Why B vitamins only help some people's memories
Omega-3 Fatty Acid Status Enhances the Prevention of Cognitive Decline by B Vitamins in Mild Cognitive Impairment
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
B vitamins had no cognitive benefit at all in people with low DHA levels — despite being proven effective in other trials.
Most prior studies tested B vitamins alone and claimed benefits — but this shows those benefits vanish without sufficient DHA, suggesting past trials may have failed because they didn’t screen for omega-3 status.
Practical Takeaways
If you're over 70 and worried about memory, get your plasma DHA levels tested — if they’re above 579 μmol/L, B vitamin supplements may help slow decline.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
B vitamins had no cognitive benefit at all in people with low DHA levels — despite being proven effective in other trials.
Most prior studies tested B vitamins alone and claimed benefits — but this shows those benefits vanish without sufficient DHA, suggesting past trials may have failed because they didn’t screen for omega-3 status.
Practical Takeaways
If you're over 70 and worried about memory, get your plasma DHA levels tested — if they’re above 579 μmol/L, B vitamin supplements may help slow decline.
Publication
Journal
Journal of Alzheimer's Disease
Year
2016
Authors
A. Oulhaj, F. Jernerén, H. Refsum, H. Refsum, A. Smith, C. Jager
Related Content
Claims (7)
For older people with mild memory problems, taking B vitamins might help their memory and thinking skills—but only if they already have high levels of a certain omega-3 fat (DHA) in their blood. If their DHA levels are low, the vitamins don’t seem to help at all.
For older people with mild memory problems, taking DHA (a type of omega-3 from fish) might make B vitamins work better to help with memory and thinking, while EPA (another omega-3) seems to help a little but not enough to be sure.
In older people with early memory problems, those with more DHA (a type of omega-3 fatty acid) in their blood seem to benefit more from B vitamin supplements — only 33% of them got worse over two years, compared to 59% of those who took a placebo. This suggests DHA levels might decide whether B vitamins help stop memory from getting worse.
Taking B vitamins might help protect your brain from shrinking, but only if you already have enough omega-3s in your body—like from fish or supplements.
If you're an older adult with mild memory problems and your body doesn't have enough omega-3s, taking B vitamins won't help your memory get better. But if you do have enough omega-3s, B vitamins might help.