The old adage that fish is good for the brain has more sense in it than many people realised.
There is an increasing amount of evidence that the DHA component of omega-3 fatty acids in oily fish does indeed have a key role in brain function. This is not surprising. As mentioned in the section on omega-3 fatty acids, the brain is a fat-rich organ, and around half of the fat content is DHA.
Evidence gathered over the past 20 years or more has linked DHA in particular with mental health problems such as depression, including post-natal depression, with dementias and with afflictions such as bipolar disorder and schizophrenia. Omega-3 fatty acids have also been associated with reducing aggression.