We don't know, because suicide is the only category on the chart that reflects a psychological factor. If we tracked (more correctly, if we could track) people dying of loneliness but who don't commit suicide, perhaps we'd find the number to be hugely higher. When I look at the sadness of the elderly in large cities, my sense is that number would be a lot higher. But we just don't know.
To some extent we do know. We know people who are lonely tend to be less active, and we know people who are less active tend to have worse health.
On the Greek island of Ikaria for example[1], we know that people regularly live to be 90 years old and that even at that age they remain incredibly social and physically active.
