- Researchers examined the relationship between brain age and various health indicators.
- They found that poor cardiovascular health was associated with older brain age, which was linked to poorer cognitive performance, and a smaller brain volume.
- They concluded that further research is needed to understand whether their findings apply to multiple demographics.
As the human brain ages, its structure changes. A person’s ‘brain age’ can be predicted by a computer model. This method uses MRI-based machine learning to compare an individual’s neuroanatomy with a large reference set of healthy brains.
If you subtract brain age from a person’s chronological age, you can calculate their brain-predicted age difference (brain-PAD).
Studies have found that brain-PAD can predict the 8-year mortality of
Studying how brain age interacts with other physiological health measures and health outcomes could improve our understanding of the aging process.
In a new study, researchers examined how brain-PAD relates to various health outcomes over the lifespan.
They found that brain PAD is linked to cardiovascular risk and neurodegeneration. They noted that their findings might be useful for understanding patient prognoses.
The findings were recently published in
For the study, the researchers included data from 456 individuals who were born in the same week of 1946 in Britain. Each person underwent 24 different assessments since birth on various factors, including:
- childhood cognitive ability
- adult cognition
- adult socioeconomic position
- cardiovascular measures (i.e., blood pressure, smoking status, and diabetes history at ages 36 and 69)
- polygenic risk score (genetic risk for various diseases)
- MRI brain scan between 2015 and 2018
While participants were an average of 70.7 years old at the time of the study, their average brain-predicted age was 67.9 years. Female brains were an average of 5.4 years younger than male brains after adjusting for chronological age.
The researchers found that brain age was significantly linked to higher cardiovascular risk, poorer cognitive performance, and a smaller brain volume.
They also found that an older brain age was linked to higher levels of neurofilament light protein (NfL). While NfL levels increase with age in healthy individuals, they are also linked to neural damage.
Brain-PAD was further linked to future hippocampal atrophy, an early characteristic of Alzheimer’s disease. However, the researchers found no link between brain-PAD and various biomarkers for Alzheimer’s disease.
The researchers also reported no significant link between brain-PAD and childhood cognitive performance, education level, or socioeconomic status.
Overall, they reported that the 12 metrics accounted for in their study could explain 33% of the variance in brain-PAD.
When asked what might explain the relationship between cardiovascular health and aging in the brain, Dr. Aaron Wagen, clinical research fellow at University College London, one of the study’s authors, told Medical News Today:
“The brain is the most energy demanding organ in the body, and thus requires a constant supply of oxygen.”
“Any damage to the vascular system (e.g., heart, blood vessels) that impacts the level of oxygenated blood supplied to the brain will have a negative impact on brain health, potentially resulting in cerebral small vessel disease, white matter lesions, and brain atrophy. These brain changes can happen as part of normal aging. However, poor heart health could mean they happen earlier than expected.”
— Dr. Aaron Wagen
Dr. Lee A. Baugh, an associate professor of neuroscience at the University of South Dakota, who was not involved in the study, also told MNT that cardiovascular risk factors, such as blood pressure and smoking status, have already been linked to premature brain aging.
“The precise mechanisms by which cardiovascular health and aging in the brain are linked are likely incredibly complicated, but will certainly have to do with things such blood flow delivery to the brain, cardiac hemodynamics, and arterial stiffness,” Dr. Baugh said.
“I think the more exciting question is whether the composite measurement of cardiovascular health used in the present study is providing unique information above and beyond what these individual factors provide, and the answer to that question really requires further study. That being said, it is great to see these types of connections being made between brain and body health,” he added.
MNT also asked the researchers what might explain the differences in brain age between men and women.
“In this cohort, we have seen that females outperform males in several measures, including cognitive tests. The younger brain predicted age seen in women may reflect this, [alongside] in general the differences in life expectancy in the U.K. population where women live longer than men. The mechanisms underlying this require further study, but cardiovascular health might contribute,” Dr. Wagen said.
The researchers concluded that their findings would enable further exploration into brain age and predict future decline.
As for the study’s limitations, Dr. Wagen noted that his study was conducted mainly on white British participants, and thus may not apply to other demographics.
Dr. Baugh pointed out that due to how some of the statistical analyses were performed, there is an increased likelihood of false positive results or findings that do not exist. He noted that future research should examine the relationships with more “conservative statistical approaches.”
He added that there are now multiple methods to calculate brain age other than that used in the study and that further research is needed to understand which is optimal.
NEW WAYS TO MEASURE BRAIN AGE“It will be important for the field to come up with standardized, well-validated ways to measure brain age to allow for the comparison across research studies, and especially important if results like these are ultimately used to guide healthcare decisions. It is this latter scenario that I think is the really exciting potential for this kind of research.”
— Dr. Lee A. Baugh
To help prevent premature brain aging, experts recommend several strategies to reduce cardiovascular risk factors.
“Being physically active, managing existing medical conditions, eating healthy, learning how to manage stress effectively, keeping engaged in social networks and activities [are crucial],” Dr. Baugh said.
“These are all things that we know can have a big impact on cardiovascular and brain health, essentially keeping the whole body as ‘young’ as possible,” he added.
Medical myths: All about aging
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
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
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
“[H]aving low expectations regarding aging was independently associated with not believing it important to seek health care.”
Another
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
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
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
The
As a silver lining, some research suggests that older adults can handle sleep deprivation better than young adults. A study in the
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
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
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
In the United States, an estimated
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
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
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
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.
Source - Medical News Today
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