Why do some adults in their 70s and 80s have memory and thinking skills comparable to much younger adults? Scientists from Massachusetts General Hospital suggest it’s because certain regions of their brains have retained their youthful heft.
It’s typically a normal part of aging for the brain to shrink, particularly in two areas associated with learning and memory – the prefrontal cortex, which is in charge of abstract thinking and thought analysis; and the hippocampus, involved in storage of long-term memory. Shrinkage of these areas, both of which are in the brain’s “default” network, spurs a decline in the ability to learn new things and retrieve information.
In their study, the team from Massachusetts found that in so-called “super agers” – older adults whose memory and thinking skills are comparable to young adults – the prefrontal cortex and hippocampus appeared thicker and healthier than in adults of the same age who showed signs of memory decline.
According to Dr. Whitley Legler, a clinical neuropsychologist with a practice in Vero Beach, it’s become widely accepted in recent years that brain atrophy is tied to cognitive decline. As of yet, there is no research suggesting that the effects can be reversed, but Legler says studies like the one from Massachusetts General are important. “The more we learn,” she says, “the more distinct the possibility of a discovery that can restore lost brain function.”
The study participants included 40 adults aged 70 to 80 and 41 who were between 18 and 35. A neuropsychological test called the California Verbal Learning Test (CVLT) was administered; its purpose is to assess verbal memory abilities. Legler uses it in her own practice; she says it’s a “perfectly sound” assessment.
In the CVLT, the tester reads a list that contains 16 common words, each of which belongs to one of four categories – for example, four fruits, four vegetables, four spices and four desserts. The person being tested is then asked to recall as many of these items as possible, both immediately and after a short delay.
While 23 of the 40 older participants exhibited “normal” memory and thinking results for their age group, 17 performed equally well to the younger adults in the study. Imaging studies on the brains of the 17 super-agers were then conducted, revealing that their prefrontal cortex and hippocampus were similar in size to those of the younger participants.
The team also examined a group of regions in the brain known as the salience network, which helps the brain decide what to pay attention to. They found that in super agers, several areas of the salience network had retained the “thickness” usually seen in younger people.
The intersection of the salience and default networks was also found to have this youthful thickness. This is important, as previous studies have shown this intersection to play a key role in allowing for brain networks to communicate with each other efficiently. Study co-senior author Alexandra Touroutoglou with the hospital’s department of neurology says, “We believe that effective communication between these networks is very important for healthy cognitive aging.”
Vero’s Legler says there are factors that can help prevent brain atrophy and the associated cognitive issues. She offers this guidance:
- Get enough sleep. With less than 6-8 hours of nightly sleep, the brain’s “gray matter” (where neurons reside) can shrink. “Too many people neglect getting the right amount of sleep, perhaps because they are unaware of its importance for brain function,” Legler says.
- Do not let depression go untreated. Studies have shown a link between depression and brain shrinkage, so people experiencing depression should seek help.
- Use your non-dominant hand occasionally. If you’re right-handed, use your left hand to brush your teeth, write a note, or use the remote control. “This challenges the brain, in a good way,” Legler says.
- Exercise. Any type of physical exercise can stave off cognitive decline.
- Consider cognitive therapy. Dr. Legler uses a fairly new program called RehaCom in her practice; it is designed to change the effectiveness of brain functions so that they perform at their maximum capacity. People who are interested in learning more should contact Legler or talk to their primary care physician.
The dietary supplement docosahexaenoic acid (DHA), found primarily in fish oil, has been linked to brain health. Legler says that many of her patients have reported positive effects by taking a daily dose of 600 mg, but it’s important to check with your doctor before beginning any supplement regimen.
The Massachusetts study, published in The Journal of Neuroscience, begs for more research, according to co-senior study author Dr. Bradford Dickerson, who directs the hospital’s Frontotemporal Disorders Unit. “We desperately need to understand how some older adults are able to function very well into their seventh, eighth and ninth decades,” says Dickerson. “This could provide important clues about how to prevent the decline in memory and thinking that accompanies aging in most of us.”
Dickerson adds that recognizing the factors that protect against memory decline could lead to advances in preventing and treating age-related memory loss and potentially even dementia.
Dr. Legler’s office is located at 3003 Cardinal Drive, Suite A on Vero Beach’s barrier island; the office phone is 772-231-5554.
