Older news items (pre-2010) brought over from the old website

Video games may help visuospatial processing and multitasking

Another study has come out showing that expert video gamers have improved mental rotation skills, visual and spatial memory, and multitasking skills. The researchers conclude that training with video games may serve to reduce gender differences in visual and spatial processing, and some of the cognitive declines that come with aging.

[366] Dye, M. W. G., Green S. C., & Bavelier D.
(2009).  Increasing Speed of Processing With Action Video Games.
Current Directions in Psychological Science. 18(6), 321 - 326.

http://www.eurekalert.org/pub_releases/2009-12/afps-rsa121709.php

Strategic video game improves critical cognitive skills in older adults

In the first study into the effects of playing video games for adults in their 60s and 70s, it’s been found that playing a strategic video game that rewards nation-building and territorial expansion can have pronounced effects on cognitive skills not directly related to the skills learned in the video game. The finding is also exciting as a rare demonstration of a training program that improves more than simply the task being practiced. The game "Rise of Nations" was selected because of its emphasis on resource management and planning. The researchers hoped it would benefit executive function, which is one of the cognitive functions particularly impacted by age and includes things like scheduling, planning, working memory, multitasking and dealing with ambiguity. Half of the 40 older adults in the study received 23.5 hours of training in the game. As a group, the gamers became significantly better and faster at switching between tasks as compared to the comparison group. Their working memory and their reasoning ability was also significantly improved. To a lesser extent, their short-term memory of visual cues and their ability to identify rotated objects was also improved. Training had no effect on ability to recall a list of words in order, enumeration ability or ability to inhibit certain responses. The amount of improvement was linked to performance on the game.

[813] Basak, C., Boot W. R., Voss M. W., & Kramer A. F.
(2008).  Can training in a real-time strategy video game attenuate cognitive decline in older adults?.
Psychology and Aging. 23(4), 765 - 777.

http://www.eurekalert.org/pub_releases/2008-12/uoia-svg120808.php

Frequent TV viewing during adolescence linked with risk of attention and learning difficulties

A long-running study of 678 families in upstate New York, surveyed children at 14, 16 and 22 years old (averages), and again when the children in the study had reached an average age of 33. At age 14, 225 (33.2%) of the teens reported that they watched three or more hours of television per day. Those who watched 1 or more hours of television per day at mean age 14 years were at higher risk of poor homework completion, negative attitudes toward school, poor grades, and long-term academic failure. Those who watched 3 or more hours of television per day were most likely to experience these outcomes, and moreover were at higher risk of subsequent attention problems and were the least likely to receive postsecondary education. Analysis of the data also indicated that television watching contributes to learning difficulties and not vice versa.

Johnson, J.G., Cohen, P., Kasen, S. & Brook, J.S. 2007. Extensive Television Viewing and the Development of Attention and Learning Difficulties During Adolescence. Archives of Pediatrics & Adolescent Medicine, 161 (5), 480-486.

http://www.eurekalert.org/pub_releases/2007-05/jaaj-ftv050307.php

TV has negative impact on very young children's learning abilities

Analysis of data involving some 1800 children from The National Longitudinal Survey of Youth 1979 (NLSY-Child) compared scores in mathematics, reading recognition and reading comprehension with the level of television watching before age three and from ages three to five. The analysis revealed a consistent pattern of negative associations between television viewing before age three years and adverse cognitive outcomes at ages six and seven years. Television viewing at ages three to five years, on the other hand, had a more beneficial effect, for reading recognition and short-term memory, although not mathematics or reading comprehension.

Another study in the same issue reported on a New Zealand study that compared television viewing in some 1000 people born in 1972-73 with their educational achievements at 26 years of age. The study found mean time spent watching television during childhood and adolescence was significantly associated with leaving school without qualifications and negatively associated with attaining a university degree. Television viewing during childhood (ages 5-11 years) and adolescence (ages 13 and 15 years) had adverse associations with later educational achievement. However, adolescent viewing was a stronger predictor of leaving school without qualifications, whereas childhood viewing was a stronger predictor of nonattainment of a university degree.

