Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Cutting calories could limit muscle wasting in later years

18.09.2008
Chemical concoctions can smooth over wrinkles and hide those pesky grays, but what about the signs of aging that aren't so easy to fix, such as losing muscle mass? Cutting calories early could help, say University of Florida researchers who studied the phenomenon in rats.

A restricted-calorie diet, when started in early adulthood, seems to stymie a mitochondrial mishap that may contribute to muscle loss in aging adults, the researchers reported recently in the journal PLoS One.

In rats, the scientists found pockets of excess iron in muscle cell mitochondria, the tiny power plants found in every cell. The excess iron affects the chemistry inside the mitochondria, sparking the formation of harmful free radicals that can lead a mitochondrion straight to the emergency exit, said Christiaan Leeuwenburgh, Ph.D., a UF professor of aging in the UF College of Medicine and the Institute on Aging.

Leeuwenburgh was the senior author of the study and of a related report published online this month in Aging Cell that details the damage done by excess iron in mitochondria.

"We become less efficient at an old age and we need to understand why this is," Leeuwenburgh said. "One thing, maybe, is the accumulation of redox-active metals in cells. If the mitochondria become unhappy or are ready to kick the bucket, they have proteins in the inner and outer membranes that they can open up and commit suicide. They're tricky beasts."

The suicidal mitochondria can damage the rest of the muscle cell, leading to cell death and perhaps to muscle wasting, a big problem for adults as they reach their mid-70s, Leeuwenburgh added.

"Muscle is critical for your overall well-being," Leeuwenburgh said. "As you walk, muscle functions partly as a pump to keep your blood going. Muscle is an incredible source of reserves."

The researchers found increasing amounts of iron in the muscle cells of aging rats fed a typical unrestricted diet. The older the rats got, the more iron accumulated in the mitochondria and the more damage was done to its RNA and DNA. Rats of the same ages that were kept on a calorie-restricted diet — about 60 percent of the food typically ingested — seemed to maintain more normal iron levels in mitochondria, the researchers reported.

"The novel thing here is that iron is accumulating in places it does not normally accumulate," said Mitch Knutson, Ph.D., a UF assistant professor of food science and human nutrition and a study co-author. "Such iron accumulation in muscle was quite unexpected. This may be of concern because more people are genetically predisposed to developing iron overload than we originally thought."

The problem occurs when metals such as iron accumulate in the mitochondria and react with oxygen. Iron can change the chemical structure of oxygen, triggering its metamorphosis into a free radical, an unstable atom that can upset the delicate balance inside the mitochondria. The result? Leeuwenburgh describes it sort of like internal rust.

"Not all free radicals are harmful," Leeuwenburgh said. "To just use antioxidants to neutralize all free radicals is a huge misconception because some radicals are helpful. You just need to try and target very specific free radicals that form in specific parts of the body."

Researchers don't know exactly what causes iron to accumulate in mitochondria in aging animals, but a breakdown in how iron is transported through cells could be one reason why, Leeuwenburgh said. Understanding how caloric restriction limits the problem in rats could help researchers better understand how to combat it, he added.

Russell T. Hepple, Ph.D., an associate professor of kinesiology and medicine at the University of Calgary in Canada, said the findings are another step forward in linking iron to muscle cell death, but there are more questions researchers must answer.

"They've shown that apoptosis (cell death) goes up in aging muscle but where does that happen?" Hepple asked. "There are more than muscle cells in muscle. (For example) in older adults there are inflammatory cells."

April Frawley Birdwell | EurekAlert!
Further information:
http://www.ufl.edu

More articles from Health and Medicine:

nachricht New malaria analysis method reveals disease severity in minutes
14.08.2017 | University of British Columbia

nachricht New type of blood cells work as indicators of autoimmunity
14.08.2017 | Instituto de Medicina Molecular

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>