A key speaker every year at the Science of Nutrition in Medicine Conference is Professor Michael Fenech, who is a research group leader at the CSIRO. He’s internationally regarded as an expert in understanding the relationship between DNA damage and nutrition. If you’ve ever heard him speak before you would know that while folate is a topic often at the centre of his research he is not a fan of folic acid food fortification nor the recommendation for all women to use supplements prior to and during pregnancy. I’ve heard him approach this issue from several angles, not the least of which is the danger of exposing everyone to high levels of folic acid. As Professor Fenech says, while this level of intake may be appropriate and helpful for some, it will be problematic for others. This year he mentioned the elderly as a specific at risk-group. There have been several papers published both here and in the UK (which has a similar fortification program), which suggest a link between higher folic acid intake and worse cognitive function in those elderly with low B12. A recent Victorian study (Moore et al. 2014 Among vitamin B12 deficient older people, high folate levels are associated with worse cognitive function: combined data from three cohorts. J Alzheimers Dis. 2014;39(3):661-8) found that elderly subjects with a serum B12 <250 pmol/L & red cell folate >1,594 nmol/L were more likely to have impaired cognitive performance (adjusted odds ratio (AOR) 3.45, 95% confidence interval (CI): 1.60-7.43, p = 0.002) when compared to participants with biochemical measurements within the normal range. That means almost 3.5 times the risk!
This study, alarmingly, also found that participants with high folate levels, but normal serum B12, were also more likely to have impaired cognitive performance than individuals with within-range results, but not to the same extent as the B12 deficient (about 1.7 times the risk) & other research has not consistently shown a negative impact from high folic acid alone. Professor Fenech cautions that excessively high rbc folate results are increasingly being seen in Australians and warns we won’t know the full fall-out from this for some time to come.
Of course B12 deficiency is rife in the aged community, with a UK paper recently citing that the reported B12 deficiency incidence rises to 24% and 46% among free-living & institutionalised elderly respectively when a more accurate marker of B12 status, blood methylmalonic acid, is used (Cuskelly, Mooney & Young 2007. Folate and vitamin B12: friendly or enemy nutrients for the elderly. Proc Nutr Soc.Nov;66(4):548-58.) but it also begs the question who else is at risk of excessive folic acid exposure? Anyone with possible low B12, malabsorption issues, individuals homozygous for the C677T mutation…and…..and…?
And what’s the real punchline here…well Fenech reminds us that while the key objective behind folic acid fortification is the prevention of NTD in babies – B12 supplementation alone has also shown to prevent this genetic disorder….OH BOY!
Want to read the Cuskelly et al 2007 paper on B12 and Folate? https://journals.cambridge.org/download.php?file=%2FPNS%2FPNS66_04%2FS0029665107005873a.pdf&code=07e86df3466a9d8128e851f47f408cbf