Zimmerman, F.J. & Christakis, D.A. 2005. Children’s Television Viewing and Cognitive Outcomes: A Longitudinal Analysis of National Data. Archives of Pediatrics & Adolescent Medicine, 159, 619-625.

Hancox, R.J., Milne, B.J. & Poulton, R. 2005. Association of Television Viewing During Childhood With Poor Educational Achievement. Archives of Pediatrics & Adolescent Medicine, 159, 614-618.

http://www.eurekalert.org/pub_releases/2005-07/jaaj-thn062905.php

The reports below are taken from my previous blog, and lack references

Effect on the brain

Emotional effect of video games can help creativity

As part of the search for ways to use video games educationally, a study of around 100 students has found that those who scored highly on a creativity test after playing the game Dance Dance Revolution fell into two groups: those who had a high degree of emotional arousal (measured by skin conductance) after playing and a positive mood, and (this is the weird part), those in the completely opposite camp — low arousal and negative mood.
The explanation for these somewhat paradoxical findings rests on there being two aspects to creativity — diffused attention (presumably where the happy people score), and a certain analytical ability (which is where the sad people are presumed to score).
It still seems weird, but the take-home point I guess is that being angry (high arousal, negative mood) is not conducive to creativity, and neither is medium arousal. On the other hand, I’m wondering about individual differences. I think some people probably are creative when angry, and I’d like to know about personality characteristics that might have distinguished the students who were creative when happy from those who were creative when sad. Still, interesting study.

Watching violence begets violence?

There’s lots of argument about whether watching violence on TV and in movies makes people more violent. Some studies have found a correlation, but correlational studies can always be attacked.  But now a brain imaging study has found that watching violent movie clips (but not ones with scenes of horror or physical activity) can cause the parts of your brain that suppress behaviors like inappropriate or unwarranted aggression (such as the right lateral orbitofrontal cortex, and the amygdala) to become less active. Less activation in this network is characteristic of people reporting an above average tendency to behave aggressively.

http://www.physorg.com/news116155534.html

Violent video games leave teenagers emotionally aroused

An imaging study of 44 adolescents playing either a violent or a nonviolent video game for 30 minutes has found that the group that played the violent video game demonstrated less activation in the prefrontal portions of the brain, which are involved in inhibition, concentration and self-control, and more activation in the amygdala, which is involved in emotional arousal.

http://www.eurekalert.org/pub_releases/2006-11/rson-vvg112206.php

Violent games desensitize players to violence

In a study in which 257 college students played one of eight randomly assigned violent or non-violent video games for 20 minutes, followed by a 10-minute videotape of actual violent episodes taken from TV programs and movies, has found that the real violence produced significantly lower physiological arousal (measured by galvanic skin response and heart rate) in those who had played a violent video game. There was no difference in arousal between the two groups after playing the games, and before seeing the videotape, showing that the effect was to desensitize individuals to real-life violence.

http://www.sciencedaily.com/releases/2006/07/060727162108.htm

 

Older news items (pre-2010) brought over from the old website

Cognitive benefit of reduced calories for older adults

Recent rat studies have indicated that significant calorie restriction lengthens lives, but the evidence for humans is rather more mixed. Now a German study of 50 healthy but overweight older adults (average age 60) has found that those who were on a balanced but severely restricted diet (reduced by 30%) for 3 months significantly improved their performance on a verbal memory test. Those who didn’t reduce their calorie intake but increased their consumption of unsaturated fatty acids (linked to improved cognition), and those who didn’t change their diets, showed little or no improvement. It’s important to note that the participants were overweight to start with; further research will be needed to see whether the same effect occurs with normal-weight older adults.

