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Thread: High B12 levels and increased cancer risk

  1. #1
    Festival Buddy Frank's Avatar
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    Default High B12 levels and increased cancer risk

    Prostrate cancer is a big killer in the male population and still gets relatively low exposure.

    Feel free to add your stories of Prostrate cancer and the treatments that have been endured/recommended on this thread.


    Breaking Medical News

    *Milk and Prostate Cancer: New Evidence *

    A new study in the //International Journal of Cancer// highlights the
    link between dairy consumption and prostate cancer. Researchers examined
    dairy and calcium intake in 29,133 men in the Alpha-Tocopherol,
    Beta-Carotene Cancer Prevention Study. As consumption of dairy products
    or overall dietary calcium intake increased, risk for prostate cancer
    increased. Men who consumed the most dietary calcium (greater than 2,000
    mg per day) had a 63 percent greater risk, compared with those getting
    less than 1,000 mg per day.

    Several previous studies have linked dairy products with prostate
    cancer. The new study adds to evidence that a principal reason may be
    dairy calcium. Excess dietary calcium inhibits activation of vitamin D
    in the body; vitamin D is essential for prostate health. Even though
    milk products in the U.S. are fortified with vitamin D, their large
    calcium load tends to block vitamin D activation in the body.

    Mitrou PN, Albanes D, Weinstein SJ, Pietinen P, et al. A prospective
    study of dietary calcium, dairy products and prostate cancer risk
    (Finland). //Int J Cancer//. 2007;120:2466-2473.

    For information about nutrition and health, please visit www.pcrm.org/
    <http://support.pcrm.org/site/R?i=CrHTbmv0FNoibvx6jqDsDw..>.

    Breaking Medical News is a service of the Physicians Committee for
    Responsible Medicine, 5100 Wisconsin Avenue, N.W., Suite 400,
    Washington, DC 20016.

    Physicians Committee for Responsible Medicine
    5100 Wisconsin Ave., N.W., Ste. 400
    Washington, DC 20016
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  2. #2
    Ex-admin Korn's Avatar
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    Default High B12 levels associated with an up to 3-fold increased prostate cancer risk

    I've already mentioned this study in our B12 overdose thread, but since this isnt really about B12 overdosing, but about the link between high B12 levels and prostata risk, I thought this study deserves it's own thread, so here we go:



    http://www.psa-rising.com/eatingwell/vb12_folate04.html

    [...]But when the Swedish team compared blood levels of these factors to prostate cancer risk in a prospective study of 254 men with prostate cancer and 514 matched men without known prostate cancer, they found something odd and surprising.

    Folate and B12 were expected to be protective against prostate cancer, because folate, vitamin B12 and homocysteine are essential for methyl group metabolism and thus also for DNA methylation. Abnormal methylation, primarily hypermethylation of certain genes including tumor suppressors, has been implicated in prostate cancer development.

    But in fact, increasing plasma levels of folate and vitamin B12 were statistically significantly associated with increased prostate cancer risk, with an odds ratio of 1.60 for folate and 2.63 for vitamin B12 for highest vs. lowest quartile.

    Increasing plasma homocysteine levels were associated with a reduced risk of borderline significance.

    After adjustment for body mass index and smoking, a statistically significant increased risk remained only for vitamin B12.

    The researchers say: "Our results suggest that factors contributing to folate status are not protective against prostate cancer. On the contrary, vitamin B12, associated with an up to 3-fold increase in risk, and possibly also folate, may even stimulate prostate cancer development. These findings are novel and should be explored further in future studies."

    More here:
    http://www.nature.com/ncpuro/journal...cpuro0134.html


    B12 is also associated with lowering cancer risk. Too much or too little of something normally isn't a good idea.
    Last edited by Korn; Oct 11th, 2008 at 09:46 AM. Reason: This was the first post in a similar thread, now merged with this one

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    Ex-admin Korn's Avatar
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    Default Re: High B12 levels associated with an up to 3-fold increased prostata cancer ri

    Here's some relevant comments from Dr. McDougall's site:



    Animal Fat May Accelerate Prostate Cancer

    Saturated fat intake predicts biochemical failure after prostatectomy by Sara Strom in the June 2008 issue of the International Journal of Cancer showed, “that high prediagnostic saturated fat (HSF) intake was associated with a 2-fold increased risk of biochemical failure in this cohort of 390 Caucasian men with localized PCa treated with prostatectomy…Men who were both obese and consumed HSF diets had the shortest biochemical-failure-free-survival (19 months), and nonobese men who consumed LSF diets had the longest biochemical-failure-free-survival (46 months, p < 0.001).”1The study was based on a food frequency questionnaire. Biochemical failure was determined by a significant rise in prostate specific antigen (PSA) levels.

    Comment:

    Studies of populations of people and laboratory studies of animals consistently show that foods, especially meat, dairy, and added free fats cause and promote the growth of prostate cancer. This study says the diet eaten by a patient with prostate cancer can influence the growth of the cancer. Saturated fat, which is primarily found in red meat, chicken, milk, and cheese, cuts in half the time it takes for the cancer to come back (based on PSA). It is fair to assume this same rich diet will cause the patient to die sooner.

    Saturated fat is just one cancer-promoting component of the rich Western diet. The cholesterol, animal protein, and environmental chemicals found in these foods are also known to make cancer grow faster. Just as important are the missing ingredients. Dietary fiber, vitamins and minerals, and thousands of other plant-derived (phyto) chemicals keep the body healthy by discouraging cancer growth.

    A study by Dean Ornish has begun to show the benefits of a truly healthy diet, like ours, for prostate cancer patients.2 Published in the September 2005 issue of The Journal of Urology, his research found, “Intensive lifestyle changes may affect the progression of early, low grade prostate cancer in men.” A total of 93 men with elevated PSA levels (4 to 10 ng/ml), with a Gleason score of less than 7, and who had not undergone conventional treatments, were split into two groups. For one year, one group followed a low-fat vegan diet and the other continued with the American diet (control group). Because of a rise in PSA levels or signs of disease progression, 6 in the control group eventually underwent conventional therapy (surgery, radiation, chemotherapy) – none in the vegan diet group required further treatment. PSA decreased 4% in the vegan diet group and rose 6% in the control American-diet group.

