TUESDAY, Dec. 30 (HealthDay News) -- Scientists have unmasked what appears to be a major mechanism contributing to normal, age-related cognitive decline.

Happily, it's a mechanism that is amenable to change: rising blood glucose levels, which means that exercise might be the antidote.

Researchers reporting in the December issue of Annals of Neurology showed that rising blood sugar levels, a normal part of aging, affect a part of the hippocampus, a part of the brain critical to learning and memory.

"This would suggest that anything to improve regulation of blood glucose would potentially be a way to ameliorate age-related memory decline," said senior study author Dr. Scott Small, an associate professor of neurology at the Taub Institute for Research on Alzheimer's Disease and the Aging Brain at Columbia University Medical Center in New York City.

The findings may also help explain why people who exercise don't have as many cognitive problems as they age: Exercise helps stabilize blood glucose levels.

"We had previously shown that physical exercise strengthens a part of the brain involved with aging but, at the time, we didn't know why physical exercise would have this selective benefit," Small said. "Now we have a proposed mechanism. We think it's because subjects who exercised had better glucose handling."

It's well known that damage to the hippocampus is evident with Alzheimer's disease, and there has been some suggestion that this region of the brain is also affected by normal aging.

The researchers used MRI to record the functioning of the hippocampus in 240 healthy older people (average age almost 80). Sixty of the participants had type 2 diabetes, while 74 had brain "infarcts" -- some damage to brain tissue. Diabetes and infarcts were each linked with separate areas of the hippocampus, indicating that different mechanisms are at work in each disorder.

The findings were confirmed in animal tests.

"The paper identifies an etiology [cause] for normal age-related memory decline," Small explained. "Elevations in blood glucose levels differentially target the dentate gyrus part of the hippocampus implicated in aging and, as we age, we develop a slight but gradually worsening difficulty in handling blood sugar levels."

That difficulty coincides with the beginning of loss of cognitive function, Small added.

"In my opinion, that's an interesting hypothesis and needs to be studied -- that exercise helps improve cognitive functioning through that mechanism, but I think there are other mechanisms as well," said Bryan Freilich, a clinical neuropsychologist at Montefiore Medical Center in New York City.

Mark Mapstone, an associate professor of neurology at the University of Rochester Medical Center in New York, said: "If these findings are replicated and confirmed, I think the implications could be very important, specifically, that maintaining optimal blood sugar levels throughout aging is a feasible way to [slow or prevent] cognitive decline. It goes beyond diabetes to look at people who don't have diabetes. The implication is even if you don't have a clinical condition of diabetes, that you can still do something about cognitive aging."

More information

For more on healthy aging, visit the U.S. National Institute on Aging.

TUESDAY, Dec. 30 (HealthDay News) -- The type 2 diabetes epidemic that continues to sweep across the United States has left an estimated 24 million Americans struggling with the disease, up more than 3 million people since 2005.

And, of course, with the epidemic comes the wave of illnesses and disabilities brought on by diabetes -- heart disease and stroke, blindness, amputations, kidney disease and nervous system damage.

Doctors are trying to reverse the tide in two ways.

First, they're continuing to press the public to adopt healthy lifestyle changes that can head off type 2 diabetes, or, at the very least, help control it if it's already present. And researchers are pushing to develop new drugs to help people manage their diabetes more effectively.

"You have to look at the management of diabetes as a package, really," said Ann Albright, director of the U.S. Centers for Disease Control and Prevention's Division of Diabetes Translation. "You really need to be taking advantage of all the tools in the toolbox."

Unfortunately, much of America continues to be slow in picking up those tools, particularly needed lifestyle changes, despite mounting evidence that they're very effective.

In type 2 diabetes, either the body doesn't produce enough of the hormone insulin or the cells "ignore" the insulin, which is needed for the body to use blood sugar, or glucose, for energy. Lack of exercise and being overweight are key contributors to type 2 diabetes.

Some type 2 diabetes medications have come under scrutiny recently after research found that a leading drug, Avandia, seemed to increase the risk of heart attack.

"That created a fair amount of uproar about drug safety in diabetes," said Dr. John Buse, director of the Diabetes Care Center at the University of North Carolina School of Medicine, and president of medicine and science for the American Diabetes Association.

Advisors to the U.S. Food and Drug Administration have recommended that drugs designed to control type 2 diabetes be subjected to more thorough safety reviews. The FDA has left Avandia on the market, however, concluding that the risk of heart attack isn't higher than that associated with similar drugs.

The concern now is that worries over heart attack have led many people to leave their diabetes untreated, abandoning their medication without picking up other drugs or other means of controlling the disease, Buse said.

"A lot of people stopped their diabetes drugs and didn't start others," he said. "There's a lot of concern that those people have lost control of their diabetes."

Some excitement has been generated by another drug for type 2 diabetes named Byetta, Buse said. The injectable medication not only controls blood sugar, but has been shown to help diabetics lose weight, he said.

