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Food & Nutrition Research Briefs, April 2009
Aged laboratory animals that ate a diet rich in the berry and grape compound
pterostilbene performed better in tests than those in a group that did not eat
the enriched diet, according to the results of a new study by Agricultural
Research Service (ARS) scientists. Pterostilbene reversed measurable negative
effects of aging on brain function and behavioral performance. The results
indicated that in aging rats, pterostilbene was effective in reversing
cognitive decline, and that improved working memory was linked to pterostilbene
levels in the hippocampus region of the brain.
Details
Scientific contact:
James
A. Joseph, (617) 556-3178,
Jean
Mayer USDA Human Nutrition Research Center on Aging, Boston,
Mass.
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A diet rich in antioxidant compounds from berries
and grapes reversed cognitive decline and improved working memory in aged
laboratory animals.
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Growing conditions like weather have been found to
influence the levels of antioxidants in soybean.
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Agricultural Research Service (ARS) scientists have found that weather and
climate play key roles in levels of a family of antioxidants tucked inside
soybean seeds. Researchers analyzed the content of tocopherols in soybean seeds
grown at several locations in Maryland between 1999 and 2002. Weather was
relatively normal between 1999 and 2001, but extreme drought and warmer
temperatures characterized 2002. There were small but significant increases in
the proportion of alpha-tocopherol in beans from the same genetic line grown in
warmer, full-season locations on Maryland's Eastern Shore, compared to beans
that matured under slightly cooler conditions. But under extreme drought
conditions in 2002, early maturing lines had as much as a 3.5-fold increase in
relative alpha-tocopherol content, compared to the other years during which
rainfall was adequate.
Details
Scientific contact:
Steven
J. Britz, (301) 504-6625 ext. 241,
Food
Components and Health Laboratory, ARS Henry A. Wallace Beltsville
Agricultural Research Center, Beltsville, Md.
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A microscopic biological sensor that detects Salmonella bacteria in
lab tests has been developed by an Agricultural Research Service (ARS)
scientist and university colleagues. The sensor could be adapted to detect
other foodborne pathogens as well. The sensor is part of an evolving science
known as nanotechnology, the study and manipulation of materials on a molecular
or even atomic level, measured in billionths of a meter, which is about 10 to
100 times thinner than a human hair. The biosensors include fluorescent organic
dye particles attached to Salmonella antibodies. The antibodies hook
onto Salmonella bacteria and the dye lights up like a beacon, making the
bacteria easier to see.
Details
Scientific contact:
Bosoon
Park, (706) 546-3396,
Quality
and Safety Assessment Research Unit, ARS Richard B. Russell Research
Center, Athens, Ga.
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A microscopic biological sensor that can detect
Salmonella bacteriashown here in a petri dishin lab tests
has been developed by an Agricultural Research Service scientist and university
colleagues.
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Plant pigments commonly found in colorful fruits
and vegetables appear to have a protective effect against bone loss in older
adults, according to a new study. Photo courtesy of National Institutes of
Health.
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Findings from a new study funded by the Agricultural Research Service (ARS)
suggest that natural plant pigments called carotenoids may help protect against
bone loss in older men and women. Over the course of the four-year study,
carotenoids were associated with some level of protection against losses in
bone mineral density at the hip in men and at the lumbar spine in women. No
significant associations were observed at other bone sites. The results suggest
there is a protective effect of carotenoids, particularly of lycopene, against
bone loss in older adults. The researchers concluded that carotenoids may
explain, in part, the previously observed protective effects of fruit and
vegetable consumption on bone mineral density.
Details
Scientific contact:
Katherine
Tucker, (617) 556-3351,
Jean
Mayer USDA Human Nutrition Research Center on Aging, Boston,
Mass.
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A new study funded in part by the Agricultural Research Service (ARS)
suggests that neutralizing an acid-producing diet may be an important key to
reducing bone breakdown, or "turnover," while aging. The study comes
on the heels of several ARS-reported studies suggesting that consuming
more-than-recommended amounts of calcium may not be the main answer to
protecting bone. A group of 78 volunteers had been provided either of two
bicarbonatespotassium or sodiumalong with their usual diet and
exercise regimes. The bicarbonate groups consumed an amount of bicarbonate
equivalent to about nine servings of fruits and vegetables daily. The results
showed that the 78 volunteers in the bicarbonate groups had significant
reductions in biomarkers that are associated with bone loss and fracture than
the 84 in the no-bicarbonate group.
Details
Scientific contact:
Bess
Dawson-Hughes, (617) 556-3066,
Jean
Mayer USDA Human Nutrition Research Center on Aging, Boston,
Mass.
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Neutralizing an acid-producing diet, which can be
done by eating fruits and vegetables, appears to be an important key to
reducing bone breakdown while aging.
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The plant on the left received no UV light; the
middle plant received only UV-A light; and the plant on the right received both
UV-A and UV-B light, resulting in higher levels of phenolic
antioxidants.Photo courtesy of Steve Britz, ARS.
