April 19, 2016 — One element that distinguishes humans from other primates is the high levels of omega-3 fatty acids within the brain. These long chain polyunsaturated fats play an important role in the cell membranes of neurons and other cells of the body, increasing permeability and controlling some signaling between cells. Deficiencies in omega-3 in both animals and humans has been shown to be correlated with increased mental health problems and even a higher risk of suicide.
Over the years, a lot of research has been done with omega-3s to see if supplements could help with various psychiatric problems from depression to autism to dementia. Anyone following news coverage will see headlines going from boom to bust for omega-3s, “no help” says one study, “strong benefit for depression” says another. How do we make sense of it all?
First a little overview. Omega-3 fatty acids for supplementation come in three major varieties, ALA, EPA, and DHA. It’s a bit of an alphabet soup, but bear with me. ALA is the precursor molecule that can be converted to EPA and DHA in the body, but the rate of conversion is never higher than 20% or so. That means if you take a lot of ALA (found in flax or chia seeds), you end up with a lot of excess omega-3 in your body that may not be particularly useful to the brain. All polyunsaturated fatty acids are delicate, easily made rancid with exposure to oxygen, so having extra omega-3s the body can’t use well may not be the best idea. EPA and DHA, on the other hand, are the fatty acids found in fish oil, and DHA is the major long chain omega-3 fatty acid in the human brain. There is an algae-made vegan DHA supplement that is added to milk and formula that you might have seen in the grocery store.