The largest and most detailed study of its type concludes that there are links between physical fitness and improved cognitive performance. The researchers also show that this boost in mental powers is associated with white matter integrity.
Over recent years, there has been a great deal of research into how bodily fitness might influence the mind.
For instance, studies have concluded that physical fitness can reduce the risk of dementia, relieve depressive symptoms, and more.
There is also evidence that physical activity boosts the cognitive performance of healthy individuals, people of different ages, and participants with cognitive impairments.
Similarly, some studies have shown positive links between physical fitness and changes in brain structure.
The authors of the latest study in this field, who published their findings in Scientific Reports, note that previous studies had certain limitations.
In some cases, for instance, they did not account for variables that could play an important role.
As an example, researchers could associate low levels of physical fitness with higher blood pressure. If a study finds that high physical fitness has links with cognitive abilities, scientists could argue that in fact, it is lower blood pressure that boosts cognitive power.
The same could apply for several factors that have links with fitness, such as body mass index (BMI), blood glucose levels, and education status.
Also, most studies concentrate on only one marker of mental performance at a time, such as memory.
As the authors of the current study explain, “studies investigating associations between [physical fitness], white matter integrity, and multiple differential cognitive domains simultaneously are rare.”
The latest experiment, carried out by scientists from University Hospital Muenster in Germany, attempts to fill in some of the gaps. Using a large sample of healthy people, the scientists retested the links between physical fitness, brain structure, and a wide range of cognitive domains.
They also wanted to ensure that they accounted for as many confounding variables as possible. Additionally, the scientists wanted to understand whether the link between cognitive ability and physical fitness was associated with white matter integrity.
White matter in the brain relays messages between disparate parts of the brain and coordinates communication throughout the organ.
Also, research has suggested drinking tea could be good for your brain and stave off age-related decline.
Scientists now say regularly consuming a brew could be a simple lifestyle choice that benefits brain health.
Three-dozen adults who were all aged 60 or above were asked to take part a range of cognitive tests for the study.
Researchers led by a team based at the National University of Singapore also took Magnetic Resonance Imaging (MRI) scans of the volunteers.
All of the participants, from Singapore, were also asked about how often they drink green, black or oolong tea, as well as coffee.
Results showed participants who drank tea at least four times a week for around 25 years had more connected brains.
Lead researcher, Dr. Feng Lei, said: “Our results offer the first evidence of positive contribution of tea drinking to brain structure.”
He added they also “suggest that drinking tea regularly has a protective effect against age-related decline in brain organisation.”
Lei said: “Take the analogy of road traffic as an example – consider brain regions as destinations, while the connections between brain regions are roads.
“When a road system is better organised, the movement of vehicles and passengers is more efficient and uses less resources.
“Similarly, when connections between brain regions are more structured, information processing can be performed more efficiently.”
The study, which also involved a team from the universities of Cambridge and Essex, was published in the scientific journal Aging.
The research is believed to have been the first of its kind, with no other studies having examined the effect of tea on brain networks.
It is not the first time scientists have found benefits from drinking tea – studies have suggested it can ward off type 2 diabetes and help you live longer.
German researchers last year credited polyphenols inside tea for helping to combat ‘internal stress’, as long as they are taken alongside a zinc supplement.
In 2017, one study suggested tea could smooth out spikes in blood sugar levels. Another suggested tea drinkers were less likely to get cognitive impairment.
The latter also carried out by Lei and colleagues, speculated that green and black teas contain bioactive compounds that improve memory.
Lei said: “Tea has been a popular beverage since antiquity, with records referring to consumption dating back to… approximately 2700 BC, in China.
“Tea is consumed in diverse ways, with brewed tea and products with a tea ingredient extremely prevalent in Asia, especially in China and Japan.”
He added: “A large number of studies have suggested the reduction of inter-regional connectivity is associated with brain ageing. Our study suggests tea drinking is effective in preventing or ameliorating cognitive decline and tea drinking might be a simple lifestyle choice that benefits brain health.”
Meanwhile, sparring could damage the brain of boxers, research suggests. Scientists analysed 20 amateur boxers and Muay Thai fighters after they sparred for a total of nine minutes.
One hour later, tests showed the boxers’ “brain-to-muscle communication” was down by six per cent.
They also performed 52 per cent worse on memory tests. Both of these were back to normal after 24 hours.
The researchers worry these “transient brain changes” are “reminiscent of effects seen following brain injury”.
It is unclear whether there is a “safe threshold” when it comes to sparring, the team at the University of Stirling added.
The results come amid a wave of worrying evidence showing a link between blows to the head and dementia.
“Although transient, we found brain changes observed after sparring are reminiscent of effects seen following brain injury,” lead author Dr. Thomas Di Virgilio said.
“Our findings are important because they show routine practices may have immediate effects on the brain.
“It is not possible to say whether there is a “safe” threshold when it comes to the level of impact in sparring.
“Further research is required to help sportspeople – and the academic community – fully understand the dangers posed by sub concussive impacts, routine in sport, and any measures that can be taken to mitigate against these risks.”
Concern is growing over the long-term health risks of traumatic brain injuries acquired during sport, the researchers wrote in the journal Frontiers in Human Neuroscience.
