Latest Research News

A comparison of Alzheimer’s prevalence across the world using 'age-standardized' data (which predict Alzheimer's rates if all countries had the same population birth rate, life expectancy and age structure) has found a strong correlation between national sanitation levels and Alzheimer's, with better hygiene associated with higher rates of Alzheimer’s.

Analysis of post-mortem with and without dementia has found lipopolysaccharide, a component of an oral bacterium (Porphyromonas gingivalis), in four out of 10 Alzheimer’s disease brain samples, but not in any of the 10 brains of people who didn’t have Alzheimer’s.

Gingivitis is extremely common, and about 64% of American seniors (65+) have moderate or severe periodontal disease.

The finding adds to evidence linking gum disease and Alzheimer’s.

Glucose levels linked to cognitive decline in those with MCI

A new review from The Cochrane Library, based on six trials involving 289 people, has concluded that exercise can improve cognition and the ability of older people with dementia to carry out daily activities, such as walking short distances or getting up from a chair. However, there was no clear effect of exercise on depression in older people with dementia, and the reviewers say that more evidence is needed to understand how exercise could reduce the burden on family caregivers and health systems.

There are five healthy behaviors that appear to significantly reduce the risk of dementia,

A pilot study involving 17 older adults with mild cognitive impairment and 18 controls (aged 60-88; average age 78) has found that a 12-week exercise program significantly improved performance on a semantic memory task, and also significantly improved brain efficiency, for both groups.

A study that followed 800 Swedish middle-aged women from 1968 to 2005 has found that high levels of stress in middle age increased Alzheimer’s risk by 21% and risk of any dementia by 15%.

Of the 800 women, 425 died during the course of the study while 153 (19%) developed dementia (of whom 104 developed Alzheimer’s), at an average age of 78. The number of stressors and long-standing distress were independently associated with Alzheimer’s.

A study comparing blood serum levels of the DDT metabolite, DDE, in 86 patients with Alzheimer's disease (average age 74) and 79 controls (average age 70), has found that levels of DDE were 3.8 times higher in 74 of the 86 Alzheimer’s patients (86%). Having the Alzheimer’s gene, APOe4, plus high levels of the pesticide, produced more severe cognitive impairment.

A small study involving 52 people aged 32-72 has found that those whose parents both had Alzheimer's disease showed more severe abnormalities in brain volume and metabolism and 5-10% more amyloid plaques in certain brain regions, compared to those with either a father or mother, or neither parent, with the disease. There were 13 in each group.

Consistent with previous research, those whose mother had Alzheimer's disease showed a greater level of the Alzheimer's disease biomarkers than those whose father had the disease.

Data from the population-based Finnish Cardiovascular Risk Factors, Aging and Incidence of Dementia (CAIDE) study has revealed that healthy dietary choices in midlife may prevent dementia in later years. Out of 2,000 participants, 1,449 took part in the follow-up. The participants were 39 to 64 years old at baseline and 65 to 75 years old at follow-up.

Those who ate the healthiest diet at around age 50 had an almost 90% lower risk of dementia in a 14-year follow-up study than those whose diet was the least healthy.

A mouse study has found that mice (genetically engineered for Alzheimer’s) who were sleep deprived for eight weeks, not only showed significant cognitive impairment, but also showed a significant increase in the amount of tau protein that became phosphorylated and formed tangles. The other main characteristic of Alzheimer’s, amyloid-beta plaques, was not affected.

The findings are consistent with growing evidence of a link between sleep disturbance and Alzheimer’s, and suggests that chronic sleep disturbance accelerates Alzheimer’s pathology, and should be treated.

Data from 1.1 million young Swedish men (conscription information taken at age 18) has shown that those with poorer cardiovascular fitness were 2.5 times more likely to develop early-onset dementia later in life and 3.5 times more likely to develop mild cognitive impairment, while those with a lower IQ had a 4 times greater risk of early dementia and a threefold greater risk of

Data from 1,425 cognitively healthy older adults (70-89) has found that a diagnosis of chronic obstructive pulmonary disease (COPD) was associated with an 83% greater risk of developing non-amnestic mild cognitive impairment. The greatest risk was among patients who had COPD for more than five years.

We know that the E4 variant of the APOE gene greatly increases the risk of developing Alzheimer’s disease, but the reason is a little more mysterious. It has been thought that it makes it easier for amyloid plaques to form because it produces a protein that binds to amyloid beta.

I’ve talked before about the evidence linking diabetes to an increased risk of Alzheimer’s disease, but now a new study suggests that elevated blood sugar levels increase Alzheimer’s risk even in those without diabetes, even in those without ‘pre-diabetes’.

A study involving nearly 6,000 African American older adults has found those with a specific gene variant have almost double the risk of developing late-onset Alzheimer’s disease compared with African Americans who lack the variant. The size of the effect is comparable to that of the ‘Alzheimer’s gene’, APOE-e4.

Providing some support for the finding I recently reported — that problems with semantic knowledge in those with mild cognitive impairment (

Previous research has pointed to an association between not having teeth and a higher risk of cognitive decline and dementia. One reason might have to do with inflammation — inflammation is a well-established risk factor, and at least one study has linked gum disease to a higher dementia risk. Or it might have to do with the simple mechanical act of chewing, reducing blood flow to the brain. A new study has directly investigated chewing ability in older adults.

Sad to say, another large study has given the thumbs down to ginkgo biloba preventing Alzheimer’s disease.

