|
B
|
rain aging is inevitable to some
extent, but not uniform; it affects everyone, or every brain, differently.
Slowing down brain aging or stopping it altogether would be the ultimate elixir
to achieve eternal youth. Is brain aging a slippery slope that we need to
accept? Or are there steps we can take to reduce the rate of decline?
Share
on PinterestBrain aging is experienced by everyone differently. The rate of
cognitive decline affects some people more than others.
At around 3 pounds in weight, the
human brain is a staggering feat of engineering with around 100 billion
neurons interconnected via trillions of synapses.
Throughout our lifetime our brain
changes more than any other part of our body. From the moment the brain begins
to develop in the third week of gestation to old age, its complex structures
and functions are changing, networks and pathways connecting and severing.
During the first few years of life,
a child's brain forms more than 1 million new neural connections every second. The size
of the brain increases fourfold in the preschool period and by age 6 reaches
around 90 percent of adult volume.
The frontal lobes - the area of the
brain responsible for executive functions, such as planning, working memory,
and impulse control - are among the last areas of the brain to mature, and they
may not be fully developed until 35 years of
age.
Normal brain aging
As we age, all our body systems
gradually decline - including the brain. "Slips of the mind" are
associated with getting older. People often experienced those same slight
memory lapses in their 20s and yet did not give it a second thought.
Share
on PinterestHaving slight memory slips is normal in both younger and older
people.
Older individuals often become
anxious about memory slips due to the link between impaired memory and Alzheimer's disease.
However, Alzheimer's and other dementias are not a
part of the normal aging process.
Common memory changes that are
associated with normal aging include:
- Difficulty learning something
new: Committing new information
to memory can take longer.
- Multitasking: Slowed processing can make processing and
planning parallel tasks more difficult.
- Recalling names and numbers: Strategic memory that helps memory of names and
numbers begins to decline at age 20.
- Remembering appointments: Without cues to recall the information,
appointments can be put safely in storage and then not accessed unless the
memory is jogged.
While some studies show that one third of
older people struggle with declarative memory (memories of facts or events that
have been stored and can be retrieved), other studies indicate that one fifth
of 70-year-olds perform cognitive tests just as well as their 20-year-old
counterparts.
Scientists are currently piecing
together sections of the giant puzzle of brain research to determine how the
brain subtly alters over time to cause these changes.
General changes that are thought to
occur during brain aging include:
- Brain mass: Shrinkage in the frontal lobe and hippocampus -
areas involved in higher cognitive function and encoding new memories -
starting around the age of 60 or 70 years.
- Cortical density: Thinning of the outer-ridged surface of the brain
due to declining synaptic connections. Fewer connections may contribute to
slower cognitive processing.
- White matter: White matter consists of myelinated nerve fibers
that are bundled into tracts and carry nerve signals between brains cells.
Myelin is thought to shrink with age, and as a result, slow processing and
reduce cognitive function.
- Neurotransmitter systems: Researchers suggest that the brain generates less
chemical messengers with aging, and it is this decrease in dopamine,
acetylcholine, serotonin, and
norepinephrine activity that may play a role in declining cognition and
memory and increased depression.
In understanding the neural basis of
cognitive decline, researchers can uncover which therapies or strategies may
help slow or prevent brain deterioration.
Recent discoveries in brain aging
Several brain studies are ongoing to
solve the brain-aging conundrum, and discoveries are being frequently made.
Stem cells
Recently, researchers from Albert
Einstein College of Medicine in New York revealed in a mouse study that stem cells in the brain's hypothalamus
likely control how fast aging occurs in the body.
"Our research shows that the
number of hypothalamic neural stem cells naturally declines over the life of
the animal, and this decline accelerates aging," says Dr. Dongsheng Cai,
Ph.D., professor of molecular pharmacology at Einstein. "But we also found
that the effects of this loss are not irreversible. By replenishing these stem
cells or the molecules they produce, it's possible to slow and even reverse
various aspects of aging throughout the body."
Injecting hypothalamic stem cells
into the brains of normal old mice and middle-aged mice, whose stem cells had
been destroyed, slowed or reversed measures of aging. The researchers say this
is a first step toward slowing the aging process and potentially treated
age-related diseases.
SuperAgers
"SuperAgers" are a rare
group of individuals over the age of 80 years who have memories as sharp as
healthy people decades younger.
MEDICAL NEWS
TODAY NEWSLETTER
Stay in the know. Get our free daily newsletter
Expect in-depth, science-backed
toplines of our best stories every day. Tap in and keep your curiosity
satisfied.
SIGN
UP NOW
Your privacy is
important to us
Share
on PinterestSuperAgers' brains shrink at a slower rate than people of the same
age.