    Because money for research comes primarily from pharmaceutical companies, and secondarily from food companies making their money from the products that are causing and promoting cancer, too little research proving the benefits of a low-fat, plant-food based diet is likely to ever be done. The result is simply more suffering and death of your friends and relatives.

    1) Strom SS, Yamamura Y, Forman MR, Pettaway CA, Barrera SL, DiGiovanni J. Saturated fat intake predicts biochemical failure after prostatectomy. Int J Cancer. 2008 Jun 1;122(11):2581-5.

    2) Ornish D, Weidner G, Fair WR, Marlin R, Pettengill EB, Raisin CJ, Dunn-Emke S, Crutchfield L, Jacobs FN, Barnard RJ, Aronson WJ, McCormac P, McKnight DJ, Fein JD, Dnistrian AM, Weinstein J, Ngo TH, Mendell NR, Carroll PR. Intensive lifestyle changes may affect the progression of prostate cancer. J Urol. 2005 Sep;174(3):1065-1070.

  4. #4
    Ex-admin Korn's Avatar
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    Default Re: High B12 levels associated with an up to 3-fold increased prostata cancer ri

    Some more links about prostate cancer and animal products:

    From dfwnetmall.com
    Dairy and Prostate Cancer

    From cancerproject.org:
    Prostate Cancer: Prevention and Survival
    Cancer of the prostate is strongly linked to what men eat. Again, animal products are consistently indicted: Milk, meat, eggs, cheese, cream, butter, and fats are found, in one research study after another, to be linked to prostate cancer.
    From physicians-background.com:
    Milk and Prostate Cancer

    From drmirkin.com:
    Does milk cause cancer?

  5. #5
    Ex-admin Korn's Avatar
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    Default Re: Milk and Prostate Cancer: New Evidence

    Here's a study from 2008 on a group of men with prostate cancer who changed their lifestyle and started to live on a predominantly plant based, low-fat diet..


    "The 30 men who enrolled did not undergo surgery or radiation therapy to treat their
    low-risk tumors; rather, they underwent comprehensive lifestyle changes (low-fat, whole-foods, plant-based nutrition; stress management techniques; moderate exercise; and participation in a psychosocial group support)."

    Among the changes they observed in the 30 men, was "changes in prostate gene expression". THe gene related changes happened after only three months and affected 500 gens (favorably).

    More about the link between prostate cancer and intake of animal products (and high B12 levels) here.

  6. #6
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    Default Meat and dairy increases prostate cancer risk

    http://news.bbc.co.uk/1/hi/health/7655405.stm





    Meat 'ups prostate cancer risk'


    Hormone may stimulate development of cancer cells

    Eating meat and dairy products may increase the risk of prostate cancer, research suggests.
    Such a diet raises levels of a hormone called Insulin-like Growth Factor-1 (IGF-1) which promotes cell growth.
    A University of Oxford team examined the results of 12 studies, featuring a total of nearly 9,000 men.
    They found men with high blood levels of IGF-1 were up to 40% more likely to develop prostate cancer than those with low levels.
    The study appears in the journal Annals of Internal Medicine.
    IGF-1 plays a key role in the growth and development of children and adolescents.
    In adults it continues to regulate cell growth and death, but it can also inhibit the death of cells which have come to the end of their natural life cycle.
    Extent unclear
    Lead researcher Dr Andrew Roddam said the degree to which diet influenced IGF-1 levels was unclear.
    But he said levels could be up to 15% higher in people who ate a lot of meat and dairy products.
    Dr Roddam said: "There is a need to identify risk factors for prostate cancer, especially those which can be targeted by therapy and/or lifestyle changes.
    "Now we know this factor is associated with the disease we can start to examine how diet and lifestyle factors can affect its levels and whether changes could reduce a man's risk."
    Dr Roddam said raised levels of IGF-1 were likely not only to increase the risk of developing prostate cancer, but also to aid the spread of tumours.
    Research shows that cells fed IGF-1 grow much more quickly.
    However, Dr Roddam said there was no evidence to suggest that measuring IGF-1 levels could be used to develop a new test to screen for prostate cancer.
    Each year in the UK more than 34,000 men are diagnosed with prostate cancer and around 10,000 die of the disease.
    Dr Lesley Walker, of the charity Cancer Research UK, which funded the study, said: "While there are established risk factors associated with prostate cancer of age, family history, and ethnicity, there are no clear data on modifiable risk factors."
    Last edited by Korn; Oct 11th, 2008 at 09:00 AM. Reason: This was the first post in a similar thread
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  7. #7
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    Default Re: Meat increases prostate cancer risk

    And, funnily enough, studies have shown that masturbation can lower the risk as well, so if yer a veggie wanker then it's a good chance something else will kill you rather than the P cancer!

    It's a scary disease, was speaking to a doctor friend the other week and he was saying that if a man lives to be 85 then he WILL have prostate cancer 99% certain. It may not be malignant but cancerous cells will be present in the gland.
    Disobedience is the true foundation of liberty!

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    Default Re: Meat increases prostate cancer risk

    *This has nothing to do with the thread, I apologize* but I totally read the title of the thread as: "Meat increses prostitution." To stay on topic, Wow, gogs67... I never realized guys were that likely to get it... That is pretty scary.
    Until we stop harming all other living beings, We are still savages.

  9. #9
    Ex-admin Korn's Avatar
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    Default Re: High B12 levels associated with an up to 3-fold increased prostate cancer ri

    As already mentioned in various threads (see list below), there is a link between some cancer types and animal product intake. The main difference between a vegan and meat based diet (in terms of nutrients) is the B12 intake.

    Cancer, adaptation and the vegan diet

    Cancer and animal products

    Red Meat 'Linked To Breast Cancer'

    Bacon & Skinless Chicken Associated With Bladder Cancer / Dairy Products May Increase Testicular Cancer Risk

    Red meat and cold cuts linked to colorectal cancer


    I came across an article/discussion today about a possible link between using injectible B12 supplements and brain tumor risk:
    http://www.tradersnarrative.com/conf...unkie-669.html
    My only concern with taking B-12 is that there is some limited evidence to that suggests there is a higher risk of developing a brain tumor when using injectable B12 supplementation. The current reasoning as to why this may happen has to do with the manner in which B-12 works in the brain. B-12 supplementation can help protect the existing structures in the brain as well as assist the brain in repairing certain structures.
    These effects can also be used by harmful cancerous cells, thus allowing a brain tumor to form or accelerate in growth through the use of B-12 concentrations that would not otherwise exist in the body.

