"The truth is rarely pure and never simple"   Oscar Wilde 

I wrote a post a couple of days ago entitled "Twelve recent research studies on diet, psychological symptoms & wellbeing (1st post): overall dietary quality & depression".  I said that glancing back over recent research studies that I have noticed & downloaded to my personal database, I was struck by a whole series on the effects of diet on psychological state.  I've listed twelve that caught my eye in the last several months - the first post gave half a dozen on overall dietary quality & depression, whereas this post focuses more on specific dietary components.

I read a lot of research.  When I find an article of particular interest I download it to my bibliographic database - EndNote - which currently contains over 14,000 abstracts. 

I read a lot of research.  When I find an article of particular interest I download it to my bibliographic database - EndNote - which currently contains over 13,800 abstracts. 

You know how it is - no buses in sight, then two come along at once.  It's been a bit similar for good research on diet and depression.  There have been plenty of studies on individual components of diet and mood (e.g. fish, folate, other B vitamins), but very little on the possible psychological effects of diet as a whole.  Then in October's edition of Archives of General Psychiatry, along came:

Here are half a dozen studies on diet (see below for all abstracts and links).  The first three are about the benefits of healthy lifestyle.  Trichopoulou & colleagues evaluated the contribution of nine widely accepted components of the Mediterranean diet (high intake of vegetables, fruits and nuts, legumes, fish, and cereals; low intake of meat and dairy; high ratio of monounsaturated to saturated lipids; and moderate intake of ethanol) in the inverse association of this diet with all cause mortality.  They concluded that "The dominant components of the Mediterranean diet score as a predictor of lower mortality are moderate consumption of ethanol, low consumption of meat and meat products, and high consumption of vegetables, fruits and nuts, olive oil, and legumes.

Fish, fish oils, and n-3 fatty acids are often in the health news.  Here are seven recent papers illustrating the breadth of fish oil relevance.  The papers look at treatment of rheumatoid arthritis, the potential of flax as a dietary source of n-3 fatty acids, effects on indicators of cardiovascular disease, potential protection against dementia, reduction in mortality, and importance in pregnancy.  The papers also illustrate the patchwork, three steps forward/one step back, meandering, spreading, accretion of scientific knowledge.  As the proverb goes "One swallow doesn't make a summer".  Similarly, a single research study is usually simply one brick in the gradual building of our knowledge.  For more on fish and n-3 fatty acids, see other relevant blog posts I've written, articles in the linked Connotea database, and some recommended websites.