Dairy & Calcium

Updated: Apr 11

When majority of people can't properly digest a food, should it be considered a "healthy food"? 65% of human population is lactose intolerant, knowingly or unknowingly. This is not surprising considering there is no need for it past infancy, but yet we find every way possible to add it to our meals in varying forms, be it milk, cream, cheese, butter, ghee or yogurt.

The new Canadian Food Guide now has taken dairy out as a food category, recommending water as choice of drink.

Saturated Fat & Cholesterol

Dairy products are the top source of saturated fat, which contributes to heart disease, type 2 diabetes and Alzheimer's disease. Dairy products also contain dietary cholesterol which increases risk for heart disease as well. There has also been associations found between dairy and increased risk of breast, prostate and ovarian cancers.

Cheeses are typically 70% fat - most of which is usually saturated fat.

Bone Health

Even though there is a general belief that milk is important for strong bones, this is only a marketing tactic by the dairy industry to increase their sales. Studies have shown the consumption of dairy products having none to very little benefit for bone health. Meta-analyses looking at this have found no overall improvements in fracture risk in those who consumed more dairy. Even in people who consumed dairy milk in their teenage years did not benefit later in life from lowered fracture risk.

Study looking at people consuming a complete plant-based diet who consumed a minimum of 525mg of calcium per day did not have any higher fracture rates than those who consumed animal products.

Calcium is not the only important factor for bone health. Having adequate amounts of vitamin D, vitamin K, and magnesium are all very important for bone health. Vitamin D increases absorption of calcium, vitamin K reduces bone turnover and magnesium helps with better bone mineral density. However, the most important factor for bone health is actually weight bearing exercises. To build healthy bones, you have to stress your bones. This can include walking, running or weight lifting.

For healthy bones, it is important to get the right nutrients but also to move your body regularly.

Prostate Cancer

High intakes of dairy has also been linked to prostate cancer. A meta-analysis analyzing 32 different studies found total dairy products, total milk, low-fat milk, and cheese intakes to be associated with an increased risk for prostate cancer. Another study tracking 21,660 participants for 28 years found increased risk for prostate cancer for people consuming 2.5 servings or more of dairy products per day compared to those who consumed 0.5 servings or less per day. This increased risk is most likely due to increases in insulin-like growth factor (IGF-1). Consuming dairy products including cow's milk on a regular basis has been shown to increase IGF-1 blood levels in humans. Studies looking at diverse populations have consistently found a strong link between high IGF-1 blood levels and prostate cancer risk.

Breast Cancer

The high fat content of dairy and the hormones found in milk, cheese and other dairy products have been linked to breast cancer. Among women previously diagnosed with breast cancer, the Life After Cancer Epidemiology study found women consuming one or more servings of high-fat dairy products including cheese, ice cream, whole milk, etc. daily had a 49% higher breast cancer mortality compared to women consuming less than half a serving daily. Another study found women consuming a quarter to a third cup of cow's milk per day to have a 30% increased risk for breast cancer. One cup per day increased the risk even further by 50% and 2-3 cups were associated with even higher risk of 80%.

Dairy & Mortality

A study looking at over 100,000 people found significantly higher mortality rates in people who consumed 3 or more servings of milk per day compared to people who drank less than 1 serving per day.

Other Sources of Calcium

Calcium is an essential nutrient and you can get ample calcium from plant-based foods without the negative effects of dairy consumption.

Tofu, broccoli, kale, collard greens, beans, lentils, breads, cereals, nuts, seeds and plant-based, calcium-fortified milks.

More detailed graphic on plant-based calcium sources can be found here and the breakdown of plant-based milks here. References:

  1. Maruyama, K. et al. Exposure to exogenous estrogen through intake of commercial milk produced from pregnant cows. Pediatrics International. 2010;52:33-38.

