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Food & Nutrition Research Briefs, January 2008
Fast-Acting Carbs May Hasten Vision Loss Over Time
Consuming higher-than-average amounts of so-called "fast
carbohydrates" that cause blood sugar levels to spike and fall rapidly
could be a risk factor for central vision loss with aging. Scientists supported
by the Agricultural Research Service (ARS) and grants reported these findings
this year in the American Journal of Clinical Nutrition. Consuming a
diet high in fast carbs is also suspected of being involved in the vision loss
that sometimes occurs in people with diabetes.
Details
Scientific contact:
Allen Taylor, (617) 556-3156, ARS Jean Mayer USDA Human Nutrition Research
Center on Aging, Boston, Mass.
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Simulation of AMD-related vision loss (top) and
normal vision. Images courtesy National Eye Institute.
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Psychologist James Penland performs an
electroencephalogram, which measures responses from a volunteer's brain.
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Mineral Nutrition's Impact on Neonatal Development
Agricultural Research Service (ARS) scientists now have described how
adequate amounts of copper are important to brain function. Their animal model
studies suggest that levels of copper intake are critical to the fetus during
pregnancya concept called "nutritional programming." Study rats
were fed low-copper diets during gestation, lactation, or both. Those rats'
pups, when compared to pups born to mothers fed copper-sufficient diets,
exhibited slowed development of the dentate gyrus and hippocampal areas of
their brains.
Details
Scientific contact:
W. Thomas Johnson, (701) 795-8411, USDA-ARS Grand Forks Human Nutrition
Research Center, Grand Forks, N.D.
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Diet for Brain Development, From the Beginning
Studies looking into how diet and nutrition affect central nervous system
development from birth are being conducted by Agricultural Research Service
(ARS)-funded scientists. The scientists are using noninvasive tools to assess
infant, toddler and school-aged children's psychological, neurological and
physiological development, as well as other brain-related functions.
Details
Scientific contact:
Thomas M. Badger, (501) 364-2785, USDA-ARS Arkansas Children's Nutrition
Center, Little Rock, Ark. badgerthomasm@uams.edu
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A baby is weighed for a long-term ARS study on
developmental effects of different infant formulas.
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Many fruits can boost levels of antioxidants in
blood and lead to lower risk of chronic degenerative disease.
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Data on Food Antioxidants Released
Measures of the antioxidant capacities of 277 selected foods were released
recently by Agricultural Research Service (ARS) scientists. The new database
provides easy access to antioxidant values for a wide variety of foods, many of
which may be excellent sources of healthful compounds. Many of the fruits,
nuts, vegetables and spices listed were analyzed for their Oxygen Radical
Absorbance Capacity, known as ORAC. ORAC is one of a number of methods
available to evaluate the antioxidant capacities of foods. The new release
expands upon the 2004 data released by ARS on estimates of the antioxidant
capacity of 171 foods.
Details
Scientific contact:
David Haytowitz, (301) 504-0714, USDA-ARS Nutrient Data Laboratory, Beltsville,
Md.
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When It Comes to Vitamins, More Is Not Always Better
Scientists funded by the Agricultural Research Service (ARS) found an
interesting association among seniors aged 60 and older whose vitamin B12 blood
levels were low. Aging and taking stomach-acid blockers can contribute to a
gradual lessening of B12 absorption in the body. People with high folate and
low B12 status were found to be at a disadvantage when compared to those with
normal folate and low B12 status; the former group was more likely to exhibit
both anemia and cognitive impairment.
Details
Scientific contact:
Martha S. Morris, (617) 556-3302, ARS Jean Mayer USDA Human Nutrition
Research Center on Aging, Boston, Mass.
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Epidemiologist Martha Morris and biochemist Jacob
Selhub examine apparent associations between B vitamin status and cognitive
test results.
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Pinto beans.