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Growing the right type of green leaf lettuce during winter in a
greenhouseand exposing it to the right type of ultraviolet lightcan
boost levels of nutritionally beneficial carotenoids, according to an
Agricultural Research Service (ARS) study. Supplemental ultraviolet-A light
(UV-A) and ultraviolet-B light (UV-B) greatly increased the carotenoid and
chlorophyll concentrations of the green leaf lettuce varieties, while slightly
but significantly reducing the levels of those compounds in the red varieties.
Interestingly, significantly higher levels of other phenolic phytochemicals
were produced in the red leaf lettuce varieties, compared to the green leaf
lettuce varieties under the same UV treatment conditions. Among the green leaf
lettuce varieties, under identical light and growing conditions,
"Concept" had about 10 times the level of lutein, a carotenoid, as
"Black-Seeded Simpson." Also, the amount of lutein in two green
varieties"Marin" and "Waldmann's Dark
Green"more than doubled after receiving both supplemental UV-A and
UV-B light, when compared to lettuce that received only regular light.
Details
Scientific contact:
Steven
J. Britz, (301) 504-6625, ext. 241,
Food
Components and Health Laboratory, ARS Henry A. Wallace Beltsville
Agricultural Research Center, Beltsville, Md.
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A team of investigators at a research center funded by the Agricultural
Research Service (ARS) has identified new genetic sites harboring common
variations in DNA that are linked to imbalances in concentrations of blood
lipids (fats). The findings provide another step forward in understanding the
genetic contribution to dyslipidemia, a condition marked by overproduction of
low-density lipoprotein (LDL "bad" cholesterol) and triglycerides,
and underproduction of high-density lipoprotein (HDL
"good"cholesterol). While each of the 30 genetic sites, called loci,
identified conferred a modest effect individually, the analysis suggests that
the more lipid-risk variants found in one individual, the higher his or her
association with dyslipidemia. Together, the 30 sites explain a significant
percentage of the genetic contribution to lipid levels among individuals.
Details
Scientific contact:
Jose
Ordovas, (617) 556-3102,
Jean
Mayer USDA Human Nutrition Research Center on Aging, Boston,
Mass.
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A new study associates 11 new genetic sites with
cholesterol and triglyceride levels in people. Image courtesy of Microsoft
Clipart.
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For people aged 31-50, eating a high proportion of
"fast food" is associated with a higher body mass index (BMI).
Image courtesy of Microsoft Clipart.
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A study by Agricultural Research Service (ARS) nutritionist Rhonda Sebastian
shows that among U.S. men and women aged 31 to 50, obtaining a greater
proportion of total calories from conventional fast-food restaurants was
associated with a higher BMI, or body mass index. Sebastian and colleagues
analyzed the eating habits of more than 2,000 volunteers aged 19 to 50. The
significant relationship between BMI and fast-food intake found among the 31-
to 50-year age group was not found among the 894 volunteers who were in the 19-
to 30-year age group.
Details
Scientific contact:
Rhonda
Sebastian, (301) 504-0343,
ARS
Beltsville Human Nutrition Research Center, Beltsville, Md.
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A prototype pressure chamber and camera system that finds very small cracks,
called microcracks, in fresh eggshells has been developed by Agricultural
Research Service (ARS) scientists. The device could help the fresh egg industry
find microcracks that can often go undetected during grading. The technology
emulates human graders who squeeze eggs along suspected cracks to see if the
cracks open. The camera then takes a picture before and while the crack is
opening to "see" if the shell is cracked. The system detected 99.4
percent of eggshell cracks while recording almost no false positives (only 0.3
percent). In comparison, professional human graders had an 85.8 percent crack
detection rate and 1.2 percent false positives.
Details
Scientific contact:
Kurt C.
Lawrence, (706) 546-3527,
Quality
and Safety Assessment Research Unit, ARS Richard B. Russell Research
Center, Athens, Ga.
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A pressure chamber finds very small cracks in
fresh eggshells.
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ARS researchers are working out ways to raise
saltwater fish like this pompano hundreds of miles from the nearest ocean.
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An Agricultural Research Service (ARS) team including agricultural engineer
Timothy J. Pfeiffer, fish nutritionist Martin A. Riche, and fish biologist
Charles R. Weirichall based in Ft. Pierce, Fla.is determining how
to best raise cobia and pompano inland, hundreds of miles from the nearest
ocean or bay, in huge tanks of fresh or only slightly salty water. The tanks
are part of what's known as a "recirculating aquaculture system," or
"RAS," in which water is cleaned and used again and again. These
systems offer the potential to reduce discharge of everyday fish-farm effluent
to as little as 3 percentor lessof the total amount of water used
each day. Fish wastes and unused food collected in the system could be recycled
as nutrient-rich compost.
Details
Scientific contact:
Timothy
J. Pfeiffer, (772) 465-2400, ext. 360,
ARS
Harry K. Dupree Stuttgart National Aquaculture Research Center, Fort.
Pierce, Fla.
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