Latest Research News

Data from the Nurses' Health Study Cognitive Cohort, involving 19,409 older women (70-81), has found that higher levels of long-term exposure to air pollution were associated with faster rates of cognitive decline over a four-year period.

For each 10 micrograms per cubic meter of air increase in pollutants, cognitive decline was comparable to two years of age-related decline.

Pollution exposure was estimated from geography. Cognition was tested by three telephone interviews, administered at roughly two-year intervals.

A study involving 1,575 older adults (aged 58-76) has found that those with DHA levels in the bottom 25% had smaller brain volume (equivalent to about 2 years of aging) and greater amounts of

The first study to look at the effects of the drug ecstasy on infant development has shown that infants exposed to ecstasy before they were born tend to be behind, especially in motor and coordination skills, at four months.

A new study explains how marijuana impairs

A small study of the sleep patterns of 100 people aged 45-80 has found a link between sleep disruption and level of amyloid plaques (characteristic of Alzheimer’s disease). The participants were recruited from the Adult Children Study, of whom half have a family history of Alzheimer’s disease.

Sleep was monitored for two weeks. Those who woke frequently (more than five times an hour!) and those who spent less than 85% of their time in bed actually asleep, were more likely to have amyloid plaques. A quarter of the participants had evidence of amyloid plaques.

A review of 10 observational and four intervention studies as said to provide strong evidence for a positive relationship between physical activity and academic performance in young people (6-18). While only three of the four intervention studies and three of the 10 observational studies found a positive correlation, that included the two studies (one intervention and one observational) that researchers described as “high-quality”.

Back in 2008, I reported on a small study that found that daily doses of Pycnogenol® for three months improved

I have reported often on studies pointing to obesity as increasing your risk of developing dementia, and on the smaller evidence that calorie restriction may help fight age-related cognitive decline and dementia (and help you live longer). A new mouse study helps explain why eating less might help the brain.

The study involved 104 healthy older adults (average age 87) participating in the Oregon Brain Aging Study. Analysis of the nutrient biomarkers in their blood revealed that those with diets high in omega 3 fatty acids and in vitamins C, D, E and the B vitamins had higher scores on cognitive tests than people with diets low in those nutrients, while those with diets high in trans fats were more likely to score more poorly on cognitive tests.

Iron deficiency is the world's single most common nutrient deficiency, and a well-known cause of impaired cognitive, language, and motor development. Many countries therefore routinely supplement infant foods with iron. However, a new study suggests that, while there is no doubt that such fortification has helped reduce iron deficiency, it may be that there is an optimal level of iron for infant development.

The study involved 1,292 children followed from birth, whose cortisol levels were assessed at 7, 15, and 24 months. Three tests related to executive functions were given at age 3. Measures of parenting quality (maternal sensitivity, detachment, intrusiveness, positive regard, negative regard, and animation, during interaction with the child) and household environment (household crowding, safety and noise levels) were assessed during the home visits.

In yet another study of the effects of pollution on growing brains, it has been found that children who grew up in Mexico City (known for its very high pollution levels) performed significantly worse on cognitive tests than those from Polotitlán, a city with a strong air quality rating.

Obesity has been linked to cognitive decline, but a new study involving 300 post-menopausal women has found that higher BMI was associated with higher cognitive scores.

Of the 300 women (average age 60), 158 were classified as obese (waist circumference of at least 88cm, or BMI of over 30). Cognitive performance was assessed in three tests: The Mini-Mental Statement Examination (MMSE), a clock-drawing test, and the Boston Abbreviated Test.

In the last five years, three studies have linked lower neighborhood socioeconomic status to lower cognitive function in older adults. Neighborhood has also been linked to self-rated health, cardiovascular disease, and mortality. Such links between health and neighborhood may come about through exposure to pollutants or other environmental stressors, access to alcohol and cigarettes, barriers to physical activity, reduced social support, and reduced access to good health and social services.

Research into the effects of cannabis on cognition has produced inconsistent results. Much may depend on extent of usage, timing, and perhaps (this is speculation) genetic differences. But marijuana abuse is common among sufferers of schizophrenia and recent studies have shown that the psychoactive ingredient of marijuana can induce some symptoms of schizophrenia in healthy volunteers.

Now new research helps explain why marijuana is linked to schizophrenia, and why it might have detrimental effects on attention and memory.

One survey of nearly 200 undergraduate college students who were not living with a parent or legal guardian found that 55% reported getting less than seven hours sleep. This is consistent with other surveys. The latest study confirms such a result, but also finds that students tend to think their sleep quality is better than it is (70% of students surveyed described their sleep as "fairly good" or better).

In the first mouse study, when young and old mice were conjoined, allowing blood to flow between the two, the young mice showed a decrease in neurogenesis while the old mice showed an increase. When blood plasma was then taken from old mice and injected into young mice, there was a similar decrease in neurogenesis, and impairments in memory and learning.

In a small study, 266 older adults with mild cognitive impairment (aged 70+) received a daily dose of 0.8 mg folic acid, 0.5 mg vitamin B12 and 20 mg vitamin B6 or a placebo for two years. Those treated with B vitamins had significantly lower levels of

A three-year study following 1,262 healthy older Canadians (aged 67-84) has found that, among those who exercised little, those who had high-salt diets showed significantly greater cognitive decline. On the bright side, sedentary older adults who had low-salt consumption did not show cognitive decline over the three years. And those who had higher levels of physical activity did not show any association between salt and cognition.

