The research, reviewing 11 studies and involving 15,315 participants, follows the recent decision by the Food Standards Agency to make the addition of folic acid mandatory in flour or bread.
The additive is seen as a means of increasing folate intake in women so as to prevent birth defects in unborn children.
The new research, published in the July edition of the Journal of Epidemology and Community Health, concluded there was a link between depression and low folate levels.
"Countries with mandatory fortification of bread are less likely to have low population levels of folate," Simon Gilbody, who led the research, told BakeryandSnacks.com.
The conclusion follows the same team's research published in the American Journal of Epidemology, which indicated that people with depression commonly have a gene that means they process folate less efficiently.
"We used an unbiased and scientific method to judge the association between low mood and low folate, and found this was an additional benefit that has only previously been hinted at," said Gilbody. "Fortification has another potential benefit in this respect, and I would like to see this tested in a trial of folate supplementation for those with depression."
With folate linked to the production of serotonin in the brain, researchers claim that depression could be limited if folic acid was to be added to bread or flour.
"I am generally in favour of fortification of bread, since the potential health benefits of fortification are substantial, and the risks are minimal," added Gilbody.
According to the Office for National Statistics last year, one in six people in the UK suffered from some kind of neurotic disorder, such as anxiety or depression, in 2000.
The University of York said depression will soon become the second leading cause of disability worldwide, and affects between five and ten per cent of individuals.
The UK exports £301m worth of biscuit and cake products per year and £56m of bread.
An FSA report has noted that the UK's trading partners would be less likely to import its flour and flour-based products when they are fortified with folic acid.
Source: Journal of Epidemiology and Community Health
July 2007, Volume 61, Number 7
"Is low folate a risk factor for depression? A meta-analysis and exploration of heterogeneity"
Authors: S Gilbody, T Lightfoot, T Sheldon
