Category: Dementia

90% use too much of an everyday substance that can cause inflammation of blood vessels in the brain, which is linked to dementia.

A high-salt diet is linked to cognitive decline and possibly dementia, research finds.

Salt causes the delicate lining of the brain’s blood vessels to inflame, because of signals sent from the gut.

Fully 90 percent of Americans consume above the recommended dietary maximum of 2,300 mg per day.

Dr Costantino Iadecola, study co-author, said:

“We discovered that mice fed a high-salt diet developed dementia even when blood pressure did not rise.

This was surprising since, in humans, the deleterious effects of salt on cognition were attributed to hypertension.”

The effect was quickly reversed by lowering salt intake.

The conclusions come from a study in which mice were fed a high-salt diet that is equivalent to a high-salt diet in humans.

Subsequently, the mice had much worse cognitive function.

Their brains showed 28 percent less activity in the cortex and 25 percent less in the hippocampus.

They had problems getting around a maze and did not show the usual interest in new objects placed in their cage.

They also had poorer blood flow in their brains and the integrity of the blood vessels there was worse.

However, these changes were reversed once the mice were returned to a normal diet.

The scientists found that these changes had nothing to do with higher blood pressure.

Worse cognitive functioning in the mice was seen even when the mice had normal blood pressure.

They were the result of signals sent from the gut to the brain.

These activated an immune response in the brain which increased levels of interleukin-17.

This eventually resulted in the inflammation of the delicate lining of the brain’s blood vessels.

The study was published in the journal Nature Neuroscience (Faraco et al., 2018).

Usually neurons shrink while we sleep, allowing waste products to clear.

A single night of lost sleep increases proteins in the brain linked to Alzheimer’s, research shows.

People not allowed to sleep for one night showed elevated levels of beta amyloid, the clumps of protein seen in the brains of people with Alzheimer’s.

As these build up, they hamper the brain’s ability to function.

Dr Ehsan Shokri-Kojori, the study’s first author, said:

“We certainly show that even oe night of sleep deprivation can increase the levels of these harmful beta amyloid compounds.

That’s a very logical assumption, I would say, and it’s consistent with prior research.”

The researchers recruited 20 healthy people who were allowed to sleep normally one night and were kept up the next night.

Brain scans were used to assess levels of beta amyloid.

Dr Ehsan Shokri-Kojori explained:

“…the beta amyloid increases were observed in regions of the brain important to memory and thought.

These included the hippocampus, which has been tied to memory, and the thalamus, which is an important hub for relaying sensory information to the brain.”

Usually, while we sleep, neurons in the brain get smaller, which allows waste products to be cleared.

Dr. Andrew Varga, a sleep scientist not connected to the study, said:

“It makes intuitive sense that if you have chronically high levels of beta amyloid they would congregate together and form plaques, but that piece of it is not fully fleshed out.”

The study was published in the journal Proceedings of the National Academy of Sciences (Shokri-Kojori et al., 2018).

The fruits and vegetables that provide the highest protection against cognitive decline.

Certain fruits and vegetables that contain antioxidant flavonols appear to protect against cognitive decline.

Flavanols, which are a type of flavonoid, are found in nearly all fruits and vegetables, as well as in tea.

Consuming around one cup of dark leafy greens each day is linked to retaining stronger cognitive abilities with age.

Kaempferol and myricetin

A flavanol called kaempferol was linked to the highest level of protection by the research.

Typical foods that contain high levels of kaempferol include beans, tea, kale, spinach and broccoli.

Another flavanol called myricetin was also protective, although not quite to the same extent as kaempferol.

Typical foods that contain high levels of myricetin include wine, tea, kale, oranges and tomatoes.

Quercetin, which is found in tea, apples, kale and tomatoes was also protective, but at a still lower level.

Dr Thomas M. Holland, the study’s first author, said:

“It’s exciting that our study shows making specific diet choices may lead to a slower rate of cognitive decline.

Something as simple as eating more fruits and vegetables and drinking more tea is an easy way for people to take an active role in maintaining their brain health.”

Slowing cognitive decline

For the study, almost 1,000 people were divided into groups based on the amount of flavanols in their diet.

The group consuming the most flavanols got 15 mg a day — the amount that would come from a single cup of dark leafy greens.

Study participants were tracked over an average of 7 years and given regular cognitive tests.

These revealed that people who consumed the highest levels of flavanols experienced the slowest decline in their cognitive abilities.

The study’s authors explained:

“Results suggest dietary intakes of total flavonols and several flavonol constituents may be associated with slower decline in global cognition and multiple cognitive abilities with older age.”

As with any correlational research like this one, the study cannot prove that there is a link, merely that there is an association.

Related

• People who eat more foods containing flavanols have a lower risk of developing Alzheimer’s.

The study was published in the journal Neurology (Holland et al., 2022).

Some signs of the vitamin deficiency include include poor sleep, symptoms of depression, headaches, weak muscles and tiredness.

Vitamin D deficiency increases the risk of dementia, research finds.

Adequate levels of vitamin D could prevent almost one-in-five cases of dementia from occurring, the study estimates.

People with low levels of vitamin D have lower brain volumes and are also at a higher risk of strokes — a condition in which the blood supply is cut off to part of the brain.

Professor Elina Hyppönen, study co-author, said:

“Vitamin D is a hormone precursor that is increasingly recognised for widespread effects, including on brain health, but until now it has been very difficult to examine what would happen if we were able to prevent vitamin D deficiency.”

Researchers examined data from almost 300,000 people in the UK Biobank study.

A genetic analysis of the data suggested that low levels of vitamin D are causing the increase in dementia risk.

Professor Hyppönen said:

“Our study is the first to examine the effect of very low levels of vitamin D on the risks of dementia and stroke, using robust genetic analyses among a large population.

In some contexts, where vitamin D deficiency is relatively common, our findings have important implications for dementia risks.

Indeed, in this UK population we observed that up to 17 per cent of dementia cases might have been avoided by boosting vitamin D levels to be within a normal range.”

Worldwide, vitamin D deficiency is very common.

Changing this could help to reduce the dementia risk for many, explained Professor Hyppönen:

“Dementia is a progressive and debilitating disease that can devastate individuals and families alike.

If we’re able to change this reality through ensuring that none of us is severely vitamin D deficient, it would also have further benefits and we could change the health and wellbeing for thousands.

Most of us are likely to be ok, but for anyone who for whatever reason may not receive enough vitamin D from the sun, modifications to diet may not be enough, and supplementation may well be needed.”

How to correct a vitamin D deficiency

Around one-in-five people are thought to have a vitamin D deficiency.

Some signs of vitamin D deficiency include include poor sleep, symptoms of depression, headaches, weak muscles and tiredness.

A deficiency in this vitamin is particularly prevalent among people with darker skin, who do not leave the house or who are pregnant or have problems with absorption.

Vitamin D supplementation is one option for correcting the problem.

Around 10 mcg per day is the dose often recommended.

A change of diet can also help the problem.

Vitamin D is particularly abundant in foods like milk, liver, fatty fish, and egg yolks.

The study was published in the American Journal of Clinical Nutrition (Navale et al., 2022).