Food and Behaviour Research

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16 December 2016 - Nutraingredients - Could folic acid decrease dementia risk?

Nathan Gray

FAB RESEARCH COMMENT:

The UK government was recently criticised for rejecting renewed calls to fortify basic foodstuffs with folic acid (vitamin B9). This is already standard policy in many developed countries (but not in the EU) in order to reduce rates of serious neurological disorders such as spina bifida. (Furthermore, low levels in pregnancy are also linked with more subtle impairments of brain development such as autism and language problems).
See:
In this new study from France, older adults with the highest intakes of folate (the natural form of folic acid, found in leafy vegetables and other whole foods) had a 50% lower risk of dementia than those with the lowest intakes. For details, see:
The authors point out that previous inconsistent findings may reflect the combining of data from countries with and without folic acid fortification - and that the current data support the idea that fortification in countries with low general population intakes might help to prevent age-related cognitive decline and dementia.

While the current study design cannot address causality, other evidence from clinical trials has already indicated that supplementation with B vitamins can help to prevent cognitive decline (although effects also depend on status of other nutrients). See:

Supplementation with folic acid might help reduce the long-term risk of dementia in populations with low baseline levels and no fortification programs, research suggests.

The study, published in Nutrients, evaluated the potential of dietary B vitamins to influence the long-term risk of dementia in a population of more than 1,300 French participants – finding that while intakes of vitamin B6 and vitamin B12 had no association to dementia development higher intakes of folic acid (vitamin B9) are linked to a decreased incidence of dementia.

Led by Sophie Lefèvre-Arbogast from the University of Bordeaux and INSERM, the team noted that while previous studies have suggested B vitamins may lower the risk of dementia, “epidemiological findings, mostly from countries with folic acid fortification, have remained inconsistent.”

“We found in a large cohort of older persons from France—a country with no folic acid fortification and relatively low average intake levels—a strong association between a higher intake of folate and a lower long-term risk of dementia,” the authors wrote.

“It is thus possible that folate is protective for the brain in lower intake ranges (as those observed in France) and becomes inefficient (…) at higher ranges,” said the team.

“The protective role of folate in populations with relatively low basal folate status such as France may be worth exploring in future dementia prevention trials,” they suggested.

Folic acid fortification

To date 78 countries globally have implemented mandatory fortification programmes for folic acid with the aim of preventing neural tube defects (NTDs) in babies. But despite growing calls from NGOs, health experts and researchers, many EU member states have not implemented mandatory fortification programmes.

As such many European countries have a lower intake of folic acid in the general population, the team noted – who suggested that inconseistencies between studies on folic acid in the North America and Europe may be due to lower baseline levels.

“The most evident reason may pertain to differences in baseline intakes between French and US populations, with lower intakes reported in France, a country with limited supplement use and no folic acid fortification,” said the authors – who noted that previous studies in other low-baseline European countries such as Italy, the Netherlands and the UK have suggested higher folic acid intake could be linked to dementia and memory in older people.