"Consumption of whole grains has been associated with a lower body weight and lower blood pressure," said co-author Penny Kris-Etherton, distinguished professor of nutritional sciences at Penn State. "We thought that incorporating whole grains into a heart-healthy weight loss diet may provide the same benefits to people at risk from chronic diseases."
The researchers recruited 50 obese adults – 25 male and 25 female – between ages 20 to 65 and known to have metabolic syndrome, a cluster of symptoms that increase the risk of developing cardiovascular disease and diabetes.
They were randomly assigned to either a group that received instructions to have all of their grain servings from whole grains or all of their grain servings from refined grains.
"We asked participants in the whole grain group to focus on foods that had whole grains as the first ingredient," said lead author Heather Katcher, a Penn State Ph.D. recipient and currently a dietetic intern at Tulane University.
Over the 12-week study period, all participants received the same dietary advice on weight loss, and encouragement to participate in moderate physical activity. Researchers also asked participants to consume five daily servings of fruits and vegetables, three servings of low-fat dairy products, and two servings of lean meat, fish or poultry.
The study's findings are published in the January 2008 issue of the American Journal of Clinical Nutrition.
Results from the study showed that waist circumference and body weight decreased significantly in both groups – between 8-11 pounds on average – but weight loss in the abdominal region was significantly greater in the whole grain group.
According to Katcher, the whole grain group experienced a 38 percent decrease in C-reactive protein levels in their blood. A high level of this inflammatory marker is thought to place patients at a higher risk for diabetes, hypertension and cardiovascular disease.
"Typically you would expect weight loss to be associated with a decrease in C-reactive protein, but the refined grain group showed no decrease in this marker of inflammation even though they lost weight," said Kris-Etherton.
The Penn State researcher suggests that the finding is because the consumption of refined grains has been linked to increased levels of the protein. So even though people in the refined grain group lost weight, the fact that they ate so many refined grains probably negated the beneficial effect of weight loss on C-reactive protein levels.
While it is not fully clear how exactly the protein is decreased in the whole grain group, Richard Legro, M.D., professor of obstetrics and gynecology at Penn State Hershey Medical Center and a co-investigator, says the scale of reduction is similar to that seen with the use of statin drugs, highlighting the potential of diet to prevent serious medical complications.
Participants in the whole grain group also showed an increased intake of fiber and magnesium, both of which may prevent or delay the potential onset of diabetes.
Researchers say the study is timely as it addresses the wide choice of whole grains in the market.
"There are a lot of foods around that claim they contain whole grain but are not really major sources of whole grain," said Kris-Etherton. She recommends whole grain foods where at least 51 percent of the grain comes from whole grain. These include oatmeal, whole grain cereal, brown rice, whole-wheat pasta and snacks such as granola bars, popcorn and whole-wheat crackers.
"This is the first clinical study to prove that a diet rich in whole grains can lead to weight loss and reduce the risk of several chronic diseases," added Kris-Etherton.
Amitabh Avasthi | EurekAlert!
Smart Data Transformation – Surfing the Big Wave
02.12.2016 | Fraunhofer-Institut für Angewandte Informationstechnik FIT
Climate change could outpace EPA Lake Champlain protections
18.11.2016 | University of Vermont
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.
Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
02.12.2016 | Medical Engineering
02.12.2016 | Agricultural and Forestry Science
02.12.2016 | Physics and Astronomy