Association Between Vitamin D and Risk of Colorectal Cancer: A Systematic Review of Prospective Studies

ArticleinJournal of Clinical Oncology 29(28):3775-82 · August 2011with48 Reads
DOI: 10.1200/JCO.2011.35.7566 · Source: PubMed
Abstract
To conduct a systematic review of prospective studies assessing the association of vitamin D intake or blood levels of 25-hydroxyvitamin D [25(OH)D] with the risk of colorectal cancer using meta-analysis. Relevant studies were identified by a search of MEDLINE and EMBASE databases before October 2010 with no restrictions. We included prospective studies that reported relative risk (RR) estimates with 95% CIs for the association between vitamin D intake or blood 25(OH)D levels and the risk of colorectal, colon, or rectal cancer. Approximately 1,000,000 participants from several countries were included in this analysis. Nine studies on vitamin D intake and nine studies on blood 25(OH)D levels were included in the meta-analysis. The pooled RRs of colorectal cancer for the highest versus lowest categories of vitamin D intake and blood 25(OH)D levels were 0.88 (95% CI, 0.80 to 0.96) and 0.67 (95% CI, 0.54 to 0.80), respectively. There was no heterogeneity among studies of vitamin D intake (P = .19) or among studies of blood 25(OH)D levels (P = .96). A 10 ng/mL increment in blood 25(OH)D level conferred an RR of 0.74 (95% CI, 0.63 to 0.89). Vitamin D intake and blood 25(OH)D levels were inversely associated with the risk of colorectal cancer in this meta-analysis.
    • "Isoflavones and procyanidins, but not other subclasses, were inversely associated with the reduced CRC incidence. Thus, these findings partially supported flavonoid subclasses might be considered as promising candidates for potential chemopreventive agents, such as aspirin, metformin, vitamin D [31][32][33][34][35]. Flavonoids, as a diverse group of polyphenol, are considered as a potential anti-carcinogenic agent. "
    [Show abstract] [Hide abstract] ABSTRACT: Objective: To systematically evaluate the relationship between flavonoids intake and colorectal cancer risk by conducting a meta-analysis. Results: Our meta-analysis included 18 studies involving 16,917 colorectal cancer cases in 559,486 participants in relations to flavonoids intake during six to twenty-six years of follow-up. Our results indicated that specific flavonoid subclasses, such as procyanidins (OR = 0.75; 95% CI, 0.66-0.86) and isoflavones (OR = 0.87; 95% CI, 0.78-0.98), showed protective effects against colorectal cancer risk. There was no enough evidence indicating that increased consumption of total flavonoids were significantly associated with reduced risk of colorectal cancer (OR = 0.94, 95% CI, 0.81-1.09). There was no publication bias across studies. Methods: We performed a systematic search of PubMed, Web of Science and the Cochrane Library databases for relevant articles before December 2015. A random-effects model was used to estimate summary odds ratios and 95% confidence intervals (CIs) for associations between flavonoids and colorectal cancer risk. We assessed heterogeneity among studies by the Cochran Q and I2 statistics. Conclusions: Our meta-analysis provides comprehensive evidence and partly supported the hypothesis that higher habitual intake of foods rich in procyanidins and isoflavones may potentially decrease colorectal cancer incidence. More prospective studies are warranted to verify this protective association.
    Article · Apr 2016
    • "Calcitriol treatment mostly influences the anti-inflammatory profiles of cytokines by increasing TH2 cytokines (IL-3, IL-4, IL-5, IL-10) and inhibiting pro-inflammatory Th1 cytokines (IL-2, IFN-, TNF-) [67, 68] (Table 1). The prospective, case–control, observational studies suggest an inverse relationship between Vitamin D active metabolite 1,25-dihydroxyvitamin D3 (25(OH)D) and CRC6970717273. These data reiterate the positive effects of Vitamin D on inhibition of CRC. "
    [Show abstract] [Hide abstract] ABSTRACT: Epidemiological and laboratory data support the protective effects of bioactive nutrients in our diets for various diseases. Along with various factors, such as genetic history, alcohol, smoking, exercise, and dietary choices play a vital role in affecting an individual's immune responses towards a transforming cell, by either preventing or accelerating a neoplastic transformation. Ample evidence suggests that dietary nutrients control the inflammatory and pro-tumorigenic responses in immune cells. Immunoprevention is usually associated with the modulation of immune responses that help in resolving the inflammation, thus improving clinical outcome. Various metabolic pathway-related nutrients, including glutamine, arginine, vitamins, minerals, and long-chain fatty acids, are important components of immunonutrient mixes. Epidemiological studies related to these substances have reported different results, with no or minimal effects. However, several studies suggest that these nutrients may have immune-modulating effects that may lower cancer risk. Preclinical studies submit that most of these components may provide beneficial effects. The present review discusses the available data, the immune-modulating functions of these nutrients, and how these substances could be used to study immune modulation in a neoplastic environment. Further research will help to determine whether the mechanistic signaling pathways in immune cells altered by nutrients can be exploited for cancer prevention and treatment. This article is protected by copyright. All rights reserved.
    Full-text · Article · Feb 2016
    • "Even though studies on total cancer incidence and mortality may be more relevant from a public health point of view and for prevention than cause specific cancer incidence and mortality, they are uninformative with respect to potential cancer site specific vitamin D effects. For example, previous studies have suggested clear inverse associations of vitamin D with breast [33, 63, 183] and colorectal cancer risk [63, 112, 122, 175, 189], but not with other cancers. The apparently stronger association with total cancer mortality among women than among men observed in the present meta-analysis may be determined to a large part by the strong association with breast cancer, the by far most common cancer among women and the lack of an association with prostate cancer that is common among men. "
    Full-text · Article · Jan 2016 · Molecular Nutrition & Food Research
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