Selenium supplements — worth it or waste of time?

we probably have the most expensive

urine in the world thanks to the vast

amounts of herbs vitamins and mirrors we

consume each day the question is are

there life saving or maybe just a waste

of time and money or perhaps they're

even harmful Casey barrows has been

investigating one of them one of the

most popular mineral supplements is

selenium it's needed by the cells in our

bodies to keep them working properly and

there's been a belief that low serum

selenium that's the selenium in our


is linked to cancer risk I don't think

we can absolutely correlate prostate

cancer or other types of cancer risk

with selenium intake but in New Zealand

we know the sores are low we've got one

of the highest breast cancer prostate

cancer and I think it's a second highest

colorectal cancer incidence at the

moment whether that's selenium or

whether it's some other component of the

New Zealand diet we simply don't know

but if we can find a way to overcome

this obviously it's going to be

desirable for the population the

selenium levels are usually measured by

serum selenium and that seems to be

affected by dietary intake it's also

affected though by other things and so

for example in our own studies cigarette

smokers have a lower serum selenium

compared with their dietary intake than

do other individuals in the population

our prostate cancer subjects have a

lower solute serum selenium level than a

control population so certainly in some

groups it seems to be lower and that may

be reflected in dietary intake it may

also reflect a genetic component the

selenium composition of a diet is very

strongly dependent on where that plant

has grown or whether an animal has

grazed and so we known to be low in the

selenium content of our soils we've been

slowly bringing it up in the New Zealand

diet by bringing in Australian wheat but

it's still from our local studies

suggest it's not quite as high

as in Australia or in America or parts

of Europe now while Australia does have

some selenium rich soils it's far from

uniform so it's not guaranteed that all

our wheat and beef for example have

enough selenium or that you're not have

adequate amounts in our bodies so how

much do we actually need what's clear

from animal studies is that there's a

u-shaped curve to little selenium is a

really bad idea but so is too much

selenium and and our evidence in the New

Zealand population suggests exactly the

same thing that it's not a good idea to

have a serum selenium level less and 100

nanograms per mil which is significantly

less than you'd normally have in

Australia or America or some of these

other sorts of countries but you also

don't want to go above a level of much

more than about 160 nano grams per mil

the best way of testing whether selenium

works in cancer prevention is to do a

trial comparing it to a dummy tablet but

as Lynette Ferguson explains one of the

biggest trials created some problems

what happened was that five years after

it started they actually stopped the

trial because they were worried diabetes

seemed to be somewhat increasing and

other sorts of hints of adverse effects

rather than positive effects there's

been debates over what should be the

recommended daily intake of selenium and

and I understand that Australia has

actually decreased their recommended

amounts from 75

micrograms per day to 55 micrograms per

day and a New Zealand also has that

recommended amount

but maybe to reflect that you can with a

normal diet get about that level but

it's hard a much higher there's a range

of dietary supplements that contain

selenium a lot of them have got selenium

in the form of Selina methionine or it

might be inorganic selenium and you can

also buy a form of selenium that's

organic selenide yeast so how do you

know whether your health would be

improved by taking one of these selenium

supplements well the fact is in the

trial professor Fergusson mentioned

while on average there was no effect it

did seem that people with low selenium

levels benefited professor Fergusson

believes that people at risk should

think about having their serum selenium

levels tested with a blood test we found

it it's affected by lifestyle factors

cigarette smoking for example seems to

decrease serum selenium and our

population genotype also has an effect

on serum selenium so unless you know

you're starting serum selenium you're

not going to know whether you're going

to benefit from dietary changes that

enhance selenium intake or whether some

sort of supplement might be beneficial

if you go into a supplement the one that

we've been working with is an organic

form of selenium and it's a solenoid

yeast and certainly in a proportion of

our population it looks as though it's

beneficial to supplement with that