  2. Michaelsson, K et al. Milk intake and risk of mortality and fractures in women and men: cohort studies. BMJ. 2014.⁣ ⁣

  3. Park, SM et al. A milk protein, casein, as a proliferation promoting factor in prostate cancer cells. World J Mens Health. 2014.⁣ ⁣

  4. Bischoff-Ferrari, HA et al. Milk Intake and Risk of Hip Fracture in Men and Women: A Meta-Analysis of Prospective Cohort Studies. J Bone Miner Res. 2011.⁣ ⁣

  5. Bian, S et al. Dairy product consumption and risk of hip fracture: a systematic review and meta-analysis. BMC Public Health. 2018.⁣

  6. ⁣Feskanich, D et al. Milk consumption during teenage years and risk of hip fracture in older adults. JAMA Pediatr. 2014.⁣ ⁣

  7. Michaelsson, K et al. Milk intake and risk of mortality and fractures in women and men: cohort studies. BMJ. 2014.⁣ ⁣

  8. Appleby, P et al. Comparative fracture risk in vegetarians and non-vegetarians in EPIC-Oxford. Eur J Clin Nutr. 2007.⁣ ⁣

  9. Burckhardt, P. Calcium revisited, part III: effect of dietary calcium on BMD and fracture risk.

  10. Bischoff-Ferrari, HA et al. Fracture prevention with vitamin D supplementation: a meta-analysis of randomized controlled trials. JAMA. 2005.⁣ ⁣

  11. Price, CT. et al. Essential Nutrients for Bone Health and a Review of their Availability in the Average North American Diet. Open Orthop J. 2012.⁣ ⁣

  12. Bolland MJ, Leung W, Tai V, Bastin S, Gamble GD, Grey A, Reid IR. Calcium intake and risk of fracture: systematic review. BMJ. 2015 Sep 29;351:h4580.

  13. Aune, D et al. Dairy products, calcium, and prostate cancer risk: a systematic review and meta-analysis of cohort studies. AJCN. 2014.⁣ ⁣

  14. Song Y, Chavarro JE, Cao Y, et al. Whole milk intake is associated with prostate cancer-specific mortality among U.S. male physicians. J Nutr. 2013;143:189-196.

  15. Qin L, Xu J, Wang P, Tong J, Hoshi K. Milk consumption is a risk factor for prostate cancer in Western countries: evidence from cohort studies. Asia Pac J Clin Nutr. 2007;16:467– 476.

  16. Chan JM, Stampfer MJ, Ma J, Gann PH, Gaziano JM, Giovannucci E. Dairy products, calcium, and prostate cancer risk in the Physicians’ Health Study. Am J Clin Nutr. 2001;74:549-554.

  17. Voskuil DW, Vrieling A, van’t Veer LJ, Kampman E, Rookus MA. The insulin-like growth factor system in cancer prevention: potential of dietary intervention strategies. Cancer Epidemiol Biomarkers Prev. 20 05;14:195 –203.

  18. Qin LQ, He K, Xu JY. Milk consumption and circulating insulin-like growth factor-I level: a systematic literature review. Int J Food Sci Nutr. 2009;60 Suppl 7:330-340.

  19. Qin LQ, He K, Xu JY. Milk consumption and circulating insulin-like growth factor-I level: a systematic literature review. Int J Food Sci Nutr.2009;60:330-340.

  20. Cohen P. Serum insulin-like growth factor-I levels and prostate cancer risk—interpreting the evidence. J Natl Cancer Inst. 1998;90:876–879.

  21. Shi R, Berkel HJ, Yu H. Insulin-like growth factor-I and prostate cancer: a meta-analysis. Br J Cancer. 2001;85:991–996.

  22. Xing MY, Xu SZ, Shen P. Effect of low-fat diet on breast cancer survival: a meta-analysis. Asian Pac J Cancer Prev. 2014;15(3):1141-4.

  23. McCann SE, Hays J, Baumgart CW, Weiss EH, Yao S, Ambrosone CB. Usual Consumption of Specific Dairy Foods Is Associated with Breast Cancer in the Roswell Park Cancer Institute Data Bank and BioRepository. Curr Dev Nutr. 2017 Feb 16;1(3):e000422.

  24. Kroenke CH, Kwan ML, Sweeney C, Castillo A, Caan BJ. High- and low-fat dairy intake, recurrence, and mortality after breast cancer diagnosis. J Natl Cancer Inst. 2013 May 1;105(9):616-23.

  25. Fraser GE, Jaceldo-Siegl K, Orlich M, Mashchak A, Sirirat R, Knutsen S. Dairy, soy, and risk of breast cancer: those confounded milks. Int J Epidemiol. 2020 Feb 25:dyaa007.