8693 -- 10/29/00
Replaces 7572 


Gabe Mirkin, M.D.

An article in the Journal of the National Cancer institute presents 
an example how you should respond to newspaper reports of scientific 
journal articles. This article reports men with low tissue levels of 
selenium are at increased risk for prostate cancer (1). Does that 
mean that lack of selenium CAUSES prostate cancer and that you 
should start taking selenium supplements? You should not take 
selenium pills indiscriminately because taking too much selenium 
causes nerve damage, vomiting, nausea, feeling sick, white ridges on 
nails, hair loss, mottling of teeth, and loss of nails. Therefore 
you need to interpret the data correctly or you could poison 
yourself and shorten your life. 

The association between low tissue levels of selenium and prostate 
cancer could be that men are doing something that causes prostate 
cancer and also causes them to have low levels of selenium. Whole 
grains are a seed that has a thick coat called the husk. It is 
filled with endosperm that contains starch as a food for the germ 
that is the baby plant inside the seed. Selenium is found in the 
germ of grains. It is not found in the endosperm. Bakery products 
and pastas are made from flour that is made by removing the germ 
with its selenium and grinding the endosperm to make the flour. So 
commercial flour does not contain measurable amounts of selenium 
unless it is made from whole grains. So men with low tissue levels 
of selenium are the ones who do not eat whole grains. The germ also 
contains all the Energy B vitamins, almost all other minerals such 
as chromium, zinc, and so forth, and much of the phytochemicals that 
prevent disease. So the increased risk for prostate cancer in men 
with low tissue levels of selenium may be caused by lack of many 
minerals, vitamins and phytochemical , not just selenium.

I interpret this study to show that you should eat lots of whole 
grains and not single out lack of selenium as the major cause of 
prostate cancer. Incidently, several other articles show that low 
levels of selenium are also associated with increased risk for colon 
cancer (2,3). And the same thinking also applies to eating whole 
grains, rather than flour. I am not saying that flour is a poison. 
There is nothing harmful about bakery products and pastas. It is 
harmful to lack essential nutrients, so as long as you eat seeds, 
nuts, beans, whole grains, beans vegetables and fruits, it is
 perfectly alright to eat bakery products and pastas. If you are 
concerned that you are not getting enough selenium in your diet, ask 
your doctor to cut off a piece of your toenail and send it to a 
commercial lab to measure its selenium content. If your toenails are 
full of selenium, you do not lack that mineral. 

1) J of the National Cancer Institute August, 1998.

2) JAMA 1996(December 25);276(24):1957-1963.

3) Russo, M.W.; Murray, S.C.; Wurzelmann, J.I.; Woosley, J.T.; 
Sandler, R.S. Plasma selenium levels and the risk of colorectal 
adenomas. Nutrition and Cancer - an International Journal. 
1997;28(2):125-129. People in North Dakota have high blood levels 
of selenium and do not have reduced incidence of cancer. 

4) Blot H et al. J Nat Cancer Institute 1993;85:1483-1492.

5) van Nord PA et al. Int J Epidemiol. 1987;16:318-322. Selenium 
does not reduce cancer of breast and bladder.