Latest Research News

Alzheimer's gene affects IQ from childhood

Analysis of some old longitudinal studies has found that those carrying the APOE4 gene scored lower on IQ tests during childhood and adolescence. The effect was much stronger in girls than in boys, and affected reasoning most strongly.

IQ scores were lower by 1.91 points for each APOE4 allele carried. But boys scored only an average of 0.33 points lower, while girls scored almost 3 points lower for each APOE4 allele.

Almost all the participants (92%) were white.

Dietary choline linked to reduced dementia risk & better cognition

Data from a large, long-running Finnish study, involving some 2,500 men aged 42-60, has found that dietary intake of phosphatidylcholine was associated with a reduced risk of dementia (the risk was 28% lower in men with the highest intake compared to the lowest). Men with the highest intake of dietary phosphatidylcholine also excelled in tests measuring their memory and linguistic abilities.

The key sources of phosphatidylcholine in the study population's diet were eggs (39%) and meat (37%).

Data from the large and very long-running Framingham Heart Study has revealed that people who drink sugary drinks frequently are more likely to have poorer memory, smaller overall brain volume, and a significantly smaller hippocampus. Moreover, a second study found that those who drank diet soda daily were almost three times as likely to develop stroke and dementia over a 10-year period, compared to those who didn’t – suggesting that substituting artificial sweeteners for the sugar doesn’t make matters better.

The effect of smell on learning and memory was investigated in an experiment that used three different ambient odors (osmanthus, peppermint, and pine).

Osmanthus was used to see whether there was a difference in performance depending on whether the smell was novel or familiar. Peppermint and pine were used to see whether the appropriateness or inappropriateness of the smell made a difference to memory.

A study involving 61 women, of whom 33 were chronically stressed caring for a spouse or parent with dementia, has found that highly stressed people who ate a lot of high-fat, high-sugar food were likely to have:

• a larger waistline,
• more truncal fat,
• higher oxidative damage, and
• more insulin resistance.

This association was not found among the low-stress women who ate the same amount of unhealthy food.

The findings are consistent with animal studies.

Data from the American National Health and Nutrition Examination Survey (NHANES) III, involving 3,659 individuals (men aged 55+; women 65+), has found that the more muscle mass older adults have, the less likely they are to die prematurely. The findings add to the growing evidence that overall body composition — and not the widely used body mass index (BMI) — is a better predictor of mortality.

http://www.eurekalert.org/pub_releases/2014-03/uoc--oab031314.php

A three-year study involving 152 adults aged 50 and older, of whom 52 had been recently diagnosed with mild cognitive impairment and 31 were diagnosed with Alzheimer's disease, has found that those with mild or no cognitive impairment who initially had amyloid-beta plaques showed greater cognitive decline than those whose brain scans were negative for plaques. Moreover, 35% of plaque-positive participants who started with MCI progressed to Alzheimer's, compared to 10% without plaque, and they were more than twice as likely to be started on cognitive-enhancing medication.

A study, involving 371 patients with mild cognitive impairment, has found that those with depressive symptoms had higher levels of amyloid-beta, particularly in the frontal cortex and the anterior and posterior cingulate gyrus (both involved in mood disorders such as depression).

The findings suggest that late-life depression could be a major risk factor for developing Alzheimer's faster than others.

http://www.eurekalert.org/pub_releases/2014-06/sonm-dit060814.php

A French study involving 36 healthy older adults (60-80), prescreened for amyloid deposits in the brain to exclude people who might have preclinical Alzheimer’s disease, has found a linear increase in gray matter volume in proportion to the number of years of education (7-20 years).

A study involving older adults has found that diabetes was associated with higher levels of tau protein and greater brain atrophy.

The study involved 816 older adults (average age 74), of whom 397 had mild cognitive impairment, 191 had Alzheimer's disease, and 228 people had no cognitive problems. Fifteen percent (124) had diabetes.

Those with diabetes had greater levels of tau protein in the spinal and brain fluid regardless of cognitive status. Tau tangles are characteristic of Alzheimer's.