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.
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 conditionsTrusted Source, 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.”
“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.
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 senescenceTrusted Source (where cells stop dividingTrusted Source 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.
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.
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.”
Around 300,000 generations ago, the human species split from an ancient ancestor that we share with chimpanzees. Since then, human life expectancy at birth has doubled.
Over the last 200 years, life expectancy at birth has doubled again. As animals go, humans perform well in longevity.
According to the World Health Organization (WHO), “Between 2000 and 2050, the proportion of the world’s population over 60 years will double from about 11% to 22%Trusted Source.”
With these facts in mind, dispelling the many myths associated with aging seems more pressing than at any point in our evolutionary history. In this article, we will tackle myths associated with exercise, cognitive ability, sex, and more.
This is not entirely untrue. As we age, our body does experience wear and tear from decades of use. However, physical deterioration does not have to be complete, and people can often slow it down.
As the WHO explain, “Increased physical activity and improving diet can effectively tackle many of the problems frequently associated with old age.” These problems include reduced strength, increased body fat, high blood pressure, and reduced bone density.
Some research suggests that merely expecting physical deterioration increases the likelihood that someone will physically deteriorate.
In one studyTrusted Source, scientists surveyed 148 older adults about their aging, lifestyles, and general health expectations.
They concluded that expectations regarding aging “play an important role in the adoption of physically active lifestyles in older adults and may influence health outcomes, such as physical function.”
So, although some deterioration is likely, managing expectations will help individuals make better life choices to maintain physical health and fitness later in life.
An older study investigated how perceptions of aging influenced an individual’s likelihood of seeking medical attention. The authors of the study, which included data from 429 older adultsTrusted Source, concluded:
“[H]aving low expectations regarding aging was independently associated with not believing it important to seek health care.”
Another studyTrusted Source looked at individual attitudes to aging during late middle-age and how they might influence their overall lifespan. The authors concluded that “older individuals with more positive self-perceptions of aging, measured up to 23 years earlier, lived 7.5 years longer than those with less positive self-perceptions of aging.”
In short, keeping active, eating right, and maintaining a positive outlook can often slow the physical deterioration associated with older age.
From the previous section, it is clear that this is a myth. According to an older article in Neuropsychobiology, keeping active can boost muscle strength, reduce fat, and improve mental health.
Some people think that, once they reach a certain age, there is no point in exercising, as they believe that it will provide no benefit. This is another myth. In one studyTrusted Source, researchers put 142 adults aged 60–80 through a 42-week weight-lifting regime.
The scientists found that the course increased “dynamic muscle strength, muscle size, and functional capacity.”
There is also good evidence that regular exercise can reduce the risk of developing Alzheimer’s disease and other forms of dementia. A study, which involved 1,740 older adults, found that regular exercise was “associated with a delay in onset of dementia and Alzheimer’s disease.”
However, people should consult their doctor before embarking on a new exercise regime if they have a medical condition. For example, the National Health Service (NHS) in the United Kingdom indicate that people with certain conditions associated with age, such as osteoporosis, should avoid high impact exercise.
However, the vast majority of older adults can indulge in some form of physical activity.
Some people believe that older adults need more sleep than younger adults, perhaps because of the stereotype that older people enjoy a nap. Others say that older adults need less sleep, which might stem from the stereotype that older adults rise early in the morning.
These myths are relatively difficult to unpick because there are many factors involved. It is undoubtedly true that older adults have more difficulty getting to sleep and that their sleep tends to be more fragmentedTrusted Source.
This might help explain why some older adults need to nap in the day. As the human body changes with age, it can disrupt the circadian (daily) rhythms.
This, in turn, can impact sleep. The relationship is multifaceted, too: if a person’s circadian rhythms become disrupted, it can influence other aspects of their physiology, such as hormone levels, which might also impact their sleep.
Aside from circadian disruptions, certain diseases that occur more commonly in older adults, such as osteoarthritis and osteoporosis, can cause discomfort, which might adversely influence an individual’s ability to get to sleep or stay asleep.
Similarly, some conditions cause shortness of breath, including chronic obstructive pulmonary disease (COPD) and congestive heart failure; this can also make sleeping more challenging.