Major international trials have found repeated concussions can lead to chronic traumatic encephalopathy (CTE), which in turn can cause dementia.
Meanwhile, perceived stress may detrimentally impact oral health which, in turn, may lead to cognitive decline among specific elderly communities, according to two new studies.
Oral health can be a surprisingly good indicator of a person’s well-being. Not only can oral diseases reduce a person’s quality of life, but they can also increase the risk of other serious conditions.
Researchers have linked gum disease and tooth loss to the occurrence of stroke. An article published in the Journal of Indian Society of Periodontology in 2010 concluded that gum disease could raise a person’s risk of heart disease by around 20 per cent. It is, however, necessary to carry out more research in these areas.
Teams at Rutgers University in New Brunswick, NJ, have now focused on a different link — the one between oral health and cognitive decline.
A recently published review of 23 studies found evidence of a relationship between oral health and cognitive aspects, such as memory and executive function.
Now, a team from Rutgers University carried out two separate studies into cognitive decline and perceived stress. Both papers appear in the Journal of the American Geriatrics Society.
The studies focused on Chinese American adults with a minimum age of 60. “Racial and ethnic minorities are particularly vulnerable to the negative consequences of poor oral health,” explains XinQi Dong, director of Rutgers University’s Institute for Health, Health Care Policy, and Aging Research.
He continues, “Minorities have less access to preventive dental care that is further exacerbated by language barriers and low socioeconomic status. Older Chinese Americans are at particular risk for experiencing oral health symptoms due to lack of dental insurance or not visiting a dental clinic regularly.”
Participants for both studies came from the Population Study of Chinese Elderly in Chicago (PINE). The first study quizzed people on their oral health and gave them five cognitive tests to complete.
The second study asked participants if they had ever experienced dry mouth issues. Researchers then asked them to measure their perceived stress, social support, and social strain levels using pre-defined scales.
Social support referred to how often they felt able to open up to or rely on their family members or friends. Researchers defined social strain as how often participants experienced excessive demands or criticism from friends or relatives.
Out of the more than 2,700 Chinese Americans interviewed, almost half reported tooth-related symptoms. Just over a quarter said they had experienced dry mouth.
There was no significant relationship between gum and cognitive problems. However, researchers believe participants may have been less likely to report gum symptoms due to finding them less problematic.
The researchers did find a link between cognitive decline — specifically global cognition and episodic memory decline — and tooth symptoms. Episodic memory issues themselves have a link to the onset of dementia.
The researchers found a similar association in the second study. Those who reported more perceived stress were more likely to report dry mouth. Spousal social support or strain did not reduce this relationship, but support from friends appeared to protect against dry mouth in some way.
“However, the potential overload of such support could be detrimental to oral health outcomes among older Chinese Americans,” notes study author Weiyu Mao, assistant professor at the University of Nevada’s School of Social Work.
Oral health is key
Any conclusion formed from self-reported data has its limitations. However, the team believes their findings point to a need for better awareness of immigrant health and psychosocial influences on said health.
Dong says they “demonstrate the importance of examining immigrant oral health outcomes later in life to understand the specific type of outcomes of different cultural groups.”
“The studies further serve as a call to action for policymakers to develop programs aimed at improving oral health preventive and dental care services in this high risk population.”
Meanwhile, to investigate, the researchers took data from the Human Connectome Project, which includes MRI brain scans from 1,206 adults with an average age of 28.8.
Some of these participants also underwent further tests. In total, 1,204 participants completed a walking test in which they walked as quickly as they could for two minutes. The researchers noted the distance.
A total of 1,187 participants also completed cognitive tests. In these, the scientists assessed the volunteers’ memory, reasoning, sharpness, and judgment, among other parameters.
Overall, the researchers showed that individuals who performed better in the two-minute walking test also performed significantly better in all but one of the cognitive tasks.
Importantly, this relationship was significant even after controlling for a range of factors, including BMI, blood pressure, age, education level, and sex.
The researchers also associated this cognitive improvement with higher levels of fitness with improvements in the structural integrity of white matter. The authors conclude: “With the present work, we provide evidence for a positive relationship between [physical fitness] and both white matter microstructure as well as cognitive performance in a large sample of healthy young adults.”
“It surprised us to see that even in a young population cognitive performance decreases as fitness levels drop.”
Lead researcher, Dr. Jonathan Repple, continued, “We knew how this might be important in an elderly population, which does not necessarily have good health, but to see this happening in 30-year-olds is surprising.”
“This leads us to believe that a basic level of fitness seems to be a preventable risk factor for brain health.”
The current study has many strengths, not least the extensive database of MRIs. Repple explained that “normally when you are dealing with MRI work, a sample of 30 is pretty good, but the existence of this large MRI database allowed us to eliminate possibly misleading factors and strengthened the analysis considerably.”
However, because researchers carried out the tests at one point in time, it is not possible to see how fitness and cognitive ability changes over time. It is also not possible to say that becoming fitter causes a boost in cognitive ability.
Future studies will need to ask whether increasing an individual’s level of fitness also increases cognitive ability.
Also, by design, the current study only investigated healthy young people. How this interaction might be different in older populations or people with mental health conditions will require further work.
Taking previous studies into account, it is becoming increasingly clear that there are strong links between physical fitness and mental agility.
By Chukwuma Muanya