A form of inulin, a carbohydrate
commonly used as a low-calorie fat substitute in food products, may boost the
amount of calcium that teenage girls absorb from their diets. That could lead
to stronger bones, say researchers. They tested the calcium-boosting power of a
commercially available form of inulinRaftilose SDP®supplied by
Orafti, the study sponsor.
The study involved 29
girlsages 11 through 14who normally consumed a calcium-rich diet.
During the first three weeks, the girls drank calcium-fortified orange juice
containing either the inulin or a placebo as part of a 1,300-milligram calcium
diet. Following a two-week break, the girls repeated the study, with the inulin
group now receiving the placebo and vice versa.
While on the placebo, the girls
absorbed 416 mg of the calcium in their diet, about what researchers expected.
But while taking the supplemental inulin, absorption jumped 18 percent to an
average of 494 mg. The difference of nearly 80 mg is about the same amount of
calcium that a child would normally absorb from 7 ounces of milk.
Calcium absorption in adolescents
normally peaks at dietary levels of 1,300 to 1,500 mg per day, the recommended
level for this age group. But even those who meet this recommendation normally
only absorb about 30 percent of the calcium available in their dietsor
400 mg a day. The addition of inulin appears to raise the bar for the maximum
absorption of calcium.
The researchers believe that inulin
could boost the absorption of calcium from diets containing lower amounts of
calcium as well. Inulin also acts as dietary fiber, yielding about 1.5 calories
per gram, compared to 4 calories per gram for fully digestible carbohydrates
like sugar and 9 calories per gram for fat. Natural sources include onions,
asparagus, leeks, garlic, artichokes, bananas, wheat, rye, barley, and chicory.
For more information, contact
Steven A. Abrams, (713) 798-7000,
Children's Nutrition Research Center at
Baylor College of Medicine, Houston, TX
Back to Contents
U.S. kids today are eating more
food and more calories than kids did 20 years ago, according to the latest U.S.
Department of Agriculture data on the food intakes of nearly 10,000 children
nationwide. ARS nutritionists combined data from a special 1998 nationwide
survey of 5,559 children from birth to 9 years old with those from the 1994-96
national survey (CSFII) of all age groups. The earlier survey included 4,253
children to age 9. Trends gleaned from the combined data generally concur with
the 1994-96 findings.
Snacks contributed a significant
percent of daily caloriesaround 20 percent, on average. Among the most
frequently reported snacks for the ages 9 and under were milk, fruits, cookies,
candies, crackers, popcorn, pretzels and corn chips. Eighty-three percent of
kids snacked on the day surveyedup from 65 percent in the 1977-78 survey.
Over the last two decades, soft
drink consumption increased 21 percent among 2- to 5-year-olds and 37 percent
among 6- to 9-year-olds. Both age groups also drank more fruit juices and fruit
drinks26 percent and 11 percent more, respectively. Milk consumption, on
the other hand, dropped 4 percent among the preschoolers and 10 percent among
the older group. Twice as many kids ate crackers, popcorn, pretzels and corn
chips in the 90s as did kids in the 70s.
Children's diets provided adequate
intakes of most nutrients. However, vitamin E, zinc, calcium, iron and vitamin
B6 intakes were troublesome. Nearly two-thirds of the children
failed to get the 1989 Recommended Dietary Allowances (RDA) for vitamin E and
zinc. Half did not meet the RDA for calcium, and close to one-third fell short
of the RDA for iron and vitamin B6.
Summary tables of the combined data
are now on
line.
For more information, contact
Sharon Mickle, (301) 504-0341,
Food Surveys
Research Group, Beltsville, MD
Back to Contents
Flavonoids in orange and other
citrus juices not only give the juices their flavors and colors; they are also
potent antioxidants. And some are known to kill cancer cells growing in
culture. Now ARS scientists believe they know how.
Several citrus flavonoids inhibit
certain cytochrome P450 enzymes, the researchers recently reported in
Toxicology, 2000 (vol. 144, pp. 31-38). That's important because some of
these enzymes can turn cigarette smoke, pesticides and other so-called
procarcinogens into forms that promote cancer. One P450 enzyme1B1is
present in high levels in breast and prostate cancer cells but is rarely seen
in normal cells.
The tests show that
hesperetinthe most abundant flavonoid in orange juiceblocks P450
1B1 from metabolizing procarcinogens, reducing the chances that the body could
turn these substances into carcinogens. Hesperetin's effect on this enzyme
might lead to the development of alternatives to traditional cancer
chemotherapy that affects healthy as well as diseased cells.
For more information, contact
Richard Mayer, (561) 462-5897,
U.S. Horticultural
Research Laboratory, Ft. Pierce, FL
Back to Contents
Beans could claim a place among red
wine and colorful fruits, berries and vegetables as cancer- and heart
disease-fighting foods. An ARS food quality geneticist has found some of the
same antioxidants in bean coats that give these other foods their anti-aging
properties. The finding is inspiring scientists to find ways to boost the
already high nutritional value of beans and could lead to more iron and other
vitamins and minerals, as well as more antioxidants.
