Top 5 Brain Health Headlines of 2012

This was a great year for brain science, which is especially good news for those of us in middle age and beyond.

Following is a rundown of five major developments that came to light in 2012 as researchers continue to work on unlocking the secrets of the brain to plot new ways for keeping our minds agile and sharp as we age.

1. To keep your mind young, be like a bee. We already do all we can to limit the effects of aging on our brain. But what if we could actually reverse them? Arizona State University researchers attracted much buzz this summer when they revealed that adult honeybees experience reverse brain aging when they take on responsibilities usually handled by younger bees.

While older bees were out foraging for food, scientists removed younger "nurse" bees from the nest, leaving behind only the babies and the queen. When the older bees returned, about half eventually began caring for the babies themselves, and those bees experienced age-reversing changes in the molecular structure of their brains, including higher levels of the protein Prx6, which is believed to help maintain memory function and ward off dementia. They also lived longer.

(MORE: Can New Gene Research Show Us How to Reverse the Aging Process?)

The Arizona State team hopes their discovery can spur the development of drugs that increase production of key proteins to preserve brain function in humans. That may take decades. In the meantime, their experiment adds to the evidence that when we take on fresh challenges that maintain and stretch "plasticity" in our brains, we can limit the negative effects of aging. Learn more about the possibilities of reverse aging in the brain.

2. Marijuana may save the aging brain. It was a big year for advocates of the healing power of marijuana. Voters in Connecticut and Massachusetts legalized the use of medical marijuana, bringing the number of states with such laws to 18. In Colorado and Washington, voters decriminalized marijuana use altogether. And research into cannabinoids, the drug's active chemical components, bolstered the theory that they may hold the key to limiting dementia and Alzheimer's. Cannabinoids can regulate inflammation in the brain and promote the growth of new neural pathways, even in cells damaged by age or trauma. As more research identifies inflammation as a potential cause of degenerative brain diseases, marijuana has been getting a closer look as a preventive medication. 

(MORE: Can the Nation Support Boomers' Mental Health Needs?)

3. Alzheimer's can be detected sooner — but would you want to know? Scientists learned a great deal about Alzheimer's disease in 2012. A major federally supported study of an extended Colombian family with a strong genetic predisposition for the disease revealed that signs of the disease appear in the brain far earlier than imagined. The brains of some members of the extended family showed changes as early as age 18, even though the first symptoms of Alzheimer's did not generally appear until 45.

On another front, the Food and Drug Administration approved new scanning technology using a radioactive substance that seeks out and tags the plaques in the brain that are thought to be the cause of Alzheimer’s. Under a PET scan, the radioactive tags "light up," highlighting any plaques.

(MORE: 6 Memory Problems That Shouldn't Worry You)

The new technique, however, has raised medical and ethical concerns, primarily because current Alzheimer's treatments have not kept up with detection methods. The effects of Alzheimer's are long term and irreversible, and no medication can stop its advance. But early-onset patients often remain highly functional for many years, at least in some cognitive areas. If you had the disease, without debilitating symptoms, would you rather remain unaware? And if you have a family history of Alzheimer’s, would you want to be told there were plaques in your brain even if you didn’t have any symptoms? Learn more about the new campaign against Alzheimer's and the debate over early detection.

4. Dementia may be a type of diabetes. A provocative theory which gained support in 2012 suggests that Alzheimer's may be considered "Type 3" diabetes, because several features of the degenerative disease appear, like diabetes, to be linked to problems with insulin signaling. In the brains of deceased elderly Alzheimer's patients, Brown Medical School neuropathologist Suzanne de la Monte found that insulin receptors were 80 percent lower than in normal brains. In Alzheimer's patients, it appears, the brain gradually becomes resistant to insulin.

(MORE: Diabetes Doesn't Have to Lead to Eye Trouble)

Type 2 diabetes patients are at least twice as likely to develop Alzheimer's disease than others. But most Alzheimer's patients are not diabetics and other researchers believe insulin resistance will eventually be shown to be just one of several possible causes of Alzheimer's, including genetics.

Still, the new theory is cause for both concern and encouragement. If our high-fat diet is truly a root cause of dementia, as it is of diabetes, then the nation's obesity crisis may have us facing an epidemic of both diseases. But while there is no cure for either condition, a treatment that approached Alzheimer's as a form of diabetes by targeting insulin resistance could help reverse some effects. In limited testing this year that will be expanded in 2013, the delivery of insulin via a nasal spray showed promise in improving subjects' attention and performance on memory tests. Learn more about the connection between insulin and Alzheimer's.

5. A love of the arts will help your brain age better. The idea that exercise strengthens our minds and bodies is not new. But recent research makes a strong case that engagement with the arts may be just as powerful in preserving mental health and acuity throughout our lives. In one study, people who learned to play a musical instrument as children appeared to experience less decline in brain function as they aged than others, outperforming adults without musical training in tests of memory and cognitive ability.

This concept was promoted in Arts & the Mind, a special produced by Twin Cities Public Television, which made an especially striking case for the power of dance to ward off dementia in older people. Neuroscientist Peter Davies of New York’s Albert Einstein Medical Center told producers that participation in dance programs appeared to reduce the development of dementia by maybe 75 percent, a rate of success he called much greater than any drug "even on the horizon."

The reason seems to be that dance combines mental and physical acuity, posing an especially productive challenge to the brain. The evidence is clear, says the show's executive producer, Gerry Richman. "Art will help us get older," he claims. "It’s not going to stop us from getting Alzheimer’s or cancer, but what it can do is keep us stronger mentally for as long as we’re going." Learn more about the link between cognition and the arts.

Read more about the major brain health trends of 2012:

• Cognitive Decline Can Affect Your Walk Before Your Memory
• Web Surfing May Be Helping Us Ward Off Dementia
• Older Adults With Hearing Loss Found Five Times More Likely to Develop Dementia
• Why We're Hardwired for Midlife Reinvention
• Silent Strokes Emerge as a Strong Predictor of Alzheimer's