Dietary changes affect levels of biomarkers associated with Alzheimer's

In a study involving 20 healthy older adults (mean age 69.3) and 29 older adults who had amnestic mild cognitive impairment (mean age 67.6), half the participants were randomly assigned to a high–saturated fat/high–simple carbohydrate diet (HIGH) and half to a low–saturated fat/low–simple carbohydrate diet (LOW) for four weeks, in order to investigate the effects on biomarkers associated with Alzheimer’s.

Binge drinking occurs most frequently among young people, and there has been concern that consequences will be especially severe if the brain is still developing, as it is in adolescence. Because of the fact that it is only some parts of the brain — most crucially the

Most research into the importance of folate and B12 levels has centered on seniors, and it does seem clear now that having adequate levels of these vitamins is important for maintaining cognitive functioning as you get older.

Another study showing the value of exercise for preserving your mental faculties in old age. This time it has to do with the development of small brain lesions or infarcts called "silent strokes." Don’t let the words “small” and “silent” fool you — these lesions have been linked to memory problems and even dementia, as well as stroke, an increased risk of falls and impaired mobility.

Sleep can boost classroom performance of college students

There’s a lot of evidence that memories are consolidated during sleep, but most of it has involved skill learning. A new study extends the findings to complex declarative information — specifically, information from a lecture on microeconomics.

The brain tends to shrink with age, with different regions being more affected than others. Atrophy of the

Following animal research indicating that binge drinking damages the

Following several recent studies pointing to the negative effect of air pollution on children’s cognitive performance (see this April 2010 news report and this May 2011 report), a study of public schools in Michigan has found that 62.5% of the 3660 schools in the state are located in areas with high levels of industrial pollution, and those in areas with the highest industrial air pollution levels had the l

Growing evidence has pointed to the benefits of social and mental stimulation in preventing dementia, but until now no one has looked at the role of physical environment.

Imaging the brains of 10 young men who were long term users of ecstasy and seven of their healthy peers with no history of ecstasy use has revealed a significantly smaller

A new study finds out why curcumin might help protect against dementia, and links two factors associated with Alzheimer’s and Parkinson’s diseases: DNA damage by reactive oxygen species (ROS), and excessive levels of copper and iron in parts of the brain. It turns out that high levels of copper or iron help generate large numbers of ROS and interfere with DNA repair.

Growing evidence links obesity and poorer cognitive performance. Many factors associated with obesity, such as high blood pressure, type 2 diabetes and sleep apnea, damage the brain.

A study following 837 people with

Supporting earlier research, a study involving 8,534 older adults (65+; mean age 74.4) has found those who were obese in middle age had almost four times (300%) more risk of developing dementia. Those who were overweight in middle age had a 1.8 times (80%) higher risk of developing dementia.

Participants were drawn from the Swedish Twin Registry. Height and weight had been measured at a mean age of 43.3, and 29.8% were defined as overweight or obese. Dementia was diagnosed in 350 participants (4.1%), with a further 114 (1.33%) diagnosed as questionable.

Laparoscopic surgery makes intense demands on cognitive, perceptual and visuospatial abilities, rendering it particularly vulnerable to the effects of alcohol (and also making it a sensitive indicator). In a real-world type experiment, students and experts participated in a study looking at the effects of previous-night’s carousing on next-day’s performance on the Minimally Invasive Surgical Trainer Virtual Reality (for which all participants received training, providing baseline scores).

A study in which mice were exposed to polluted air for three 5-hour sessions a week for 10 weeks, has revealed that such exposure damaged neurons in the

Adding to the growing evidence that social activity helps prevent age-related cognitive decline, a longitudinal study involving 1,138 older adults (mean age 80) has found that those who had the highest levels of social activity (top 10%) experienced only a quarter of the rate of cognitive decline experienced by the least socially active individuals (bottom 10%). The participants were followed for up to 12 years (mean of 5 years).

A study involved 117 older adults (mean age 78) found those at greater risk of coronary artery disease had substantially greater risk for decline in verbal fluency and the ability to ignore irrelevant information. Verbal memory was not affected.

The findings add to a growing body of research linking cardiovascular risk factors and age-related cognitive decline, leading to the mantra: What’s good for the heart is good for the brain.

From the Whitehall II study, data involving 5431 older participants (45-69 at baseline) has revealed a significant effect of midlife sleep changes on later cognitive function. Sleep duration was assessed at one point between 1997 and 1999, and again between 2002 and 2004. A decrease in average night’s sleep from 6, 7, or 8 hours was significantly associated with poorer scores on tests of reasoning, vocabulary, and the MMSE. An increase from 7 or 8 hours (but not from 6 hours) was associated with lower scores on these, as well as on tests of phonemic and semantic fluency.

A study involving 614 middle-aged vineyard workers has found that those who were exposed to pesticides were five times as likely to perform more poorly on cognitive tests compared to those not exposed, and twice as likely to show cognitive decline over a two-year period.

Binge drinking is, unfortunately, most common among adolescents (12-20 years). But this is a time when brains are still developing. Does this make them more vulnerable to the detrimental effects of excessive alcohol?