According to an older articleTrusted Source, certain medications, including beta-blockers, bronchodilators, corticosteroids, decongestants, and diuretics, can also interfere with sleep. Older adults are more likely to be taking these types of medication, sometimes together.
The Centers for Disease Control and Prevention(CDC)Trusted Source state that people aged 61–64 need 7–9 hours, and people aged 65 or older need 7–8 hours of sleep each night. It just might be more difficult for them to get that all-important shut-eye.
As a silver lining, some research suggests that older adults can handle sleep deprivation better than young adults. A study in the Journal of Sleep ResearchTrusted Source found that older adults scored better following a sleep deprivation intervention than younger adults in a range of measures, including negative affect, depression, confusion, tension, anger, fatigue, and irritability.
Osteoporosis is a condition where bones gradually become weaker. Some people believe that it only affects women. This is not true; it can affect either sex and people of any age. However, osteoporosis is indeed much more common in older people, white people, and females.
According to an overview articleTrusted Source, the International Osteoporosis Foundation estimate that globally, around 1 in 3 women over 50 have osteoporosis, and about 1 in 5 men will experience a bone fracture related to osteoporosis in their lifetime.
Another related myth is that osteoporosis is inevitable for women as they age. As the figures above attest, two-thirds of women over 50 do not have osteoporosis. To minimize risks, the National Institute on AgingTrusted Source advise people to eat foods rich in calcium and vitamin D and exercise regularly.
The term cognitive decline refers to a gradual decrease in mental functioning with age, but before we tackle the facts of the matter, we dismiss a couple of associated myths:
Dementia is inevitable as you age
According to the WHO, the risk of developing dementia increases with age, but it does not affect all older adults. Worldwide, an estimated 5–8%Trusted Source of people over 60 have dementia. That means that 92%–95% of people aged 60 or older do not have dementia.
In the United States, an estimated 13.9%Trusted Source of people over 71 have dementia, meaning that 86.1% of people over 71 do not have dementia.
Cognitive decline leads to dementia
Contrary to popular opinion, cognitive decline does not necessarily signal the start of dementia.
People who go on to develop dementia tend to experience cognitive decline first. However, not everyone who experiences cognitive decline will develop dementia.
One older studyTrusted Source estimated that 22.2% of people in the U.S. aged 71 or older experience cognitive decline. Of these, each year, 11.7%–20% develop dementia.
Cognitive decline is inevitable
As the above statistics show, cognitive decline is not inevitable, regardless of the long-held myth that older adults experience a mental slowing down. And, importantly, there are ways to reduce the risk.
In 2015, the Alzheimer’s Association evaluated the evidence of modifiable risk factors for both dementia and cognitive decline. Their reportTrusted Source, presented to the World Dementia Council, explains that “there is sufficient evidence to support the link between several modifiable risk factors and a reduced risk for cognitive decline.”
They identified that maintaining regular physical activity and managing classic cardiovascular risk factors, such as diabetes, obesity, smoking, and high blood pressure were strongly associated with a reduced risk of cognitive decline.
They also found good evidence that a healthful diet and lifelong learning or cognitive training also reduce the risk of cognitive decline.
Whether this is a genuine myth or merely an excuse, some older adults say that there is no point in giving up smoking at “their age.” This is not true. As the NHS clearly explain:
“No matter how long you have smoked for and no matter how many cigarettes you smoke a day, your health will start to improve as soon as you quit. Some health benefits are immediate, some are longer-term, but what matters is that it’s never too late.”
Some people believe that older adults lose their ability to enjoy sex and that their sexual organs become unfit for purpose. This, thankfully, is a myth.
It is true that the risk of erectile dysfunction (ED) and vaginal dryness increases as people age, but for most individuals, these are not insurmountable problems.
Sildenafil (Viagra) and lubricants or hormone creams can work wonders in many cases. Before taking Viagra, though, it is essential to speak with a doctor, as it is not suitable for everyone.
An article in the International Journal of Clinical PracticeTrusted Source indicates that around 0.4% of men aged 18–29 experience ED, compared with 11.5% of men aged 60–69. However, flipping that statistic on its head makes it much less daunting — almost 9 out of 10 men in their 60s do not have ED.
