Table 2.

Effects of dairy products on breast cancer incidence

Subgroup analysis	No. of studies	Cases	Participants	HR	95%CI	p	Heterogeneity (I2) (%)
All populations	25	30,334	726,673	0.95	0.91–0.99	0.019	63.2
ER+ breast cancer	4	6466	185,355	0.79	0.68–0.92	0.002	66.4
ER- breast cancer	4	6466	185,355	1.06	0.92–1.22	0.42	0
PR+ breast cancer	3	3611	87,569	0.75	0.58–0.97	0.027	73.9
PR- breast cancer	3	3611	87,569	1.05	0.90–1.21	0.56	0
ER+/PR+ breast cancer	5	11,563	184,989	0.92	0.85–1.01	0.075	73.0
ER−/PR- breast cancer	5	11,563	184,989	0.96	0.88–1.05	0.36	32.5
Premenopausal population	8	14,863	653,249	1.02	0.97–1.07	0.37	5.9
Postmenopausal population	8	14,863	653,249	1.00	0.97–1.04	0.83	0
Fermented dairy products	14	16,280	496,747	0.98	0.95–1.02	0.25	41.9
Fermented dairy products for ER+/PR+ breast cancer	2	2414	50,815	1.01	0.97–1.05	0.62	12.3
Fermented dairy products for ER−/PR- breast cancer	2	2414	50,815	1.03	0.92–1.15	0.63	37.4
Fermented dairy products for the premenopausal population	6	14,425	561,870	0.98	0.94–1.03	0.52	0
Fermented dairy products for the postmenopausal population	6	14,425	561,870	0.96	0.93–0.99	0.021	0
Non-fermented dairy products	13	17,145	594,111	0.99	0.94–1.03	0.54	0
Non-fermented dairy products for the premenopausal population	6	14,425	561,870	1.03	0.97–1.09	0.33	0
Non-fermented dairy products for the postmenopausal population	6	14,425	561,870	1.03	0.98–1.08	0.30	20.2
High fat dairy products	12	19,208	624,176	1.06	1.00–1.13	0.066	63.7
High fat dairy products for premenopausal populations	6	17,873	584,718	1.01	0.96–1.07	0.61	0
High fat dairy products for the postmenopausal population	6	17,873	584,718	1.00	0.95–1.04	0.87	0
Low fat dairy products	11	19,699	615,226	0.98	0.94–1.03	0.50	63.1
Low fat dairy products for the premenopausal population	6	17,873	584,718	0.94	0.89–1.00	0.048	33.5
Low fat dairy products for the postmenopausal population	6	17,873	584,718	1.04	0.99–1.09	0.15	22.6

HR: hazard ratio; CI: confidence interval; ER: estrogen receptor; PR: progesterone receptor