The Brain Doesn’t Break From Damage—It Breaks From Energy Debt (And Almost No One Thinks This Way)
Let’s begin by looking at aging and longevity through the lens of neuron survival. Most conversations about aging revolve around damage. Oxidative damage. DNA damage. Protein damage. The story we are usually told is that aging is the slow accumulation of wear and tear until the system finally breaks. That framing sounds intuitive, but it is incomplete. Cells do not usually fail because damage suddenly appears. They fail because their ability to repair damage, buffer stress, and maintain energy quietly erodes over time. Aging, at its core, is better understood as a progressive loss of energy resilience. Neurons are one of the earliest and clearest indicators of this process. They are among the most energy-demanding cells in the body, and unlike many other tissues, they cannot easily be replaced. They must maintain electrical gradients every second, transmit signals across long distances, repair DNA continuously, and coordinate complex networks that never truly shut off. This means neurons live very close to their energetic limits even under normal conditions. As NAD+ availability declines with age, neurons become less capable of surviving inflammatory stress, metabolic stress, and excitotoxic stress. Long before neurons actually die, this loss of resilience shows up as slower processing speed, poorer stress tolerance, impaired memory consolidation, reduced emotional regulation, and diminished adaptability. People feel “off” years or decades before anything that would qualify as neurodegeneration appears on a scan. From a longevity perspective, this reframes the goal entirely. Longevity is not primarily about adding years at the very end of life. It is about preserving cognitive, emotional, and functional capacity across the middle decades where most people actually live. Strategies that stabilize energy metabolism and reduce unnecessary NAD+ depletion are therefore plausibly longevity-aligned even if they do not regenerate tissue or reverse existing damage. The key shift is this: longevity is less about creating new cells and more about preventing avoidable cell loss.