- A University of Florida study that evaluated about 12,000 older adults over 10 years found that those who felt lonely had a 105% increased risk of developing dementia.
- Another Japanese study that analyzed eating alone —a marker of social isolation— found a 68% increased risk of developing dementia for those who did it regularly.
- The article points out that loneliness can even change the structure of the brain: smaller volumes of gray matter in areas related to emotion and memory.
In short: it’s not just a matter of “having company,” but of having meaningful conversations, emotional connections, and active social stimulation. Loneliness triggers chronic stress responses (such as elevated cortisol) that damage the hippocampus—the key region for memory—faster than normal.
Why does this habit affect memory so much?
1. Stress and neuroinflammation
When an older person feels isolated, their brain interprets it as a sign of social “threat.” This activates the stress system: elevated cortisol, brain inflammation, and accelerated neuronal damage.
2. Less cognitive stimulation
Social interaction activates multiple networks in the brain: language, attention, working memory, emotion, and facial recognition. When it disappears (or is minimized), the brain has less “training,” which promotes premature cognitive decline.
