Omega-3 fatty acids supplementation on stress-induced changes to kynurenine metabolism and mood in physically active and inactive males

A typical western diet has shifted towards greater intake of omega-6 fatty acids at the expense of intake of omega-3 fatty acids. Considering proinflammatory functions of omega-6 fatty acids, this type of diet can increase inflammation in the body. Inflammation has been shown to play a key role in behavioural and mood disturbances, including negative affect and low mood. Meanwhile, studies have demonstrated anti-inflammatory properties of omega-3 supplements. Particularly, effectiveness of one of the omega-3 fatty acids, Docosahexaenoic acid (DHA), has been reported to reduce inflammation. Numerous studies have been conducted on the effects of anti-inflammatory properties of omega- 3 fatty acids on mood. However, the results from those studies are not consistent and most research in this area implemented supplementation protocols shorter than 3 months – time crucial to achieve a significant increase of DHA in human blood cells. Moreover, inflammation seems to be only one of the triggers of negative affect and low mood. Mood disturbances seem to be additionally mediated by psychosocial stress. For example, evidence from animal models have shown that different types of psychosocial stress may enhance changes in the brain resembling those observed in depressed patients. The biological mechanism that might explain this phenomenon is kynurenine metabolism, which seems to change under psychosocial stress and inflammatory factors. In this model resilience to stress-induced mood disturbances was mediated by physical activity. Specifically, an increased activity of PGC-1α in skeletal muscle, which is activated during endurance-type activity, lead to a higher kynurenine aminotransferase - an enzyme converting kynurenine (KYN) to kynurenic acid (KYNA). Nevertheless, the evidence comes from animal studies only and there are no corresponding studies conducted on humans. Based on the previous research in the area, the main project objectives are: 1. To compare biochemical parameters (KYN and KYNA, markers of oxidative stress, and markers of inflammation) between physically active and inactive males 2. To determine the impact of a 3-month supplementation with omega-3 fatty acids on mood, inflammation markers and oxidative stress, and changes in KYN and KYNA 3. To determine the impact of the stress manipulation test (TSST) on mood and changes in KYN and KYNA before and after the omega-3 fatty acids supplementation