    Still, though, there is conclusive link, just anecdotal evidence. I believe that the potential benefits outweigh the risks. Still, there are risks. Just very low probablility.

    However, there is no link to the sources for these findings - has anyone here seen this report? There's also a post in that discussion suggesting links between "the cyanide form of B-12 has resulted in blindness" - and another poster writes about a link between using cyanocobalamin (the most common for of B12 in supplements) and organ damage (both claims are without links/sources).

    This info would maybe have been better off in the B12 overdose/megadose thread, but 'side effects', 'B12 overdose symptoms' and links between high intake of B12 and certain types of cancer are all related to each other...

    Links between high B12 levels and cancer have been reported several times, both in humans and animals. It wouldn't surprise me if B12 is the link between the increased cancer rate among meat eaters either.

    Furthermore - maybe the fact that humans have been including meat in their diet, maybe the body is 'defending itself' from overdosing on B12 by reducing it's ability to synthesize it's own....? (More about this later!)

    Animal-Based Nutrients Linked With Higher Risk Of Stomach And Esophageal Cancers
    ScienceDaily (Oct. 31, 2001) — Yale School of Medicine researchers have found that a diet high in cholesterol, animal protein and vitamin B12 is linked to risk of a specific type of cancer of the stomach and esophagus that has been increasing rapidly.

  10. #10
    Ex-admin Korn's Avatar
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    Default Re: High B12 levels associated with an up to 3-fold increased prostate cancer ri

    Red and Processed Meat Increases Risk of Prostate Cancer
    This was published on PCRM's site today.
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    Ex-admin Korn's Avatar
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    Default Re: High B12 levels associated with an up to 3-fold increased prostate cancer ri

    Folate and B12 were expected to be protective against prostate cancer, because folate, vitamin B12 and homocysteine are essential for methyl group metabolism and thus also for DNA methylation. Abnormal methylation, primarily hypermethylation of certain genes including tumor suppressors, has been implicated in prostate cancer development.

    But in fact, increasing plasma levels of folate and vitamin B12 were statistically significantly associated with increased prostate cancer risk, with an odds ratio of 1.60 for folate and 2.63 for vitamin B12 for highest vs. lowest quartile.

    Increasing plasma homocysteine levels were associated with a reduced risk of borderline significance.

    After adjustment for body mass index and smoking, a statistically significant increased risk remained only for vitamin B12.


    The researchers say: "Our results suggest that factors contributing to folate status are not protective against prostate cancer. On the contrary, vitamin B12, associated with an up to 3-fold increase in risk, and possibly also folate, may even stimulate prostate cancer development. These findings are novel and should be explored further in future studies."
    It's too bad that The Vegan Society's site, which now has an article dedicated to prostate cancer, doesn't even mention these findings. They still seem to belong to the group of vegans and non-vegans who claim that one should never worry about taking too much B12, which often happens to be the same people who, when discussing the association between B12 and homocysteine/heart disease, never mention the ongoing controversy about this topic.
    Last edited by Korn; May 22nd, 2010 at 09:19 AM.
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    Ex-admin Korn's Avatar
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    Default Re: Cancer, adaptation and the definition of 'omnivores'

    Here's a link already posted in another thread:
    Cancer Incidence and Mortality After Treatment With Folic Acid and Vitamin B12
    An excerpt:
    Results During study treatment, median serum folate concentration increased more than 6-fold among participants given folic acid. After a median 39 months of treatment and an additional 38 months of posttrial observational follow-up, 341 participants (10.0%) who received folic acid plus vitamin B12 vs 288 participants (8.4%) who did not receive such treatment were diagnosed with cancer (hazard ratio [HR], 1.21; 95% confidence interval [CI], 1.03-1.41; P = .02). A total of 136 (4.0%) who received folic acid plus vitamin B12 vs 100 (2.9%) who did not receive such treatment died from cancer (HR, 1.38; 95% CI, 1.07-1.79; P = .01). A total of 548 patients (16.1%) who received folic acid plus vitamin B12 vs 473 (13.8%) who did not receive such treatment died from any cause (HR, 1.18; 95% CI, 1.04-1.33; P = .01). Results were mainly driven by increased lung cancer incidence in participants who received folic acid plus vitamin B12. Vitamin B6 treatment was not associated with any significant effects.

    Conclusion Treatment with folic acid plus vitamin B12 was associated with increased cancer outcomes and all-cause mortality in patients with ischemic heart disease in Norway, where there is no folic acid fortification of foods.
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  13. #13
    Ex-admin Korn's Avatar
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    Default Re: High B12 levels associated with an up to 3-fold increased prostate cancer ri

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    Ex-admin Korn's Avatar
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    Default Several studies link high B12 and meat intake to esophageal cancer

    I've already mentioned this study from 2001 in another thread:
    Animal-Based Nutrients Linked With Higher Risk Of Stomach And Esophageal Cancers
    ScienceDaily (Oct. 31, 2001) — Yale School of Medicine researchers have found that a diet high in cholesterol, animal protein and vitamin B12 is linked to risk of a specific type of cancer of the stomach and esophagus that has been increasing rapidly.
    Here's another study which was released a week ago:
    High Intake of Folate from Food Sources Is Associated with Reduced Risk of Esophageal Cancer in an Australian Population.
    This is good news for vegans, because it's hard not to have good folate levels on a plant based diet.

    In addition to finding a link between low folate levels and esophageal cancer, the same study also found that supplemental thiamin, riboflavin, niacin, and vitamin B-12 were associated with increased esophageal adenocarcinoma risk. The study also found that cancer risk is increased with folate from supplements, but not with folate from food:

    Increasing intake of folate from foods was associated with reduced EAC risk (P-trend = 0.01) and mitigated the increased risks of ESCC associated with smoking and alcohol consumption. In contrast, high intake of folic acid from supplements was associated with a significantly elevated risk of BE with dysplasia. High intakes of riboflavin and methionine from food were associated with increased EAC risk, whereas increasing betaine intake was associated with reduced risks of BE without (P-trend = 0.004) or with dysplasia (P-trend = 0.02).
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    Default Re: Several studies link high B12 and meat intake to esophageal cancer

    That's such a worrying statistic about the b12 and high meat intake. I wish they would publish these findings straight on the main msn.com page or some place like that so a lot of people could read this!

