Category: Dementia

The study looked directly at levels of this vitamin in the brain, about which little is known.

Higher levels of vitamin D in the brain are linked to better cognitive function and less decline with age, a study finds.

Indeed, adequate vitamin D levels have repeatedly been linked to lower dementia risk (1, 2, 3) by research.

One study has even suggested that adequate levels of vitamin D could prevent almost one-in-five cases of dementia (Navale et al., 2022).

However, the link remains somewhat controversial, with other studies finding no connection (also: Owusu et al., 2018).

This research, though, looked directly at vitamin D levels in the brain, about which little is known.

Professor Sarah Booth, study co-author, said:

“This research reinforces the importance of studying how food and nutrients create resilience to protect the aging brain against diseases such as Alzheimer’s disease and other related dementias.”

Vitamin D markers

The study, which tracked the cognitive health of 290 seniors, analysed their brain tissue for vitamin D after they died.

Dr Kyla Shea, the study’s first author, said:

“Many studies have implicated dietary or nutritional factors in cognitive performance or function in older adults, including many studies of vitamin D, but all of them are based on either dietary intakes or blood measures of vitamin D.

We wanted to know if vitamin D is even present in the brain, and if it is, how those concentrations are linked to cognitive decline.”

The researchers found that people with higher levels of vitamin D in their brains had better cognitive function.

However, they found no link between vitamin D markers and other physiological signs of Alzheimer’s.

This means it is difficult to pinpoint the mechanism by which vitamin D might be beneficial.

Dr Shea said:

“Dementia is multifactorial, and lots of the pathological mechanisms underlying it have not been well characterized.

Vitamin D could be related to outcomes that we didn’t look at yet, but plan to study in the future.”

How much vitamin D?

Despite these findings, it is not recommended to take high levels of vitamin D as a preventative measure.

Recommended doses are 600 IU per day for people under 70 and 800 IU for those over 70.

Dr Shea said:

“We now know that vitamin D is present in reasonable amounts in human brains, and it seems to be correlated with less decline in cognitive function.

But we need to do more research to identify the neuropathology that vitamin D is linked to in the brain before we start designing future interventions.”

The study was published in the journal Alzheimer’s & Dementia (Shea et al., 2022).

Prescription drugs taken by millions of people around the world can affect memory.

Memory loss is not always a result of ageing.

Here are five types of drugs that can affect memory.

1. Antidepressants (tricyclic)

The older type of antidepressants — known as tricyclics — have been linked to memory loss.

Some of the drug names include:

• desipramine (Norpramin),
• imipramine (Tofranil),
• clomipramine (Anafranil),
• and doxepin (Sinequan).

Around half of people taking them report problems concentrating and one-third say they have memory loss.

2. Anxiety drugs

Benzodiazepines include drugs marketed under the names Valium, Ativan, Klonopin and Xanax.

These drugs are often prescribed for anxiety and other mental health issues such as OCD, insomnia and post-traumatic stress disorder.

Unfortunately they are also linked to memory loss and even Alzheimer’s.

Dr Helene Alphonso, a psychiatrist and Director of Osteopathic Medical Education at Texas University, said:

“Current research is extremely clear and physicians need to partner with their patients to move them into therapies, like [modern] anti-depressants, that are proven to be safer and more effective.”

3. Statins

Statins are prescribed to many people to keep their cholesterol in a safer range.

The Food and Drug Administration lists memory loss, forgetfulness and confusion as possible side-effects of the drug.

Some people do report memory problems when taking them, but the studies conducted so far are inconclusive.

Statins include:

• Atorvastatin (Lipitor),
• lovastatin (Mevacor),
• fluvastatin (Lescol),
• and pravastatin (Pravachol).

4. Beta-blockers

Beta-blockers slow the heart rate and are used to lower blood pressure.

They are also prescribed to those with congestive heart problems.

Typical names include:

• Carvedilol (Coreg),
• atenolol (Tenormin),
• metoprolol (Lopressor, Toprol),
• and propranolol (Inderal),

Beta-blockers, though, may also cause the loss of emotional memories.

