Research indicates that obesity may play a role in accelerating brain aging.
- Obesity increases the risk of health problems such as heart disease,
stroke, type 2 diabetes, arthritis, and several types of cancer.
- New research suggests that it may also accelerate brain aging.
- The researchers found that obesity and a high fat diet damaged blood
vessels in the brains of mice, reducing oxygen supply to brain cells and
leading to cognitive decline.
Obesity is a growing public health concern worldwide.
According to the World Health Organization (WHO), in 2022, 16% of people around
the world had obesity.
Prevalence in the United States is much higher, with
the Centers
for Disease Control and Prevention (CDC) reporting that in 2020, 41.9%
of people were living with obesity.
The condition is a growing concern in younger people — the
WHO reports that 160 million children and adolescents around the world were
living with obesity in 2022.
A person with overweight has an increased risk of health problems,
and these risks are greater the more overweight a person is. Obesity increases
the risk of many health conditions, including:
- cardiovascular
disease (mainly heart disease and stroke)
- type
2 diabetes
- musculoskeletal
disorders like osteoarthritis
- some
cancers (endometrial, breast, and colon)
A new study, to be presented at the American Physiology Summit April 4–7 in Long Beach,
CA, and the results of which are yet to be published in a peer-reviewed
scientific journal, suggests that obesity may also accelerate brain aging and
lead to cognitive decline.
Lead study author Dr. Sharon Negri, a postdoctoral fellow in the Department
of Neurosurgery at the University of Oklahoma Health Sciences Center,
told Medical News Today:
“Diet-induced obesity is known to
trigger a range of systemic inflammatory responses that can have widespread
effects on the body, including the cerebrovasculature. One primary reason
obesity might induce senescence in the cerebrovasculature is due to the chronic
inflammatory state it creates.”
Obesity
damages blood vessels in the brain
Studies suggest
that obesity is associated with reduced brain function. The exact mechanism is
not known, but inflammation —
which is a known effect
of obesity — may affect cognitive function.
“Adipose tissue in obese individuals secretes various
bioactive molecules, including pro-inflammatory cytokines, which can circulate
and affect distant organs, including the brain,” Dr. Negri explained.
“These
inflammatory signals can contribute to vascular cells aging, facilitating the
development of senescence in the brain, thus impairing the vessels’ ability to
regulate blood flow and respond to neural activity,” she added.
Several
studies show that people with obesity or a high body mass index (BMI) have reduced cerebral blood
flow, which may be associated with
impaired cognitive function, particularly in older people.
In this latest study, the researchers looked at how obesity
and a high fat diet affected the brain blood vessels in mice and what effect
this had on cognitive function.
They fed novel transgenic mice (p16-3MR mice, in
which senescent cells can be visualized and selectively eliminated) on a diet
containing 60% fat or a 10% fat diet.
In the mice on the high fat diet, the researchers saw an
increase in senescence (where cells stop dividing but do not die, releasing
chemicals that may cause inflammation) of endothelial cells in the blood
vessels, compared with the mice on the regular diet.
“The findings in the present animal study indicate that
obesity and unhealthy dietary habits contribute to the accumulation of damage
in blood vessels, which diminishes oxygen delivery to specific brain regions
and may culminate in cognitive deterioration,” Kelsey Costa, a registered dietitian nutritionist and
founder of Dietitian Insights, who was not involved in the study, told MNT.
High-fat
diet leads to cognitive impairment
The high fat diet increased the number of senescent
endothelial cells in mice and also showed impaired cognitive function measured
on the radial arm water maze test (RAWM).
To investigate the significance of these senescent cells,
researchers treated older mice with obesity on a high fat diet with
Navitoclax/ABT263, which selectively kills these cells. Following treatment,
the mice showed improved cognitive function.
“Obesity-related inflammation may contribute to vascular
dysfunction, potentially affecting cognitive processes, Şebnem Ünlüişler, a
genetic engineer at the London Regenerative Institute, who was not involved in the
study, told MNT.
“Even though the research was conducted on mice, it gives us
useful hints about what could happen in people.”
“It’s exciting that removing
senescent cells improved the brains of obese mice, suggesting a way to help
with obesity-related brain problems. Eliminating senescent cells in the brains
of obese mice using Navitoclax seemed to improve brain vasculature, which could
be a good way to deal with obesity-related cognitive decline.”— Şebnem
Ünlüişler, genetic engineer
“Our research, along with studies from other groups, has
demonstrated that strategies designed to eliminate senescent cells can
significantly reverse or prevent the cognitive decline associated with aging,”
Negri said.
“This promising discovery, however, does not mean we advocate
for the use of Navitoclax by healthy elderly individuals as a direct
therapeutic measure,” she cautioned.
Ünlüişler agreed that more evidence was needed.
“Further research into the molecular mechanisms involved and
assessing Navitoclax’s safety and efficacy in human cognitive function would be
enlightening,” she said.
Maintaining
a healthy weight may preserve cognitive function
Negri advised that maintaining a healthy weight or, for those
with obesity, losing weight helps prevent cerebrovascular and cognitive changes
in older age.
“Our primary objective is to delve
into the specific role that senescent cells play both in the natural aging
process and in relation to obesity. By focusing on these areas, we aim to
uncover the fundamental mechanisms by which aging affects our bodies and minds.
Ultimately, our research seeks to pave the way for developing targeted,
effective strategies that not only improve the aging process but also
significantly enhance the overall quality of life in our later years.”— Sharon
Negri, lead study author
“Losing weight
and maintaining a healthy weight can […] reduce inflammation and oxidative
stress, both of which are implicated in cerebrovascular damage and cognitive
decline. Additionally, a healthy weight supports good physical health, which is
closely linked to brain health,” said Negri.
Costa echoed this advice:
“While more clinical research is needed, this is far from the
first study to suggest that weight and nutrition directly affect brain health,”
she noted. “Therefore, maintaining a healthy weight through proper diet and
exercise may be essential in preserving vascular health and cognitive function
as we age.”
“While regular physical activity and
an overall healthy dietary pattern are key, some specific foods and nutrients
are being studied for their positive impacts on vascular health. A few of these
include blueberries, plums, beetroot, pomegranate juice, and omega-3 fatty
acids found in fish, nuts, and seeds. These foods have been shown to improve
blood flow, reduce inflammation, and protect against oxidative stress.”— Kelsey
Costa, registered dietitian
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