  16. #16
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    Default Re: Several studies link high B12 and meat intake to esophageal cancer

    Just need one of those shock medical programs made by Vegans showing ALL these studies I think. 6 part documentary series? put it on Channel 4 (UK) with a title like...can't think of one but something to do with animals being dangerous generally catches attention.

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    Default Re: Several studies link high B12 and meat intake to esophageal cancer

    Yeah that would be good! I used to love Channel 4 in the UK btw, shame you can't get it here in Canada.

    I would just love itif this sort of information would be more easy to find for people because all the info is already out there, but you always need to make an effort to find it. I would like it if people had no excuse and can't say 'oh but 'I didn't know'. I think a regular show on channel 4 or the BBC would be good.

  18. #18
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    Default Re: Several studies link high B12 and meat intake to esophageal cancer

    Quote khadagan View Post
    I think a regular show on channel 4 or the BBC would be good.
    ORRRRRRRR....a Vegan TV channel! :O...VEGANVISION...and Veganvision +1 just for double exposure

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    Default Re: Several studies link high B12 and meat intake to esophageal cancer

    I would love a vegan tv channel!! I think they should add a regular vegan cooking show to any food channel. Maybe drop a few facts in there, not too many though, you don't want to put anyone off by preaching , more importantly show people how nice vegan foods can be and you really don't need any animal foods

  20. #20
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    Default Re: Several studies link high B12 and meat intake to esophageal cancer

    http://www.youtube.com/watch?v=rYX18NGTwls
    Just remembered this and another video where they told people who were suffering from diet based illness and made them all go vegan and saw how much they improved after 2 weeks, can't find the video of a Texas cowboy kinda guy who was crying after he saw how much his health improved.

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    Default Re: Several studies link high B12 and meat intake to esophageal cancer

    Quote VagabondVegan View Post
    Re: Several studies link high B12 and meat intake to esophageal cancer http://www.youtube.com/watch?v=rYX18NGTwls Just remembered this and another video where they told people who were suffering from diet based illness and made them all go vegan and saw how much they improved after 2 weeks, can't find the video of a Texas cowboy kinda guy who was crying after he saw how much his health improved.
    Thanks for posting this link, very interesting!

  22. #22
    Ex-admin Korn's Avatar
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    Default Re: High B12 levels associated with an up to 3-fold increased prostate cancer ri

    Here's a similar report from American Association for Cancer Research (Feb 2010)
    Circulating Folate, Vitamin B12, Homocysteine, Vitamin B12 Transport Proteins, and Risk of Prostate Cancer: a Case-Control Study, Systematic Review, and Meta-analysis

    Am excerpt from the abstract:
    Results: In the ProtecT study, increased B12 and holo-haptocorrin concentrations showed positive associations with prostate cancer risk [highest versus lowest quartile of B12 odds ratio (OR) = 1.17 (95% confidence interval, 0.95-1.43); Ptrend = 0.06; highest versus lowest quartile of holo-haptocorrin OR = 1.27 (1.04-1.56); Ptrend = 0.01]; folate, holo-transcobalamin, and tHcy were not associated with prostate cancer risk. In the meta-analysis, circulating B12 levels were associated with an increased prostate cancer risk [pooled OR = 1.10 (1.01-1.19) per 100 pmol/L increase in B12; P = 0.002]; the pooled OR for the association of folate with prostate cancer was positive [OR = 1.11 (0.96-1.28) per 10 nmol/L; P = 0.2) and conventionally statistically significant if ProtecT (the only case-control study) was excluded [OR = 1.18 (1.00-1.40) per 10 nmol/L; P = 0.02].

    Conclusion: Vitamin B12 and (in cohort studies) folate were associated with increased prostate cancer risk.

    Impact: Given current controversies over mandatory fortification, further research is needed to determine whether these are causal associations. Cancer Epidemiol Biomarkers Prev; 19(6); 1632–42. ©2010 AACR.
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    Ex-admin Korn's Avatar
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    Default Re: High B12 levels associated with an up to 3-fold increased prostate cancer ri

    Animal foods, protein, calcium and prostate cancer risk: the European Prospective Investigation into Cancer and Nutrition

    We examined consumption of animal foods, protein and calcium in relation to risk of prostate cancer among 142 251 men in the European Prospective Investigation into Cancer and Nutrition. Associations were examined using Cox regression, stratified by recruitment centre and adjusted for height, weight, education, marital status and energy intake. After an average of 8.7 years of follow-up, there were 2727 incident cases of prostate cancer, of which 1131 were known to be localised and 541 advanced-stage disease. A high intake of dairy protein was associated with an increased risk, with a hazard ratio for the top versus the bottom fifth of intake of 1.22 (95% confidence interval (CI): 1.07–1.41, Ptrend=0.02). After calibration to allow for measurement error, we estimated that a 35-g day−1 increase in consumption of dairy protein was associated with an increase in the risk of prostate cancer of 32% (95% CI: 1–72%, Ptrend=0.04). Calcium from dairy products was also positively associated with risk, but not calcium from other foods. The results support the hypothesis that a high intake of protein or calcium from dairy products may increase the risk for prostate cancer.
    British Journal of Cancer (2008) 98, 1574–1581. doi:10.1038/sj.bjc.6604331 www.bjcancer.com
    Published online 1 April 2008
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    Default Re: High B12 levels and increased cancer risk

    x
    Last edited by Consistency; Nov 11th, 2012 at 03:24 PM.

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    Ex-admin Korn's Avatar
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    Default Re: High B12 levels and increased cancer risk

    Here's another site mentioning 'troubling' B12/cancer connections: Is a Vitamin B12 Overdose Safe?:

    One case was reported of leukemia resulting from a vitamin B12 megadose used in the treatment pernicious anemia.
    http://www.amjmed.com/article/0002-9...872-6/abstract
    I have only seen the abstract of that report, and find a bit vague, because it doesn't say clearly that the cancer came from the B12 megadose.