[361] Witte, A. V., Fobker M., Gellner R., Knecht S., & Floel A.
(2009).  From the Cover: Caloric restriction improves memory in elderly humans.
Proceedings of the National Academy of Sciences. 106(4), 1255 - 1260.

http://sciencenow.sciencemag.org/cgi/content/full/2009/127/1?etoc

Calorie restriction may help prevent Alzheimer's

A mouse study has found that beta-amyloid peptides can be reduced by restricting calorie intake, primarily through a low carbohydrate diet. Conversely, a high caloric intake based on saturated fat was shown to increase levels of beta-amyloid peptides. This is the first study to suggest that caloric restriction might inhibit the generation of beta-amyloid peptides, but there have been a number of studies providing evidence that high cholesterol, obesity, and other cardiovascular risk factors increase the likelihood of Alzheimer’s.

Qin, W. et al. 2006. Neuronal SIRT1 Activation as a Novel Mechanism Underlying the Prevention of Alzheimer Disease Amyloid Neuropathology by Calorie Restriction. Journal of Biological Chemistry, 281 (31), 21745-21754.

http://www.sciencedaily.com/releases/2006/06/060614113128.htm

Fewer calories may slow Alzheimer's

Restricting the diets of genetically engineered mice by 40% over 4 weeks reduced the build-up of plaques in the brain that are linked to Alzheimer's disease by 50%. It remains to be seen whether such dietary changes would similarly affect humans. Researchers are now looking to isolate the specific factors of the diet restriction which are important.

Patel, N.V., Gordon, M.N., Connor, K.E., Good, R.A., Engelman, R.W., Mason, J., Morgan, D.G., Morgan, T.E. & Finch, C.E. (in press). Caloric restriction attenuates Aβ-deposition in Alzheimer transgenic models. Neurobiology of Aging, In Press, Corrected Proof, Available online 25 November 2004.

http://www.eurekalert.org/pub_releases/2004-12/uosc-fcm121404.php

Calorie restriction leads to some brain benefits but not others in mice

A mouse study has found that although severe calorie restriction prevents certain aging-related changes in the brain, such as the accumulation of free radicals, and impairments in coordination and strength, the reduced diet did not seem to prevent age-related cognitive impairment.

Dugan, L.L. et al. 2004. Presented on Sunday, Oct. 24 at Neuroscience 2004, the Society for Neuroscience's 34th Annual Meeting in San Diego.

http://www.eurekalert.org/pub_releases/2004-10/wuso-crl102204.php

Meal skipping protects the nerve cells of mice

A new mouse study suggests fasting every other day may protect brain neurons as well as or better than either vigorous exercise or caloric restriction. The mice were allowed to eat as much as they wanted on non-fasting days, and did not, overall, eat fewer calories than the control group. Their nerve cells however, proved to be more resistant to neurotoxin injury or death than nerve cells of both the calorie-restricted mice or the control group. Previous research has found that meal-skipping diets can stimulate brain cells in mice to produce a protein called brain-derived neurotrophic factor (BDNF) that promotes the survival and growth of nerve cells. The researchers are now investigating the effects of meal-skipping on the cardiovascular system in laboratory rats.

[1429] Anson, M. R., Guo Z., de Cabo R., Iyun T., Rios M., Hagepanos A., et al.
(2003).  Intermittent fasting dissociates beneficial effects of dietary restriction on glucose metabolism and neuronal resistance to injury from calorie intake.
Proceedings of the National Academy of Sciences of the United States of America. 100(10), 6216 - 6220.

http://www.eurekalert.org/pub_releases/2003-04/nioa-msh042403.php

Calorie restriction reduces age-related brain cell death

A recent rat study has shown that certain proteins that increase with age and are linked to cell death were significantly reduced in the brains of rats whose calories were limited (but nutritionally dense, to guard against malnutrition). Moreover, the levels of a beneficial protein known to protect against neuron death were twice as high in older rats whose calories were restricted by 40%. This is consistent with a number of studies of other species that have found calorie restriction not only boosts life span and general health but also increases mental capacity.