Intercourse between older people may be less fast and furious, but that is not necessarily a bad thing. As one author writes, “Growing old does not necessarily discontinue a healthy sexual life, but it does call for redefining its expression.”
There are certain benefits, too. For instance, a male’s penis often becomes less sensitive, helping them maintain an erection longer.
It is true that as some people grow older, they do not have the same sexual desire or drive as when they were young, but this is by no means the case for everyone.
To end this section on a high, below is a quote from a survey study that involved 158 older adults. Although the participants reported that they were having less sex than a decade earlier, the authors write:
“A remarkably robust sex life was evidenced by both the men and the women, even until advanced old age.”
Overall, most of the myths surrounding age seem to center on inevitability. People believe that it is inevitable that they will gradually crumble into dust as their lives become increasingly unbearable, boring, passionless, and painful.
Although certain aspects of health might decline with age, none of the above is inevitable for everyone. As we have discovered, a positive psychological outlook on aging can benefit the physical aspects of aging.
Welcome to the latest edition of our Medical Myths series. Today, to mark World Alzheimer’s Day, we will be tackling myths relating to both Alzheimer’s disease and dementia at large.
In our Medical Myths series, we approach medical misinformation head on. Using expert insight and peer reviewed research to wrestle fact from fiction, MNT brings clarity to the myth riddled world of health journalism.
Today, an estimated 5.8 millionTrusted Source people aged 65 years or older in the United States have dementia.
Due to the fact that the average lifespan of people in the U.S. has increased over recent decades, some experts project that by 2050, the number of older adults with dementia could reach 13.8 millionTrusted Source.
Figures of this stature spark justifiable fear, and, as we have found in previous Medical Myths articles, fear tends to breed misconceptions.
In this article, we aim to dispel 11 of these myths.
This statement is not true. Dementia is not a normal part of aging.
According to a report that the Alzheimer’s Association published, Alzheimer’s disease, which is the most common form of dementia, affects 3% of people aged 65–74 years in the U.S.
As a result of the risk increasing as we age, 17% of people aged 75–84 years and 32% of people aged 85 years and older have a dementia diagnosis.
This is not quite correct. Alzheimer’s is a type of dementia, accounting for 60–80% of all dementia cases. Other types of dementia include frontotemporal dementia (FTD), vascular dementia, mixed dementia, and Lewy body dementia.
The National Institute on AgingTrusted Source define dementia as “the loss of cognitive functioning — thinking, remembering, and reasoning — and behavioral abilities to such an extent that it interferes with a person’s daily life and activities.”
Although dementias share certain characteristics, each type has a distinct underlying pathology.
Alzheimer’s disease is associated with a buildup of so-called plaques and tangles in the brain. These structures interfere with brain cells, eventually killing them. In contrast, brain cell death in vascular dementia occurs due to a lack of oxygen, which can result from a stroke, for instance.
FTD, as another example, occurs when abnormal protein structures form in the frontal and temporal lobes of the brain, causing the brain cells in these regions to die.
A common myth is that dementia is purely genetic. In other words, if a person’s family member has a dementia diagnosis, they are guaranteed to develop dementia later in life. This is not true.
Although there is a genetic component to some forms of dementia, the majority of cases do not have a strong genetic link.
As we learned above, rather than genetic factors, the most significant risk factor for dementia is age. However, if a parent or grandparent developed Alzheimer’s when they were younger than 65 years, the chance of it passing on genetically is higher.
Early-onset Alzheimer’s is relatively uncommon, though. It occurs in about 5.5%Trusted Source of all Alzheimer’s cases.
As the majority of dementia cases are Alzheimer’s disease, this means that most dementia cases are not hereditary. FTD, which is much less common, has a stronger genetic link, but if a parent or grandparent develops the condition, it does not mean that children or grandchildren are guaranteed to develop it.
Developing healthy habits is essential for living a happy and fulfilling life. It can be challenging to maintain a healthy lifestyle, but incorporating regular exercise and a balanced diet can help you achieve your health goals. In this article, we'l