    The article Folic acid, B12 may increase cancer risk on webmd.com mentions lung cancer risk:

    This finding was mainly driven by an increase in lung cancer incidence among the folic acid and B12-treated patients.
    Seventy-five (32%) of the 236 cancer-related deaths among the study participants were due to lung cancer, and the cancer incidence among the study group was 25% higher than in the population of Norway as a whole.

    Roughly 70% of all the patients in the study were either current or former smokers, including more than 90% of those who developed lung cancer.



    Other Views

    In a statement issued in response to the study, a spokesman for the supplement-industry trade association Council for Responsible Nutrition (CRN) noted that the lung cancer finding has not been seen in other studies.

    "The real headline of this study should be that smoking increases the risk of lung cancer -- the study found that a total of 94% of the subjects who developed lung cancer were either current or former smokers," CRN Vice President for Scientific and Regulatory Affairs Andrew Shao, PhD, says in a news release.

    In the U.S., mandatory folic acid fortification of flour and grains has been in effect for just over a decade, and fortification has succeeded in dramatically lowering the incidence of neural tube birth defects.
    Shao says the fact that lung cancer rates have also dropped during this time in both men and women suggest folic acid and B12 do not promote lung cancer.
    Bettina F. Drake, PhD, of Washington University in St. Louis School of Medicine, says it is not likely that fortification has led to an increase in cancers in the U.S. In fact, several studies suggest just the opposite.
    "We would expect to see an excess in cancers within a few years after folic acid fortification began, and we have not seen that," she tells WebMD.
    Drake says it is possible that folic acid protects against cancer at certain points in life and promotes the growth of cancers at other times. It may also be true that too little folate in the blood or too much of the B vitamin are both associated with an increased risk for cancer.

    It's already known that cancer is associated both with too high and too low levels of B12.

  26. #26
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    Default Re: Cancer, adaptation and the definition of 'omnivores'

    Quote Korn View Post
    Here's a link already posted in another thread:
    Cancer Incidence and Mortality After Treatment With Folic Acid and Vitamin B12
    An excerpt:
    This study also serves as a good reference re. whether to get folic acid from food or from supplements. It's easy to get enough folic acid from food on a vegan diet, but not so easy on a standard diet (which is why USA and other countries fortify food regularly with B9). And of course it serves as a warning against getting more B12 from supplements that the amount one actually need.
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    Default Re: High B12 levels and increased cancer risk

    Here's yet another study focusing on the possible link with a high intake of B12 and folic acid supplements and cancer:

    Control of prostate cancer associated with withdrawal of a supplement containing folic acid, L-methyltetrahydrofolate and vitamin B12: a case report.



    PMID:21867542

    A few short excerpts:

    Introduction

    This is the first report of possible direct stimulation of hormone-resistant prostate cancer or interference of docetaxel cytotoxicity of prostate cancer in a patient with biochemical relapse of prostatic-specific antigen. This observation is of clinical and metabolic importance, especially at a time when more than 80 countries have fortified food supplies with folic acid and some contemplate further fortification with vitamin B12.
    His PSA level continued to rise exponentially for 18 weeks, thus we assumed docetaxel resistance. The patient revealed that he was ingesting a supplement of 10 daily dose units of Intrinsi B12/folate (Metagenics, San Clemente, CA, USA. Each dose unit contained 20 mg of porcine intrinsic factor and 500 μg of vitamin B12, as well as 400 μg of FA, and 400 μg of L-5-methyltetrahydrofolate (for a total of 800 μg of mixed FAs). On 11 February 2010, his PSA* level reached 21.3 ng/mL, and on 25 February 2010, his serum FA level was assayed to be 134 ng/mL (normal range 5 ng/mL to 24 ng/mL), his serum vitamin B12 level was > 1500 pg/mL (normal range 300 pg/mL to 900 pg/mL), his serum testosterone level was < 20 ng/mL (normal range 212 ng/mL to 755 ng/mL), and his total serum homocysteine was 12.0 μmol/L (normal range 7 μmol/L to 12 μmol/L).

    The patient discontinued the oral supplement on day 900 (Figure ​(Figure1),1), and within two weeks his serum PSA level started to decline.
    Studies of patient use of health store supplements, many of which are known to affect DNA metabolism and DNA methylation markers, have revealed that up to 50% of cancer patients ingest large doses of vitamins and other supplements, such as probiotics, which contain "safe" bacteria that generate copious amounts of folates within the bowel. A recent study in our clinic revealed that a majority of cancer patients present with hypervitaminosis or hypovitaminosis of at least one or more of the B vitamins noted in Figure ​Figure2.2. As we have discussed herein, castration, drugs, diet, vitamin supplements, and probiotics may modulate tumor cell metabolism as well as gene expression by epimethylation and synthesis of DNA. We are concerned about the finding that many gas stations and liquor stores in the USA sell so-called "quick energy" liquid supplements that contain large amounts of B vitamins, including vitamins B6 and B12 and FA.

    PSA:
    A protease secreted by the epithelial cells of the prostate gland. Serum levels are elevated in patients with benign prostatic hyperplasia and prostate cancer and are used as a screening test for prostate cancer.
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    Default Re: High B12 levels and increased cancer risk

    PMID: 24249744, Dec 2013
    http://www.ncbi.nlm.nih.gov/pubmed/24249744
    Elevated plasma vitamin B12 levels as a marker for cancer: a population-based cohort study


    Abstract

    BACKGROUND:

    A substantial proportion of patients referred for plasma vitamin B12 (cobalamin [Cbl]) measurement present with high Cbl levels, which have been reported in patients with different cancer types. However, the cancer risk among patients with newly diagnosed high Cbl levels has not been adequately examined.
    METHODS:

    We conducted this cohort study using population-based Danish medical registries. Patients referred for Cbl measurement with levels greater than the lower reference limit (≥200 pmol/L) were identified from the population of Northern Denmark during the period of 1998 to 2009 using a database of laboratory test results covering the entire population. Data on cancer incidence (follow-up 1998-2010), Cbl treatment, and prior diagnoses were obtained from medical registries. Patients receiving Cbl treatment were excluded. Cancer risks were calculated as standardized incidence ratios (SIRs) with 95% confidence intervals (CIs), stratified by plasma Cbl levels. All statistical tests were two-sided.
    RESULTS:

