Environmental concerns are causing many key components of currently
used fumigants to lose their federal registrations. And some stored-product
insect pests are beginning to develop resistance to some widely used
fumigants. These two trends could spell trouble for bulk grains that
must be held in storage until markets open up for their sale and use.
So researchers have been testing oils extracted from 16 medicinal plants
and spices for their effects against one important pest, the rice weevil,
Sitophilus oryzae. This tiny insect causes major problems in
granaries worldwide, reducing the grain's nutritional value and ability
to germinate and exposing it to odor, mold, and heat damage.
The most potent antiweevil oils proved to be found in Japanese mint,
Mentha arvensis. Its active ingredient, menthone, could provide
the basis for a new, environmentally friendly fumigant. But additional
testing is needed to determine its impact on grain's smell and taste.
Bruce C. Campbell, USDA-ARS
Mycotoxin Research Unit, Albany, California; phone (510) 559-5846.
Don't Forget Your Folate!
Careful scrutiny of data from NHANES III, a recent nationwide health
and nutrition survey, showed that fortification of grain products with
the B vitamin folate may help reduce memory loss in the over-60 set.
The researchers were looking for a relationship between blood homocysteine
levels and memory loss. Homocysteine is a byproduct of our own amino
acid metabolism that has been implicated in the risk of stroke.
Previous research had shown its levels to be higher in elderly persons
with low vitamin B intakesespecially folate. B vitamins are involved
in the synthesis of chemicals crucial to brain function. It is also
possible that homocysteine itself might be toxic to nerve cells.
This nutrition analysis confirmed a link between elevated homocysteine
and memory loss in elders. But survey subjects with blood folate levels
in the upper half seemed to be protected from memory loss, even if their
homocysteine levels were high. So it appears to be important to maintain
an adequate folate intakenow easier thanks to industry fortification
of grain products.
Martha M. Morris,
Jean Mayer USDA Human Nutrition
Research Center on Aging at Tufts University, Boston, Massachusetts;
phone (617) 556-3302.
High-Selenium Broccoli Stymies Some Cancers
Broccoli stores selenium in an especially useful form (called SeMSC)
that is easily converted into an active anticancer agent. Now scientists
have succeeded in greatly boosting the selenium in specially grown broccoli.
Earlier studies showed that laboratory rats fed experimental high-selenium
broccoli and broccoli sprouts developed fewer precancerous lesions when
exposed to known carcinogens than did rats given selenium saltseither
selenate or selenite. The rats were fed the rough equivalent of a 200-microgram
human dose of selenium daily.
The new tests showed that high-selenium broccoli sprouts protected
the rats against precancerous lesions in the colon, while high-selenium
broccoli protected against mammary tumors.
Specially produced for this research, the experimental broccoli heads
and sprouts used in these studies aren't available commercially. And
further study is needed to show whether these findings will also prove
true in humans.
John W. Finley,
USDA-ARS Grand Forks Human
Nutrition Research Center, Grand Forks, North Dakota; phone (701)