In an ongoing exploration of the origins of dementia, researchers from the United States and Israel coordinated a large cohort study to examine a common nutritional deficiency – folate, or vitamin B9.
We already know that blood folate levels diminish with age, but what we didn’t know is the effect this loss has on cognition.
Here’s what the authors of this latest study say…
Researchers examined the medical records of 27,188 people aged 60 to 75 years old. These participants exhibited no preexisting dementia for at least a decade before their blood folate levels were checked.
After testing, the researchers continued to monitor the patients’ records for a dementia diagnosis or death.
Nearly Seven Out of Ten Got Dementia
Among the people with folate deficiencies, the rate of dementia was 3.4 percent. And the incidence of death from any cause was under eight percent.
Those without a deficiency experienced rates of dementia of 3.2 percent and all-cause death rates of four percent.
These differences might not sound that significant at first. But after the scientists factored in co-occurring conditions, including diabetes, vitamin B12 deficiency, cognitive decline, and depression, the numbers became meaningful.
The team found that people with folate deficiency had a 68 percent higher risk of a dementia diagnosis, writing, “Evidence suggests that serum folate deficiency increases the likelihood of deficits in cognitive performance and neurological functioning.”
What’s more, people with folate deficiency had a three times higher risk of dying from any cause.
The scientists’ findings appear in the journal Evidence-Based Mental Health.1
Folate Testing as a Screening Tool?
The study’s lead author, Anat Rotstein, Ph.D., breaks down the significance of the recent research.
“This study is important because it critically characterizes the association between a widely used and simple-to-measure biomarker serum folate (vitamin B9 in the blood) and the risks of dementia and all-cause mortality.”
Could folate level testing be used as a screening tool, as deficiencies are associated with symptoms?
But there appears to be a chicken or the egg scenario at play here. It’s called reverse causation.
Simply put, reverse causation refers to a situation where the outcomes precede and trigger the exposure instead of the other way around.
In this study, Dr. Rotstein and her team examined the possibility that folate deficiencies could arise from – not before – preclinical dementia.
This particular scenario was hard for researchers to dismiss as it takes time for cognitive decline to set in.
“Our results show moderate evidence for reverse causation in dementia, suggesting that serum folate deficiency may be a consequence of the onset of dementia rather than its cause (not so with all-cause mortality).”
Plainly put, if dementia is responsible for a drop in folate, it may help doctors identify people in early stages of the disease.
Drawbacks of the Study
The researchers do point out some critical limitations of the research.
To begin with, the data was drawn from individuals ages 60 to 75 who were asked to undergo serum folate screening. Would a random sample produce more accurate estimates for a broader population? Maybe.
Additionally, this was an observational study and researchers did not consider undetected genetic factors.
I believe folate screening could provide another pathway to early diagnosis of dementia.
The study’s authors suggest that yearly or biannual folate testing may be helpful to those with a family history of dementia or who are approaching middle or later life. But there are two sides to this coin. Some would say, “Why waste the money if there are no symptoms?”
Others may argue that you’ll never know unless you check, and if you wait until you have symptoms, it can be harder to restore lost cognition.
Talk it over with your doctor. It may be good to check folate and vitamin B12 levels at the same time since these two brainy nutrients work together.
In the meantime, safeguard your brain with wise lifestyle choices, including exercise, diet, targeted supplementation, stress management, and social engagement.