Carotenoids and breast cancer risk: a meta-analysis and meta-regression

Abstract

The purpose of this article is to comprehensively summarize the associations between carotenoids and breast cancer and quantitatively estimate their dose-response relationships. We searched PubMed, Embase, and Cochrane databases (from January 1982 to 1 May 2011) and the references of the relevant articles in English with sufficient information to estimate relative risk or odds ratio and the 95% confidence intervals, and comparable categories of carotenoids. Two reviewers independently extracted data using a standardized form; with any discrepancy adjudicated by the third reviewer. 33 studies met the inclusion criteria. Comparing the highest with the lowest intake: dietary α-carotene intake significantly reduced the breast cancer risk by 9.0% (pooled RR = 0.91; 95% CI: 0.85-0.98; P = 0.01), dietary β-carotene intake reduced the risk by 6.0% (pooled RR = 0.94; 95% CI: 0.88-1.00; P = 0.05); total β-carotene intake reduced the risk by 5.0% (pooled RR = 0.95; 95% CI: 0.90-1.01; P = 0.08) when data from cohort studies were pooled. Significant dose-response relationships were observed in both the higher intake of dietary and total β-carotene with reduced breast cancer risk when data from cohort studies (P (trend) < 0.01, P (trend) = 0.03) and case-control studies (P (trend) < 0.01, P (trend) < 0.01) were pooled, respectively. Dietary α-carotene intake could reduce the breast cancer risk. The relationships between dietary and total β-carotene intake and breast cancer need to be confirmed. No significant association between dietary intake of β-cryptoxanthin, lutein/+zeaxanthin, and lycopene and breast cancer was observed.

β-Carotene 15,15′-monooxygenase 1 single nucleotide polymorphisms in relation to plasma carotenoid and retinol concentrations in women of European descent

“…A meta-analysis suggests that dietary intake of aand b-carotene is associated with a 9% and 6% lower breast cancer risk, respectively, comparing highest versus lowest intakes (10). These modest associations may result from attenuation of a stronger causal association due to misclassification of an individual's internal carotenoid dose as measured by his or her dietary intake.…”

Adolescent Carotenoid Intake and Benign Breast Disease

“…Our findings align with recent pooled studies andmeta-analyses suggestinganinverse association between dietary intake/ circulating levels of b-carotene and breast cancer risk in adult women. [2][3][4][5] In the 2 existing pooled analyses, both blood levels and dietary intake of a-carotene and lutein/zeaxanthin were also inversely associated with breast cancer risk, particularly risk of ERnegative breast cancer. The highest intakes (top quartile) of these nutrients were associated with lower risk of BBD in this study, although the associations did not reach statistical significance.…”

“…Studies of dietary carotenoid intake and breast cancer have been inconsistent, although overall, these studies suggest a protective role of a-and b-carotene. 3,4 A pooled analysis of 18 prospective cohort studies found that women with higher intakes of a-carotene, b-carotene, and lutein/zeaxanthin had a lower risk of estrogen receptor (ER)-negative but not ER-positive breast cancer. 5 Carotenoids may also reduce risk of developing benign breast disease (BBD), a groupofbreastlesions thatcan develop during adolescence and young adulthood and are associated with higher risk of breast cancer.…”

β-Cryptoxanthin Synergistically Enhances the Antitumoral Activity of Oxaliplatin through ΔNP73 Negative Regulation in Colon Cancer

“…However, controversial results have been published, such as those describing no association between b-cryptoxanthin and risk of colon (20), breast (21), ovarian (22), and prostate cancer (23), and non-Hodgkin lymphoma (24).…”