Selenium, vitamin E supplements increase prostate cancer risk?

Another vitamin and mineral supplement ‘scare’ hit the headlines recently with claims from USA research that high supplement doses of (jointly) vitamin E and the mineral Selenium could increase prostate cancer risks. Although the purpose of the research was to attempt to find a positive correlation (for prostate and select nutrients) it was reported that their findings appeared to suggest the opposite.

This led to a round of media stories and at Cytoplan we received a number of calls and emails from concerned customers seeking clarification on the implications of the news. There were a number or robust responses both critical of the research implications and particularly the way it had been reported by elements of the media (some might say ‘hyped’).

We supply links to two news items from media outlets that reported, and supported, the apparently critical aspects of the research and were critical (in general) of taking many (or all) supplements; these stories (links below) are from the Daily Mail and Harvard Health Blog.

In balance as a response against some of the seemingly alarmist reporting we supply a link (below) to a transcript of an interview on Dr Mark Porter’s Inside Health show (Radio Four) with Margaret Rayman, Professor of Nutritional Medicine at the University of Surrey. Thankfully she provides some sensible and reasoned information on the research including an explanation on Selenium food sources; abridged comments include the following:

“Expressed real concern that these findings were even being reported at all, as US levels of selenium are much higher, due to North American crops being grown in more selenium rich soil, and so were irrelevant to UK news. She also mentioned that there is huge evidence to support the claim that a number of health conditions could be improved by taking a small additional amount of selenium, but that there’s never any benefit in taking “heroic” doses, and she would not recommend the additional 200mg that was given to these participants on top of a selenium rich diet.”

Importantly nowhere in the research does it show the supplement forms of Selenium or vitamin E used. We did contact the study authors and they do not seem to think the form is important and hence will not declare this information. However, EFSA (The European Food Safety Authority) have found certain supplement forms of Selenium to be wholly safe, even at high doses, yet we also know the same is not true of sodium selenite for example.

So in our opinion the form of selenium is vitally important, food selenium is taken up by the body until all the body storage pools are full and then the body stops taking it in. This is not so with sodium selenite where there is no control mechanism to regulate its uptake in the body. So supplement ‘form’ is vital, and of course dose is important too. World health data tells us we need in total 3-5ug of Selenium per kg body weight per day, taking account intake (of Selenium) from food which is about 35ug/day in the UK.

We would suggest that the vitamin E supplementation is the likely ‘rogue’ in this particular research example. We know that high levels of fat soluble antioxidants that are not supported by high levels of water soluble antioxidants will create a high free radical load that predisposes to cancer. So the study design was extremely bad, probably designed to fail, the forms of supplement used were equally bad, and considered unimportant; and the intervention was incomplete. Moreover vitamin E as alpha tocopherol, one isomer of vitamin E, does not have the same action as nature identical vitamin E with 8 isomers. The former is of little benefit to health and the latter wholly beneficial.

So we would agree with Professor Rayman; this poor science should never reach publication where it serves to scaremonger and worry the public unnecessarily.

We include a link below to a pdf document from EFSA in which selenium-enriched yeast supplements (i.e. a food based supplement) were researched and found to be safe, effective and the safest form of selenium to use. This again highlights the difference between isolated supplement forms of selenium versus food forms (as per selenium-enriched yeast) – food substances fit into normal metabolic regulatory and feedback systems which govern correct uptake, distribution and storage for health – whilst isolates do not.

Moreover the only reason that sodium selenite/selenate are on the positive list of approved substances is because they had been used for 30 years at the time of the Food Supplements directive and hence had “grandfather rights” – they have never unfortunately had the testing or scrutiny that the newly approved substances have.

I would urge that please anyone who has concerns on this matter please do contact me Amanda (details below). However we would stress that we would not recommend anyone to take a high doses of specific nutrients unless there is a compelling health reason to do so.

In closing anyone looking to take a supplement whether comprising a single vitamin, mineral or other nutrient, or a multi-formulation (such as a multivitamin) if in any doubt should seek the advice of a health professional or advice directly from the supplement company, particularly if you have any pre-existing health conditions. And when looking at multi-formulations choose one specifically tailored to your age and gender (and again mindful of pre-existing health conditions if applicable).

RELEVANT LINKS:
BBC 4 Inside Health: Selenium & Vitamin E supplements in men
European Food Safety Authority: Selenium-enriched yeast, (2008) 766, 1-42
Daily Mail: Bin those vitamin pills
Harvard Health: Selenium, vitamin E supplements increase prostate cancer risk

If you have any questions regarding this article, any of the health topics raised, or any other health matters please do contact me (Amanda) by phone or email at any time.

Amanda Williams
Cytoplan
amanda@cytoplan.co.uk
01684 310099

Last updated on 15th December 2014 by