Manhattan, Kansas
January 23, 2009
Led by 87 percent of the nation´s
teenage girls and 78 percent of U.S. women age 20 or older,
today´s average American eats far too little calcium - the most
abundant mineral in the human body.
Calcium is best known for its role in deciding the lifelong,
year-to-year strength or weakness of bones and teeth. The fact
is, however, calcium intake is crucial to every bodily function,
from nerves and muscles to glands and blood vessels.
That´s why plant scientists at
Kansas State and Texas A&M
universities are working to make meeting daily calcium needs
easier. Their plan is to expand people´s range of calcium-rich
food choices.
"Thus far, few vegetables are good sources of calcium. And,
those few aren´t a significant part of the average U.S. diet,"
said Sunghun Park, K-State horticulturist and the project´s lead
scientist.
The researchers´ first results include a 25 to 32 percent hike
in the in-bred calcium supplied by common leaf lettuce. The team
now hopes to raise their lettuce lines´ nutrient value even
further.
Today, most of the calcium Americans eat comes from such dairy
products as milk, yogurt and cheese, according to the Office of
the Surgeon General. Some also comes from "fortified" products
(orange juice, bread, cereals) and such dark, leafy greens as
bok choy, collards and broccoli.
"To expand that list, we´re using a strategy called
biofortification. We´re working to genetically improve what we
know are popular vegetables, to make them more nutrient-dense,"
Park said.
The researchers´ first report says their biofortified leaf
lettuce lines are reproducing true to form and growing robustly
under greenhouse conditions. Yet, the report emphasizes a
different finding.
In an unusual move, the researchers submitted their "new"
lettuce to the Sensory Analysis Center in K-State´s Department
of Human Nutrition. And, a panel of scientific evaluators there
found the enhanced lettuce to be no different from "regular"
leaf lettuce in flavor, bitterness or crispness.
"In other words, if you were to encounter both of them in a
salad or hamburger, you wouldn´t be able to tell which was
which. That could make a big difference in public acceptance, if
and when a product like ours enters the market," said team
member Kendal Hirschi, who is a pediatrics and human genetics
professor at the Baylor College of Medicine, as well as an
associate research director at Texas A&M´s Vegetables and Fruit
Improvement Center.
Right now, however, marketability isn´t the prime concern for
the lettuce research team - which also includes two more K-State
horticulturists, two K-State sensory analysts and the director
of environment technologies at Edenspace Systems.
They don´t think their research project is complete. They´re
looking into boosting their leaf lettuce´s calcium content
further by such methods as adding calcium to the plants´ growing
soil and/or immersing the harvested leaves in a calcium-rich
solution.
Immersions of calcium have a long history as a post-harvest
firming agent. Today, they´re prolonging the shelf life of such
fruits and vegetables as apples, cantaloupes, strawberries and
carrots.
But, whether they also "up" fresh produce´s calcium content is
still an unknown, Park said.
"All we´ve established explicitly so far is that modifying a
single plant-calcium transporter will increase calcium content
without having a negative impact on lettuce quality. That´s just
one step toward getting biofortified lettuce on store shelves.
Even so, our scientific approach should now be applicable to
numerous other food
crops, too," said Mark Elless of Edenspace, which is newly
headquartered in Manhattan, Kan., with its newest research
facilities in nearby Junction City, Kan.
An abstract and the research team´s entire report, "Sensory
analysis of calcium-biofortified lettuce," is available on the
Plant Biotechnology Journal´s Web site at
http://www3.interscience.wiley.com/cgi-bin/fulltext/121451954/HTMLSTART.
A colorful outline of Americans´ challenges with calcium -- "The
2004 Surgeon General´s Report on Bone Health and Osteoporosis:
What It Means to You" -- is at
http://www.surgeongeneral.gov/library/bonehealth/docs/OsteoBrochure1mar05.pdf.
K-State Research and Extension is a short name for the Kansas
State University Agricultural Experiment Station and Cooperative
Extension Service, a program designed to generate and distribute
useful knowledge for the well-being of Kansans. Supported by
county, state, federal and private funds, the program has county
Extension offices, experiment fields, area Extension offices and
research centers statewide. Its headquarters is on the K-State
campus in Manhattan.
Other news
from Texas A&M
University |
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The U.S. Office of the Surgeon
General is projecting that
unless
something changes radically and
soon, the outcome 11 years from
now
for 61.4 million Americans will
be problems with low bone mass
or
osteoporosis (low bone mass,
plus deterioration). That number
will
include half of all Americans
over age 50 in 2020. It will
equal one
in five of the U.S. Census
Bureau´s July 2008 population
estimate.
The great majority won´t know
they have a problem unless or
until
they break a bone - typically in
hip, wrist or spine. The Surgeon
General expects hip fracture
totals to double or even triple
by 2040.
Often associated with aging or
steroid consumption, weak bones
already lead to 1.5 million
fractures each year. Medical
expenses
from the osteoporosis-related
fractures alone add up to $18
billion.
Another worrisome statistic: A
year after today´s annual
300,000 hip
fracture patients leave the
hospital, an average 20 percent
of them
are dead;. Another 20 percent
are in a nursing home, and many
of the
rest are so afraid of falling
that they´ve become isolated
and/or
depressed.
So long as humans are alive,
their skeleton is undergoing
constant
remodeling. Existing bone tissue
breaks down, and its calcium
washes
away in the person´s urine. New
bone gets deposited, using about
99
percent of what´s made available
through the person´s on-going
calcium intake.
As people age, the balance
between the break-down and
build-up
processes makes some major
shifts. Nonetheless, people can
work to
promote or keep bone health at
any stage of life.
The key ingredients for that
work are getting the recommended
amounts
of calcium and vitamin D (to
help the calcium work) and
exercising
both regularly and frequently.
Source: Office of the Surgeon
General |
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