|Title||Are imprecise methods obscuring a relation between fat and breast cancer?|
|Publication Type||Journal Article|
|Year of Publication||2003|
|Authors||Bingham, SA, Luben, R, Welch, A, Wareham, N, Khaw, K-T, Day, N|
|Date Published||2003 Jul 19|
|Keywords||Aged, Breast Neoplasms, Cohort Studies, Diet Records, Dietary Fats, Eating, Female, Health Status, Humans, Incidence, Male, Middle Aged, Research Design, Risk Factors, Surveys and Questionnaires|
Pooled analyses of cohort studies show no relation between fat intake and breast-cancer risk. However, food-frequency questionnaire (FFQ) methods used in these studies are prone to measurement error. We assessed diet with an FFQ and a detailed 7-day food diary in 13070 women between 1993 and 1997. We compared 168 breast-cancer cases incident by 2000 with four matched controls. Risk of breast cancer was associated with saturated-fat intake measured with the food diary (hazard ratio 1.22 [95% CI 1.06-1.40], p=0.005, per quintile increase in energy-adjusted fat intake), but not with saturated fat measured with the FFQ (1.10 [0.94-1.29], p=0.23). Dietary measurement error might explain the absence of a significant association between dietary fat and breast-cancer risk in cohort studies.