Dairy Intake And Prostate Cancer

Discussion in 'Cancer' started by j., Mar 2, 2013.

  1. j.

    j. Guest

    Dairy intake and 1,25-dihydroxyvitamin D levels in men at high risk for prostate cancer.

    OBJECTIVE Dairy food intake has been associated with prostate cancer in previous work, but the mechanism by which this occurs is unknown. Dairy calcium may suppress circulating levels of potentially cancer-protective 1,25-hydroxyvitamin D (1,25(OH)2D). We examined the associations of dairy, milk, calcium, and vitamin D intake with plasma 1,25(OH)2D levels among 296 men (194 black, 102 non-black) enrolled in a high risk program for prostate cancer from 10/96 to 10/07. METHODS All participants completed diet and health history questionnaires and provided plasma samples, which were assessed for levels of 25-hydroxyvitamin D and 1,25(OH)2D. We used multivariate linear regression to examine associations with 1,25(OH)2D. RESULTS After adjustment for age, race, energy intake, BMI, and alcohol intake, we observed no associations for any of our variables of interest with 1,25(OH)2D, or any meaningful differences in estimates by race or vitamin D status. CONCLUSION Our findings, in a sample including a large proportion of black participants, do not confirm previous findings showing an inverse association between calcium intake and 1,25(OH)2D levels. As such, they suggest that future work should explore other mechanisms by which dairy foods and calcium might increase prostate cancer risk.

    Link
     
  2. OP
    j.

    j. Guest

    Might I suggest adding synthetic vitamins to milk?
     
  3. jyb

    jyb Member

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    What's wrong with synthetic vitamins, btw? I take vit D supps for example. Why would there be impurities in the milks ones and not in my supplements?
     
  4. cliff

    cliff Member

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    They use carriers to disperse the supplements in milk, the most problematic is probably polyscorbate 80
     
  5. LucH

    LucH Member

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    [moderator edit: posts moved from: Why Ray recommends eating lots of calcium]

    Calcium from vegetables and other foodstuff or from supplement (not to high) are OK. From supplement, provided you get enough Vitamins D3 and K2.
    But not from dairies, in certain circumstances.
    According to this study, not very concluant (weak), youd need to take more than 721 mg calcium not to elevate a prostate cancer risk, by people at risk. Risk 38 %.

    http://www.ncbi.nlm.nih.gov/pmc/article ... rt=classic
    The impact of cow's milk-mediated mTORC1-signaling in the initiation and progression of prostate cancer. Bodo C Melnik et al. Nutr Metab (Lond). 2012.
    Prostate cancer (PCa) is dependent on androgen receptor signaling and aberrations of the PI3K-Akt-mTORC1 pathway mediating excessive and sustained growth signaling. The nutrient-sensitive kinase mTORC1 is upregulated in nearly 100% of advanced human PCas. Oncogenic mTORC1 signaling activates key subsets of mRNAs that cooperate in distinct steps of PCa initiation and progression.
    Mammalian milk is presented as an endocrine signaling system, which activates mTORC1, promotes cell growth and proliferation and suppresses autophagy. Naturally, milk-mediated mTORC1 signaling is restricted only to the postnatal growth phase of mammals. However, persistent consumption of cow´s milk proteins in humans provide highly insulinotropic branched-chain amino acids (BCAAs) provided by milk´s fast hydrolysable whey proteins, which elevate postprandial plasma insulin levels, and increase hepatic IGF-1 plasma concentrations by casein-derived amino acids. BCAAs, insulin and IGF-1 are pivotal activating signals of mTORC1. Increased cow´s milk protein-mediated mTORC1 signaling along with constant exposure to commercial cow´s milk [highlight=yellow]estrogens[/highlight] derived from pregnant cows may explain the observed association between high dairy consumption and increased risk of PCa in Westernized societies.

    Personnal obervation: This study is not very strong. But you won't get a strong proof. If you want to limit cheese or milk from non-organic source (one or two serves) and if you moderate the PI3K-Akt-mTORC1 pathway, you won't probably have any trouble with dairies.
    :yellohello
    LucH

    PS: I know the interpretation of the study about insulin is incorrect, but IGF-1 and mTor stimulation are evident. Not a problem for most people, except at risk.
     
  6. haidut

    haidut Member

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    Thanks...but the study says that it is the protein of milk that is the causative factor, not calcium itself. Also, all protein raises mTOR/IGF-1, so this relationship should be present for all protein rich in BCAA and that includes meat, eggs, and even some plant protein.
     
  7. jb116

    jb116 Member

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    As hair it pointed out that study's about protein where the op is about calcium. But now that that has brought up, and yes is OT, it still questions the peaty foundation of milk focus as well as eggs and meat protein. Any thoughts?
     
  8. haidut

    haidut Member

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    There have been actual double blind placebo controlled trials with calcium from both supplement and milk. The trials were for other conditions, so the population was not exactly random but still these trials never found any increase in cancer risk and some of them specifically monitored for that given how bad the reputation of calcium is in some circles. It could be the phosphate in milk/meat that is raising the cancer risk, not the BCAA or calcium.
     
  9. Giraffe

    Giraffe Member

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    I screened the article LucH has linked, and I think it is biased.

    There is a reference to a study within the EPIC project. I only screened it:

    "For dairy products, yoghurt intake was associated with an increased risk (the HR for the highest versus the lowest fifth of intake was 1.17, 95% confidence interval (CI): 1.04 – 1.31; Ptrend ¼ 0.02), but there was no evidence of an association with intakes of milk and milk beverages or cheese."

    Whereas after adjusting for education, marital status, exercise... (aka multivariate hazard ratios or short BS):

    "The results support the hypothesis that a high intake of protein or calcium from dairy products may increase the risk for prostate cancer."

    No mention of vitamin K2 in the original article. From another study (link here post 96470) that also was part of the EPIC project:

    "In summary, we found inverse associations between the dietary intake of menaquinones and the risk of prostate cancer. The associations were strongest for menaquinones from dairy products and in advanced cancer cases."

    "According to our data, dairy products contribute 60% to total intake of menaquinones, and it seems that menaquinones from dairy products have a more pronounced effect than those from meat products. These observations contrast with those from numerous prospective studies that suggest a positive association between the intake of dairy products, especially dairy calcium, and prostate cancer."
     
  10. DaveFoster

    DaveFoster Member

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    Thank you Giraffe. You saved my milk.
     
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