Can eating fish help boost intelligence levels?

My grandmother always used to say that fish was good for the brain.  A lot of research is now available now to back up these old folk tales.  Our brains are very fatty organs  and we require essential fats for their efficient functioning.  Fish intake in pregnant women has been positively linked to cognitive performance (mental functioning) in infants.  In November last year I wrote about how the food we eat can affect brain function and mentioned that essential omega 3 fats seem particularly important. 

Research has suggested that the long chain omega 3 fatty acids, EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), found in oily fish such as salmon, mackerel, sardines and trout provide many benefits to the brain, including improving learning and memory and helping to fight against mental disorders such as depression, mood disorders, schizophrenia, and dementia.

A recent report (1) has suggested that teenage boys who regularly eat fish may be doing their brains some good.  The researchers collected food intake data from almost 5000 teenage boys aged 15 in Sweden.  The participants also completed intelligence tests.  The scientists then looked to see if there was any association between fish intake and cognitive performance (mental functioning).  There was a positive association between how much fish was eaten per week at age 15 and cognitive performance measured 3 years later.  Eating fish more than once per week was associated with a significantly higher intelligence test score, verbal performance and visuospatial performance (visual perception of the spatial relationships of objects) when compared to eating fish less than once per week.

This association between fish consumption and intelligence score was the same in lower and higher educated groups of boys, in other words the education level of the boys did not seem to influence the relationship between frequency of fish consumption and cognitive performance (1)

It is not known exactly why fish consumption is linked to improved cognitive performance but the most widely held theory is that the essential fats found in oily fish have positive effects on mental functioning.  Essential fats accumulate in the brain when the foetus is developing (for more info read my blog post on postnatal depression) and essential fats are necessary for the continued efficient functioning of our brains.  Omega 3 fatty acids also have anti inflammatory properties and may be working to positively affect the immune system.

The teenage years are important since the brain is ‘plastic’, it can reorganise the connections between cells and this affects intelligence, emotional and social behaviour.  Brain plasticity is important for learning new skills or recovering from injury.  Diet may well be playing a role here.  Even in older adults there have been some links between fish and omega 3 intake and cognitive functioning so getting enough omega 3 fats throught our lifetimes seems very important.

There are many different nutrients that are essential for the efficient functioning of the brain but omega 3 fatty acids certainly seem to be gaining validity as one of the more important factors.  Eating a healthy balanced diet that includes omega 3 fats is important for many aspects of health.  If you do not regularly eat oily fish you may wish to consider a supplement that provides 250-350mg EPA and 250-350mg DHA daily.  Vegetarians and vegans can get omega 3 fats (the shorter chain variety) from flaxseeds and walnuts or a supplement providing 500-1000mg alpha-linolenic acid daily could be considered.  Some vegetarian algal and phytoplankton supplements are now becoming available these contain the longer chain omega 3 fats (EPA and DHA).

(1)Aberg MA et al.  2009.  Fish intake of Swedish male adolescents is a predictor of cognitive performance.  Acta Paediatr. 98(3):555-60

Written by Ani Kowal