It is a familiar food, but the latest evidence is prompting researchers to take a much closer look at its neurological effects.
On your side, face-up or face-down? The position which best clears metabolic waste from your brain at night.
On your side, face-up or face-down? The position which best clears metabolic waste from your brain at night.
Sleeping on your side removes waste from the brain most efficiently.
As a result, sleeping on your side may help reduce the risk of Alzheimer’s and other neurological diseases.
Professor Maiken Nedergaard, one of the study’s authors, said:
“It is interesting that the lateral sleep position is already the most popular in human and most animals — even in the wild — and it appears that we have adapted the lateral sleep position to most efficiently clear our brain of the metabolic waste products that built up while we are awake.
The study therefore adds further support to the concept that sleep subserves a distinct biological function of sleep and that is to ‘clean up’ the mess that accumulates while we are awake.
Many types of dementia are linked to sleep disturbances, including difficulties in falling asleep.
It is increasing acknowledged that these sleep disturbances may accelerate memory loss in Alzheimer’s disease.
Our finding brings new insight into this topic by showing it is also important what position you sleep in.”
The study of mice tested the brain’s ‘clean-up’ mechanism in three different sleeping positions:
Scientists monitored how cerebrospinal fluid (CSF) flowed through the brain and exchanged with interstitial fluid.
This pathway — called the glymphatic pathway — clears waste from the brain most efficiently at night.
Professor Helene Benveniste, another of the study’s authors, said:
“The analysis showed us consistently that glymphatic transport was most efficient in the lateral position when compared to the supine or prone positions.
Because of this finding, we propose that the body posture and sleep quality should be considered when standardizing future diagnostic imaging procedures to assess CSF-ISF transport in humans and therefore the assessment of the clearance of damaging brain proteins that may contribute to or cause brain diseases.”
The research was published in the Journal of Neuroscience (Lee et al., 2015).
Pet owners retain their cognitive abilities better with age than those without pets.
Pet owners retain their cognitive abilities better with age than those without pets.
Having a pet may slow the rate of cognitive decline.
Older people who have pets such as a cat or a dog, especially for longer than five years, demonstrate better cognitive health.
This may put pet owners at a lower risk of developing dementia.
The benefit could be down to an increase in people’s physical activity as well as the stress-reducing effects of animals.
Dr Tiffany Braley, study co-author, said:
“Prior studies have suggested that the human-animal bond may have health benefits like decreasing blood pressure and stress.
Our results suggest pet ownership may also be protective against cognitive decline.”
The study included almost 1,400 older people, half of whom owned pets, with one-third owning pets over the long-term.
They were given a series of cognitive tests, including of their ability to remember words and do simple arithmetic.
The results revealed that pet owners retained their cognitive abilities better with age than people without pets.
The longer people had owned a pet, the greater the cognitive benefit.
Dr Braley said:
“As stress can negatively affect cognitive function, the potential stress-buffering effects of pet ownership could provide a plausible reason for our findings.
A companion animal can also increase physical activity, which could benefit cognitive health.
That said, more research is needed to confirm our results and identify underlying mechanisms for this association.”
Pets have been linked to all sorts of mental health benefits, both in the short- and long-term.
For example, ten minutes spent petting a cat or dog can significantly reduce stress.
And petting a dog for as little as three minutes increases levels of oxytocin, sometimes known as the ‘love hormone’.
In the longer term, people living with mental illness report a range of benefits from having pets:
Having a dog as a childhood pet can even decrease the risk of developing schizophrenia later in life.
Emotional support animals can also be beneficial to people with mental health problems, another study finds.
Depression, anxiety and loneliness were reduced over a year in people who were given a cat or dog as a companion.
The study was presented at the American Academy of Neurology’s 74th Annual Meeting (Shieu et al., 2022).
90% use too much of an everyday substance that can cause inflammation of blood vessels in the brain, which is linked to dementia.
Sleep disturbance is common in dementia, but the reason is unclear.
People highest in this trait were significantly less likely to develop dementia over 14 years.
Higher levels of this vitamin in midlife may give protection against dementia years later.
The amount of steps that reduces the risk of Alzheimer’s.
The memories of people with low levels of this vitamin decline three times faster.
The memories of people with low levels of this vitamin decline three times faster.
Low levels of vitamin D among older people are linked to memory loss.
Those with low levels of vitamin D decline three times faster than those with adequate levels.
Professor Joshua Miller, one of the study’s authors, said:
“Independent of race or ethnicity, baseline cognitive abilities and a host of other risk factors, vitamin D insufficiency was associated with significantly faster declines in both episodic memory and executive function performance.
This work, and that of others, suggests that there is enough evidence to recommend that people in their 60s and older discuss taking a daily vitamin D supplement with their physicians.
Even if doing so proves to not be effective, there’s still very low health risk to doing it.”
The study included almost 400 older people and around 60% had low levels of vitamin D.
In fact, around one-quarter were found to be deficient (very low) and 35% insufficient (just low) in vitamin D.
African-Americans and Hispanics were more likely than white people to be low in vitamin D.
These are high-risk groups because those with darker skins cannot absorb as much from the sun.
The results showed that the cognitive abilities of people deficient in vitamin D declined two to three times faster than those with adequate levels.
Professor Charles DeCarli, the study’s first author and director of the Alzheimer’s Disease Center at UC Davis, said:
“We expected to see declines in individuals with low vitamin D status.
What was unexpected was how profoundly and rapidly [low vitamin D] impacts cognition.”
The other major source of vitamin D is the diet — particularly the consumption of dairy products.
Professor DeCarli said:
“I don’t know if replacement therapy would affect these cognitive trajectories.
That needs to be researched and we are planning on doing that.
This is a vitamin deficiency that could easily be treated and that has other health consequences.
We need to start talking about it.
And we need to start talking about it, particularly for people of color, for whom vitamin D deficiency appears to present an even greater risk.”
The study was published in the journal JAMA Neurology (DeCarli et al., 2015).
Elderly people low in this vitamin were more than twice as likely to develop dementia.
Elderly people low in this vitamin were more than twice as likely to develop dementia.
Low levels of Vitamin D are substantially associated with developing Alzheimer’s and dementia in older people.
An international team of scientists used data from 1,685 elderly Americans who were followed for around five years.
None had dementia problems at the start of the study, but after an average of five years, 171 had developed dementia, 102 of whom had Alzheimer’s disease.
The study found that, amongst those who developed dementia, those with low vitamin D levels were 53 percent more likely to develop the disease.
Amongst those who were severely deficient, the risk increased by 125 percent.
Similar increases in risk were seen for Alzheimer’s disease: low levels of vitamin D increased risk by 69 percent and severe deficiency by 122 percent.
Dr David Llewellyn of the University of Exeter Medical School, who led the study, said:
“We expected to find an association between low Vitamin D levels and the risk of dementia and Alzheimer’s disease, but the results were surprising — we actually found that the association was twice as strong as we anticipated.
Clinical trials are now needed to establish whether eating foods such as oily fish or taking vitamin D supplements can delay or even prevent the onset of Alzheimer’s disease and dementia.
We need to be cautious at this early stage and our latest results do not demonstrate that low vitamin D levels cause dementia.
That said, our findings are very encouraging, and even if a small number of people could benefit, this would have enormous public health implications given the devastating and costly nature of dementia.”
The study was published in the journal Neurology (Littlejohns et al., 2014).
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