) lean fish (3 x 150g portions of cod/week), (3) fatty fish (3 x 150g portions of salmon/week), and (4) fish oil (DHA/EPA capsules, no other seafood), and followed these diets for 8 consecutive weeks.


A food frequency questionnaire (FFQ) measuring seafood intake among young adults in Europe was validated in a separate study (56 subjects).


Subjects in the intervention were 324 (20-40 years, BMI 27.5-32.5 kg/m2). Measurements at baseline (week 0), midpoint (week 4) and endpoint (week 8) were dietary intake, body weight and other anthropometric variables, fatty acids in erythrocyte membrane, blood lipids, fasting glucose and -insulin, vitamin D, markers of antioxidant status, inflammation and bone metabolism.


Weight loss was significantly higher in men on seafood diets compared with men in the control group, showing an additional body weight reduction of 1 kg. The Cod diet promoted a higher reduction in total cholesterol than control. HDL tended to decreased less in the diets of salmon and fish oil compared to control. Triglycerides decreased more in the groups receiving seafood compared with the control.



Erythrocyte main fatty acids of the volunteer group 2 (cod diet) at baseline (B) and at endpoint (E) of the intervention study



Lean fish consumption decreased soluble intercellular adhesion molecule-1 (sICAM-1). An increase of soluble vascular adhesion molecule-1 (sVCAM-1) was observed on diets with fatty fish and fish oil.


Increased fish or fish oil consumption did not significantly affect biomarkers of bone turnover in the weight loss diets for 8 weeks.