The brain, that three-pound control tower above your neck, is one of the most complex objects in the universe. And despite the power it holds to dictate every human function, it still needs toning and challenging to perform at its best in the face of age and disease. Memories of that junior high dance, coordination to jump rope, logic to solve a riddle: that's important stuff up there. This issue of Thrive picks some brains — and good ones, at that — for guidance on how to protect and preserve the body's most important organ.
USE IT OR LOSE IT
The secret to Nana's carrot cake, the ability to hit a baseball, and the butterflies of a first kiss — cells in the brain possess the pieces of our lives and dictate the thinking, feeling, moving, communicating, and breathing that each day demands. By the numbers, the human brain is a three-pound network of 100 billion neurons, or nerve cells. Each neuron communicates and clusters with 100,000 others. Arm-like branches called dendrites provide the infrastructure for the thousands of electric signals the brain sends every millisecond. Beyond the physiology of synapses and grey matter, though, those figures add up to an organ responsible for the entire human experience.
For decades, medical and scientific communities believed giving up our memories and/or abilities was an inevitable consequence of aging. And because no prevention or prescription cocktail can override our genetic blueprints, forgetfulness, slower reaction times, and even senility were considered a given on the elderly's list of complaints.
Newer research, however, shows that although some degeneration of brain cells occurs naturally over time, we are not helpless victims of age and disease. Ways to protect that precious lump of tissue and fluid do exist, and the earlier those steps are taken, the more effective they are in protecting our most treasured keepsake.
YET ANOTHER REASON TO DO THE SHAG
Dr. David Bachman, professor of neurosciences and co-director of the Alzheimer's Research and Clinical Programs at Medical University of South Carolina, is the first to admit the mystery still hidden inside the matrix-like organ. What he knows for sure, though, is that physical exercise is integral to maintaining a healthy brain. "People who don't exercise have a higher risk for intellectual decline," Bachman says.
Dr. Lotta Granholm-Bentley, a neuroscientist and director of the Center on Aging at MUSC, says of brain maintenance, "Consider it like a muscle."
The brain feeds off glucose and oxygen, so maintaining the 400 miles of capillaries used to distribute this fuel around the brain is essential. Exercise increases cardiac output and raises the amount and efficiency of blood flow throughout the body, including the brain. This strengthens blood vessels, helping the brain transmit more quickly and effectively, actions that also help lower the risk for stroke.
Physical activity also ignites the production of antioxidants, the body's homegrown answer to free radicals, the roaming particles that can cause cell death or malfunction. This increases the brain's ability to heal itself as well as strengthens it resistance against disease. Granholm-Bentley cites several published studies where adults who walked just twice a week had a lower risk for Alzheimer's than their sedentary counterparts.
Other health problems linked with a lack of exercise such as diabetes, hypertension, and elevated cholesterol levels are bad for the brain, too (see "Feed Your Mind" on pg. 11). Both untreated high blood pressure and obesity have been tied to increased risk for dementia and Alzheimer's disease. Granholm-Bentley points out that physical brain training doesn't mean vigorous exercise. Three to five 30-minute sessions per week will do, as long as they get the blood pumping — line dancing, ping-pong, and gardening all count.
Four and a half million people currently suffer from Alzheimer's in the United States, and that figure could increase fivefold by 2050. An even more urgent issue is the 76 million baby boomers who are or soon will be reaching prime age for dementia and other degenerative brain diseases. Dr. Warachal Faison is part of a team of physicians and researchers at MUSC working on the Alzheimer's Disease Neuroimaging Initiative (ADNI), a four-year study comparing types of mental impairment over time sponsored by the National Institutes of Health. Faison says besides our individual health, we need to consider the costs — monetarily and emotionally — such diseases create for society.
"The time is now," she says.
NOW OR NEVER
People possess a certain amount of cognitive ability when they are born. Those abilities materialize in the membranes of the neurons and form what neurologists refer to as the cognitive reserve, the brain's storage shed. Stimulation such as education encourages the growth, efficacy, and flexibility of the connections inside those membranes, thus fortifying the cognitive reserve. The contents of this storage shed determine the brain's ability and likelihood of preserving function and developing resistance against diseases.
"There is more truth to the 'use it or lose it' saying than we thought," Bachman says. Brain cells left isolated and unused eventually shut down, a process that happens more quickly than the generation of new cells. So even people with higher education, whose brains are shown to be more resilient to Alzheimer's, will experience degeneration if stimulation isn't sustained. Fortunately, the belief held for much of the 20th century that the brain cannot respond to stimulation past its prime developmental years (the first 10) was wrong.
"There is no data to suggest that at any point it is too late," Bachman says, pointing out that he has seen brains of people into their 70s change with stimulation.
By continuing to stimulate the brain throughout life, the complexity and number of dendrites increase, giving the brain the only known protection against time and disease. Some of the most recognized evidence of this process comes from the Nun's Study, a longitudinal experiment that tested the cognitive ability of more than 800 women. Images of their brains over time showed that those who engaged in mentally stimulating activities over five years reduced their age-related decline in overall mental abilities by 50 percent, in concentration and attention span by 60 percent, and in mental processing speed by 30 percent.
SO WHAT COUNTS AS STIMULATION?
"There is no evidence that simply practicing rote memorization is that helpful," Bachman says of training your brain. The catch, research has illustrated, is that the stimulation challenges the brain to reach beyond its routine and existing knowledge.
"It is the act of doing something new that promotes brain health," Granholm-Bentley says. It was not enough, she explains, that Grandma practiced pieces on the piano she knew by heart, no matter how difficult they were. The key to her intact mind, even at 85, lay in the novelty of her choices. By consistently challenging her brain to make connections it had never made — unseen note patterns and new finger movements — Grandma sparked her neurons to fire, which enhanced her cognitive reserve and increased her ability to fight off disease.
Stimulation exists in myriad forms, and although it can target a particular brain function, memory or relational thinking for instance, experts agree that kind of specificity is not necessary. "When you practice visual spatial training, you will improve in that task," Bachman explains. "But not for visual memory."
The best results come from activities that simultaneously engage various parts of the brain. Knitting, square dancing, practicing a new language — these and similar tasks force the brain to process information while coordinating motor skills and are some of the best ways to stimulate the brain. Bachman, along with the Alzheimer's Association, touts the positive effect socialization has on brain health. Socializing, Bachman explains, involves processing information from conversations, anticipating what people will say next, remembering what has been said, and reading body language. "It takes a lot more skill than people realize — until they lose it."
To be effective, pursuing such activities, interacting with different environments, and seeking challenges for the brain have to be features of a lifestyle. A lifestyle, experts agree, that includes not only seeking out new stimuli but also minimizing stress, which creates hormones that can affect brain function negatively, avoiding large quantities of alcohol, illegal substances, and TV, protecting the noggin during physical activity, oh, and don't smoke — the habit has been linked to greater risk for Alzheimer's.
So go ahead, engage your brain; worry less about losing memories and focus on making more because some things — Nana's carrot cake among them — are just too sweet to forget.
MUSC Alzheimer's Research & Clinical Programs (5900 Core Road, Suite 203, North Charleston) offers free informational tours and memory assessments for people 50 years of age and older. 740-1592
Alzheimer's Association Palmetto Chapter Helpline: 800-636-3346 (www.scpalmettoalz.org)
Alzheimer's Association website at www.alz.org