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 362 children with reading problems has found that 16 weeks of daily 600 mg supplements of omega-3 DHA from algal sources improved their sleep. According to a sleep questionnaire filled out by parents, 40% of these children had significant sleep problems. Monitoring of 43 of the poor sleepers found that children taking daily supplements of omega-3 had nearly one hour (58 minutes) more sleep and seven fewer waking episodes per night compared with children taking a placebo.

A new study shows that a combination of inflammation and hypoxia activates microglia in a way that persistently weakens the connection between neurons, contributing to brain damage in conditions such as stroke and Alzheimer's disease.

http://www.eurekalert.org/pub_releases/2014-03/uobc-scb031214.php

Data from two longitudinal studies of older adults (a nationally representative sample of older adults, and the Alzheimer’s Disease Neuroimaging Initiative) has found that a brief cognitive test can distinguish memory decline associated with healthy aging from more serious memory disorders, years before obvious symptoms show up.

Moreover, the data challenge the idea that memory continues to decline through old age: after excluding the cognitively impaired, there was no evidence of further memory declines after the age of 69.

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.

A small study involving 50 younger adults (18-35; average age 24) has found that those with a higher BMI performed significantly worse on a computerised memory test called the “Treasure Hunt Task”.

The task involved moving food items around complex scenes (e.g., a desert with palm trees), hiding them in various locations, and indicating afterward where and when they had hidden them. The test was designed to disentangle object, location, and temporal order memory, and the ability to integrate those separate bits of information.