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Eating Beans Helps Lower Cholesterol
Consuming as little as one-half cup of cooked dry beans every day helped
volunteers lower their total cholesterol levels in an Agricultural Research
Service (ARS) study in North Dakota. These results, published in the November
issue of the Journal of Nutrition by the ARS scientists and their
colleagues, add to a growingand convincingbody of evidence that
beans are a heart-healthy food choice.
Details
Scientific contact:
Philip Reeves, (701) 795-8497,USDA-ARS Grand Forks Human Nutrition
Research Center, Grand Forks, N.D.
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Scientist Developing Bread Rich in Beta-Glucan
An Agricultural Research Service (ARS) chemist is baking soft white bread
that resembles any store-bought loaf, except for a key difference: its
beta-glucan content. Research suggests that, when ingested, this soluble fiber
helps the body regulate blood glucose and lower "bad" cholesterol,
diminishing the risk of coronary heart disease. The bread owes its 0.75 grams
of beta-glucan per serving to C-TRIM, a barley- and oat-bran-based powder
developed at the ARS National Center for Agricultural Utilization Research in
Peoria, Ill.
Details
Scientific contact:
Abdellatif Mohamed, (309) 681-6331, Cereal Products and Food Science
Research Unit, Peoria, Ill.
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Scanning electron microscope image of
Campylobacter jejuni.
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New Campylobacter-Detecting Medium Licensed
A quicker, simpler way to distinguish between Campylobacter species
has now been licensed for manufacture by two U.S. companies: Becton Dickinson
and Co. of Franklin Lakes, N.J., and Neogen Corp. of Lansing, Mich. An
Agricultural Research Service (ARS) scientist began working with Polish
scientists in 1987 to develop the new medium, which was patented in 1999. The
new culture medium, called Campy-Cefex, is specifically designed to detect and
differentiate C. jejuni and C. coli mixtures of
food-contaminating microbes. These two bacteria are important causes of
foodborne illness. Campy-Cefex selects for Campylobacter among competing flora
in a sample, cultivating colonies that resemble tiny water droplets. From
these, microbiologists can estimate the level of Campylobacter contamination in
the sample.
Details
Scientific contact:
Norman J. Stern, (706) 546-3516, Poultry Microbiological Safety Research Unit,
Athens, Ga.
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Secrets of Fish Oil Compound Probed
A compound found in oil-rich fish such as salmon reshaped the blood lipid
profiles of volunteers in an Agricultural Research Service (ARS)-led study.
Blood samples taken after fasting, and within eight hours after meals, showed
that DHA reduced the number of small LDL (low-density lipoprotein) particles by
22 percent. LDLµs small particles are the size most harmful to the
cardiovascular system. The research, reported earlier this year in the
American Journal of Clinical Nutrition, is likely the first to
analyzein high-triglyceride malesDHA's effects on both fasting and
post-meal triglycerides, and on quantities and sizes of different types of
cholesterol particles.
Details
Scientific contact:
Darshan Kelley, (530) 752-5138, ARS Western Human Nutrition Research Center,
Davis, Calif.
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Salmon, often eaten with bagels, contains a
healthful omega-3 fatty acid.
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Technician Holly Sisson (left) and horticulturist
Elizabeth Baldwin homogenize guava for antioxidant and pigment analyses.
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U.S.-Thai Scientific Efforts Peg Guava's Nutritional Value
A cooperative study by Agricultural Research Service (ARS) and Thai
scientists has shown that guava fruit is high in antioxidants, adding it to the
list of other antioxidant-rich foods such as blueberries, black beans and
broccoli. In the study, guava's antioxidant content ranked just below that of
blueberries, which is No. 1 in antioxidant activity. Other fruits ranking
surprisingly high were carambola, lychee, mango and papaya.
Details
Scientific contact:
Elizabeth A. Baldwin, (863) 293-4133 ext. 120, Citrus and Subtropical
Products Research Laboratory, Winter Haven, Fla.
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