Research table: Dairy products and breast cancer risk

This summary table contains detailed information about research studies. Summary tables are a useful way to look at the science behind many breast cancer guidelines and recommendations. However, to get the most out of the tables, it’s important to understand some key concepts. Learn how to read a research table.

Introduction: Dairy products are under study as a factor that may be linked to:

• Increased breast cancer risk
• Decreased breast cancer risk

Some researchers have suggested the high fat content of many dairy products or traces of growth hormones in milk may be linked to an increased breast cancer risk [1-2].

Other researchers have studied whether the calcium and vitamin D in dairy products may be linked to a lower breast cancer risk [3].

A pooled analysis of data from more than 20 studies found no link between dairy product intake (including milk, cheese and yogurt) and breast cancer risk [4].

However, data from the Nurses’ Health Study II found women who ate 2 or more servings of high-fat dairy products (such as whole milk or butter) per day had a higher risk of breast cancer before menopause than women who ate fewer servings [5].

It’s unlikely eating or drinking dairy products is linked to breast cancer after menopause. However, more research is needed to draw solid conclusions about a possible link to breast cancer before menopause.

Learn more about dairy products and breast cancer risk.

Learn about the strengths and weaknesses of different types of studies. 

See how this risk factor compares with other risk factors for breast cancer.

Study selection criteria: Prospective cohort studies with at least 450 breast cancer cases, pooled analyses and meta-analyses.

Table note: Relative risk above 1 indicates increased risk. Relative risk below 1 indicates decreased risk.

Study	Study Population (number of participants)	Follow-up (years)	Type of Dairy Product	Relative Risk of Breast Cancer for Women with the Highest Dairy Intake versus Women with the Lowest Intake, RR (95% CI)
				Before Menopause	After Menopause
Prospective cohort studies
EPIC Cohort [6]	319,826 (7,119 cases)	9	Total milk: 439 g/day vs. none	1.00 (0.85-1.18)	1.09 (0.98-1.22)
			Whole milk: 150 g/day vs. none	1.04 (0.89-1.22)	1.03 (0.92-1.16)
			Cheese: 82 vs. 6 g/day	0.97 (0.82-1.15)	0.96 (0.86-1.08)
			Butter: 13 g/day vs. none	1.28 (1.06-1.53)	1.02 (0.91-1.13)
Nurses’ Health Study [7]	88,691 (3,482 cases)	16	Dairy products: 3 or more vs. 1 or fewer servings/day	0.80 (0.63-1.03)	0.97 (0.85-1.12)
			Milk: At least one glass/day vs. 3 or fewer glasses/month	0.73 (0.56-0.94)	1.01 (0.87-1.17)
Nurses’ Health Study II [5,8-9]	90,503 (3,191 cases)	22	Dairy products during early adulthood: 5 vs. Less than 1 serving/day	1.01 (0.96-1.05)*	0.97 (0.92-1.03)*
	44,264 (1,318 cases)	15	Dairy products during the teen years: 5 vs. 2 servings/day	1.14 (0.83-1.57)*	1.14 (0.85-1.53)*
	90,655 (714 cases)	8	Dairy foods during adulthood: 4 vs. 1 serving/day	1.03 (0.79-1.36)
			Low-fat dairy foods during adulthood: 3 vs. Less than 1 serving/day	0.82 (0.63-1.06)
			High-fat dairy foods during adulthood: 2 vs. Less than 1 serving/day	1.36 (1.03-1.75)
	39,268 (455 cases)	8	Milk during the teen years: Highest vs. Lowest	0.98 (0.71-1.34)
Cancer Prevention Study II [10]	68,567 (2,855 cases)	8-9	Dairy products: 3 or more vs. Less than 1 serving/day		0.81 (0.69-0.96)*
			Milk: 3 or more servings/day vs. none		0.88 (0.76-1.02)
Northern Sweden Health and Disease Study [11]	52,734 (1,921 cases)	20	Milk: 3 vs. less than 1/2 servings/day		1.17 (1.00-1.36)
Swedish Mammography Cohort [12]	33,780 (1,870 cases)	17	Milk: 2 or more servings/day vs. none		Hormone receptor-positive breast cancer: 1.30 (1.02-1.65)†,‡ Hormone receptor-negative breast cancer: 0.90 (0.50-1.60)†,‡
Norwegian Women and Cancer Study [13]	64,904 (1,407 cases)	9	Dairy products: 324 g or more vs. Fewer than 107 g/day	1.07 (0.69-1.65)	1.01 (0.83-1.23)
			Milk: 270 g or more vs. Less than 49 g/day	1.23 (0.78-1.94)	1.03 (0.85-1.25)
Black Women’s Health Study [14]	52,062 (1,268 cases)	12	Milk: 143 g/day or more vs. none	1.24 (0.74-2.08)	1.00 (0.60-1.67)
Fraser et al. [15]	52,795 (1,057 cases)	8	Dairy products: Highest vs. lowest	1.20 (0.80-1.80)	1.23 (1.05-1.45)
			Milk: Highest vs. lowest	1.38 (0.77-2.46)	1.54 (1.22-1.93)
Women’s Health Study [3]	31,487 (1,019 cases)	10	Dairy products: 3 or more vs. Less than 1 serving/day	0.64 (0.42-0.95)	1.07 (0.82-1.39)
Netherlands Cohort Study [16]	62,573 (941 cases)	6	Milk and milk products: 2 vs. Less than 1 glass/day		0.91 (0.67-1.24)
Malmö Diet and Cancer cohort [17]	15,773 (544 cases)	10	Whole milk: Highest vs. lowest		0.65 (0.48-0.88)
			Low-fat milk: Highest vs. lowest		1.07 (0.85-1.35)
Pooled and meta-analyses
Diet and Cancer Pooling Project [18]	21 studies (36,899 cases)	7-19	Dairy foods: Highest vs. lowest		0.95 (0.91-0.98)†
Dong et al. [19]	10 studies	10§	Dairy foods: Highest vs. lowest	0.79 (0.63-0.99)	0.92 (0.83-1.01)
			Milk: Highest vs. lowest	0.79 (0.60-1.02)	1.01 (0.94-1.09)
Missmer et al. [4]	351,041 (7,379 cases)	up to 15	Dairy fluids: Highest vs. lowest	0.96 (0.90-1.02)	1.00 (0.98-1.01)
			Dairy solids: Highest vs. lowest	0.87 (0.68-1.11)	1.05 (0.94-1.16)
Wu et al. [20]	4 studies		Milk: Highest vs. lowest		1.00 (0.96-1.03)
	2 studies		Milk: Highest vs. lowest	0.98 (0.92-1.04)

