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
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
www.surgeongeneral.gov/library/bonehealth/docs/OsteoBrochure1mar05.pdf.

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