Firstly, the 3 most important types of omega-3 are: ALA, EPA & DHA. The ones that provide us with the most health benefits are the latter 2, EPA & DHA. They are what we call essential fatty acids, meaning our bodies cannot synthesise them, so we must consume them through the diet. We can do this by eating oily fish such as salmon, mackerel and sardines 2-3 times per week (or through supplementation). It is possible to consume nuts & seeds rich in ALA (which in-turn can be converted to EPA & DHA) but this is far from optimal as our bodies can only convert a small percentage of this.
The first and most strongly supported health benefit is that omega-3 consumption has been shown in the research to reduce triglyceride levels. Remember, with high levels of triglycerides, particularly for those with hypertriglyceridemia, there comes an increased risk of stroke and heart disease. However, if you are at risk of any diseases, be sure to always consult with your doctor and don’t simply follow guidelines you read online.
Secondly, excessive inflammation can contribute to numerous diseases. Omega-3 has well known anti-inflammatory properties via different mechanisms (inhibits activation of pro-inflammatory transcription factors in addition to activating anti-inflammatory ones), therefore potentially reducing an individual’s risk of these diseases. For example, human trials have demonstrated benefits of omega-3 in arthritis and stabilising atherosclerotic plaques.
So can vitamin D also play a role in muscle function? Well, there is a growing body of evidence supporting this claim, particularly in elderly populations where vitamin D levels are typically sub-optimal. A study conducted by Agergaard et al. (3) found that following 12 weeks of supplementation, elderly men saw improvements in muscle quality, which in-turn may have the potential to improve their quality of life and independence.
Regarding athletic performance, Owens et al. (4) showed that by elevating an individual’s vitamin D status, they incurred a positive effect on muscle force recovery following a bout of damaging eccentric exercise. Additionally, Close and colleagues (5) demonstrated that following an 8-week vitamin D supplementation protocol, individuals were shown to significantly improve their 10-metre sprint and vertical jump performances. However, the research on young athletic populations is limited, with some reporting positive effects and others non at all. What seems likely though, is that individuals with low levels of vitamin D will observe health and performance benefits should they address the issue and improve their vitamin D status.
Finally, the current evidence would suggest that omega-3 consumption, at a dosage equal to or greater than 1,000mg (1g) per day, would have beneficial effects on those suffering from depression. The exact mechanism behind this needs to be studied further, but speculations have been made suggesting one of the reasons may be due to omega-3 decreasing the production of proinflammatory cytokines which have been related to depression.