- A new study of mice shows that a naturally occurring flavonoid can slow down the degradation of vitamin B6 in the brain.
- A deficiency in vitamin B6 has long been associated with poorer cognitive function.
- Vitamin B6 supplementation alone to improve cognition has yielded mixed results in trials.
- The study’s authors hope that greater cognitive benefits may be achieved by combining the flavonoid with B6 supplementation.
Insufficient vitamin B6 is linked to cognitive impairment, and a new study presents a novel approach to maintaining adequate B6 levels.
The study in mice finds that a naturally occurring flavonoid, 7,8-dihydroxyflavoneTrusted Source, can directly bind to and inhibit a B6-degrading enzyme, thus helping to preserve levels of B6 in the brain.
The enzyme is pyridoxal phosphatase (PDXP).
The study follows previous work from the same team led by Antje Gohla, PhD, at the Institute of Pharmacology and Toxicology of the Universitet Würzburg in Germany. That work demonstrated improved spatial learning and memory capacity in mice when their pyridoxal phosphatase was de-activated.
Connecting B6 and cognitive health
Jacqueline Becker, PhD, neuropsychologist and health services researcher at the Icahn School of Medicine at Mount Sinai’s Division of General Internal Medicine, was not involved in the study.
“Several studies have examined the impact of B6 on cognition,” said Becker. “Specifically, that maintaining adequate levels of B vitamins, and vitamin B6 in particular, is essential for optimal neurotransmitter synthesis and homocysteine metabolism, and thus may have a direct impact on cognitive function.”
“Vitamin B6 deficiency has long been linked to cognitive impairment, particularly in areas that correlate with hippocampal functioning,” Becker said.
The hippocampus is believed to be important for age-dependent memory consolidation and learning and, therefore, cognition.
In the brain, said Becker, B6 “aids in the synthesis of neurotransmitters — e.g., serotonin, dopamine, gamma-aminobutyric acid — and helps reduce homocysteine levels in the blood.”
She noted as well that B6 is linked to mood, a known factor in cognitive health.
“Cognitive dysfunction is a cardinal symptom of depression, particularly deficits in attention and psychomotor speed,” she pointed out.
The problem with B6 supplementation alone
So far, the benefits of enhancing levels of B6 via supplementation as a therapeutic method are unclear. Clinical trials have yielded mixed results, “particularly in areas that correlate with hippocampal functioning,” according to Becker.
The new study may help explain that. Gohla said her team found that “PDXP is substantially upregulated — [or strengthened] — in the hippocampus of middle-aged compared to young mice.”
This aligns with age-related memory loss that occurs with aging.
Said Gohla, “This suggests that a therapeutic vitamin B6 supplementation alone may not be sufficient to elevate the levels of B6 in the brain — simply because the supplemented B6 would be immediately degraded by hyperactive PDXP.”
“In contrast,” the study finds, “combining B6 supplements with PDXP inhibitors that block B6 degradation may be much more effective in boosting cellular B6 levels.”
