The study – published in Nutrition Journal​ – evaluated the effects of omega-3 fatty acid supplementation on cognitive performance measures in order to better evaluate a possible relationship between cognitive functions and cardio-metabolic risk parameters.

Led by Professor Inger Björck of Lund University, Sweden, the research team gave 40 healthy participants aged between 15 and 72 a daily supplement containing three grams of omega-3 PUFA fish oil or a placebo for five weeks before testing cognitive functions and metabolic risk markers such as blood pressure, serum triglycerides, and fasting glucose measures.

“Daily intake of omega-3 PUFA from fish oil during five weeks significantly improved cognitive functions (working memory capacity) in healthy subjects,”​ said Björck and her colleagues.

“In addition, inverse relations were obtained between cardiometabolic risk factors and cognitive performance, indicating a potential of dietary prevention strategies to delay onset of metabolic disorders and associated cognitive decline,”​ they added.

The researchers said such a relationship between outcomes in cognitive tests and metabolic risk factors also highlights the importance of early dietary prevention to prevent cognitive declines that are associated with metabolic disorders.

Study details​

Björck and her team noted that higher plasma levels of omega-3 fatty acids have been suggested to be associated with a lower risk of age related cognitive decline, and to beneficially affect metabolic risk factors.

The team therefore aimed to assess the potential relationship between supplementation with omega-3 PUFAs, measures of metabolic health, and cognitive functioning.

Björck and her colleagues assessed this in a balanced crossover trial in which 40 participants ages between 51 and 72 were given either three grams of omega-3 fatty acids per day or a placebo pill containing no omega-3.

The omega-3 supplement was given in five pills, each of which contained 600 mg omega-3 PUFA (EPA 300 mg, DHA 210 mg and 90 mg unspecified) while the placebo was provided as two tablets per day containing in total 366 mg dicalcium phosphate (E 341), 150 mg microcrystalline cellulose (E 460) and 4 mg magnesium salts of fatty acids (E 470b).

The omega-3 supplement and placebo were both were consumed for five weeks, separated by a five week washout period. Cognitive performance was determined by tests measuring working memory (WM) and selective attention, in addition to metabolic risk factors being measured.

Björck and her team reported that supplementation with the omega-3 pills resulted in better performance in working memory tests compared with placebo.

In addition the omega-3 was found to lower plasma triacylglycerides and systolic blood pressure.

The team revealed that systolic blood pressure, fasting glucose, and serum TNF-alpha (a cytokine involved in systemic inflammation) concentrations, were inversely related to the performance in cognitive tests.

Source: Nutrition Journal​

Published online ahead of print, doi: 10.1186/1475-2891-11-99​

“Effects of supplementation with n-3 polyunsaturated fatty acids on cognitive performance and cardiometabolic risk markers in healthy 51 to 72 years old subjects: a randomized controlled cross-over study”​

Authors: Anne Nilsson, Karl Radeborg, Ilkka Salo, Inger Björck