Recent research reveals that older adults may have a genetic edge, showcasing enhanced cognitive abilities as they age.
A study conducted by scientists at the University of Illinois at Chicago School of Medicine found that individuals aged over 80, referred to as “very old people,” produce double the number of new neurons in the hippocampus—an area crucial for learning and memory—compared to the average elderly individual. The findings were published in the journal Nature on Wednesday.
Study co-author and UIC director, Orly Lazarov, stated, “This discovery indicates that very old individuals possess molecular capabilities that enhance their cognitive performance, evidenced by increased neurogenesis. Neurogenesis represents one of the most profound forms of brain plasticity.”
In essence, the brains of very old individuals are more adaptable, fostering improved cognitive functions.
The term “super-elderly” describes those over 80 who exhibit memory capabilities comparable to individuals 20 to 30 years younger, determined by a delayed word recall test, according to Dr. M. Marcel Mesulam, founder of the Meshulam Cognitive Neurology and Alzheimer’s Disease Research Institute. This designation was introduced by a professor from Northwestern University’s Feinberg School of Medicine.
In this groundbreaking study, Lazarov and colleagues analyzed 38 brains from five distinct groups: healthy adults under 40, healthy older adults, those in early cognitive decline, Alzheimer’s disease patients, and super-elderly individuals. Notably, six super-aged brains were contributed by Northwestern University’s Super Aging Program, which celebrated its 25th anniversary last year.
The researchers investigated neurons at varying developmental stages within brain tissue samples, discovering that very old individuals possess twice as many “immature” neurons compared to healthy older adults, and 2.5 times more than Alzheimer’s patients.
Historically, it was believed that mammals had a fixed number of neurons from birth, but research in the 1960s and 1970s unveiled adult neurogenesis in rodents and primates.
Subsequent studies have indicated that this phenomenon occurs within the human hippocampus’s dentate gyrus, although evidence remains mixed, and the underlying processes are still unclear.
“We’ve affirmed the existence of neurogenesis and its involvement in learning and memory in animal models,” Lazarov commented. “Determining if the human brain functions similarly is a pivotal question for our research.”
Lazarov’s findings suggest that the adult brain can generate new neurons in response to age and cognitive status.
The study revealed that very old brains exhibit “signs of resilience,” allowing them to cope with aging while maintaining superior cognitive performance.
Moreover, the research identified changes in astrocytes and CA1 neurons that regulate memory and cognition within the aging hippocampus.
Despite the study’s advancements, authors noted limitations, such as small sample sizes and significant variability among human brain samples.
Very Old Individuals Provide Insights Beyond 25 Years
According to the Northwestern Super Aging Program, this research marks the first identification of genetic distinctions between very old and conventional older adults.
Tamar Geffen, co-director of the program and co-author of the study, stated, “These individuals, aged 80 and above, exhibit immature neurons that continuously rewire, making their hippocampus distinct from that of other seniors.”
The program has also uncovered various discoveries related to these exceptionally healthy seniors, ranging from personality traits to neurological anomalies. For instance, Geffen noted that very elderly individuals often describe themselves as extroverts, with other research highlighting Von Economo Neurons linked to social behavior.
“We’ve repeatedly heard about the importance of social interactions for healthy aging, while isolation can have adverse effects in old age,” she noted.
Furthermore, these seniors tend to embrace change and remain receptive to new experiences, often identifying as low-level neurotics, according to Geffen.
While a typical human brain shrinks with age, a phenomenon exacerbated by Alzheimer’s, researchers at Northwestern discovered that the brains of very old individuals exhibit significantly slower shrinkage rates.
In a 2017 study published in the American Medical Association Journal, Northwestern researchers noted that very old individuals demonstrate resilience against neurofibrillary tangles, or tau protein changes associated with Alzheimer’s.
Concerning immunity, very elderly individuals have numerous questions, with their brains containing microglia—immune cells that activate during neurodegenerative diseases. A 2019 study in Frontiers in Aging Neuroscience revealed that very old individuals had fewer activated microglia compared to dementia patients, paralleling amounts found in those 30 to 40 years younger.
Staying Sharp Without Being Super Old
The findings suggest that the very elderly may have won the genetic lottery regarding cognitive health.
Sel Yackley, an 86-year-old participant in Northwestern’s Super Aging Program, noted, “We feel fortunate; we’re forming new neurons.”
Residing in Chicago, Yackley humorously remarked on her “super-senior duties,” which include knitting, going to the gym, crafting jewelry, singing, and managing her daily to-do list. Although she has faced limited in-person interactions, she’s prioritized keeping in touch via phone, email, and Zoom.
While she proudly identifies as a super senior citizen, Yackley acknowledges that age-related cognitive impairment can still affect her.
“At times, my memories feel fresh, and other times they slip away,” she stated.
Importantly, there are several wellness strategies individuals can adopt throughout adulthood to preserve cognitive health, noted Dr. Jennifer Paul-Durai, medical director of the Inova Brain Health and Memory Disorders Program in Northern Virginia. “Now is the moment to focus on enhancing cognitive function, long before natural decline or dementia occur,” she advised.
Dr. Paul-Durai emphasized, “The concept of super-aging provides a sense of regained control. With rising dementia and Alzheimer’s rates correlating with increased lifespan, maintaining cognitive sharpness is vital.” She encourages discussions focused on strategies to mitigate cognitive decline rather than solely highlighting the lack of a cure for Alzheimer’s disease.
This latest research underscores the brain’s capacity for adaptability, with Paul-Durai likening it to a ball of clay. “While some inherit better quality clay than others, it remains moldable throughout life to foster and shape neural pathways.”
However, if left unattended, clay solidifies and becomes hard to work with, similar to how our brains respond when we neglect cognitive engagement and physical activity.
“Our brains require active use and continuous cognitive engagement to remain flexible,” Paul-Durai explained.
Prioritizing overall health is also crucial for fostering brain plasticity, as factors like unmanaged chronic illnesses and untreated psychological traumas can hinder neuron development.
“It’s essential to advocate for preventive brain health measures before significant societal fractures emerge,” she advised. “We must emphasize the importance of taking proactive steps over merely highlighting the absence of Alzheimer’s solutions.”
Yackley, a former journalist, attributes her cognitive resilience to her career path, sharing, “My curiosity led me to explore numerous stories and conduct many interviews, which may have contributed to my neuronal health.”
Her advice to those who aren’t super seniors is to remain actively engaged, both mentally and physically.
“Don’t get caught up in counting the years. Stay active, both mentally and physically,” Yackley encouraged.
Source: www.nbcnews.com
