Resistant starch attenuates colonic DNA damage induced by higher dietary protein in rats

Nutr Cancer. 2005;51(1):45-51. doi: 10.1207/s15327914nc5101_7.


Epidemiologic studies suggest that dietary complex carbohydrates are protective against colorectal cancer but dietary protein may increase risk. However, experimental data to support these relationships are scant. We have shown in rats that consumption of a high-protein (25% casein) diet for 4 wk resulted in a twofold increase in damage to colonocyte DNA compared with a low-protein (15% casein) diet. This was associated with thinning of the colonic mucous barrier and increased levels of fecal p-cresol. Addition of resistant starch as a high-amylose maize starch to the diet increased cecal short-chain fatty acid pools and attenuated DNA damage, suggesting protection against genotoxic agents. In humans, this could translate to altered risk of colonic cancer.

MeSH terms

  • Animals
  • Cell Division / drug effects
  • Colon / cytology
  • Colon / drug effects*
  • Colon / pathology
  • Comet Assay
  • Cresols / analysis
  • DNA / drug effects
  • DNA Damage / drug effects*
  • Dietary Proteins / administration & dosage*
  • Dietary Proteins / adverse effects
  • Fatty Acids, Volatile / analysis
  • Feces / chemistry
  • Intestinal Mucosa / cytology
  • Intestinal Mucosa / drug effects
  • Male
  • Random Allocation
  • Rats
  • Rats, Sprague-Dawley
  • Starch / administration & dosage*
  • Starch / metabolism*


  • Cresols
  • Dietary Proteins
  • Fatty Acids, Volatile
  • 4-cresol
  • Starch
  • DNA