* Results were similar when high-fat and low-fat dairy products were examined separately.

† Results combined premenopausal women and postmenopausal women.

‡ Women who consumed 3 or more servings per day of yogurt, hard cheese, cottage cheese and other fermented dairy products did not have an increased risk of breast cancer compared to those who consumed none of these products. Relative risk for hormone receptor-positive breast cancer was 0.89 (0.69-1.14) and relative risk for hormone receptor-negative breast cancer was 0.69 (0.39-1.21).

§ Median years of follow-up among the studies.

References

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2. Ganmaa D, Sato A. The possible role of female sex hormones in milk from pregnant cows in the development of breast, ovarian and corpus uteri cancers. Med Hypotheses. 65:1028-37, 2005.
3. Lin J, Manson JE, Lee IM, Cook NR, Buring JE, Zhang SM. Intakes of calcium and vitamin D and breast cancer risk in women. Arch Intern Med. 167(10):1050-9, 2007.
4. Missmer SA, Smith-Warner S-A, Spiegelman D, et al. Meat and dairy food consumption and breast cancer: a pooled analysis of cohort studies. Int J Epidemiol. 31(1):78-85, 2002.
5. Cho E, Spiegelman D, Hunter DJ, et al. Premenopausal fat intake and risk of breast cancer. J Natl Cancer Inst. 95(14):1079-85, 2003.
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13. Hjartåker A, Thoresen M, Engeset D, Lund E. Dairy consumption and calcium intake and risk of breast cancer in a prospective cohort: the Norwegian Women and Cancer study. Cancer Causes Control. 21(11):1875-85, 2010.
14. Genkinger JM, Makambi KH, Palmer JR, Rosenberg L, Adams-Campbell LL. Consumption of dairy and meat in relation to breast cancer risk in the Black Women’s Health Study. Cancer Causes Control. 24(4):675-84, 2013.
15. 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. 49(5):1526-1537, 2020.
16. Voorrips LE, Brants HAM, Kardinaal AFM, Hiddink GJ, van den Brandt PA, Goldbohm RA. Intake of conjugated linoleic acid, fat, and other fatty acids in relation to postmenopausal breast cancer: the Netherlands Cohort Study on Diet and Cancer. Am J Clin Nutr. 76(4):873-82, 2002.
17. Wirfält E, Li C, Manjer J, et al. Food sources of fat and sex hormone receptor status of invasive breast tumors in women of the Malmö Diet and Cancer cohort. Nutr Cancer. 63(5):722-33, 2011. 
18. Wu Y, Huang R, Wang M, et al. Dairy foods, calcium, and risk of breast cancer overall and for subtypes defined by estrogen receptor status: a pooled analysis of 21 cohort studies. Am J Clin Nutr. 114(2):450-461, 2021.
19. Dong JY, Zhang L, He K, Qin LQ. Dairy consumption and risk of breast cancer: a meta-analysis of prospective cohort studies. Breast Cancer Res Treat. 127(1):23-31, 2011.
20. Wu J, Zeng R, Huang J, et al. Dietary protein sources and incidence of breast cancer: a dose-response meta-analysis of prospective studies. Nutrients. 8(11): 730, 2016. 

Updated 11/08/23