The researcher found eight
flavonoids in the bean coat, six of which are particularly strong antioxidants.
Flavonoids are the colored pigments that appear to be the protective factor in
red wine and other foods. Bean colors range from the plain-white great Northern
through the cranberry bean's cream with red streaks and flecks to the
maroon-red adzukiand all the way to the totally black bean. Those with
brownish and red-brown coats appear to have the most antioxidant potential.
This research also uncovered a link
between one of the flavonoids, a color gene, and resistance to bean mosaic
disease, which is a major threat to bean farmers. This is the first time such a
link has been made. So the ARS scientist and Michigan State University
colleagues are searching for more links while trying to identify and learn the
function of all the genes for canning quality, disease resistance and
nutrition.
For more information, contact
George L. Hosfield, (517) 355-0110,
ARS Sugarbeet and Bean Research Unit, East Lansing, MI
Back to Contents
Nearly two-fifths of the U.S.
population may be flirting with marginal vitamin B12 status. A
careful look at 3,000 men and women in the ongoing Framingham (Massachusetts)
Offspring Study found 39 percent with plasma B12 levels in the "low
normal" rangebelow 258 picomoles per liter. While this is well above the
currently accepted deficiency level of 148 pmol/L, some people exhibit
neurological symptoms in the higher range, says the lead researcher. More than
16 percent of the subjects fell below 185 pmol/La level where many people
may be deficient
One surprise of the study: The
youngest groupthe 26- to 49-year-oldshad about the same B12
status as the oldest group65 and up. Most earlier studies had
focused on the elderly because they were thought to be at higher risk for
deficiency.
B12 deficiency can cause
a type of anemia marked by fewer but larger red blood cells. It can also cause
walking and balance disturbances, a loss of vibration sensation, confusion,
and, in advanced cases, dementia. The body requires B12 to make the
protective coating surrounding the nerves, so inadequate B12 can
expose nerves to damage.
The good news is that most people
can improve their B12 status by eating more fortified cereals and
dairy products. These foods were nearly as effective as supplements containing
B12 for getting people's blood levels above the danger zone, the
researchers reported in the American Journal of Clinical Nutrition, 2000
(vol. 71, pp. 514-522). Supplement use dropped the percentage of volunteers in
the danger zoneplasma B12 below 185 pmol/Lfrom 20
percent to 8. Eating fortified cereals five or more times a week or being among
the highest third for dairy intake reduced, by nearly half, the percentage of
volunteers in that zonefrom 23 and 24 percent, respectively, to 12 and 13
percent.
Oddly, the researchers found no
association between plasma B12 levels and meat, poultry and fish
intake, even though these foods supply the bulk of B12 in the diet.
The study subjects were eating enough of these foods; the vitamin wasn't
getting absorbed.
For more information, contact
Katherine Tucker, (617) 556-3351,
Jean Mayer USDA Human Nutrition Research
Center on Aging at Tufts University, Boston, MA
Back to Contents
Cinnamon adds zest to more than
just food. The spice contains substances that, in test tube studies at least,
wake up body cells to the hormone insulin. Because insulin regulates glucose
metabolism and thus controls the level of glucose in the blood, the substances
may have the potential to delay or prevent adult-onset, or type 2, diabetes.
ARS has filed a patent application
on the active substances. The most activemethylhydroxy chalcone polymer
(MHCP)increased glucose metabolism roughly 20-fold in the test tube assay
of fat cells. MHCP and the other active compounds are water soluble and so are
not found in the spice oils sold as food additives. Whether they are effective
in people remains to be tested.
Nearly 6 percent of the U.S.
population15.7 million peoplehave diabetes, and one-third of them
don't even know it. The large majority of diabetes cases are type 2, the kind
that emerges when body cells fail to recognize and respond to insulin as well
as they once did.
A search for a natural way to keep
blood sugar levels normal began more than a decade ago, when ARS scientists
assayed plants and spices used in folk medicine. They found that a few spices,
especially cinnamon, made fat cells much more responsive to insulin. With help
from other ARS chemists, the researchers identified the compounds in cinnamon
responsible for its activity. None of the approximately 50 other plant extracts
they evaluated have come close to MHCP's level of activity.
For more information, contact
Richard A. Anderson, (301)
504-8091, Nutrient Requirements
and Functions Laboratory, Beltsville, MD
Back to Contents
New findings underscore the need to
better educate U.S. Hispanics on how to prevent diabetes or minimize its
impact. A study of elderly Hispanics living in Massachusetts shows that those
who have diabetes are more likely to lose muscle and the ability to move around
with ease or take care of basic needs, such as eating, dressing, bathing and
toileting.
