Could antioxidants make us more, not less, prone to diabetes? Study says yes

Oct 06, 2009

We've all heard about the damage that reactive oxygen species (ROS) - aka free radicals - can do to our bodies and the sales pitches for antioxidant vitamins, skin creams or "superfoods" that can stop them. In fact, there is considerable scientific evidence that chronic ROS production within cells can contribute to human diseases, including insulin resistance and type 2 diabetes.

But a new report in the October 7th adds to evidence that it might not be as simple as all that. The researchers show that low levels of ROS - and in particular -- might actually protect us from diabetes, by improving our ability to respond to insulin signals.

"Our studies indicate that 'physiological' low levels of ROS may promote the insulin response and attenuate early in the progression of type 2 diabetes, prior to overt obesity and hyperglycemia," said Tony Tiganis of Monash University in Australia. "In a way, we think there is a delicate balance and that too much of a good thing - surprise, surprise - might be bad."

Tiganis' team found that mice with a deficiency that prevented them from eliminating physiological ROS didn't become insulin resistant on a high-fat diet as they otherwise would have. They showed that those health benefits could be attributed to insulin-induced signals and the uptake of glucose into their muscles. When those animals were given an antioxidant, those benefits were lost, leaving the mice with more signs of diabetes.

Tiganis said whether antioxidants are ultimately good for people will probably depend on their state of health or disease. "In the case of early and the development of insulin resistance, our studies suggest that antioxidants would be bad for you." Under some conditions, treatments designed to selectively increase ROS in muscle - if they can be devised - might even help, he says.

It's not the first time studies have suggested that antioxidants can be a negative, Tiganis adds. Studies in worms have suggested that antioxidants can shorten lifespan, as have some epidemiological studies in humans. Other recent reports indicate that may negate the longer-term benefits of exercise training by lowering the activity of certain genes involved in ROS defense.

Tiganis said it will ultimately be important to work out at what stage ROS go from being good to bad. He suspects it probably depends on the levels and/or the source of their generation. (ROS are generated both on the surfaces of cells and within cells by mitochondria, which convert nutrients such as glucose into energy, he explained.)

Although any health implications of the new findings would require further study, the findings lead Tiganis to suspect it is best not to take daily antioxidant vitamins, especially if you are otherwise healthy. "Do exercise," he says, as this is a natural source of ROS that may promote insulin action.

Source: Cell Press (news : web)

Explore further: The impact of bacteria in our guts

add to favorites email to friend print save as pdf

Related Stories

Exercise pivotal in preventing and fighting type II diabetes

Feb 07, 2007

One in three American children born in 2000 will develop type II diabetes, according to the U.S. Centers for Disease Control and Prevention (CDC). A new study at the University of Missouri-Columbia says that acute exercise ...

Apelin hormone injections powerfully lower blood sugar

Nov 04, 2008

By injecting a hormone produced by fat and other tissues into mice, researchers report in the November Cell Metabolism that they significantly lowered blood sugar levels in normal and obese mice. The findings suggest that t ...

Low doses of a red wine ingredient fight diabetes in mice

Oct 02, 2007

Even relatively low doses of resveratrol—a chemical found in the skins of red grapes and in red wine—can improve the sensitivity of mice to the hormone insulin, according to a report in the October issue of Cell Metabolism. As ins ...

Recommended for you

The impact of bacteria in our guts

Aug 22, 2014

The word metabolism gets tossed around a lot, but it means much more than whether you can go back to the buffet for seconds without worrying about your waistline. In fact, metabolism is the set of biochemical ...

Stem cell therapies hold promise, but obstacles remain

Aug 22, 2014

(Medical Xpress)—In an article appearing online today in the journal Science, a group of researchers, including University of Rochester neurologist Steve Goldman, M.D., Ph.D., review the potential and ch ...

New hope in fight against muscular dystrophy

Aug 22, 2014

Research at Stockholm's KTH Royal Institute of Technology offers hope to those who suffer from Duchenne muscular dystrophy, an incurable, debilitating disease that cuts young lives short.

Biologists reprogram skin cells to mimic rare disease

Aug 21, 2014

Johns Hopkins stem cell biologists have found a way to reprogram a patient's skin cells into cells that mimic and display many biological features of a rare genetic disorder called familial dysautonomia. ...

User comments : 0