Key Takeaways
Adult neurogenesis is hard to measure in living people. The popular numbers are estimates, not personal scores.
- The often-quoted figure is a model-based estimate from retrospective carbon dating of postmortem tissue. It is not a direct count in a living person and should not be treated as an individual production rate. [1]
- The Nature study identified molecular signatures of proliferating progenitors and immature neurons across adulthood, ageing, and Alzheimer disease. It did not establish that SuperAgers make twice as many new neurons as everyone else. [2]
- Exercise, sleep, learning, and social connection are commonly associated with broader brain and health benefits. Current human evidence cannot reduce those benefits to a guaranteed neuron count or predict the brain one reader will have at 75. [3]
Common questions
Does the adult brain really grow 700 new neurons a day?
The 700-neuron figure came from a model based on carbon dating in postmortem tissue. Researchers did not count new neurons inside a living brain. Treat 700 as an estimate for a study population, not your daily production number. [1]
Did the 2026 Nature study prove that adult neurogenesis continues throughout life?
The Nature paper found molecular signs of dividing progenitor cells and immature neurons across adult ages. It strengthened the case for adult neurogenesis. It did not prove that every adult keeps the same rate or that SuperAgers make twice as many neurons. [2]
Can exercise and sleep increase neurogenesis and protect memory as I age?
Exercise, sleep, learning and social contact support brain health for several reasons. Human studies cannot tell you how many neurons a habit adds or predict your memory at 75. [3]
Can an MRI or blood test measure how many new neurons my brain makes?
No routine MRI or blood test counts new neurons in an individual. Research uses postmortem tissue, molecular markers, cell features, and statistical models. Those methods cannot produce a personal neurogenesis score. [1] [2]
What can I do now to protect memory if neurogenesis cannot be measured?
Regular movement, adequate sleep, control of vascular risk, continued learning, and social contact support brain health. Human research cannot tell you how many neurons any 1 habit adds. [3]
References
- Spalding, K. L., Bergmann, O., Alkass, K., et al. (2013). Dynamics of hippocampal neurogenesis in adult humans. Cell, 153(6), 1219–1227. https://pubmed.ncbi.nlm.nih.gov/23746839/
- Disouky, A., Sanborn, M. A., Sabitha, K. R., et al. (2026). Human hippocampal neurogenesis in adulthood, ageing and Alzheimer’s disease. Nature, 652, 1264–1273. https://doi.org/10.1038/s41586-026-10169-4
- Livingston, G., Huntley, J., Liu, K. Y., et al. (2024). Dementia prevention, intervention, and care: 2024 report of the Lancet standing Commission. The Lancet, 404, 572–628. https://doi.org/10.1016/S0140-6736(24)01296-0
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