In the population study “Milk Intake and Risk of Mortality and Fractures in Women and Men,” researchers following more than 100,000 men and women in Sweden for about 20 years found significantly higher rates of bone and hip fractures, heart disease, cancer, and premature death in general for women who drank more milk. Three glasses a day was associated with nearly twice the risk of dying early. Men with higher milk consumption were also recorded having a higher risk of premature death. A meta-analysis of all such cohort studies, however, failed to find a significant relationship between milk and mortality. Findings of a 2015 meta-analysis found that men with high intakes of dairy products—milk, low-fat milk, and cheese, but not nondairy sources of calcium—did appear to increase total prostate cancer risk.
All animal-based foods contain sex steroid hormones, such as estrogen. These hormones naturally found even in organic cow’s milk may play a role in the various associations identified between dairy products and hormone-related conditions, including acne, diminished male reproductive potential, and premature puberty. The hormone content in milk may explain why women who drink it appear to have five times the rate of twin births compared with women who do not drink milk.
When it comes to cancer, leading experts have expressed concern that the hormones in dairy and other growth factors could potentially stimulate the growth of hormone-sensitive tumors. Experimental evidence also suggests that dairy may also promote the conversion of precancerous lesions or mutated cells into invasive cancers in vitro.
Image Credit: Amanda Rae. This image has been modified.
Popular Videos for Dairy
All Videos for Dairy
Sugar Industry Attempts to Manipulate the Science
How the food industry responds to “health food faddists.”
Treating Reflux in Babies with Diet
Treating the cause of infant reflux with maternal cow’s milk elimination.
Dairy & Cancer
How do we explain the increased risk of prostate cancer but the decreased risk of colon cancer associated with dairy consumption?
Best Foods for Halitosis & Gingivitis
The best and worst foods for bad breath and gum inflammation.
How to Treat Periodontitis with Diet
Plant-based diets are put to the test in the treatment of periodontal disease.
Is Butter Really Back? What the Science Says
Is butter—and other saturated fats—bad for you or not?
Dietary Cholesterol & Cancer
The relationship between the consumption of eggs and other cholesterol-rich foods and cancers of the colon, breast, endometrium, pancreas, and throat.
How the Dairy Industry Designs Misleading Studies
How the meat and dairy industries design studies showing their products have neutral or even beneficial effects on cholesterol and inflammation.
Is Cheese Healthy? Compared to What?
Dairy is compared to other foods for cardiovascular (heart attack and stroke) risk.
Is Cheese Really Bad for You?
What about the recent studies that show cheese has neutral or positive health effects?
The Best Diet for Upset Stomach
What to avoid and what to eat to help with dyspepsia.
Benefits of a Macrobiotic Diet for Diabetes
What happens when you add massive amounts of carbs to the daily diet of type 2 diabetics in the form of whole grains?