In the UK it used to start aged 65 for men and 60 for women. It is now being adjusted to 67 for all:
https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/310231/spa-timetable.pdf
But this wont be enough. I expect it to continue to rise, however, any reduction in value is a real difficulty. Pensioners vote, more than any other age group, so for any political party to cut their benefits is extremely difficult. Possibly a cross part imitative would work, but as the left wing did much better than expected in the recent election, this is unlikely in the foreseeable future!