[552] Shelke, R. R. J., & Leeuwenburgh C.
(2003).  Life-long calorie restriction (CR) increases expression of apoptosis repressor with a caspase recruitment domain (ARC) in the brain.
FASEB J.. 02-0803fje - 02-0803fje.

http://www.eurekalert.org/pub_releases/2003-01/uof-usc010903.php

Older news items (pre-2010) brought over from the old website

Fat around the middle increases the risk of dementia

Data from the Prospective Population Study of Women in Gothenburg, involving a representative sample of 1,462 nondemented women followed from 1968 at ages 38-60 years, and followed-up in 1974, 1980, 1992, and 2000, has revealed that women who were broader around the waist than the hips in middle age ran slightly more than twice the risk of developing dementia when they got old. However, unlike other studies, no link was found to a high BMI. It should be noted, though, that obesity and overweight were relatively unusual among the participants of this study.

Gustafson, D. R., Backman, K., Waern, M., Ostling, S., Guo, X., Zandi, P., et al. (2009). Adiposity indicators and dementia over 32 years in Sweden. Neurology, 73(19), 1559-1566.

http://www.eurekalert.org/pub_releases/2009-11/uog-fat112309.php

Fast food a potential risk factor for Alzheimer's

Genetically engineered mice fed a diet rich in fat, sugar and cholesterol for nine months developed a preliminary stage of the morbid irregularities that form in the brains of Alzheimer's patients. The findings suggest that a ‘fast food’ diet could be a contributory factor in those with the Alzheimer’s gene.

Akterin, S. 2008. From cholesterol to oxidative stress in Alzheimer's disease: A wide perspective on a multifactorial disease. Doctoral thesis, Karolinska Institutet.
Thesis available at: http://diss.kib.ki.se/2008/978-91-7409-172-4/

http://www.eurekalert.org/pub_releases/2008-11/ki-ffa112808.php

Low levels of good cholesterol linked to memory loss, dementia risk

Previous research has focused on total or LDL cholesterol levels because they are proven risk factors for cardiovascular disease, but data from the Whitehall II study has found that low levels of high-density lipoproteins (HDL) — the "good" cholesterol — in middle age were associated with a significantly greater risk of memory loss by age 60. Total cholesterol and triglycerides did not show a link with memory decline. To raise HDL and lower LDL cholesterol, the American Heart Association recommends exercising regularly; eliminating trans fats from the diet; reducing the intake of all fats, especially saturated fats; and consuming monounsaturated fats, such as olive, canola and peanut oils. (for more advice on cholesterol see www.americanheart.org/cholesterol)

[1144] Singh-Manoux, A., Gimeno D., Kivimaki M., Brunner E., & Marmot M. G.
(2008).  Low HDL cholesterol is a risk factor for deficit and decline in memory in midlife: the Whitehall II study.
Arteriosclerosis, Thrombosis, and Vascular Biology. 28(8), 1556 - 1562.

http://www.eurekalert.org/pub_releases/2008-06/aha-llo062708.php

High cholesterol in your 40s increases risk of Alzheimer's disease

A study involving nearly 10,000 people who underwent health evaluations between 1964 and 1973 when they were between the ages of 40 and 45, has found that those with total cholesterol levels between 249 and 500 milligrams were one-and-a-half times more likely to develop Alzheimer's disease than those people with cholesterol levels of less than 198 milligrams. People with total cholesterol levels of 221 to 248 milligrams were more than one-and-a-quarter times more likely to develop Alzheimer's disease. High cholesterol increased risk regardless of midlife diabetes, high blood pressure, obesity, smoking and late-life stroke.

The research was presented at the American Academy of Neurology Annual Meeting in Chicago, April 12 – April 19.

http://www.eurekalert.org/pub_releases/2008-04/aaon-hci040208.php

Obesity significantly increases dementia risk

A review of 10 international studies published since 1995, covering just over 37,000 people, has found that obesity increased the relative risk of dementia by an average of 42% compared with normal weight. Being underweight increased the risk by 36%. For Alzheimer's Disease and vascular dementia, specifically, obesity was an even more significant risk: 80% and 73%, respectively. With regards to Alzheimer’s, obesity was more likely to be a risk factor for women, but men were more affected when it came to vascular dementia.

