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Breast Cancer Risk Escalates from Dairy Milk Consumption: New Study

Breast Cancer Risk: The Rise & Fall of Dairy Milk

Recent research has revealed a higher Breast Cancer risk linked to dairy milk intake. Europe and North America have been eating dairy for centuries in the preserved forms of cheese and butter. Milk, on the other hand, used to be primarily consumed by children. In fact, the Nestle Chocolate company started out making infant formula and powdered milk. It was the 20^th century health movement that promoted milk as the magic bullet to health leading to its perception as a staple food. Marketing efforts to this day try to sway the masses to the proposed benefits of drinking milk.

In the past few years, the tides are turning on milk, whether because of food allergies, veganism, animal welfare, environmental impact and now its detrimental health effects. This is seen by the decline of commercial dairy sales. Furthermore, Canada’s New Food Guide of 2019 emphasizes water as the drink of choice, de-emphasizing milk and dairy products, unlike the previous 2007 guide.

Breast Cancer Risk: Cow Breast is Not Best

New evidence supports this. The International Journal of Epidemiology published a new study finding that even small amounts of dairy milk consumption increased Breast Cancer risk by up to 80%, depending on the amounts consumed (Fraser, Miles, Orlich, Jaceldo-Siegl, & Mashchak, 2019).

Breast Cancer Risk: Stats Don’t Lie

Breast Cancer statistics are scary. Twelve percent (12%) of North American women will develop invasive breast cancer over the course of their lifetime. In fact, Breast Cancer is the most commonly diagnosed cancer in North American women aside from skin cancer, averaging 25 – 30% (Canada) of all new cancers diagnosed. In North America, Breast Cancer kills 13 – 18% (Canada) of women diagnosed.

Breast Cancer Risk: Multi-Factorial

Scientists have investigated many behavioural risk factors that increase Breast Cancer risk including Obesity, Alcohol Consumption, Smoking, Coffee Consumption, Physical Activity, Sleep Duration, Dietary Factors and Nutrition such as Vitamin D levels (Momenimovahed & Salehiniya, 2019).

Breast Cancer Risk: Soy or Dairy, That is the Question

There has been some limited research studying dietary factors. Soy’s phytoestrogens (plant estrogens) may be associated with a reduced Breast Cancer risk, although the evidence is conflicting and frustrating with apparent limitations (Ziegler 2004). Other research has shown that Dairy intake increases Breast Cancer risk using Japan’s dietary changes since World War II correlating to increased annual breast cancer death rates (Li, Ganmaa, & Sato, 2003).

Breast Cancer Risk: New Study Soy Vs Dairy

This latest study by researchers at Loma Linda University wanted to differentiate the effects of dairy and soy on Breast Cancer. They theorized that dairy may increase Breast Cancer risk, due to the ecological data above. Fraser et al., 2019 tested this hypothesis with their Adventist Health Study-2, a national Cohort narrowed down to almost 53,000 women over 30 years old. Vegans and vegetarians comprised of 40% of participants, either consuming no meat, eggs or dairy (vegans) or eggs & dairy at levels 60% lower than average US amounts (vegetarians).

Breast Cancer Risk: Starting the Milk Study

Each participant initially completed a questionnaire documenting food frequency information including dairy and soy intake, alcohol intake, physical activity, ethnicity, family history of breast cancer, health & reproductive history including hormonal and medication use and breast cancer screening.

Breast Cancer Risk: Highlights of the Milk Study

Key notes of this study were that all participants were initially cancer-free, that 50% of the group consumed the US average amount of dairy, and many participants ingested more soy than the general population. As such, there was an explicit contrast between those consuming dairy versus soy. This created a very clear association between breast cancer incidence and soy & dairy consumption.

Breast Cancer Risk: The Big Reveal of the Milk Study

This observational study followed these participants for 7.9 years to find 1,057 women diagnosed with Breast Cancer. The following findings were revealed:

• Soy exhibited NO protective effect against Breast Cancer
• Soy does NOT impact Breast Cancer Risk
• Dairy, specifically Milk, INCREASED Breast Cancer Risk
• Dramatic Reduction Breast Cancer Risk substituting Soy for equivalent amount of Dairy Milk
• Previous Lower Risk with Higher Soy Consumption may be due to ABSENCE of Dairy Milk
• Dairy Milk Daily Amounts 1/4 to 1/3 cup INCREASED Breast Cancer Risk 30%
• Dairy Milk Daily Amounts 1 cup INCREASED Breast Cancer Risk 50%
• Dairy Milk Daily Amounts 2 – 3 cups INCREASED Breast Cancer Risk 70 – 80% respectively
• Full Fat, Reduced Fat & No Fat Dairy Milks have the SAME effect
• Breast Cancer Risk Increase related to Dairy Milk NOT Cheese & Yogourt
• Vegans (No Dairy or Eggs) had LESS Breast Cancer than Vegetarians (Consume Dairy & Eggs)

