By Marcia Wood
March 15, 2002
A study of selenium, under way in
northern California, may reveal important clues about the role of this
essential nutrient in the human body. The research will help determine whether
tomorrow's breads, pastas and other flour-based foods should be fortified with
selenium to boost health. That's according to research chemist Chris Hawkes of
the ARS Western Human Nutrition Research
Center at Davis, Calif.
Hawkes is leading the study and is collaborating with investigators from the
Nutrition Center, the University of
California at Davis School of Medicine and
Medical Center and the
University of California at San Francisco.
The researchers are scrutinizing selenium's effects on the immune,
cardiovascular and reproductive systems and on body composition--that is, the
relative amount of fat-to-lean tissue such as muscle. Theyre doing that
by regularly testing more than 30 healthy men, aged 18 to 45, who have
volunteered for the investigation. The study eventually will encompass 48
In the first year of the two-year study, half of the volunteers take a daily
capsule that provides five-and-one-half times the Recommended Dietary Allowance
of selenium in the form of high-selenium yeast. The other volunteers take a
daily placebo, a capsule that looks the same but contains yeast, but no
At prescribed intervals over the two-year period, volunteers report to the
Nutrition Center to give samples of blood and other specimens and to undergo
tests. A test of cardiovascular fitness, for example, will indicate whether
increasing selenium intake enhances blood flow in arteries. Studies done
elsewhere showed that arteries did not properly expand and contract in
laboratory animals raised on selenium-deficient feed.
Seafood--and grains and meats from regions with selenium-rich soils--are
good sources of this mineral. Other sources include dairy products and
The March 2002
issue of the agency's Agricultural Research magazine tells more.
ARS is the U.S. Department of
Agriculture's chief scientific research agency.