High folate intake is associated with lower breast cancer incidence in postmenopausal women in the Malmö Diet and Cancer cohort.
BACKGROUND
Epidemiologic studies of associations between folate intake and breast cancer are inconclusive, but folate and other plant food nutrients appear protective in women at elevated risk.


OBJECTIVE
The objective was to examine the association between folate intake and the incidence of postmenopausal breast cancer.


METHODS
This prospective study included all women aged >or=50 y (n = 11699) from the Malmö Diet and Cancer cohort. The mean follow-up time was 9.5 y. We used a modified diet-history method to collect nutrient intake data. At the end of follow-up, 392 incident invasive breast cancer cases were verified. We used proportional hazard regression to calculate hazard ratios (HRs).


RESULTS
Compared with the lowest quintile, the incidence of invasive breast cancer was reduced in the highest quintile of dietary folate intake (HR: 0.56; 95% CI: 0.35, 0.90; P for trend = 0.02); total folate intake, including supplements (HR: 0.56; 95% CI: 0.34, 0.91; P for trend = 0.006); and dietary folate equivalents (HR: 0.59; 95% CI: 0.36, 0.97; P for trend = 0.01).


CONCLUSIONS
A high folate intake was associated with a lower incidence of postmenopausal breast cancer in this cohort.
Ericson
Ulrika
U
Department of Clinical Sciences, Lund University, Malmö, Sweden. ulrika.pettersson@med.lu.se
Sonestedt
Emily
E
Gullberg
Bo
B
Olsson
Håkan
H
Wirfält
Elisabet
E
D000368:Aged; D000428:Alcohol Drinking; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000473:pathology / Q000517:prevention & control*; D015331:Cohort Studies; D005260:Female; D005492:Folic Acid / Q000627:therapeutic use*; D006801:Humans; D015994:Incidence; D007899:Leisure Activities; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D017698:Postmenopause; D016016:Proportional Hazards Models; D012907:Smoking / Q000453:epidemiology; D012959:Socioeconomic Factors; D013548:Sweden / Q000453:epidemiology
D005492:Folic Acid