Beydoun, M.A., Beydoun, H.A. & Wang, Y. 2008. Obesity and central obesity as risk factors for incident dementia and its subtypes: a systematic review and meta-analysis. Obesity Reviews, 9 (3), 204–218.

http://www.physorg.com/news129376360.html

Larger belly in mid-life increases risk of dementia

A study involving 6,583 people measured abdominal fat at age 40 to 45, and dementia occurrence some 36 years later. Those with the highest amount of abdominal fat were found to be nearly three times more likely to develop dementia than those with the lowest amount of abdominal fat. Having a large abdomen increased the risk of dementia regardless of overall weight and existing health conditions, although being obese as well did increase the risk. Those more likely to have abdominal obesity, were women, non-whites, smokers, people with high blood pressure, high cholesterol or diabetes, and those with less than a high school level of education.

Whitmer, R.A., et al. 2008. Central obesity and increased risk of dementia more than three decades later. Neurology, published online ahead of print March 26

http://www.eurekalert.org/pub_releases/2008-03/aaon-lbi031808.php

Not enough 'good' cholesterol makes it harder to recover from stroke

A large study involving men and women over age 35 in the United States, Canada, and Scotland who had suffered a mild to moderate stroke within the past three months, found several factors predicted memory and disability problems after stroke: increased age, non-Caucasian race, recurrent stroke, diabetes, stroke in the left hemisphere of the brain, higher levels of homocysteine and lower levels of high-density lipoproteins (HDL), otherwise known as “good” cholesterol. “People with low levels of HDL, high levels of homocysteine, and diabetes are twice as likely as those without such problems to have poorer cognitive function and greater disability after stroke … (and) stroke recovery was the most difficult for people over the age of 57 with high levels of homocysteine ...”

[735] Newman, G. C., Bang H., Hussain S. I., & Toole J. F.
(2007).  Association of diabetes, homocysteine, and HDL with cognition and disability after stroke.
Neurology. 69(22), 2054 - 2062.

http://www.eurekalert.org/pub_releases/2007-11/aaon-ne112007.php

Alzheimer’s most often found in combination with other disease

Post-mortem data from a large, long-running study has found that only 30% of people with signs of dementia had Alzheimer’s disease alone. 42% had Alzheimer’s disease with cerebral infarcts (strokes) and 16% had Alzheimer’s disease with Parkinson’s disease (including two people with all three conditions). Infarcts alone caused another 12% of the cases. Vascular dementia caused another 12%. In those without dementia, brain autopsy revealed the presence of Alzheimer’s in 24% of cases, and infarctions in 18%. The finding that Alzheimer’s pathology with cerebral infarcts is a very common combination in people with dementia adds to emerging evidence that dementia risk might be reduced with the same tools we use for cardiovascular disease such as control of blood cholesterol levels and hypertension.

Schneider, J.A., Arvanitakis, Z., Bang, W. & Bennett, D.A. 2007. Mixed brain pathologies account for most dementia cases in community-dwelling older persons. Neurology, published ahead of print June 13

http://www.eurekalert.org/pub_releases/2007-06/nioa-sfm061207.php

More on why high cholesterol might increase your risk of Alzheimer’s

A cell study provides more understanding of why there might be a link between cholesterol and Alzheimer's disease. The study found that proteins which help control cholesterol levels in arterial walls were also present in neurons, and when the genes for these proteins were over-expressed, production of amyloid beta protein fell. The finding suggests a new approach to slowing Alzheimer’s. The study also showed that the apoE protein is extremely good at regulating cholesterol removal from neurons — the gene for this protein is a well-known genetic risk factor for Alzheimer's.

The study appeared in the February issue of the Journal of Biological Chemistry.

http://www.newscientist.com/article/mg19325905.200?DCMP=NLC-nletter&nsref=mg19325905.200

Predicting dementia risk

A large Scandinavian study has succeeded in calculating middle-aged people's chances of developing dementia later in life with 70% accuracy. The study confirms the importance of lifestyle factors. The study assessed factors such as blood pressure, body fat and cholesterol levels in 1,400 middle-aged Finns in the 1970s and 1980s, and found that those who at 40 were obese, or had high blood pressure, or high cholesterol levels, were twice as more likely to develop dementia by the age of 60. Having all three of these risk factors increased their chances six-fold. Other risk factors were age and low education.

