Low levels of folate in the blood may be linked to a heightened risk of dementia and death from any cause in older persons, suggests new research published in the journal Evidence Based Mental Health.
Previous studies have suggested that folate deficiency affects cognition and nerve signalling in the brain, making it a possible risk factor for subsequent dementia.
However, it was previous unclear how the two factors were linked, with reverse causation a possibility – that folate deficiency could be a consequence of pre-clinical dementia rather than its cause.
Their study analysed the medical records of 27,188 older Israeli adults, all aged between 60 and 75 years old.
Analysing participants charts between 2014 and 2017, with a strict requirement that no participants had recorded signs of dementia for the 10 years preceding this period, researchers searched for a link between folate deficiency and the onset of dementia.
Of the participants, 3418 (or just under 13 per cent) were folate deficient, defined as levels below 4.4 ng/ml, and researchers found that not only were these participants more likely to develop dementia, they were more likely to have passed away from any cause during the four year window studied.
In percentage terms, 3 per cent of those without deficiency developed dementia, with rates increasing to 3.5 per cent in the deficient cohort.
But the really dramatic finding came when analysing the incidence of mortality from any cause.
Whilst 4 per cent of non-deficient participants passed away from any cause during the study period, double the amount (8 per cent) of folate deficient participants died during the same period.
However, this isn’t the full picture.
After researchers accounted for factors such as co-existing diabetes, depression, cognitive decline, vitamin B12 deficiency, smoking and the use of folic acid supplements, the folate deficient were 68 per cent more likely to be diagnosed with dementia and nearly three times as likely to die from any cause.
Researchers speculated as to the root, biological cause of these findings, noting that folate deficiency might affect homocysteine levels – an amino acid which, when elevated, has been associated with dementia – and therefore the vascular risk of dementia.
Secondly, they note that low folate levels may compromise DNA repair of neurons, making them vulnerable to oxidative damage, which in turn might speed up brain cell ageing and damage.
Ultimately, researchers conclude that this study highlights the importance of older persons keeping up with routine blood tests to screen for folate deficiency.
“The implications for public health policy appear to be to reliably monitor serum concentrations of folate in older adults and treat deficiency for preventative measures and/or as part of implemented therapeutic strategies while regularly reviewing patients’ clinical outcomes,” they write.
However, as this was an observational study, researchers note they still cannot declare a causal link.
For this, a controlled experiment would be needed, testing cohorts of folate deficient and folate supplemented older persons in a double-blinded fashion.
More about folate and folate deficiency
Folate is a B-group vitamin (B9) that your body uses to:
- make DNA
- form red blood cells
- grow and repair cells and tissues
It is present naturally in a variety of foods, including rice, fruit, green vegetables, legumes and beef liver.
However, many older adults may benefit from supplementation, with around one in five Australians aged 50 and over having a folate deficiency.
Apart from the suspected risk of dementia, low folate can contribute to heart disease, cancer risk and stroke in older adults.
Folic acid, the synthetic form of folate, is used for this purpose, and is a widely available over-the-counter pharmacy product.
However, consult with a doctor prior to beginning supplementation, as there are harms associated with excessive folic acid levels, also.