The randomized, double-blind trial took place over five years, involving 2854 older adults (70+) who had presented to their primary care physician with memory complaints. Half were given a twice-daily dose of 120 mg standardised ginkgo biloba extract and half a placebo.

New research suggests that reliance on the standard test Alzheimer's Disease Assessment Scale—Cognitive Behavior Section (ADAS-Cog) to measure cognitive changes in Alzheimer’s patients is a bad idea. The test is the most widely used measure of cognitive performance in clinical trials.

A small study shows how those on the road to Alzheimer’s show early semantic problems long before memory problems arise, and that such problems can affect daily life.

There's quite a bit of evidence now that socializing — having frequent contact with others — helps protect against cognitive impairment in old age. We also know that depression is a risk factor for cognitive impairment and dementia. There have been hints that loneliness might also be a risk factor. But here’s the question: is it being alone, or feeling lonely, that is the danger?

A large Dutch study, following 2173 older adults for three years, suggests that it is the feeling of loneliness that is the main problem.

It’s been unclear whether hormone therapy helps older women reduce their risk of Alzheimer’s or in fact increases the risk. To date, the research has been inconsistent, with observational studies showing a reduced risk, and a large randomized controlled trial showed an increased risk. As mentioned before, the answer to the inconsistency may lie in the timing of the therapy. A new study supports this view.

I reported a few months ago on some evidence of a link between disturbed sleep and the development of Alzheimer’s. Now a mouse study adds to this evidence.

The mouse study follows on from an earlier study showing that brain levels of amyloid beta naturally rise when healthy young mice are awake and drop after they go to sleep, and that sleep deprivation disrupted this cycle and accelerated the development of amyloid plaques. This natural rhythm was confirmed in humans.

Memory problems in those with mild cognitive impairment may begin with problems in visual discrimination and vulnerability to interference — a hopeful discovery in that interventions to improve discriminability and reduce interference may have a flow-on effect to cognition.

HIV-associated dementia occurs in around 30% of untreated HIV-positive patients. Surprisingly, it also is occasionally found in some patients (2-3%) who are being successfully treated for HIV (and show no signs of AIDS).

A new study may have the answer for this mystery, and suggest a solution. Moreover, the answer may have general implications for those experiencing cognitive decline in old age.

Back in 2009, I reported briefly on a large Norwegian study that found that older adults who consumed chocolate, wine, and tea performed significantly better on cognitive tests. The association was assumed to be linked to the flavanols in these products. A new study confirms this finding, and extends it to older adults with mild cognitive impairment.

Two years ago, I reported on a clinical trial of a nutrient cocktail called Souvenaid for those with early Alzheimer’s. The three-month trial, involving 225 patients, had some success in improving verbal recall, with those with the mildest level of impairment benefiting the most.

While the ‘Alzheimer’s gene’ is relatively common — the ApoE4 mutation is present in around 15% of the population — having two copies of the mutation is, thankfully, much rarer, at around 2%. Having two copies is of course a major risk factor for developing Alzheimer’s, and it has been thought that having a single copy is also a significant (though lesser) risk factor. Certainly there is quite a lot of evidence linking ApoE4 carriers to various markers of cognitive impairment.

Dementia is a progressive illness, and its behavioral and psychological symptoms are, for caregivers, the most difficult symptoms to manage. While recent research has demonstrated how collaborative care can reduce these symptoms and reduce stress for caregivers, the model requires continuous monitoring of the symptoms. What’s needed is a less arduous way of monitoring changes in symptoms.

Following on from mouse studies, a human study has investigated whether caffeine can help prevent older adults with mild cognitive impairment from progressing to dementia.

A study involving those with a strong genetic risk of developing Alzheimer’s has found that the first signs of the disease can be detected 25 years before symptoms are evident. Whether this is also true of those who develop the disease without having such a strong genetic predisposition is not yet known.

The study involved 128 individuals with a 50% chance of inheriting one of three mutations that are certain to cause Alzheimer’s, often at an unusually young age. On the basis of participants’ parents’ medical history, an estimate of age of onset was calculated.

A new study, involving 1,219 dementia-free older adults (65+), has found that the more omega-3 fatty acids the person consumed, the lower the level of beta-amyloid in the blood (a proxy for brain levels). Consuming a gram of omega-3 more than the average per day was associated with 20-30% lower beta-amyloid levels. A gram of omega-3 equates to around half a fillet of salmon per week.

Here’s a different aspect to cognitive reserve. I have earlier reported on the first tranche of results from this study.

Interpreting brain activity is a very tricky business. Even the most basic difference can be interpreted in two ways — i.e., what does it mean if a region is more active in one group of people compared to another? A new study not only indicates a new therapeutic approach to amnestic mild cognitive impairment, but also demonstrates the folly of assuming that greater activity is good.

Genetic analysis of 9,232 older adults (average age 67; range 56-84) has implicated four genes in how fast your

A review of 15 randomized controlled trials in which people with mild to moderate dementia were offered mental stimulation has concluded that such stimulation does indeed help slow down cognitive decline.

Following on from research showing an association between lower walking speed and increased risk of dementia, and weaker hand grip strength and increased dementia risk, a large study has explored whether this association extends to middle-aged and younger-old adults.

The study involved 74 non-smokers with amnestic MCI (average age 76), of whom half were given a nicotine patch of 15 mg a day for six months and half received a placebo.

More data from the long-running Mayo Clinic Study of Aging has revealed that, in this one part of the U.S. at least,

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