[2404] Kivipelto, M., Ngandu T., Laatikainen T., Winblad B., Soininen H., & Tuomilehto J.
(2006).  Risk score for the prediction of dementia risk in 20 years among middle aged people: a longitudinal, population-based study.
The Lancet Neurology. 5(9), 735 - 741.

http://society.guardian.co.uk/health/story/0,,1836464,00.html

Low cholesterol also associated with impaired cognition

Data from 789 men and 1,105 women from the Framingham Heart Study has found that those who had the lowest total cholesterol performed significantly more poorly on tests of similarities, word fluency, and attention/concentration than patients with higher cholesterol levels. Those in the lowest total cholesterol group (a level of under 200) were 49% more likely to perform poorly and 80% more likely to perform very poorly than were participants in the highest total cholesterol group (240 to 380). The finding should not be taken as a warning against those with high cholesterol taking medication to lower it; the study applies to those with naturally low cholesterol levels, and previous studies have shown that both high and low cholesterol have led to poor cognitive performance.

[1242] Elias, P. K., Elias M. F., D'Agostino R. B., Sullivan L. M., & Wolf P. A.
(2005).  Serum cholesterol and cognitive performance in the Framingham Heart Study.
Psychosomatic Medicine. 67(1), 24 - 30.

http://preventdisease.com/news/articles/021505_low_cholesterol_mental.shtml

Loss of body mass linked to development of Alzheimer's disease

People with Alzheimer's disease are known to lose weight and body mass after they have the disease, but now the Religious Orders Study has revealed that loss in body mass index is associated with a greater risk of developing the disease. People who lost approximately one unit of BMI per year had a 35% greater risk than people with no change in BMI; those with no change in BMI had a 20% greater risk of developing the disease than that of people who gained six-tenths of a unit of BMI per year. A similar relationship was also found between changes in BMI and rate of cognitive decline. The findings are supported by recently published findings of the Honolulu-Asia Aging Study, showing that dementia-associated weight loss in Japanese-American men begins before the onset of dementia and accelerates by the time of diagnosis.

Buchman, A.S., Wilson, R.S., Bienias, J.L., Shah, R.C., Evans, D.A. & Bennett, D.A. 2005. Change in body mass index and risk of incident Alzheimer disease. Neurology, 65, 892-897.

http://www.eurekalert.org/pub_releases/2005-09/nioa-lob092105.php

More support that high cholesterol is a risk factor for cognitive impairment

A new study has found that patients with a history of high cholesterol had a lower risk of cognitive impairment three to six months after stroke. The finding likely relates to high cholesterol treatment, rather than any positive effect of cholesterol. About 45% of the patients were being treated with cholesterol-lowering drugs known as statins before their stroke. Previous observational studies have indicated that statin therapy is associated with a reduced risk of Alzheimer's disease and vascular dementia.
A study of 103 consecutive ischemic stroke patients — 41 diagnosed with VCIND (vascular cognitive impairment-no dementia) and 62 who had no evidence of cognitive impairment after their strokes — identified three statistically significant predictors of cognitive impairment: the patient's level of education, the presence of heart disease, and a history of high cholesterol (hypercholesterolemia). When the researchers controlled for education level (education being an established protective factor for cognitive impairment), only hypercholesterolemia remained as a statistically significant predictor of the risk for cognitive impairment.

The studies were presented at the American Stroke Association's 29th International Stroke Conference.

http://www.eurekalert.org/pub_releases/2004-02/aha-cdm012704.php

Alzheimer's, cardiovascular disease share risk factors

A study of 4,081 women aged 65 years and older has investigated the relationship between cardiovascular risk factors and cognitive function. The researchers found a consistent increase in cognitive health paralleling higher levels of HDL (“good” cholesterol). A less robust correlation was seen for lower levels of LDL (or "bad") cholesterol and better cognitive performance. Triglyceride levels did not appear to influence cognition.

