Article

Effect of Selenium and Vitamin E on Risk of Prostate Cancer and Other Cancers

Division of Cancer Medicine, University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX 77030, USA.
JAMA The Journal of the American Medical Association (Impact Factor: 30.39). 01/2009; 301(1):39-51. DOI: 10.1001/jama.2008.864
Source: PubMed

ABSTRACT Secondary analyses of 2 randomized controlled trials and supportive epidemiologic and preclinical data indicated the potential of selenium and vitamin E for preventing prostate cancer.
To determine whether selenium, vitamin E, or both could prevent prostate cancer and other diseases with little or no toxicity in relatively healthy men.
A randomized, placebo-controlled trial (Selenium and Vitamin E Cancer Prevention Trial [SELECT]) of 35,533 men from 427 participating sites in the United States, Canada, and Puerto Rico randomly assigned to 4 groups (selenium, vitamin E, selenium + vitamin E, and placebo) in a double-blind fashion between August 22, 2001, and June 24, 2004. Baseline eligibility included age 50 years or older (African American men) or 55 years or older (all other men), a serum prostate-specific antigen level of 4 ng/mL or less, and a digital rectal examination not suspicious for prostate cancer.
Oral selenium (200 microg/d from L-selenomethionine) and matched vitamin E placebo, vitamin E (400 IU/d of all rac-alpha-tocopheryl acetate) and matched selenium placebo, selenium + vitamin E, or placebo + placebo for a planned follow-up of minimum of 7 years and a maximum of 12 years.
Prostate cancer and prespecified secondary outcomes, including lung, colorectal, and overall primary cancer.
As of October 23, 2008, median overall follow-up was 5.46 years (range, 4.17-7.33 years). Hazard ratios (99% confidence intervals [CIs]) for prostate cancer were 1.13 (99% CI, 0.95-1.35; n = 473) for vitamin E, 1.04 (99% CI, 0.87-1.24; n = 432) for selenium, and 1.05 (99% CI, 0.88-1.25; n = 437) for selenium + vitamin E vs 1.00 (n = 416) for placebo. There were no significant differences (all P>.15) in any other prespecified cancer end points. There were statistically nonsignificant increased risks of prostate cancer in the vitamin E group (P = .06) and type 2 diabetes mellitus in the selenium group (relative risk, 1.07; 99% CI, 0.94-1.22; P = .16) but not in the selenium + vitamin E group.
Selenium or vitamin E, alone or in combination at the doses and formulations used, did not prevent prostate cancer in this population of relatively healthy men.
clinicaltrials.gov identifier: NCT00006392.

Download full-text

Full-text

Available from: Jaime Claudio, Jul 19, 2015
0 Followers
 · 
168 Views
  • Source
    • "A francia EVA prospektív tanulmányban [11] több mint kilenc évig tartó követés során sem találtak pozitív korrelációt a diabétesz kialakulása és a magasabb szérumszelénszint között. A SELECT vizsgálat – több mint 35 ezer beteg bevonásával – is hasonló eredményeket hozott [12], amiben a 2-es típusú diabétesz incidenciája csak másodlagos végpont volt. Ezzel szemben egy amerikai vizsgálatban emelkedett diabéteszkockázatot találtak szelénszupplementációban részesülő betegeknél [13]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Selenium deficiency results in profound changes in cellular defence mechanisms against oxidative stress, which plays an important role in the development of cardiovascular disease and the associated risk factors. Increased formation and decreased elimination of reactive oxygen radicals contribute to the complicated mechanisms of sepsis and related disorders. Use of selenium in prevention and treatment of the above mentioned conditions is not a new idea, but controversial data were published in relation to both fields recently. The aim of the present review is to summarize the most important results related to this area. Orv. Hetil., 154 (41), 1621-1627.
    10/2013; 154(41):1621-1627. DOI:10.1556/OH.2013.29727
  • Source
    • "These effects may be associated with the production of reactive oxygen species generated in the oxidation–reduction cycle (Jackson and Combs 2008). Other studies showed no effects of selenium supplementation (200 lg/d) on the prevention of prostate cancer in a population of relatively healthy men from the US, Canada, and Puerto Rico (Lippman et al. 2009). The association between the concentration/activity of selenium/selenoproteins in plasma and diabetes mellitus is still a matter of debate. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Selenium supplementation and its effects on Northerners have been little studied. The aim of our study was to assess the selenium levels of the inhabitants of North European Russia, the seasonal aspects of selenium supplementation, and the interrelationships between selenium levels and the levels of thyroid gland hormones. To study the particular features of selenium metabolism in Northerners over the course of 1 year, 19 healthy male Caucasian volunteers (18-21 years old) were recruited for the present study. The subjects were military guards in a Northern European region of Russia (Syktyvkar, Russia, 62°N latitude) who spent 6-10-h outdoors daily. The study was conducted over a 12-month period. Selenium levels, glutathione peroxidase (GP) activity, as well as total triiodothyronine (T3), total thyroxin (T4), free thyroxin, free triiodothyronine, and thyrotropin (TSH) levels, were determined in the blood serum. The study subjects showed low levels of plasma selenium throughout the year. We observed a noticeable decrease in plasma selenium levels during the period from May to August, with the lowest levels in July. Selenium levels in the military guards correlated with the levels of selenium-dependent GP enzyme activity throughout the year. Additionally, we demonstrated a significant correlation between selenium and pituitary-thyroid axis hormones (total T3, free T4, and TSH) in periods in which plasma selenium levels were lower than the established normal ranges. Over the course of 1 year, low levels of plasma selenium affect GP activity and thyroid hormone levels in humans living in North European Russia.
    07/2013; DOI:10.1007/s00420-013-0895-4
  • Source
    • "Both these compounds were beneficial when patterns of increased intake in diet were studied in many previous studies. However, in these clinical trials, an increased risk of prostate cancer was found in the group taking vitamin E and an increased risk of type 2 diabetes mellitus was found in the group taking selenium (Lippman and others 2009). While these were statistically nonsignificant increased risks, they were close enough to be significant (P = 0.06 and P = 0.16) that the clinical trial had to be stopped due to ethical and safety concerns. "
    [Show abstract] [Hide abstract]
    ABSTRACT: There is strong scientific evidence suggesting that regular consumption of fruits and vegetables is negatively associated with risk of developing chronic diseases. The 2010 Dietary Guidelines for Americans recommend at least 9 servings of fruits and vegetables a day based on a 2000 kcal diet. However, the average person in the United States consumes 3.6 servings of fruits and vegetables per day. In order to achieve the goal of at least 9 servings, we should continue educating Americans about the health benefits of fruits and vegetables and recommend consumers to eat a wide variety of fruits and vegetables. The key is to increase the amount up to 9 to 13 servings of fruits and vegetables a day in all forms. Fresh, cooked, and processed fruits and vegetables including frozen and canned, 100% fruit juices, 100% vegetable juices, and dried fruits are all considered as servings of fruits and vegetables. A wide variety of fruits and vegetables provide a range of nutrients and different bioactive compounds including phytochemicals (phenolics, flavonoids, and carotenoids), vitamins (vitamin C, folate, and provitamin A), minerals (potassium, calcium, and magnesium), and fibers. More and more evidence suggests that the health benefits of fruits and vegetables are attributed to the additive and synergistic interactions of the phytochemicals present in whole foods by targeting multiple signal transduction pathways. Therefore, consumers should obtain nutrients and bioactive compounds from a wide variety of whole foods for optimal nutrition and health well-being, not from expensive dietary supplements.
    06/2013; 78 Suppl 1:A18-25. DOI:10.1111/1750-3841.12101
Show more