Disease Proof

Grandmothers' unhealthy diets may predispose subsequent generations to breast cancer

One of the biggest contributors to adult cancers is an unhealthy childhood diet.1

Cancer takes years and years to develop. In fact,  a woman's diet during pregnancy is known to influence the risk of childhood cancers in her children.2 A woman’s risk of breast cancer similarly is influenced during fetal development by her mother’s dietary habits.3 But breast cancer risk may begin even earlier than this.

An animal study suggests that breast cancer risk may be transmitted even from previous generations – that a grandmother’s unhealthy diet may translate into increased breast cancer risk for her granddaughters. 

The researchers conducted their study as follows:  A generation of female rats (grandmothers) was fed either a normal or high-fat diet during pregnancy - the high-fat diet provided an excess amount of omega-6 fat, attempting to partially mimic the standard American diet, with its abundance omega-6-rich animal products and oils.  Mother and granddaughter rats were fed a normal diet, and granddaughter rats either had two normal diet grandmothers, two high-fat diet grandmothers, or one of each. “Granddaughter” rats were given a chemical carcinogen to initiate breast cancer, and researchers recorded whether or not they developed tumors.4

These were their findings:

  • 50% of the rats with two normal diet grandmothers developed breast tumors
  • 68% of the rats with one high-fat diet grandmother developed breast tumors
  • 80% of the rats with two high-fat diet grandmothers developed breast tumors5

Based on these results, an unhealthy diet may cause inheritable changes in gene expression, causing subsequent generations to be more susceptible to breast cancer-initiating factors such as chemical carcinogens. Family-related risk of breast cancer is usually thought to be related only to specific genes, such as BRCA1 and BRCA2, which are known to increase breast cancer risk. However, this study points to non-genetic, but family-related transmission of risk via dietary habits.

These findings imply that what mothers eat during pregnancy not only affects their children, but their children’s children as well.


1. Maynard M, Gunnell D, Emmett P, Frankel S, Davey Smith G. Fruit, vegetables, and antioxidants in childhood and risk of adult cancer: the Boyd Orr cohort. JEpidemiol Community Health. 2003 Mar;57(3):218-25

2. Kwan ML et al. Maternal diet and risk of childhood acute lymphoblastic leukemia. Public Health Rep. 2009 Jul-Aug;124(4):503-14.

Tower RL et al. The epidemiology of childhood leukemia with a focus on birth weight and diet. Crit Rev Clin Lab Sci. 2007;44(3):203-42.

Petridou E et al. Maternal diet and acute lymphoblastic leukemia in young children.Cancer Epidemiol Biomarkers Prev. 2005 Aug;14(8):1935-9.

Jensen CD et al. Maternal dietary risk factors in childhood acute lymphoblastic leukemia (United States).Cancer Causes Control. 2004 Aug;15(6):559-70.

Huncharek M et al. A meta-analysis of maternal cured meat consumption during pregnancy and the risk of childhood brain tumors. Neuroepidemiology. 2004 Jan-Apr;23(1-2):78-84.

3. De Assis S, Hilakivi-Clarke L. Timing of dietary estrogenic exposures and breast cancer risk. Ann N Y Acad Sci. 2006 Nov;1089:14-35.

4. De Assis S, Cruz MI, Warri A, et al. Exposure of rat dams to a high-fat or estradiol-supplemented  diet during pregnancy alters mammary gland morphology and increases mammary cancer risk in their daughters and granddaughters. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; 2010. Abstract number 2931

5. Callaway E. New Scientist. Rats on junk food pass cancer down the generations. http://www.newscientist.com/article/dn18799-rats-on-junk-food-pass-cancer-down-the-generations.html

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Comments (3) Read through and enter the discussion with the form at the end
Geoffrey Levens - June 28, 2010 11:57 AM

Below are a couple links to research backing this article. The second actually is a study showing that the grandfather's nutrition also may play a large role!



Elisa Rodriguez - June 29, 2010 11:01 AM

Another great article Deana! Thanks for sharing this research in such an effective way.

Garry - July 13, 2010 2:39 AM

Doc, Which one has a bigger chance to become cancer.genetic or food diet?

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