Dr. Wendy Suzuki: Walking thrice weekly cuts dementia 30%

Studies in adults 65+ show that walking three times a week reduces the risk of developing dementia in the next five years by about 30%. Exercise triggers a ‘bubble bath’ of neurochemicals—serotonin, dopamine, noradrenaline, endorphins—and growth factors that specifically support the hippocampus (memory) and prefrontal cortex (attention and decision-making). The larger and ‘fluffier’ these regions are, the longer it takes neurodegenerative disease to cause noticeable symptoms.

In low-fit individuals, just 2–3 weekly 45-minute spin classes improved mood, memory, and attention. In a second study with regular exercisers allowed up to seven classes per week, cognitive and mood benefits scaled with workout frequency—“the more you exercised, the more brain change we noted.” You don’t need marathons; any heart‑rate‑raising activity (brisk walking, soccer, classes) creates measurable improvements.

The hippocampus stores long-term memories for facts and events and works best when information is repeated, tied to something familiar (association), presented in a novel or surprising way, and linked to emotion via the amygdala. Techniques like the memory palace exploit association and spatial memory. For teachers, marketers, and creators, building novelty and emotional punch into messages significantly increases recall.

During sleep, the hippocampus consolidates memories and cerebrospinal fluid clears metabolic ‘garbage’; chronic sleep loss leads to a “gunky brain” and poorer function. Social interaction—even brief greetings like saying hello to a barista—correlates with greater longevity and better brain health, while loneliness and chronic stress shrink brain regions and raise dementia risk. Strong relationships are also the biggest predictor of life satisfaction.

Excess screen and social media time is linked with increases in anxiety, depression, and suicidality, especially in young girls. Physiologically, psychological stress from comparison and online hostility triggers chronic stress responses, damaging synapses and, over time, killing brain cells. Phone addiction also displaces activities that grow the brain—movement, sleep, in‑person relationships, and time alone with one’s thoughts.