alpha-carotene and Lymphoma--Non-Hodgkin

Carotenoids may play a protective role in the development of non-Hodgkin lymphoma (NHL), but findings from epidemiological studies on the associations between carotenoid intake and NHL risk are inconsistent. We therefore performed a meta-analysis to systemically evaluate the associations. Eligible studies were identified by a search of PubMed, Web of Science, Embase, and article reference lists. We pooled risk estimates from individual studies using a random-effect model to quantify the associations between intakes of specific carotenoids and NHL risk. A total of 10 (7 case-control and 3 cohort) studies met our inclusion criteria. In the highest versus lowest analyses, intakes of alpha-carotene, beta-carotene, and lutein/zeaxanthin, but not lycopene or beta-cryptoxanthin, were associated with a significant reduced risk of NHL. The estimated summary relative risks (95% confidence intervals) for alpha-carotene, beta-carotene, and lutein/zeaxanthin were 0.87 (0.78-0.97), 0.80 (0.68-0.94), and 0.82 (0.69-0.97), respectively. Subgroup analyses showed that evidence supporting these protective associations was mostly based on studies with a case-control design. In addition, intakes of alpha-carotene and beta-carotene were associated with a significant decreased risk of diffuse large B-cell lymphoma, but not follicular lymphoma or small lymphocytic lymphoma/chronic lymphocytic leukemia. There was a significant inverse dose-response relationship between alpha-carotene intake and NHL risk (13% lower risk per 1000 μg/day increment of intake). In conclusion, our findings suggest that higher intakes of alpha-carotene, beta-carotene, and lutein/zeaxanthin might protect against NHL development. Further cohort studies with a control of plausible confounding are needed to confirm these associations.

Topics: beta Carotene; Carotenoids; Case-Control Studies; Cohort Studies; Humans; Lutein; Lymphoma, Non-Hodgkin; Observational Studies as Topic; Prognosis; Risk Factors; Zeaxanthins

Limited studies have investigated the effects of serum carotenoids on the risk of non-Hodgkin lymphoma (NHL), and the findings have been inconclusive. This study aims to assess the association between serum total or specific carotenoid levels and NHL risk. This 1:1 matched, hospital-based case-control study enrolled 512 newly diagnosed (within 1 month) NHL patients and 512 healthy controls who were matched by age (±5 years) and sex in Urumqi, China. Serum carotenoid levels were measured by HPLC. Conditional logistic regression showed that higher serum total carotenoid levels and their subtypes (e.g. α-carotene, β-carotene, β-cryptoxanthin and lycopene) were dose-dependently associated with decreased NHL risk. The multivariable-adjusted OR and their 95 % CI for NHL risk for quartile 4 (v. quartile 1) were 0·31 (95 % CI 0·22, 0·48; Pfor trend < 0·001) for total carotenoids, 0·52 (95 % CI 0·33, 0·79; Pfor trend: 0·003) for α-carotene, 0·63 (95 % CI 0·42, 0·94; Pfor trend: 0·031) for β-carotene, 0·73 (95 % CI 0·49, 1·05; Pfor trend: 0·034) for β-cryptoxanthin and 0·51 (95 % CI 0·34, 0·75; Pfor trend: 0·001) for lycopene. A null association was observed between serum lutein + zeaxanthin and NHL risk (OR 0·89, 95 % CI 0·57, 1·38; Pfor trend: 0·556). Significant interactions were observed after stratifying according to smoking status, and inverse associations were more evident among current smokers than past or never smokers for total carotenoids, α-carotene and lycopene (Pfor heterogeneity: 0·047, 0·042 and 0·046). This study indicates that higher serum carotenoid levels might be inversely associated with NHL risk, especially among current smokers.

Topics: Aged; beta Carotene; Carotenoids; Case-Control Studies; China; Cryptoxanthins; Female; Humans; Logistic Models; Lycopene; Lymphoma, Non-Hodgkin; Male; Middle Aged; Odds Ratio; Risk Factors; Smoking