Whey Protein Hydrolysate but not Whole Whey Protein Protects Against 7,12-Dimethylbenz(a)anthracene-Induced Mammary Tumors in Rats

Nutr Cancer. 2015;67(6):949-53. doi: 10.1080/01635581.2015.1055370. Epub 2015 Jul 13.


Effects of intact and processed bovine milk proteins on development of chemically induced mammary tumors in female rats were compared. AIN-93G diets were made with 20% casein (CAS), casein hydrolysate (CASH), intact whey protein (IWP), or whey protein hydrolysate (WPH). Pregnant Sprague-Dawley rats were fed the diets starting at Gestational Day 4. Offspring were fed the same diet. At 50 days, female offspring (44-49/group) were gavaged with sesame oil containing 80 mg/kg of the mammary carcinogen dimethylbenzanthracene (DMBA) and euthanized 62 days posttreatment. Rats fed WPH had an adenocarcinoma incidence of 17% compared to the rats fed CAS, CASH, and IWP diets (34%, 33%, and 36% respectively) (P < 0.001). Median palpable tumor latency for rats fed WPH was greater (61 days, P < 0.001) compared to CAS (44 days), CASH (42 days) and IWP (45 days). Tumor multiplicity was also lower (1.5 vs. 3.0, P < 0.05) in rats fed WPH than in CAS and CASH fed groups. Results demonstrate that hydrolytic processing of whey protein is required for this diet to be effective in reducing DMBA-induced mammary tumors. The bioactive compounds produced during whey protein processing and mechanisms underlying the anticancer effects of WPH are yet to be identified.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • 9,10-Dimethyl-1,2-benzanthracene / toxicity*
  • Animals
  • Carcinogens / toxicity
  • Caseins / pharmacology
  • Diet
  • Disease Models, Animal
  • Female
  • Mammary Neoplasms, Animal / chemically induced
  • Mammary Neoplasms, Animal / drug therapy*
  • Pregnancy
  • Protective Agents / pharmacology
  • Protein Hydrolysates / pharmacology*
  • Rats
  • Rats, Sprague-Dawley
  • Whey Proteins / pharmacology*


  • Carcinogens
  • Caseins
  • Protective Agents
  • Protein Hydrolysates
  • Whey Proteins
  • 9,10-Dimethyl-1,2-benzanthracene
  • casein hydrolysate