From Wikipedia

Seven Up Series

Episode Seven - Part One Of Two

Seven Up - Forty Nine

Over the course of the project the programme has in varying degrees had a direct effect on the lives of its participants. The series became popular enough that the participants often speak of being recognised in public. Their opinions of being involved in the series are often mentioned, and vary greatly among the participants. John refers to the programme as a poison pill that he is subjected to every seven years, while Paul's wife credits the series for keeping their marriage together. In 49 Up, Jackie confronts Apted on his questions, his assumptions about her life and his choice of editing.

Paul and Nick were flown back to England for the filming of 35 Up and 42 Up respectively; the trips were financed by Granada. Paul was flown back again for 49 Up and visited with Symon. Bruce was affected by Neil's plight and offered him temporary shelter in his home shortly before 42 Up, allowing Neil time to get settled in London. Despite Neil's eccentricities during his two-month stay, they clearly remained friends, with Neil later giving a reading at Bruce's wedding.