Link between vitamin E selenium and prostate cancer?

A new study released found a relationship between vitamin D, selenium, and prostate cancer. What I know is this will get a lot of press. The last big article about multiple vitamins not preventing heart disease and cognitive decline also got a lot of press. Did anyone see the link between multiple vitamins and decrease risk of cataracts? It is doubtful.

I have read the summary of the article so I really cannot fully comment on the validity of the study. It may be completely accurate. However if you read my article on the multiple vitamin you will see that that study had its faults.

What I would like to know about this study was what type of vitamin E was used. In many studies will see that they only use a synthetic vitamin E which I do not recommend. I recommend a complete mixture of vitamin E with tocotrenols.

I would also like to know what type of selenium was used in the study. All this information would be very helpful to know because studies such as this do not necessarily tell us the whole truth.

Since there are variety of types of vitamin E and selenium what the study could tell us is that these types increase the risk of prostate cancer.

I would like to compare this to a statement such as statins cause memory disturbances. (This statement is just hypothetical.) The use of one specific Staten drug in a study such as this does not tell us about all the different varieties of Staten drugs. Different ones have different effects in the same is true with vitamin E and selenium.

Remember you only get to see the bad studies in the press. It is rare that they publish the good ones.

Source: http://www.ncbi.nlm.nih.gov/pubmed/24563519

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About John Montague DC

John Montague DC is the owner of WebVitamins. He is active in the industry and is currently president of the NPA East.

Comments

  1. Carotech Inc says:

    Thank you for sharing the questions that you have asked about the study – these are questions that any reader of that article should ask.

    The publication of this study that claims that “vitamin E” (note the inverted comma, which shall be explained later on in this comment) and selenium supplements may increase, rather than decrease as originally thought, the risk of prostate cancer.

    In addition to saying that the form of selenium used matters, we would also like to add that this holds true as well for the form of “vitamin E” used to distinguish the various forms of vitamin E that are available in the market such as synthetic vitamin E (ie : dl-alpha-Tocopherol) vs. natural vitamin E (ie : d-alpha-tocopherol) and tocopherol vitamin E vs. tocotrienol vitamin E.

    To any individual who reads the full published paper with data derived from SELECT, he/she will know that the study specifically indicates PURIFIED SELENIUM and SYNTHETIC vitamin E may raise prostate cancer risk!

    In nature – there are 8 natural forms of vitamin E : d-alpha-, d-beta-, d-gamma, d-delta-tocopherol, and d-alpha-, d-beta-, d-gamma-, and d-delta-tocotrienol. This particular study did not use natural tocopherol, let alone tocotrienols.

    Since tocotrienols and other tocopherol forms were not used in the SELECT study, it is of our opinion that :-
    i) The result of elevated prostate cancer risk in this study may not be relevant to those who take natural d-alpha-tocopherol or natural vitamin E (d-mixed tocopherols) or tocotrienols (d-mixed tocotrienols). SELECT used synthetic vitamin E (all rac-α-tocopheryl acetate) where only one out of the eight vitamin E forms is biologically active / bioavailable. Hence, significantly less active biologically.
    ii) Newspaper or magazine headlines erroneously used the term “Vitamin E” in the title such as “Vitamin E Increases Prostate Cancer Risk”. Using the term vitamin E without qualifying the exact form of vitamin E used, is a disservice to the dietary supplement market. The title should have made a distinction of the form of vitamin E used in SELECT. It would have been a more appropriate and accurate representation of the SELECT study if the title had been – “Synthetic Vitamin E (dl-alpha-tocopheryl acetate) Increases Prostate Cancer Risk”. Or for this particular paper – “Baseline selenium status and effects of L-Selenomethionine and Synthetic Vitamin E supplementation on prostate cancer risk”.

    Using the term “Vitamin E” in the title/headline gives an absolutely wrong impression to readers / consumers that all types / forms of vitamin E increases prostate cancer risk, which is not what SELECT study shows, by any stretch of the imagination.

    In a number of published papers, tocotrienols have been shown to inhibit prostate cancer growth in cell and mice models. Prof. Francesco Galli of the University of Perugia showed that gamma-tocotrienol was taken up and metabolized by prostate cancer PC3 or LNCaP cells at a faster rate compared to gamma-tocopherol and alpha-tocotrienol, with alpha-tocopherol showing the slowest uptake and transformation. Prof. Galli also showed that prostate cancer PC3 or LNCaP cells supplemented with gamma-tocotrienol showed significant cell growth inhibition in a concentration dependent manner, followed by gamma-tocopherol. The alpha-forms were much less effective (1). Researchers at MD Anderson Cancer Center and East Tennessee State University reported that gamma-tocotrienol selectively inhibit PC3 cell growth but has no effect on normal prostate cells, and that gamma-tocotrienol has a greater potential to inhibit cancer cell growth at lower concentration than gamma-tocopherol (2). These researchers have also elucidated the pathways by which gamma-tocotrienol exerts a growth-inhibitory effect on prostate cancer cells (3). At Rutgers University, researchers observed significant reduction in the occurrence of prostate tumors in the mixed tocotrienol (from Tocomin, Carotech Inc.) supplemented mice compared to control mice (4). Another study by researchers at Purdue University showed that gamma-tocotrienol treatment led to increased accumulation of sphingolipids, which precedes cancer cell death. Gamma-tocotrienol also inhibited LNCaP xenograft growth by 53%, compared with 33% by gamma-tocopherol, in nude mice (5)