    We identified 333 667 persons without prevalent cancer and not receiving Cbl treatment. Six percent had Cbl levels greater than the upper reference limit (≥601 pmol/L). Cancer risk increased with higher Cbl levels and was highest during the first year of follow-up (Cbl 601-800 pmol/L: SIR = 3.44, 95% CI = 3.14 to 3.76; Cbl >800 pmol/L: SIR = 6.27, 95% CI = 5.70 to 6.88; both P < .001). The risks were particularly elevated for hematological and smoking- and alcohol-related cancers for persons with high Cbl levels.
    CONCLUSIONS:

    High Cbl levels were associated with the risk of subsequently diagnosed cancer, mostly within the first year of follow-up. This may have clinical implications for the interpretation of high Cbl levels.
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    Default Re: High B12 levels and increased cancer risk

    http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2071282/
    The above study from 1963 shows that a discussion about associations between high B12 intake and health problems (in this case, cancer) has been going on for a long time.

    From their summary:
    The effect of massive vitamin B12 dosage on serially transplanted tumours were studied in August strain rats (15 series in 2 years, PWA2 fibrosarcoma) and CAF1/JAX mice (100 series in 3 years, 32 series in one year, C1300 neuroblastoma). The vitamin treated rats' tumour growth was increased by 200 per cent [...].
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    Default Re: High B12 levels and increased cancer risk

    Here's another one: http://ebm.sagepub.com/content/71/2/226.abstract, referred to here

    " supplementary vitamin B12 caused increased growth of theRous sarcoma in chicks. (http://cancerres.aacrjournals.org/content/16/9/842.long)"
    The latter article also states that "The uptake of vitamin Bi2-Co60 correlated wellwith tumor weight except for the heavier tumors" and "Large tumors were the major sites of vita min Bis-Co60 localization in some animals."
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    Default Re: High B12 levels and increased cancer risk

    Here's yet another study suggesting a link between cancer and high B12 levels. There's an ongoing discussion about cause and effect here, some people suggest that the high B12 levels in (some of?) these studies may be a result of, and not a cause of cancer.

    The serum of an 84 year old man with disseminated carcinoma was found to contain extremely high concentrations of cobalamin and of a cobalamin binding protein with trans-cobalamin I characteristics. Tumour tissue samples obtained at necropsy contained considerably higher concentrations of cobalamin binding protein (R-binder) than normal tissues. Tumour tissues also contained increased concentrations of specific folate binding protein. In all tissues studied a close correlation existed between unsaturated cobalamin and unsaturated folate binding and between total cobalamin and total folate binding. These results suggest related mechanisms for the synthesis of cobalamin binding proteins of the R-binder class and folate binding proteins by tumour tissue.
    http://www.ncbi.nlm.nih.gov/pubmed/6096403 [PMID:6096403]
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    Default Re: High B12 levels and increased cancer risk

    http://www.ncbi.nlm.nih.gov/pubmed/2...?dopt=Abstract
    [PMID:23029349]
    BACKGROUND: Measurement of serum cobalamin levels is routinely used to diagnose cobalamin deficiency. Surprisingly, approximately 15% of patients have high cobalamin levels and no consensus exists regarding the clinical implications.

    METHODS: Hospital-treated patients above 18 years of age referred for serum cobalamin measurement were included in groups of patients [percentage cobalamin supplemented] with low (<200 pmol/L, n = 200 [6%]), normal (200-600, n = 202 [6%]) high (601-1000, n = 217 [27%]) and very high (>1000, n = 199 [53%]) cobalamin levels. Total and cobalamin-saturated (holo) transcobalamin, total haptocorrin, soluble TC receptor, sCD320, and methylmalonic acid were analyzed. Data on diagnoses and medical prescriptions was obtained through medical files and the Aarhus University Prescription Database.

    RESULTS: Among patients not cobalamin supplemented median total haptocorrin and holo transcobalamin levels were markedly higher in the groups with high/very high cobalamin levels compared to groups with low/normal cobalamin levels. Median total transcobalamin and sCD320 levels were similar across the groups. A number of diagnoses were significantly associated to very high Cbl levels (odds ratio (95% confidence interval)): alcoholism (5.74 (2.76-11.96)), liver disease (8.53 (3.59-20.23)), and cancer (5.48 (2.85-10.55)). Elevated haptocorrin levels were seen in patients with alcoholism, cancer, liver-, renal-, autoimmune-, and bronchopulmonary disease. No clinical associations to sCD320 and total and holo transcobalamin levels were found.

    CONCLUSION: In non-supplemented patients, high cobalamin levels were associated to high haptocorrin levels, and several diagnoses, including alcoholism, liver disease and cancer. Our study emphasizes that clinicians should take high serum cobalamin levels into consideration in the diagnostic process.



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  33. #33
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    Default Re: High B12 levels and increased cancer risk

    "Very high cobalamin blood levels are significantly associated to malignant hemopathies among the population of a department of internal medicine. "

    http://europepmc.org/abstract/med/17981373



    PURPOSE: The high incidence of cobalamin (vitamin B12) deficiency results in frequent dosages of this vitamin in a department of internal medicine may reveal paradoxically high blood levels ofcobalamin. The objective of the study was to estimate underlying diseases and potential diagnostic relevance of high cobalamin blood levels in internal medicine.

    METHODS: A retrospective study was conducted, including in-patients from December 2005 to July 2006 presenting high cobalamin blood levels, as determined with our laboratory normal values (200-950 pg/mL).

    RESULTS: High cobalamin blood level is not unusual (18.5% of all dosages) and, most of time, it is associated with one or several diseases, among which acute and chronic liver diseases (often of alcoholic origin), various neoplasias, malignant hemopathies (myelodysplasia, myeloproliferative diseases, multiple myeloma), renal insufficiency and transient hematologic abnormalities (neutrophilic hyperleucocytosis, hypereosinophilia). Vitamin B12 supplementation and chronic myeloid leukemia represent less than 5% of all hypervitaminemia. There is no correlation between the level of cobalamin blood level and the number of underlying diseases for each patients. However, very high cobalamin blood levels (>1275 pg/mL) are significantly associated to malignant hemopathies (p<0.05). It is noteworthy that most of diagnosed neoplasia were unknown and at a non-metastatic stage.