They have even been tested as a way of treating post-traumatic stress disorder because of their ability to block emotional memories.

Again, though, the studies are not conclusive.

4. Sleeping aids

People who cannot sleep are sometimes prescribed so-called ‘Z-drugs’.

These include:

• Zolpidem (Ambien),
• eszopiclone (Lunesta),
• and zaleplon (Sonata).

The ‘Z-drugs’ have been linked to memory loss: especially losing the ability to make new memories.

They have also been reported to cause strange behaviours like driving or cooking with absolutely no memory of the event.

What are the alternatives?

Where possible consider a psychological therapy or applicable alternative to using these drugs.

Naturally, you should always consult your physician before making changes to your medication.

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Alzheimer’s causes degeneration in part of the brain that controls this function first.

Excessive napping during the day can be an early sign of Alzheimer’s, the most common form of dementia.

Scientist tended to assume that people with Alzheimer’s disease are drowsy during the day because of poor sleep at night.

Research has now shown, though, that it is due to the degeneration of neurons that maintain wakefulness.

The tau protein, one of two proteins involved in Alzheimer’s, is responsible for the critical neurodegeneration.

Alzheimer’s causes degeneration in this part of the brain first, which is why daytime napping without night time sleep problems is an early sign of dementia.

Professor Lea T. Grinberg, study co-author, said:

“We were able to prove what our previous research had been pointing to—that in Alzheimer’s patients who need to nap all the time, the disease has damaged the neurons that keep them awake.

It’s not that these patients are tired during the day because they didn’t sleep at night.

It’s that the system in their brain that would keep them awake is gone.”

Many of the key neurons are in the hypothalamus, a part of the brain that is central for wakefulness and arousal.

These neurons are so important as they affect a large number of other critical nerve cells.

Mr Joseph Oh, the study’s first author, explained:

“You can think of this system as a switch with wake-promoting neurons and sleep-promoting neurons, each tied to neurons controlling circadian rhythms.

It’s a small number of neurons but their computational capabilities are incredible.

When these cells are affected by disease, it can have a huge effect on sleep.”

The conclusions come from a study of 33 patients with Alzheimer’s that were compared to normal controls.

Dementia and sleep

Many other studies have found a link between dementia and sleep.

People who sleep for too little or too long are at a higher risk of cognitive decline and dementia.

Indeed, people who sleep more than 9 hours a night have double the risk of developing dementia, one study found.

However, those who sleep for between 5.5 and 7.5 hours per night do not see declines in their cognitive health, even when suffering the early effects of Alzheimer’s disease.

Those sleeping longer also have lower brain volumes.

Also, getting less REM sleep — the phase in which we dream — is linked to dementia.

During sleep the brain cycles between periods of deep sleep and then up towards shallower periods of sleep in which we tend to dream, whether we remember those dreams or not.

During REM sleep the eyes move rapidly from side-to-side (hence Rapid Eye Movement Sleep).

The study was published in JAMA Neurology (Oh et al., 2022).

Risk of developing dementia is one-third lower.

Memory often worsens with age — it is a normal part of the aging process.

But, when do mild memory problems signal the onset of Alzheimer’s?

Ironically, people who realise their memory is getting worse are less likely to develop Alzheimer’s disease, research finds.

Self-awareness, then, is a healthy sign.

Doctors have long suspected that people who seem unaware of their memory problems are at higher risk of dementia, but this is one of the first studies to demonstrate it.

Researchers at McGill University in Montreal, Canada, looked at data from 450 patients experiencing mild memory deficits.

The patients’ experience of their own memory was compared with the objective views of friends and family.

Patients unaware of their memory problems turned out to be in worse shape neurologically: they had metabolic dysfunction in their brains and more amyloid proteins (these are linked to Alzheimer’s).

Two years later, patients who were more unaware of their memory problems were at triple the risk of developing dementia.

Dr Serge Gauthier, study co-author, said:

“This has practical applications for clinicians: people with mild memory complaints should have an assessment that takes into account information gathered from reliable informants, such as family members or close friends.”

The study was published in the journal Neurology (Therriault et al., 2018).