    In fact, many animal studies show gamma-tocopherol as effective in inhibiting prostate carcinogenesis (6,7). The combination of gamma-tocopherol with other vitamin E forms especially delta-tocopherol exhibit synergistic effects in inhibiting prostate cancer cells (8,9). In an in vitro study, gamma-tocopherol enriched mixture had stronger effects for inhibiting the growth and stimulating apoptosis than alpha-tocopherol in LNCaP cells (10). Gamma-tocopherol also induces growth arrest in PC-3 prostate cancer cells through regulation of fatty acid metabolism (11). A review reported that “different forms of vitamin E appear to exert different effects on prostate cancer, with alpha-tocopherol potentially increasing and gamma-tocopherol potentially decreasing the risk of the disease” (12). Helzlsouer et al. (13) reported that men with highest quintile of plasma gamma-tocopherol concentration have a fivefold reduction in prostate cancer risk, compared to the lowest quintile.

    The above studies, out of many more, collectively provided evidence that other vitamin E forms may be effective in reducing prostate cancer risk. By using only one type of vitamin E and in a synthetic form (petroleum-based), to arrive at a conclusion that ‘vitamin E’ increases the risk of prostate cancer is misleading. It severely undermines the potential benefit of other natural compounds under the same family, namely the tocotrienols and gamma-tocopherol, that offer protection against prostate cancer and have other unique biological activities.

    Magazine and newspaper editors, etc who want to carry news on this SELECT study , must correctly and specifically identify the form of vitamin E used in the study, in their titles or headlines so as not to misguide or confuse the readers / consumers and the general public!

    Take-home messages :-
    1. Synthetic vitamin E is significantly less biologically active. It is different from natural mixed tocopherols or natural mixed tocotrienols.
    2. Do not take high dose of synthetic vitamin E.
    3. Taking the full spectrum natural vitamin E (d-mixed tocopherols + d-mixed tocotrienols) or E Complete, will likely be protective.

    For more information on tocotrienols – please visit http://www.tocotrienol.org.
    Thank you.

    From Carotech Team
    http://www.carotech.net

    References:
    1. Conte C, et al. (2004). γ-tocotrienol metabolism and anti-proliferative effect in prostate cancer cells. Ann N Y Acad Sci. , 1031, 391-4.
    2. Campbell SE, et al. (2008, Special Issue – October). Gamma tocotrienol and prostate cancer: The regulation of two independent pathways to potentiate cell growth inhibition and apoptosis. Journal of Oil Palm Research , 33-43.
    3. Campbell SE, et al. (2011). Gamma-tocotrienol induces growth arrest through a novel pathway with TGFβ2 in prostate cancer. Free Radic Biol Med. , 50 (10), 1344-54.
    4. Barve, A. (2010). Mixed tocotrienol inhibit prostate carcinogenesis in TRAMP mice. Nutrition and Cancer , 62 (6), 789-794.
    5. Jiang Q, et al. (2012). Gamma-tocotrienol induces apoptosis and autophagy in prostate cancer cells by increasing intracellular dihydrosphingosine and dihydroceramide. Int J Cancer , 130 (3), 685-693.
    6. Barve A, et al. (2009). Gamma-tocopherol-enriched mixed tocopherol diet inhibits prostate carcinogenesis in TRAMP mice. Int. J. Cancer , 124, 1633-99.
    7. Takahashi S, et al. (2009). Suppression of prostate cancer in a transgenic rat model via gamma-tocopherol activation of caspase signaling. The Prostate , 69, 644-651.
    8. Jiang Q, et al. (2004). γ-tocopherol or combinations of vitamin E forms induce cell death in human prostate cancer cells by interrupting sphingolipid synthesis. PNAS , 101 (51), 17825-17830.
    9. Yang CS, et al. (2012). Does vitamin E prevent or promote cancer? Cancer Prev Res , 5 (5), 701-5.
    10. Zheng X, et al. (2011). Inhibition effect of a γ-tocopherol-rich mixture of tocopherols on the formation and growth of LNCaP prostate tumors in immunodeficient mice. Cancers , 3, 3762-3772.
    11. Campbell SE, et al. (2009). Gamma tocopherol upregulates the expression of 15-S-HETE and induces growth arrest through a PPAR gamma-dependent mechanism in PC-3 human prostate cancer cells. Nutr Cancer , 61 (5), 649-62.
    12. Vance TM, et al. (2013). Dietary antioxidants and prostate cancer: A review. Nutr Cancer , 65 (6), doi:10.1080/01635581.2013.806672.
    13. Helzlsouer KJ, et al. (2000). Association between α-tocopherol,γ-tocopherol, selenium, and subsequent prostate cancer. J. Natl Cancer Inst , 92, 2018-23.

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