[HelenM]

I understand that recently published long-term studies have discredited the idea the fibre is protective of the GI tract.

I don't know about a more recent study, but the EPIC study . (a cohort study of 478 040 men and women from 10 European countries) said this:

There is a much controversy as to whether high meat intake increases risk of bowel cancer. In the European study, we have found that high dietary fibre intake lowers and high meat intake increases risk of bowel cancer. However, there is an interaction between the different foods. Meat intake increases cancer risk only in those people with low intakes of dietary fibre; high dietary fibre or high fish intake appear to protect against the effects of meat intake and risk of bowel cancer.

Norat T et al. Meat, fish, and colorectal cancer risk: the European Prospective Investigation into cancer and nutrition. J Natl Cancer Inst. 2005;97:906-16.
All 'nutrition' abstracts for this study accessed viaEPIC-Norfolk: Publications