Browsing by Subject "Citrus"

Now showing 1 - 4 of 4
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    The Association Between Citrus Consumption and Skin Cancer: An Analysis of Risk and Nutrient-Gene Interaction
    (2020-12) Marley, Andrew Raymond; Han, Jiali; Sibg, Yiqing; Li, Xin; Li, Ming; Champion, Victoria L.
    Purpose. In the US, melanoma and non-melanoma skin cancer (NMSC) rates have increased substantially in recent decades. While many skin cancer risk factors have been established, the impact of dietary citrus, which is naturally abundant in photocarcinogenic psoralens, remains enigmatic. The purpose of this research was to investigate associations between citrus consumption and risks of melanoma and NMSC, and to conduct a genome-wide study to identify genetic variants that may modify this association. Methods. Participants from the UK Biobank were leveraged for these analyses. Citrus consumption was collected via five rounds of 24-hour recall questionnaires, with complete citrus data available for n=210,126 participants. Ascertainment of melanoma and NMSC cases were identified by international classification of disease codes via linkage with national registries. Logistic regression was used to estimate odds ratios and 95% confidence intervals for the associations between citrus consumption and skin cancer outcomes. Individual citrus products were assessed for independent associations with skin cancer risk, and established skin cancer risk factors were tested for interaction. Joint 2-degree-of-freedom (df) and 1-df tests were used to assess interaction between total citrus consumption and genetic variants. Results. After controlling for covariates, high total citrus consumption was significantly associated with increased melanoma risk, an association primarily driven by orange and orange juice consumption. Skin color was found to be a significant effect modifier for the association between total citrus consumption and melanoma risk, but only before adjusting for multiple comparisons. No significant associations were observed for high total citrus consumption or consumption of any individual citrus products and NMSC risk. Significant associations for half a serving of citrus consumption and NMSC risk were likely due to chance or confounding. Index SNPs on chromosomes 3, 9, and 16 were significant according to the joint 2-df test, and 7 SNPs on chromosome 16 displayed evidence of a citrus-gene interaction. Conclusion. My analyses provide evidence in support of high citrus consumption significantly increasing risk of melanoma, but not NMSC. I also identified SNPs on AFG3L1P that may modify this association. Future research should further explore these associations, particularly for NMSC and to confirm my genetic findings.
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    Citrus Consumption and Risk of Non-Melanoma Skin Cancer in the UK Biobank
    (Taylor & Francis, 2022) Marley, Andrew R.; Li, Ming; Champion, Victoria L.; Song, Yiqing; Han, Jiali; Li, Xin; Epidemiology, School of Public Health
    Background: Non-melanoma skin cancer (NMSC) incidence has been dramatically increasing worldwide. Psoralen, a known photocarcinogen, is naturally abundant in citrus products, leading to the hypothesis that high citrus consumption may increase NMSC risk. Methods: We fitted age- and multivariable-adjusted logistic regression models to evaluate the association between citrus consumption and NMSC risk among 197,372 UKBB participants. A total of 9,613 NMSC cases were identified using International Classification of Disease 10 codes. Citrus consumption data were collected via five rounds of 24-hour recall questionnaires. Results: We found no association between high total citrus consumption and NMSC risk, although a slightly elevated NMSC risk was observed among participants who consumed >0 to half a serving of total citrus per day (OR [95% CI] = 1.08 [1.01-1.16]). There was no association between individual citrus products and NMSC risk. Conclusion: High citrus consumption was not associated with an increased risk of NMSC in our UKBB sample. Further studies are needed to clarify these associations. Supplemental data for this article is available online at https://doi.org/10.1080/01635581.2021.1952439 .
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    Citrus-Gene Interaction and Melanoma Risk in the UK Biobank
    (Wiley, 2022) Marley, Andrew R.; Li, Ming; Champion, Victoria L.; Song, Yiqing; Han, Jiali; Li, Xin; Epidemiology, School of Public Health
    High citrus consumption may increase melanoma risk; however, little is known about the biological mechanisms of this association, or whether it is modified by genetic variants. We conducted a genome-wide analysis of gene-citrus consumption interactions on melanoma risk among 1563 melanoma cases and 193 296 controls from the UK Biobank. Both the 2-degrees-of-freedom (df) joint test of genetic main effect and gene-environment (G-E) interaction and the standard 1-df G-E interaction test were performed. Three index SNPs (lowest P-value SNP among highly correlated variants [r2 > .6]) were identified from among the 365 genome-wide significant 2-df test results (rs183783391 on chromosome 3 [MITF], rs869329 on chromosome 9 [MTAP] and rs11446223 on chromosome 16 [DEF8]). Although all three were statistically significant for the 2-df test (4.25e-08, 1.98e-10 and 4.93e-13, respectively), none showed evidence of interaction according to the 1-df test (P = .73, .24 and .12, respectively). Eight nonindex, 2-df test significant SNPs on chromosome 16 were significant (P < .05) according to the 1-df test, providing evidence of citrus-gene interaction. Seven of these SNPs were mapped to AFG3L1P (rs199600347, rs111822773, rs113178244, rs3803683, rs73283867, rs78800020, rs73283871), and one SNP was mapped to GAS8 (rs74583214). We identified several genetic loci that may elucidate the association between citrus consumption and melanoma risk. Further studies are needed to confirm these findings.
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    The Association between Citrus Consumption and Melanoma Risk in the UK Biobank
    (Oxford University Press, 2021) Marley, A. R.; Li, M.; Champion, V. L.; Song, Y.; Han, J.; Li, X.; Epidemiology, Richard M. Fairbanks School of Public Health
    Background: Melanoma incidence has been dramatically increasing worldwide. Psoralen, a known photocarcinogen, is naturally abundant in citrus products, leading to the hypothesis that high citrus consumption may increase melanoma risk. Objectives: To investigate the association between total citrus consumption and melanoma risk, and the association between individual citrus products and melanoma risk, and to test for interactions between total citrus intake and established melanoma risk factors. Methods: Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the association between citrus consumption and melanoma risk among 1592 cases and 197 372 controls from the UK Biobank cohort. Citrus consumption data were collected via five rounds of 24-h recall questionnaires. International Classification of Diseases codes were used to determine melanoma outcome. Results: After adjusting for potential confounders, participants in the highest category of total citrus intake (> 2 servings per day) had a significantly increased risk of melanoma (OR 1·63, 95% CI 1·24-2·12) relative to those with no consumption. For individual citrus products, participants with the most orange and orange juice consumption (> 1 serving per day) had a significantly increased melanoma risk relative to those with no consumption (OR 1·79, 95% CI 1·07-2·78 and OR 1·54, 95% CI 1·10-2·10, respectively). Fair- or very fair-skinned participants with high citrus consumption had an even greater melanoma risk (OR 1·75, 95% CI 1·31-2·29). Conclusions: High citrus consumption was associated with an increased risk of melanoma in a large, prospective, population-based cohort. Further validation of these findings could lead to improved melanoma prevention strategies.