1 1 The relationship between vitamin B6 and colonrectal cancer risk 維維維 B6 維維維維維維維維維維維 維維維 維維維 : 維維維維維 維維維 維維維 : 維維維維: 2012/12/25
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The relationship between vitamin B6 and colonrectal cancer risk維生素 B6 與大腸癌罹患風險之關係
實習生:王培竹指導營養師:林京美 營養師報告日期: 2012/12/25
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Vitamin B6
• Vitamin B6 is a water-soluble vitamin present in the human body as pyridoxine, pyridoxal, and pyridoxamine
• RDI:– 1.4 mg/d (♂) – 1.2 mg/d (♀)
• The main dietary sources :– poultry, fish, and meat– whole grains, legumes, and nuts
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Vitamin B6
• Regulation:– oxidative stress– immune system– carcinogenesis
• Low levels of vitamin B6:– cell proliferation ↑– C-reactive protein ↑– oxidative stress ↑– nitric oxide synthesis ↑– angiogenesis ↑
aberrations in DNA methylationimbalance in DNA precursorsdisruption in DNA repair
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Vitamin B6One-carbon metabolism
Vitamin B6
Vitamin B6
Vitamin B6
Folic acid
OxidationDetoxification
DNA synthesis
DNA methylationMTHFR
Vitamin B12
J.E. de Wit, 2011
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Dietary vitamin B6 intake and the risk of colorectal
cancerTheodoratou E, et al. Cancer Epidemiol Biomarkers Prev. 2008;17(1):171–82.
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Background
• evaluate the effect of dietary and supplementary intake of vitamin B6 on CRC and to investigate whether vitamin B6 effects are modified by folate and alcohol intakes.
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Exclusions death before ascertainmenttoo ill to participaterecurrent casesunable to give informed consent( learning difficulties or other Medical conditions.)
macronutrients, micronutrients
CRCn=2028, 16-79 yr
No-CRCn=2722, 16-79 yr
Information question (lifestyle, cancer)Semiquantitative FFQ (150 foods)
≦55 yr
MTHFR, MTR, MTRR genotypes
DNA samples were accuratelyquantified by PicoGreen
CRCn=1001
No-CRCn=1010
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Approximately 20%-30% reduction in risk for those of high versus those of low intake
Intakes of dietary and of total Vit.B6 showed a significant inverse, and dose-dependent effect on CRC risk in all models.
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Vit.B6 (dietary and total) had a similar strong inverse association with both colon, rectal, proximal, and distal cancer.
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Discussion
• Intakes of dietary vitamin B6 showed a significant, inverse, and dose-dependent effect on CRC risk.
• Intakes of Vitamin B6 supplement did not effect (associated) on CRC risk. The high dietary vitamin B6 intake from food and/or supplements had a lower CRC risk.
• Gene polymorphisms was not significantly associated with CRC.
• Folate and alcohol did not affect the relationship between vitamin B6 and CRC risk.
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Prospective study of plasma vitamin B6 and
risk of colorectal cancer in men
Lee JE, et al. Cancer Epidemiol Biomarkers Prev. 2009;18(4):1197–
202.
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Background
• evaluate the effect of plasma PLP on CRC and whether the association for plasma PLP was independent of plasma levels of one-carbon metabolites and markers of inflammation, including CRP, tumor necrosis factor-α (TNF-α), and interleukin (IL)-6.
2020
Exclusions •myocardial infarction•stroke•transient ischemic attack•cancer (except nonmelanoma skin cancer)•renal or liver disease•peptic ulcer•gout•used vitamin A supplements•used β -carotene supplements
1982
2000 No-CRC, n=371
Physicians’ Health Study n=22071
PLP , Vit.B12, folateHomocysteine , cysteineTNF- α R2 , CRP , IL-6MTHFR C677T
CRC, n=197
Randomized, double-blind, placebo-controlled tial (aspirin and β-carotene )
Self-administered questionnaires12 or 18 m FFQBlood sample, n=14196 (1982-84)
Blood sample
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A lower rick of colorectal cancer was observed mainly among participants in the two higher quartiles.
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Discussion
• The significant inverse association between plasma PLP levels and CRC risk.
• MTHFR C677T, inflammatory markers, folate, alcohol, multivitamin, aspirin, beta carotene, and BMI did not affect the relationship between PLP and CRC risk.
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Plasma levels of B vitamins
and colorectal cancer risk:the multiethnic cohort
studyLe Marchand L, et al. Cancer Epidemiol Biomarkers Prev. 2009;18(8):2195–201
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Background
• comprehensively investigate the relationships of plasma folate, pyridoxal-5′-phosphate (PLP, the active form of vitamin B6), vitamin B12, methylmalonic acid, homocysteine, and cysteine with colorectal cancer risk, accounting for suspected modifiers (alcohol intake, MTHFR C677T genotype, and plasma CRP) and potential confounders.
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Blood sample
PLP, Vit.B12, folateMMA, homocysteine, cysteineCRPMTHFR C677T
The multethnic cohort study n=≧215,000
26-page baseline questionnaireFFQBlood sample, n=67594 (2001-06)
No-CRC, n=411CRC, n=224
2006
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Discussion
• The significant inverse association between plasma PLP levels and CRC risk.
• The higher plasma folate can reduce CRC risk.
• Vitamin B12, MMA, cysteine, homocysteine was not significantly associated with CRC risk.
• MTHFR C677T, CRP, alcohol did not significant affect the relationship between PLP and CRC risk.
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CRC risk
PlasmaVit.B
Dietary Vit.B6
PlasmaVit.B6
( - ) association
with LPL and folate ( - ) association
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( - ) association
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Summary
• Finding that higher vitamin B6 intake and plasma PLP levels are associated with a lower risk of colorectal cancer, which is associated with a lower risk of colorectal cancer independent of other one-carbon metabolites, inflammatory biomarkers, MTHFR C677T and alcohol.
the significant inverse association between vitamin B6 levels and CRC risk