Breast Cancer Risk & Dairy: Understanding Why

The reason Breast Cancer risk increases with dairy milk may be due to the sex hormones in dairy milk. Dairy cows are lactating and 75% of the dairy herd is pregnant. Dairy intake and other animal proteins have been associated with higher blood levels of Insulin-like Growth Factor-1 (IGF-1) found to promote certain cancers, including Breast Cancer (Khaddour, Elshimali, Danciulescu-Miulescu, & Gradinaru, 2019).

Breast Cancer Risk & Dairy: Limitations to the Milk Study

There were some limitations to this epidemiological study despite the large sample size. The fact that it was an observational study prevented a true cause and effect hypothesis from being tested, as other factors that occur milk consumption such as caffeine intake could have played a role. The second issue was that the food frequency questionnaire was only completed once at the start of the study. It is a concern given that the study was almost eight years long and habits could change within that time period and this was not accounted for.

Breast Cancer Risk & Dairy: Final Thoughts

Dr. Fraser, Ph.D concluded that although “Dairy milk does have some positive nutritional qualities, but these need to be balanced against other possible, less helpful effects. This work suggests the urgent need for further research” (Fraser et al., 2019), especially since Breast Cancer is so prevalent and Dairy Milk is so extensively consumed.

Breast Cancer Risk: Dairy-Free Alternatives

Your local grocer carries many alternative milk options to Dairy including Almond milk, Cashew milk, Coconut milk, Hazelnut milk, Hemp milk, Rice milk, and Soy milk. Read more for information about healthy dairy alternatives, and for Keto, Vegan (Dairy-Free), Low Carb, Allergy-Free Naturopathic Recipes.

Related    Breast Self-Exam: Healthy Breast Care includes Monthly Self Checks for Breast Cancer Detection

References

Breast cancer statistics – Canadian Cancer Society [Internet]. www.cancer.ca. 2020 [cited 2 March 2020]. Available from: https://www.cancer.ca/en/cancer-information/cancer-type/breast/statistics/?region=on

Canadian Dairy Industry at a Glance – Canadian Dairy Information Centre (CDIC) [Internet]. Dairyinfo.gc.ca. 2020 [cited 2 March 2020]. Available from: https://www.dairyinfo.gc.ca/index_e.php?s1=cdi-ilc&s2=aag-ail

Dairy | Industries | WWF [Internet]. World Wildlife Fund. 2020 [cited 2 March 2020]. Available from: https://www.worldwildlife.org/industries/dairy

Fraser G, Miles F, Orlich M, Jaceldo-Siegl K, Mashchak A. Dairy Milk Is Associated with Increased Risk of Breast Cancer in the Adventist Health Study-2 (AHS-2) Cohort (P05-026-19). Current Developments in Nutrition. 2019;3(Supplement_1).

Khaddour H, Elshimali Y, Dănciulescu-Miulescu R, Gradinaru D. Relationships Between Serum Expression of IGF-1 and Metabolic Syndrome Metrics in Syrian Women with Breast Cancer. Romanian Journal of Diabetes Nutrition and Metabolic Diseases. 2019;26(4):435-443.

Li XM, Ganmaa D, Sato A. The Experience of Japan as a Clue to the Etiology of Breast and Ovarian Cancers: Relationship Between Death From Both Malignancies and Dietary Practices. Medical Hypotheses. 2003 Feb 1;60(2):268-75.

McCann S, Hays J, Baumgart C, Weiss E, Yao S, Ambrosone C. Usual Consumption of Specific Dairy Foods Is Associated with Breast Cancer in the Roswell Park Cancer Institute Data Bank and BioRepository. Current Developments in Nutrition. 2017;1(3):e000422.

Momenimovahed Z, Salehiniya H. Epidemiological Characteristics of and Risk Factors for Breast Cancer in the World. Breast Cancer: Targets and Therapy. 2019;11:151.

U.S. Breast Cancer Statistics | Breastcancer.org [Internet]. Breastcancer.org. 2020 [cited 2 March 2020]. Available from: https://www.breastcancer.org/symptoms/understand_bc/statistics

Ziegler R. Phytoestrogens and Breast Cancer. The American Journal of Clinical Nutrition. 2004;79(2):183-184.