    CONCLUSION: Very high cobalamin blood levels are significantly associated to malignant hemopathies among the population of a department of internal medicine. Referent laboratory should actively advertise the numerous diseases involved with high cobalamin blood levels.


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  34. #34
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    Default Re: High B12 levels and increased cancer risk

    "Vitamin B12 and (in cohort studies) folate were associated with increased prostate cancer risk"

    http://cebp.aacrjournals.org/content/19/6/1632.abstract?ijkey=80ff0586d39bfbcca49fab694ebecb 039fc25701&keytype2=tf_ipsecsha

    Background: Disturbed folate metabolism is associated with an increased risk of some cancers. Our objective was to determine whether blood levels of folate, vitamin B12, and related metabolites were associated with prostate cancer risk.Methods: Matched case-control study nested within the U.K. population–based Prostate testing for cancer and Treatment (ProtecT) study of prostate-specific antigen–detected prostate cancer in men ages 50 to 69 years. Plasma concentrations of folate, B12(cobalamin), holo-haptocorrin, holo-transcobalamin total transcobalamin, and total homocysteine (tHcy) were measured in 1,461 cases and 1,507 controls. ProtecT study estimates for associations of folate, B12, and tHcy with prostate cancer risk were included in a meta-analysis, based on a systematic review.Results: In the ProtecT study, increased B12 and holo-haptocorrin concentrations showed positive associations with prostate cancer risk [highest versus lowest quartile of B12 odds ratio (OR) = 1.17 (95% confidence interval, 0.95-1.43); Ptrend = 0.06; highest versus lowest quartile of holo-haptocorrin OR = 1.27 (1.04-1.56); Ptrend = 0.01]; folate, holo-transcobalamin, and tHcy were not associated with prostate cancer risk. In the meta-analysis, circulating B12 levels were associated with an increased prostate cancer risk [pooled OR = 1.10 (1.01-1.19) per 100 pmol/L increase in B12; P = 0.002]; the pooled OR for the association of folate with prostate cancer was positive [OR = 1.11 (0.96-1.28) per 10 nmol/L; P = 0.2) and conventionally statistically significant if ProtecT (the only case-control study) was excluded [OR = 1.18 (1.00-1.40) per 10 nmol/L; P = 0.02].Conclusion: Vitamin B12 and (in cohort studies) folate were associated with increased prostate cancer risk.Impact: Given current controversies over mandatory fortification, further research is needed to determine whether these are causal associations. Cancer Epidemiol Biomarkers Prev; 19(6); 1632–42. ©2010 AACR.
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  35. #35
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    Default Re: High B12 levels and increased cancer risk

    "high serum vitamin B12 level, with or without unsaturated TC I elevation, usually implies a poor prognosis in a patient with cancer."
    http://www.ncbi.nlm.nih.gov/pubmed/902243?dopt=Abstract

    [PMID:902243]

    One hundred and thirty-nine patients with non-hematologic malignancy were studied to define the incidence of vitamin
    B12-related abnormalities and correlate them with clinical findings. Based on vitamin B12-binding patterns, the following relatively distinct groups were defined: (A) 50% had normal results; (B) 6% had very high transcobalamin (TC) I and vitamin B12 levels as reported in isolated instances previously: most had hepatic metastases and early death, and all had definite metastatic disease; (C) 11% had high vitamin B12 levels with little or no unsaturated TC I elevation: most also had hepatic and other metastases and early death; (D) 23% had high vitamin B12-binding capacity with normal TC I and vitamin B12 levels: there were no distinguishing features for this group other than an increased proportion of black patients; and (E) 10% had low vitamin B12 levels, in many cases not associated with vitamin B12 deficiency or other known causes of low serum levels. Thus, high serum vitamin B12 level, with or without unsaturated TC I elevation, usually implies a poor prognosis in a patient with cancer. However, while most such patients have hepatic and other metastases, hepatic involvement was not universal nor did most patients with hepatic disease have high vitamin B12 levels. High serum TC I thus is not always due to increased granulocytic proliferation or to hepatic tumor, and alternative mechanisms for TC I accumulation should be sought.
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    Default Re: High B12 levels and increased cancer risk

    http://www.ncbi.nlm.nih.gov/pubmed/6...?dopt=Abstract



    Of 37 patients with histologically verified hepatocellular carcinoma (HCC) from Bangkok, Thailand, 34 had raised values of plasma cobalamin, and 1 presented with a markedly increased value of plasma transcobalamin I (TC I). One patient with clinical malignancy of the liver, not proven histologically to be HCC, had a raised plasma cobalamin value and a markedly increased value of TC I. From our own studies and from studies in the literature we find circumstantial evidence that TC I occasionally is produced by the malignant liver cells in HCC.
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  37. #37
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    Default Re: High B12 levels and increased cancer risk

    Paternal intake of B12 before conception: Higher levels of paternal dietary vitamin B12 appeared to be associated with an increased risk of childhood ALL" (acute lymphoblastic leukemia).

    http://www.ncbi.nlm.nih.gov/pubmed/25281326

    We investigated whether paternal dietary intake of folate before conception is associated with the risk of childhood acute lymphoblastic leukemia (ALL) in a nationwide case-control study.
    METHODS:

    Data on dietary folate intake during the 6 months before the child's conception were collected from 285 case fathers and 595 control fathers using a dietary questionnaire. Nutrient intake was quantified using a customized computer software package based on Australian food composition databases. Data on folate intake were analyzed using unconditional logistic regression, adjusting for study-matching variables, total energy, and potentially confounding variables. In a subset of 229 cases and 420 controls, data on vitamin B6 and vitamin B12 intake were also analyzed.
    RESULTS:

    No consistent associations were seen with paternal dietary intake of folate or vitamin B6. Higher levels of paternal dietary vitamin B12 were appeared to be associated with an increased risk of childhood ALL, with those in the highest tertile of consumption having an OR of 1.51 (0.97, 2.36). The use of supplements containing folate and vitamins B6 or B12 was rare.
    CONCLUSIONS:

