Prospective association between dietary fiber intake and breast cancer risk.
BACKGROUND
Mechanistic hypotheses suggest a potential effect of dietary fiber on breast carcinogenesis through the modulation of insulin-like growth factor bioactivity, estrogen metabolism and inflammation. An association between dietary fiber intake and breast cancer risk has been suggested in epidemiological studies but remains inconclusive. In particular, data is lacking regarding the different types of dietary fibers.


OBJECTIVE
The objective was to investigate the prospective relationship between dietary fiber intake and breast cancer risk, taking into account different types of dietary fiber (overall, insoluble, soluble and from different food sources: cereals, vegetables, fruits and legumes).


METHODS
4684 women from the SU.VI.MAX cohort were included in this analysis as they completed at least three 24h-dietary records within the first two years of follow-up. Among them, 167 incident invasive breast cancers were diagnosed during a median follow-up of 12.6 years (between 1994 and 2007). The associations between quartiles of dietary fiber intake and breast cancer risk were characterized using multivariate Cox proportional hazards models.


RESULTS
Total fiber intake was not associated with breast cancer risk (HR(Quartile4vs.Quartile1) = 1.29 (95%CI 0.66-2.50), P-trend = 0.5), nor was fiber intake from cereals (P-trend = 0.1), fruits (P-trend = 0.9) and legumes (P-trend = 0.3). In contrast, vegetable fiber intake was related to a decreased risk of breast cancer (HR(Q4vs.Q1) = 0.50 (0.29-0.88), P-trend = 0.03). Overall vegetable intake (in g/day) was not associated with breast cancer risk (P-trend = 0.2).


CONCLUSIONS
This prospective study suggests that vegetable fiber intake may contribute to reduce breast cancer risk, in line with experimental mechanistic data.
Nutritional Epidemiology Research Team, Sorbonne Paris Cité Research Center, Inserm (U557), Inra (U1125), Cnam, Paris 13 University, SMBH Paris 13, Bobigny, France.
Mélanie
M
Deschasaux
Laurent
L
Zelek
Camille
C
Pouchieu
Mathilde
M
His
Serge
S
Hercberg
Pilar
P
Galan
Paule
P
Latino-Martel
Mathilde
M
Touvier
D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000209:etiology*; D004043:Dietary Fiber; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012306:Risk