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May 6, 2005

Researchers extend mouse lifespan by protecting against free radicals

Topics: Nutrition and Cancer

Free radicals and hydrogen peroxide continues to be a topic of research interest in cancer and chronic disease. Hydrogen peroxide,a waste product of metabolism, can be a precursor of free radicals that can damage cells. The damage can subsequently lead to more damaging changes in the cell's chemical processes, creating a relentless cycle that leads to even more free radicals and more cellular damage.

Our best strategy for combating disease is of course to live a disease-prevention lifestyle that includes a diet that is high in antioxidants and balanced in fat intake. Epidemiological studies show that a high intake of anti-oxidant-rich foods is inversely related to cancer risk. Cancer treatment by radiation and anticancer drugs reduces inherent antioxidants and induces oxidative stress, which increases with disease progression.

But free-radicals not only affect our ability to resist or combat disease, they also affect our lifespan. Now Researchers are taking the free-radical issue beyond their relationship to diseases, and are addressing the effects of free-radicals on aging and lifespan:

- Medical News Today
Scientists at the University of Washington and their colleagues at other research centers have found a way to significantly extend the lifespan of mice while reducing the impact of the aging process. Their study, which will be published online by the journal Science on May 5, lends more credence to the free-radical theory of aging.

The theory suggests that very reactive chemicals, called "free radicals," can be damaging to the body at the cellular level. Those reactive chemicals can take part in unnecessary chemical reactions that can damage the cell components, including DNA. Some researchers believe that free radicals could contribute to or hasten heart disease, cancer, and other age-related diseases. The theory also suggests that if the body could be protected from those free radicals, then age-related diseases could be tamed and organisms - and ultimately people - may be able to live longer.

Scientists have previously been able to extend the lifespan of mice in lab experiments by managing their diets and reducing their caloric intake. Another method relied on the restriction of a growth factor, but a side effect was that the mice suffered from dwarfism. However, neither of those methods of elongating the mouse lifespan was clearly connected to the free-radical theory of aging.

(...) "This study is very supportive of the free-radical theory of aging," said Rabinovitch. "It shows the significance of free radicals, and of reactive oxygen species in particular, in the aging process."

(...) "People used to only focus on specific age-related diseases, because it was believed that the aging process itself could not be affected," Rabinovitch explained. "What we're realizing now is that by intervening in the underlying aging process, we may be able to produce very significant increases in 'healthspan,' or healthy lifespan."


Related readings:

Reducing Free Radicals - A Dietary Revolution
Mechanism of the tumor suppressive effect of MnSOD overexpression.

Superoxide dismutase, catalase and glutathione peroxidase in the spontaneously hypertensive rat kidney: effect of antioxidant-rich diet.

In vivo antitumor effect of ascorbic acid, lysine, proline and green tea extract on human colon cancer cell HCT 116 xenografts in nude mice: evaluation of tumor growth and immunohistochemistry.

Posted by Richard at May 6, 2005 8:23 AM

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