These newly recognized
disordersmuscle wasting and functional impairmentincrease the list
of known complications that may result from uncontrolled blood sugar. These
include heart disease, blindness, kidney failure and nerve damage in the
extremities, according to the researchers.
The researchers studied 556
Hispanic elders, ranging in age from 60 to 92, as well as 158 non-Hispanic
white subjects living in the same neighborhoods across Massachusetts for
comparison. They reported their findings in the American Journal of Clinical
Nutrition, 2000 (vol. 72, pp. 89-95).
Diabetes is far more prevalent
among U.S. Hispanics than among non-Hispanic whites and African Americans. And
it is more severe, judging from the number of Hispanics in the study who use
insulin rather than dietary changes or less potent drugs to control their blood
sugar.
This group consumed significantly
more protein and calories than the non-Hispanic white diabetics, but that did
not translate to higher serum albumen levels. Higher albumen levels are
recognized as a general indicator of good health and nutrition. So the findings
suggest that more advanced diabetes among Hispanics increases their risk of
inadequate nutrition.
For more information, contact
Carmen Castaneda, (617)
556-3081, Jean Mayer USDA Human Nutrition
Research Center on Aging at Tufts University, Boston, MA
Back to Contents
The health-promoting benefits of
rice branthe nutritious, light-brown layer that covers the familiar white
kernelmight be enhanced as a result of a new study being led by ARS
scientists. Agency researchers will determine whether certain food-processing
techniques can convert key compounds of bran into forms that are easier for the
body to absorb and use.
The investigation will look at both
soluble and insoluble fiber in rice bran and at antioxidant compounds, such as
ferulic acid and its close relatives, already known to prevent formation of
harmful molecules known as free radicals. The work is being conducted under a
new cooperative research and development agreement with The Rice Foundation,
Houston, Texas. In addition, a researcher at the University of California,
Davis, Medical Center in Sacramento will collaborate.
In preliminary experiments with
wheat, the ARS and university researchers showed that different techniques for
processing wheat bran into cereals made a significant difference in reducing
the incidence of a colon cancer indicator in laboratory rats. Their new studies
of rice will also track colon cancer incidence in rats. Plans call for using
three or four variations in processing the bran with a standard piece of
food-processing equipment known as an extruder.
For more information, contact
Wallace H. Yokoyama, (510) 559-5695,
Western Regional Research Center, Albany,
CA
Back to Contents
A treasure trove of
more than 6,000 watercolors of apples, blackberries, cherries, grapes,
persimmons and other fruits is safeguarded in the USDA Pomological Watercolor
Collection. This array of original prints and related materials is one of the
treasures of the National Agricultural Library in Beltsville, Maryland, managed
by ARS. Examples of the collection can be viewed on the library's
web site.
The collection makes up
one of the world's most unique holdings of late 19th- and early 20th-century
American botanical illustrations. Many of these beautiful drawings resulted
from USDA scientists' need to depict new varieties that they had developed, or
had gathered during overseas plant-collecting expeditions. Today, the drawings
are a boon to horticulturists, historians, artists and publishers. These
specialistsand othersrely on the illustrations as an invaluable
source of information about the history of fruit culture in the United
States.
For more
information, contact Susan H. Fugate,
(301) 504-5876, National Agricultural
Library, Beltsville, MD
Back to Contents
In a couple of years, consumers
won't need to cook pork chops and roasts to the consistency of shoe leather. An
innovative program to certify pigs right on the farm as free of
trichinosis-causing worms is going through its final shakedowna 2-year
pilot study. The national certification program for Trichinella-free pork is a
collaborative effort between the meat-packing industry, the National Pork
Producers Council (NPPC) and three USDA agenciesARS, the Animal and Plant
Health Inspection Service (APHIS) and the Food Safety and Inspection Service
(FSIS).
An ARS parasitologist has played a
pivotal role in the program, which is expected to be a model for controlling
other foodborne pathogensincluding some bacteriaat the source of
infection.
He says the number of pigs infected
with Trichinella spiralis has been on the decline for decades, thanks to
changes in the way most pork producers manage their operations. Not a single
positive animal turned up out of 220,000 pigs tested during a six-month study
of a midwestern packing plant and pork producers in three states. The study was
designed to test the feasibility of on-farm certification.
Now, the NPPC is encouraging pork
producers to volunteer for certification by having their operations audited by
an APHIS-accredited veterinarian. The veterinarians will be looking for
practices that would prevent a herd's exposure to infected rodents or wildlife
or to raw garbage. Participating packing plants will keep certified pigs
separate from non-certified pigs and follow a protocol developed with FSIS. The
NPPC expects 90 to 95 percent of pork- producing sites to volunteer for the
audit when certification begins in earnest in 2001.
For more information, contact
H. Ray Gamble, (301) 504-8300,
Parasite Biology and
Epidemiology Laboratory, Beltsville, MD
Back to Contents |