    We did not find any biologically plausible evidence that paternal nutrition in the period leading up to conception was associated with childhood ALL. Our finding for vitamin B12 may be a chance finding, given the number of analyses performed, or be attributable to participation bias because parents with a tertiary education had the lowest level of B12 intake and tertiary education was more common among control than case parents.
    PMID:25281326
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  38. #38
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    Default Re: High B12 levels and increased cancer risk

    "Elevated concentrations of vitamin B(12) may be associated with an increased risk for advanced stage prostate cancer, but this association requires examination in other large prospective studies."

    http://www.ncbi.nlm.nih.gov/pubmed/18268110

    [PMID:18268110]
    BACKGROUND:

    Determinants of one-carbon metabolism, such as folate and vitamin B(12), have been implicated in cancer development. Previous studies have not provided conclusive evidence for the importance of circulating concentrations of folate and vitamin B(12) in prostate cancer etiology. The aim of the present study was to investigate the relationship between prostate cancer risk and circulating concentrations of folate and vitamin B(12) in a large prospective cohort.
    METHODS:

    We analyzed circulating concentrations of folate and vitamin B(12) in 869 cases and 1,174 controls, individually matched on center, age, and date of recruitment, nested within the European Prospective Investigation into Cancer and Nutrition cohort. Relative risks (RR) for prostate cancer were estimated using conditional logistic regression models.
    RESULTS:

    Overall, no significant associations were observed for circulating concentrations of folate (P(trend) = 0.62) or vitamin B(12) (P(trend) = 0.21) with prostate cancer risk. RRs for a doubling in folate and vitamin B(12) concentrations were 1.03 [95% confidence interval (95% CI), 0.92-1.16] and 1.12 (95% CI, 0.94-1.35), respectively. In the subgroup of cases diagnosed with advanced stage prostate cancer, elevated concentrations of vitamin B(12) were associated with increased risk (RR for a doubling in concentration, 1.69; 95% CI, 1.05-2.72, P(trend) = 0.03). No other subgroup analyses resulted in a statistically significant association.
    CONCLUSION:

    This study does not provide strong support for an association between prostate cancer risk and circulating concentrations of folate or vitamin B(12). Elevated concentrations of vitamin B(12) may be associated with an increased risk for advanced stage prostate cancer, but this association requires examination in other large prospective studies.
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    Default Re: High B12 levels and increased cancer risk

    "Treatment with folic acid plus vitamin B(12) was associated with increased cancer outcomes and all-cause mortality in patients with ischemic heart disease in Norway, where there is no folic acid fortification of foods."

    http://www.ncbi.nlm.nih.gov/pubmed/19920236


    CONTEXT:

    Recently, concern has been raised about the safety of folic acid, particularly in relation to cancer risk.
    OBJECTIVE:

    To evaluate effects of treatment with B vitamins on cancer outcomes and all-cause mortality in 2 randomized controlled trials.
    DESIGN, SETTING, AND PARTICIPANTS:

    Combined analysis and extended follow-up of participants from 2 randomized, double-blind, placebo-controlled clinical trials (Norwegian Vitamin Trial and Western Norway B Vitamin Intervention Trial). A total of 6837 patients with ischemic heart disease were treated with B vitamins or placebo between 1998 and 2005, and were followed up through December 31, 2007.
    INTERVENTIONS:

    Oral treatment with folic acid (0.8 mg/d) plus vitamin B(12) (0.4 mg/d) and vitamin B(6) (40 mg/d) (n = 1708); folic acid (0.8 mg/d) plus vitamin B(12) (0.4 mg/d) (n = 1703); vitamin B(6) alone (40 mg/d) (n = 1705); or placebo (n = 1721).
    MAIN OUTCOME MEASURES:

    Cancer incidence, cancer mortality, and all-cause mortality.
    RESULTS:

    During study treatment, median serum folate concentration increased more than 6-fold among participants given folic acid. After a median 39 months of treatment and an additional 38 months of posttrial observational follow-up, 341 participants (10.0%) who received folic acid plus vitamin B(12) vs 288 participants (8.4%) who did not receive such treatment were diagnosed with cancer (hazard ratio [HR], 1.21; 95% confidence interval [CI], 1.03-1.41; P = .02). A total of 136 (4.0%) who received folic acid plus vitamin B(12) vs 100 (2.9%) who did not receive such treatment died from cancer (HR, 1.38; 95% CI, 1.07-1.79; P = .01). A total of 548 patients (16.1%) who received folic acid plus vitamin B(12) vs 473 (13.8%) who did not receive such treatment died from any cause (HR, 1.18; 95% CI, 1.04-1.33; P = .01). Results were mainly driven by increased lung cancer incidence in participants who received folic acid plus vitamin B(12). Vitamin B(6) treatment was not associated with any significant effects.
    CONCLUSION: Treatment with folic acid plus vitamin B(12) was associated with increased cancer outcomes and all-cause mortality in patients with ischemic heart disease in Norway, where there is no folic acid fortification of foods.



    [PMID: 19920236]
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  40. #40
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    Default Re: High B12 levels and increased cancer risk

    About fathers' B12 intake before conception: "high B12 intake was associated with an increased risk of CBT" (childhood brain tumors - in the offspring).

    http://www.ncbi.nlm.nih.gov/pubmed/25625505




    Abstract

    It is biologically plausible that a paternal preconception diet low in nutrients related to DNA integrity could affect sperm DNA and subsequently risk of cancer in the offspring. The aim of this analysis was to investigate whether paternal preconception dietary folate, B6, or B12 intake was associated with the risk of childhood brain tumors (CBT) in an Australian case-control study. Cases <15 years of age were recruited from 10 Australian pediatric oncology centers between 2005 and 2010, and controls from random-digit dialing, frequency-matched to cases on age, sex, and state of residence. Paternal dietary information was obtained by food-frequency questionnaires. Nutrient values were energy adjusted and divided into tertiles for analysis by unconditional logistic regression. In fathers with relevant data (237 cases and 629 controls), no association with dietary folate and B6 and risk of CBT was seen; high B12 intake was associated with an increased risk of CBT (odds ratio highest vs. lowest tertile: 1.74, 95% confidence interval: 1.14, 2.66) without an increasing trend. These results do not support the hypothesis that paternal dietary folate intake influences the risk of CBT. The increased OR observed between dietary B12 intake and risk of CBT is without any certain explanation.



    [PMID:25625505]
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