Yokoyama pointed out that further research is needed to confirm whether the effects observed in hamsters hold true for humans. He works at the Western Regional Research Center operated in Albany Calif., by the Agricultural Research Service (ARS), the principal scientific research agency of USDA.
In the investigation, hamsters were fed high-fat rations. For some animals, those rations were supplemented with one of three different kinds of juice byproducts: blueberry skins-that is, peels leftover when berries are pressed to make juice; fiber extracted from the peels; or natural compounds known as polyphenols, also extracted from the peels. Blueberry polyphenols give the fruit its purple, blue, and red coloration.
In an article published in the Journal of Agricultural and Food Chemistry in 2010, Yokoyama and his coinvestigators reported that all the hamsters that were fed blueberry-enhanced rations had from 22 to 27 percent lower total plasma cholesterol than hamsters fed rations that didn't contain blueberry juice byproducts.
Levels of VLDL (very low density lipoprotein-a form of "bad" cholesterol) were about 44 percent lower in the blueberry-fed hamsters.
Yokoyama and his coinvestigators used a procedure known as real-time reverse transcription polymerase chain reaction, or RT-PCR, to learn about the genes responsible for these effects. This approach allowed the scientists to pinpoint differences in the level of activity of certain liver genes.
In hamsters-and in humans-the liver both makes cholesterol and helps get rid of excessive levels of it. Results suggest that activity of some liver genes that either produce or use cholesterol resulted in the lower blood cholesterol levels.
The study is apparently the first published account of cholesterol-lowering effects in laboratory hamsters fed blueberry peels or fiber or polyphenols extracted from those peels.
Of course, some pieces of the cholesterol puzzle are not yet in place. For example, the researchers don't know which berry compound or compounds activated the liver genes, or which parts of the berry have the highest levels of these compounds.
Yokoyama collaborated in the study with former Albany postdoctoral research associate Hyunsook Kim and ARS research chemist Agnes M. Rimando, who is based at Oxford, Miss.
More details about this study are available in the May/June 2011 issue of Agricultural Research magazine. http://www.ars.usda.gov/is/AR/archive/may11/fruit0511.htm
USDA is an equal opportunity provider, employer and lender. To file a complaint of discrimination, write: USDA, Director, Office of Civil Rights, 1400 Independence Ave., S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice), or (202) 720-6382 (TDD).
Marcia Wood | EurekAlert!
Rutgers-led innovation could spur faster, cheaper, nano-based manufacturing
14.02.2018 | Rutgers University
New study from the University of Halle: How climate change alters plant growth
12.01.2018 | Martin-Luther-Universität Halle-Wittenberg
Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...
For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.
In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...
Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale
Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...
For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.
But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...
Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.
The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...
15.02.2018 | Event News
13.02.2018 | Event News
12.02.2018 | Event News
22.02.2018 | Life Sciences
22.02.2018 | Physics and Astronomy
22.02.2018 | Earth Sciences