Research by Northwestern University Feinberg School of
Medicine in Chicago, IL, compared SuperAgers with a control group of same-age
individuals. They found that the brains of SuperAgers shrink at a slower rate
than their age-matched peers, which results in a greater resistance to the
typical memory loss observed with age, thus revealing that age-related
cognitive decline is not inevitable.
"We found that SuperAgers are
resistant to the normal rate of decline that we see in average elderly, and
they're managing to strike a balance between life span and health span, really
living well and enjoying their later years of life," says Emily Rogalski,
associate professor at the Cognitive Neurology and Alzheimer's Disease Center
(CNADC) at Northwestern University Feinberg School of Medicine.
By studying how SuperAgers are
unique, the researchers hope to unearth biological factors that might
contribute to maintaining memory ability in advanced age.
Therapies to help slow brain aging
Factors have been discovered that
speed up brain aging. For example, obesity in midlife may accelerate brain aging by around
10 years, and both sugar and diet varieties of soda are correlated with fast-tracking brain age, having
smaller overall brain volume, poorer episodic memory, and a shrunken hippocampus.
Share
on PinterestEngaging in regular exercise may help prevent cognitive and memory
decline.
A growing body of evidence suggests
that people who experience the least declines in cognition and memory all share
certain characteristics:
- partaking in regular physical activity
- pursuing intellectually stimulating activities
- staying socially active
- managing stress
- eating healthily
- sleeping well
Recent research highlights a
plethora of ways that we can actively take charge of our health and perhaps
decrease the rate at which our brains age.
Exercise
One intervention that crops up time
and time again to stave off age-related mental decline is exercise.
A combination of aerobic and
resistance exercise of moderate intensity for at least 45 minutes each session
and on as many days of the week as possible has been reported to boost brain power in people aged 50 and over
significantly.
Likewise, other research by
the University of Miami found that individuals over the age of 50 who engaged
in little to no exercise experienced a decline in memory and thinking skills
comparable to 10 years of aging in 5 years, compared with those who took part
in moderate- or high-intensity exercise. Essentially, physical activity slowed
brain aging by 10 years.
Dancing has also shown to have an
anti-aging effect on the brain of seniors. A study conducted by the German Center for
Neurodegenerative Diseases, Magdeburg, Germany found that while regular
exercise can reverse the signs of brain aging, the most profound effect was
seen in people who danced.
Playing an instrument
Baycrest Health Sciences in Toronto,
Canada, revealed why playing a musical instrument may help older
adults ward off age-related cognitive declines and retain their listening
skills.
Share
on PinterestPlaying a musical instrument may help prevent some of the cognitive
decline that accompanies aging.
Researchers found that learning to
play a sound on a musical instrument changes brain waves in such a way that
improves an individual's listening and hearing skills. The alteration in brain
activity indicates that the brain rewires itself to compensate for disease or
injuries that might prevent a person's ability to perform tasks.
"It has been hypothesized that
the act of playing music requires many brain systems to work together, such as
the hearing, motor and perception systems," said Dr. Bernhard Ross, senior
scientist at Baycrest's Rotman Research Institute. "This study was the
first time we saw direct changes in the brain after one session, demonstrating
that the action of creating music leads to a strong change in brain
activity."
Diet
A key component of brain health is
diet. Recent research has linked omega-3 and
omega-6 fatty acids in the blood with healthy brain aging. Another study has also determined that consuming foods included
in the Mediterranean or the MIND diet is associated with a lower risk of memory
difficulties in older adults.
Research by the University of
Illinois, Champaign, IL, discovered that middle-aged people who have higher levels
of lutein - a nutrient that is found in green leafy vegetables, such as kale and spinach, and
eggs and avocados - had similar neural responses to younger individuals than of
people the same age.
"As people get older, they
experience typical decline. However, research has shown that this process can
start earlier than expected. You can even start to see some differences in the
30s," informs Anne Walk, a postdoctoral scholar and the first author of the
study. "We want to understand how diet impacts cognition throughout the
lifespan. If lutein can protect against decline, we should encourage people to
consume lutein-rich foods at a point in their lives when it has maximum
benefit."
The number of American adults over
the age of 65 is set to more than double in 40 years, rising from 40.2 million in
2010 to 88.7 million by the year 2050. Due to this aging population, it will
become increasingly important to understand the cognitive changes that go hand
in hand with aging.
While many questions remain
regarding the aging brain, research is making progress in illuminating what
happens to our cognitive functions and memory throughout our lifetime, and it
is emphasizing ways we can preserve our mental abilities to improve our quality
of life as we advance into older adulthood.
No comments:
Post a Comment