That's important, because studies have shown that if a person loses even a small amount of weight, they can decrease their diabetes risk, Albright said. Dropping just 5 percent to 7 percent of body weight can help.

"It's not huge amounts of body weight that people need to lose," she said. "Weight loss is the best way to head off type 2 diabetes."

But Byetta comes with its own concerns. The FDA plans to strengthen its warnings placed on the drug after two users died and four others were hospitalized, all for pancreatitis.

Buse said it's too soon to tell whether the drug's problems outweigh its benefits.

"Most of the excitement revolves around the weight loss on top of blood glucose control," he said. "We don't know whether this disease association with Byetta is really happening, because people with diabetes get more pancreatitis."

The concerns over type 2 diabetes medications make the need to prevent people from getting the disease even more apparent. And the best way to head off diabetes is to treat yourself right, Albright said.

"The best data we have is that lifestyle interventions are most effective in preventing diabetes," she said.

A half hour of physical activity most days of the week, adding up to 150 total minutes per week, combined with a low-calorie healthy diet, have been shown to help stave off the onset of diabetes, she said.

Once a person has diabetes, the fight shifts to managing the disease and preventing complications.

"We have a lot of problems that are connected with diabetes," Albright said. "Controlling your blood sugar, blood pressure and cholesterol is essential to prevent those complications."

One new tool that could help people control their blood sugar are glucose sensors now being developed that are placed under the skin, Buse said. The sensors monitor blood sugar levels and transmit the information to a sensor.

"You really have to adjust insulin levels based on physical activity and diet, and it can be very tricky," he said. "This gives patients a more continuous way of monitoring their blood sugar."

Added Albright: "It's critical we work on good management of the disease and preventing new cases. It's a two-sided coin we're working with here."

More information

To learn more, visit the American Diabetes Association.

WEDNESDAY, Dec. 10 (HealthDay News) -- Researchers have identified common genetic mutations between type 1 diabetes and celiac disease, suggesting that the two inflammatory disorders may stem from a shared underlying mechanism.

The finding also suggests that the two diseases may be triggered by similar environmental factors.

"Our results spotlight that much more research needs to go into investigating the environmental factors involved," said study senior author John Todd, of the Cambridge Institute for Medical Research at the University of Cambridge in the U.K. "Additionally, research investigating whether there are benefits for type 1 diabetics knowing they are positive for celiac is important. There needs to be clinical research to see if this information could help them."

Type 1 diabetes is a disease in which the body doesn't produce insulin, a hormone needed to convert blood sugar (glucose) into energy for cells.

Celiac disease is a digestive disease that damages the small intestine and interferes with absorption of nutrients from food. People with celiac disease can't tolerate gluten, a protein that's found in wheat, rye and barley, according to the U.S. National Institutes of Health.

Researchers had previously seen genetic links between type 1 diabetes and celiac disease, which, together, affect about 1 percent of the population, Todd said.

But the new research shows there is "considerable overlap, and much more than we anticipated" he said. "Almost every celiac disease susceptibility gene had an effect in type 1 diabetes."

These similarities "suggest there's an important crisscross in both these diseases," said Dr. Robert Goldstein, chief scientific officer of the Juvenile Diabetes Research Foundation (JDRF). "What's missing is how do you relate that finding to biologic function or biologic dysfunction. That's the next step."

Knowledge on biological function could one day help spur treatments or cures for the diseases, the researchers suggested.

The study, released early online Wednesday by the New England Journal of Medicine, which will publish it in the Dec. 25 issue, was co-sponsored by the JDRF.

Both type 1 diabetes and celiac disease are autoimmune disorders, meaning they both result when the body mistakenly turns on itself. In type 1 diabetes, the body attacks the pancreatic beta cells, which produce insulin. In celiac disease, it's the small intestine that is damaged.

Many people who have type 1 diabetes also have celiac disease, and vice versa. According to the study authors, the small intestine and pancreas share some characteristics.

For this study, researchers analyzed DNA from blood samples from 8,064 people with type 1 diabetes, 2,828 families (both parents and a child) with celiac disease, and 9,339 "controls" -- people who didn't have diabetes or celiac disease.

Seven "loci," or regions of a chromosome, were shared in people with both diseases. These regions may be involved in regulating the processes that cause the body's immune system to go awry.

"Our plans are to understand in more detail what effects these susceptibility genes have on the immune system," Todd explained. "Also, research to identify why the autoimmune diseases are increasing and what environmental factors are influencing this is critical."

Weimin He, assistant professor at the Texas A&M Health Science Center Institute of Biosciences and Technology in Houston, said, "In future studies, it will be interesting to determine whether intake of gluten-free food will significantly decrease the incidence of type 1 diabetes in those who have genetic mutations and are thus more susceptible to type 1 diabetes."

More information

The Juvenile Diabetes Research Foundation has more on the double diagnosis of type 1 diabetes and celiac disease.