As the U.S. population becomes more diverse, studying
the nutrition and health needs of immigrant groups becomes more important.
Several researchers at the Jean Mayer USDA Human Nutrition Research
Center on Aging (HNRCA) at Tufts University in Boston have been focusing
on the nutritional epidemiology of Hispanic elders. Hispanics are a
fast-growing group in the United States.
HNRCA researchers report that elderly Hispanics of Caribbean
origin were significantly more likely to be vitamin B12 deficient
than were non-Hispanic whites, based on a study of data collected in
the volunteers' homes. Symptoms of B12 deficiency range from
decreased memory and balance disturbances to nerve damage and cognitive
The study was conducted by Katherine Tucker, director
of HNRCA's Dietary Assessment Research Program, and was published in
the Journal of Nutrition last year. Tucker and coauthors examined
data collected from 347 Puerto Ricans, 102 Dominicans, and 154 non-Hispanic
whites living in Massachusetts and aged 60 to 93 years.
One reason for the lower levels is that the B12
in natural sources such as meat, eggs, and dairy products is tightly
bound to the proteins contained in those foods. That means unless the
consumer has enough stomach acid to break those bonds, he or she may
not absorb adequate B12. Aging and acid-blockers contribute
to the gradual lessening of B12 absorption.
"Sources of vitamin B12 that are not bound
to protein, such as supplements and fortified cereals, appear to be
protective," says Tucker. "For most people, taking a multivitamin
or regularly eating B12-fortified foods, such as breakfast
cereal, should provide protection against deficiency." She notes
that those who took supplements with B12 or ate cereal more
than four times per week were significantly less likely to have low
levels of B12.
In another study, HNRCA researchers reported significant
results from a study involving 60 Hispanic men and women over 55 with
an average 9-year history of type-2 diabetes. Indeed, among Hispanics,
diabetes prevalence is about double that among non-Hispanic whites.
The investigators asked half the volunteers to serve as
controls and half to undergo progressive resistance training, or PRT,
such as weight lifting, three times a week for 16 weeks. Before participation,
the volunteers' health was screened through an in-depth physical examination
In the exercise group, PRT reduced the requirement for
diabetes medication, reduced abdominal fat and systolic blood pressure,
increased lean tissue mass, and increased muscle strength.
The findings were reported in the December issue of Diabetes
Care by principal investigator Carmen Castaneda Sceppa. She is a
physician and acting director of the Nutrition, Physiology, and Sarcopenia
Laboratory at the HNRCA.
"Our results showed that dosages of prescribed diabetes
medications were reduced in 72 percent of exercisers, compared with
the control group," says Castaneda. Moreover, by study's end, the
exercisers were closer to meeting the Surgeon General's recommendations
for physical activity. The researchers concluded that further studies
are needed to determine the optimal intensity of PRT to produce maximal
benefits while ensuring safety.By Rosalie Marion Bliss,
Agricultural Research Service Information Staff.
This research is part of Human Nutrition, an ARS National
Program (#107) described on the World Wide Web at www.nps.ars.usda.gov.
L. Tucker and Carmen Castaneda
Sceppa are with the Jean Mayer USDA-ARS Human
Nutrition Research Center on Aging at Tufts University, 711 Washington
St., Boston, MA 02111; [Tucker] phone (617) 556-3351, fax (617) 556-3344
; [Castaneda Sceppa] phone (617) 556-3081, fax (617) 556-3083.
"The Crossroads of Nutrition and Culture" was published
in the April
2003 issue of Agricultural Research magazine.