Dietary Factors and Risk of Breast Cancer: Combined Analysis of 12 Case--Control Studies

Abstract

We conducted a combined analysis of the original data to evaluate the consistency of 12 case-control studies of diet and breast cancer. Our analysis shows a consistent, statistically significant, positive association between breast cancer risk and saturated fat intake in postmenopausal women (relative risk for highest vs. lowest quintile, 1.46; P less than .0001). A consistent protective effect for a number of markers of fruit and vegetable intake was demonstrated; vitamin C intake had the most consistent and statistically significant inverse association with breast cancer risk (relative risk for highest vs. lowest quintile, 0.69; P less than .0001). If these dietary associations represent causality, the attributable risk (i.e., the percentage of breast cancers that might be prevented by dietary modification) in the North American population is estimated to be 24% for postmenopausal women and 16% for premenopausal women.

Lifelong vegetarianism and risk of breast cancer: A population‐based case‐control study among South Asian migrant women living in England

“…Moreover, 2 of the cohorts included in this analysis have since reported protective effects for vegetable intake. The inverse trend between NSP intake (a marker of fruit and vegetable consumption) and the odds of breast cancer observed in the present study is also consistent with that from a meta-analysis of case-control studies, 35 which reported a weak, but statistically significant, protective association. Several recent studies, not included in the meta-analysis, have found similar statistically significant protective associations with various components of fibre, 36 -38 crude fibre 39 and fibre from vegetables and fruit, but not cereals.…”

Dietary lipids and endometrial cancer: the current epidemiologic evidence

“…For breast cancer, a cancer site with a risk factor profile similar to that for endometrial cancer, it has also been noted that generally case-control studies have observed elevated risks with increasing dietary fat intake [41], whereas results from cohort studies have been null [42]. However, a meta-analysis published in 2003 [43] and including 31 case-control studies and 14 cohort studies found similar weak positive associations for dietary fat intake and breast cancer for case-control (summary estimate: 1.14; 95% CI: 0.99-1.32) and cohort studies (summary estimate: 1.11; 95% CI: 0.99-1.25).…”

Intakes of plant foods, fibre and fat and risk of breast cancer – a prospective study in the Malmö Diet and Cancer cohort

“…For instance, in a case -control study in China, women in the lowest tertile of crude fibre intake and highest tertile of fat intake Plant foods, fibre and fat and risk of breast cancer I Mattisson et al had a 2.9-fold increased risk for breast cancer relative to those in the highest tertile of crude fibre intake and lowest tertile of fat intake (Yuan et al, 1995). Howe et al (1990) found a significant (P ¼ 0.002) protective effect of fibre in a combined analysis of 12 case -control studies, but this effect was not independent of bcarotene and vitamin C. No association was found in the Nurse's Health Study (Willett et al, 1992). A Canadian prospective study found a significant reduced risk in the highest fibre quintile relative to the lowest quintile (Rohan et al, 1993).…”