Do omega-3s improve brain function?
Beyond flavonoids: can omega-3s improve our brain health?
In the previous two videos we have seen that the studies investigating the effects of flavonoids on brain and cognition are quite mixed, and scientists have not reached a consensus yet. Brain-boosting supplements, however, are now quite common. In some cases, their supposed mechanism of action is through an increase in blood supply, just like flavonoids can do. But another class of molecules, omega-3s fatty acids, has received a lot of attention when it comes to both cardiovascular and cognitive health.
As we have seen in the first week, we need to gain some fatty acids through our diet, and one of them is an omega-3 fatty acid called alpha-linoleic acid (ALA). This means that, regardless of the effectiveness of ALA in improving cardiovascular or cognitive function, we need to have a regular intake of this fat. Other omega-3s are not essential, as we can synthesize them starting from ALA, nevertheless it is recommended to have a source of them in our diet, as the conversion from ALA to other fatty acids is not very efficient.
The benefit of omega-3s to the cardiovascular system is now proven, to the point that the American Heart Association recommends that all adults eat fish (particularly oily fish) twice a week. But these fats are also crucial for brain development. Therefore, it is interesting to understand which foods and superfoods contain them, and whether increased intakes of omega-3s are linked to better cognitive function, or to a better mood.
As we saw in week two, flaxseeds and chia seeds are good dietary sources of omega-3s (in particular, of ALA). Walnuts are another good source of ALA, as two other vegetable oils: canola and soybean. Oily fish, algae and krill are rich in two other important fatty acids: EPA and DHA. Although other nuts are sometimes labelled as superfoods - and they can be healthy components of our diets, if eaten in moderation, they are not considered dietary sources of omega-3s.
Regardless of their source, can omega-3s improve our brain health?
Some studies investigated the effect of omega-3s supplementation in infants and in adults, looking at their effectiveness in treating depression, preventing dementias or improving cognitive development of children.
Studies have evidenced a positive effect of omega-3s in the case of major depression: even if the results are mixed, it seems that supplementation could be effective in treating this condition, especially in combination with antidepressants. Due to the variability of the studies, there is not a consensus yet on the effectiveness of omega-3s in the treatment of major depression, but it is considered by scientists to be a promising approach, and more studies are underway.
Unfortunately, no significant effect has been found in respect to neurodegenerative diseases, nor to other psychiatric condition, such as schizophrenia.
In conclusion, the beneficial effects of omega-3s are confirmed only with respect to the cardiovascular system and do not seem to directly affect cognitive performance. However, it is worth noting that a decrease in cardiovascular disease has a beneficial effect on our brain, especially when considering the prevention of strokes.