Neutral steroid concentrations in the faeces of North American White and South African Black populations at different risks for cancer of the colon
Salyers, A.A.; Sperry, J.F.; Wilkins, T.D.; Walker, A.R.; Richardson, N.J.
South African Medical Journal 51(23): 823-827
1977
ISSN/ISBN: 0256-9574 PMID: 877814 Document Number: 121526
Rural Africans were 30 men and 54 women 20 to 43 years old from 3 areas in the Transvaal. Their diet was based on cereals, legumes, vegetables, some milk and dairy produce and meat once or twice a week. Diet had adequate energy and protein but low fat and high crude fibre. North Americans were 63 males and 45 females 5 to 25 years old living in the town of Blacksburg, Virginia and eating a typical North American diet high in meat and fat, with meat once or twice daily. Africans represented a population at low risk of colonic cancer and Americans, high risk. In faeces, Americans had a higher concentration of animal steroids than Africans and most of the neutral sterols were nonesterified. They varied in the extent of cholesterol metabolism by gut bacteria. Africans had a high proportion of their plant and animal sterols esterified to long-chain fatty acids and were much more homogeneous in their cholesterol metabolism. Tables show concentrations of 3 animal and 6 plant neutral steroids and of free and total neutral steroids. Although Americans had significantly higher concentrations of the animal steroids than the Africans the differences were not as great as the threefold difference reported by other workers (NAR 41, 6287; NAR 45, 1597). Cholesterol, coprostanol and coprostanone, median values in mg/g dry faeces, were for 84 Africans 1.8, 10.3 and 0.8 and for 98 Americans 4.9, 13.9 and 1.6.