October is National Breast Cancer Awareness month, and I want to raise awareness that childhood diets are the major cause of adult cancers, including breast cancer.  I also want to raise awareness that women are not powerless against breast cancer – mammograms for ‘early detection’ are not the only defense and do not even offer significant benefits. The most important thing to be aware of is that women can achieve meaningful risk reduction with powerful preventive lifestyle measures.
The American Institute for Cancer Research estimates that 40% of breast cancers are preventable through diet and lifestyle measures. I propose that we could prevent much more than 40% of breast cancers in the future, if we can ingrain healthy habits in our children at a young age.
Early studies found wide international variations in breast cancer rates, originally generating the hypothesis that nutrition is a major determinant of breast cancer risk. Obesity is a significant risk factor for breast cancer:
- Gaining one pound per year during adulthood can double breast cancer risk after menopause.
- Obesity alone is thought to be responsible for 17% of breast cancers.
- Obesity is associated with greater tumor burden and poorer prognosis in breast cancer patients. [2, 3]
- Production of inflammatory molecules and estrogen by body fat, as well as elevated insulin and insulin-like growth factor (IGF-1) levels are thought to contribute to obesity-related breast cancer risk. 
Plenty of experts have predicted that the explosion of childhood obesity we have seen in recent years will result in crisis proportions of heart disease and diabetes in the future, but cancer seems to be ignored. Today, over 30% of children are overweight or obese.  Clearly, with all the research demonstrating that obesity is a major risk factor for breast cancer, our young girls are in danger.
The prevalence of early puberty, another established risk factor for breast cancer, has been consistently increasing over the past 100 years. Today, by the age of 8, 18.3% of Caucasian girls, 42.9% of African-American girls, and 30.9% of Hispanic girls have already entered puberty. Obesity, soft drinks, and excessive animal protein are the likely culprits (Read more).
This is a grim indication of things to come – when these girls reach adulthood, tragically we will see an upsurge in breast cancer cases. With the increases in fast food and processed food consumption in America in the last 20 years, I predict a tragic explosion in pre-menopausal breast cancers in our country in the next 20 years.
Breast tissue is most vulnerable to carcinogenic influences when it is growing and developing – during childhood and adolescence. Children are also especially susceptible to weight gain during adolescence.  Thus, this window of time is when a healthy diet is absolutely crucial. Animal studies have demonstrated that a high-fat diet or a body fat promoting diet during puberty promotes abnormal development of breast tissue and production of inflammatory molecules, which in turn may promote tumor growth.[6, 7] Adolescent diet was examined in the Nurses’ Health Study – greater consumption of vegetables during high school was associated with a decreased risk of breast cancer, and high glycemic index foods were associated with an increased risk. 
The typical American childhood diet of chicken fingers, French fries, and mac and cheese is not harmless – it is creating a cancer-friendly environment in children’s bodies.
As parents, we must feed our children healthful foods from an early age. This is the most effective protection from future chronic disease that we can provide for them. Healthy eating is a lifetime commitment, and we can give our children a head start. Our goal should be to instill healthy habits in our children so that they grow up at a healthy weight, appreciating healthy food and exercise, and hold on to those habits as adults. In order to do this, we must set a positive example, focusing on nutrient-dense, health-promoting foods.
New research is revealing the protective effects of natural foods against breast cancer. For example, mushrooms have anti-estrogenic activity, and regular mushroom consumption is associated with a 60% decrease in cancer risk.  Cruciferous vegetables such as watercress, other leafy greens, and broccoli contain compounds known to inhibit cancer cell growth. [10, 11]
Instead of wearing a pink ribbon, eat vegetables, onions and mushrooms – and make sure to feed some to your kids.
1. Maynard, M., et al., Fruit, vegetables, and antioxidants in childhood and risk of adult cancer: the Boyd Orr cohort. J Epidemiol Community Health, 2003. 57(3): p. 218-25.
2. Cleary, M.P. and M.E. Grossmann, Minireview: Obesity and breast cancer: the estrogen connection. Endocrinology, 2009. 150(6): p. 2537-42.
3. Abrahamson, P.E., et al., General and abdominal obesity and survival among young women with breast cancer. Cancer Epidemiol Biomarkers Prev, 2006. 15(10): p. 1871-7.
4. Ogden, C.L., et al., Prevalence of high body mass index in US children and adolescents, 2007-2008. JAMA, 2010. 303(3): p. 242-9.
5. Jasik, C.B. and R.H. Lustig, Adolescent obesity and puberty: the "perfect storm". Ann N Y Acad Sci, 2008. 1135: p. 265-79.
6. Olson, L.K., et al., Pubertal exposure to high fat diet causes mouse strain-dependent alterations in mammary gland development and estrogen responsiveness. Int J Obes (Lond), 2010. 34(9): p. 1415-26.
7. Michigan State University: High-fat diet during puberty linked to breast cancer risk later in life. 2010; Available from: http://news.msu.edu/story/8233/.
8. Frazier, A.L., et al., Adolescent diet and risk of breast cancer. Cancer Causes Control, 2004. 15(1): p. 73-82.
9. Zhang, M., et al., Dietary intakes of mushrooms and green tea combine to reduce the risk of breast cancer in Chinese women. Int J Cancer, 2009. 124(6): p. 1404-8.
10. Clarke, J., R. Dashwood, and E. Ho, Multi-targeted prevention of cancer by sulforaphane. Cancer Letters, 2008. 269(2): p. 291-304.
11. Higdon, J., et al., Cruciferous vegetables and human cancer risk: epidemiologic evidence and mechanistic basis. Pharmacological Research, 2007. 55(3): p. 224-236.