New study reveals hidden risks for cognitive health

A new study finds that lower B12 levels, even within the accepted range, could be linked to cognitive decline, slower thinking, and brain damage in older adults. 

The research, conducted by the University of California, San Francisco, found that these individuals showed slower thinking, delayed reaction times, and white matter lesions — all signs associated with dementia, a team of researchers has released an article via SciTechDaily.

Vitamin B12 is essential for the production of DNA, red blood cells, and nerve tissue. But the new findings suggest that simply meeting the minimum B12 requirements may not be sufficient, particularly for older adults. In fact, having lower B12 levels within the “normal” range could increase the risk of cognitive impairment.

The study revealed that older adults with lower levels of B12 showed signs of neurological and cognitive decline. Participants with diminished B12 had more damage to the brain’s white matter — the communication network between brain regions. Additionally, these individuals performed worse on tests measuring cognitive and visual processing speeds compared to those with higher B12 levels.

Senior study author Dr. Ari J. Green, from UCSF’s Departments of Neurology and Ophthalmology, expressed concerns about the adequacy of current B12 recommendations.

“Previous studies that defined healthy amounts of B12 may have missed subtle functional manifestations of high or low levels that can affect people without causing overt symptoms,” Green noted. “Revisiting the definition of B12 deficiency to incorporate functional biomarkers could lead to earlier intervention and prevention of cognitive decline.”

The study enrolled 231 healthy participants, averaging 71 years old, who did not suffer from dementia or mild cognitive impairment. Recruited through UCSF’s Brain Aging Network for Cognitive Health (BrANCH) study, participants had an average blood B12 level of 414.8 pmol/L — well above the US minimum of 148 pmol/L.

Researchers focused on the biologically active form of B12, which provides a more accurate picture of how the vitamin is utilized by the body. After adjusting for age, sex, education, and cardiovascular risks, the study found that participants with lower active B12 levels showed slower processing speeds, a sign of subtle cognitive decline. Older individuals with lower active B12 levels also experienced delays in responding to visual stimuli, suggesting slower visual processing and overall reduced brain function.

These findings raise important questions about the sufficiency of current guidelines for vitamin B12 and highlight the need for further research into optimal levels for brain health. The study suggests that even within the normal range, lower B12 levels may have a greater impact on cognitive function than previously thought, especially as we age.

As the research continues, experts urge individuals to be mindful of their B12 levels, particularly older adults, and to consult healthcare providers to ensure they are getting the right amount of this essential vitamin.

By Naila Huseynova