A study of over 700 elderly men and women has investigated the relationship between diabetes and cardiovascular disease risk factors and cognitive health. Researchers found that the presence of coronary heart disease, high cholesterol, or hypertension increased the risk of later cognitive decline, with a particularly strong effect in African Americans. They also found that although the diagnosis of diabetes increased the risk of cognitive decline by as much as two fold, the presence of high levels of fasting glucose (therefore, low insulin levels) substantially decreased the risk of cognitive decline in diabetic patients.

Reported at The 9th International Conference on Alzheimer's Disease and Related Disorders (ICAD), July 17-22, at the Pennsylvania Convention Center in Philadelphia, Pennsylvania:

Elizabeth Devore – Plasma Cholesterol Levels and Cognitive Function in Aging Women (O3-01-02, Tues., 7/20, 3-5 pm)

Jacobo Mintzer – Effects of Diabetes Mellitus and Other Elderly CVD Risk Factors on Change in cognitive Function Later in Life (P4-015, Wed., 7/21, 12:30)

http://www.eurekalert.org/pub_releases/2004-07/aa-acd070804.php

Why diet, hormones, exercise might delay Alzheimer’s

A theory that changes in fat metabolism in the membranes of nerve cells play a role in Alzheimer's has been supported in a recent study. The study found significantly higher levels of ceramide and cholesterol in the middle frontal gyrus of Alzheimer's patients. The researchers suggest that alterations in fats (especially cholesterol and ceramide) may contribute to a "neurodegenerative cascade" that destroys neurons in Alzheimer's, and that the accumulation of ceramide and cholesterol is triggered by the oxidative stress brought on by the presence of the toxic beta amyloid peptide. The study also suggests a reason for why antioxidants such as vitamin E might delay the onset of Alzheimer's: treatment with Vitamin E reduced the levels of ceramide and cholesterol, resulting in "a significant decrease in the number of neurons killed by the beta amyloid and oxidative stress.

[2398] Cutler, R. G., Kelly J., Storie K., Pedersen W. A., Tammara A., Hatanpaa K., et al.
(2004).  Involvement of oxidative stress-induced abnormalities in ceramide and cholesterol metabolism in brain aging and Alzheimer's disease.
Proceedings of the National Academy of Sciences of the United States of America. 101(7), 2070 - 2075.

http://www.eurekalert.org/pub_releases/2004-02/aaft-nsm021004.php

High cholesterol risk factor for the development of Alzheimer-related amyloid deposits

A review of autopsy cases of patients over 40 years old found that high blood cholesterol levels were correlated with the presence of amyloid deposits in the brain in the youngest subjects (aged 40-55).

[2407] Pappolla, M. A., Bryant-Thomas T. K., Herbert D., Pacheco J., Fabra Garcia M., Manjon M., et al.
(2003).  Mild hypercholesterolemia is an early risk factor for the development of Alzheimer amyloid pathology.
Neurology. 61(2), 199 - 205.

Cholesterol not a risk factor for Alzheimer's

Previously, the long-running, large-scale Framingham study found people with elevated levels of homocysteine in the blood had nearly double the risk of developing Alzheimer’s disease (AD). The study now clarifies the inconclusive results from previous studies regarding whether plasma cholesterol levels are associated with increased risk of Alzheimer disease (AD). They found that, after adjustment for age, sex, APOE genotype, smoking, body mass index, coronary heart disease, and diabetes, there was no significant association between AD risk and cholesterol level.

[439] Tan, Z. S., Seshadri S., Beiser A., Wilson P. W. F., Kiel D. P., Tocco M., et al.
(2003).  Plasma Total Cholesterol Level as a Risk Factor for Alzheimer Disease: The Framingham Study.
Arch Intern Med. 163(9), 1053 - 1057.

http://archinte.ama-assn.org/cgi/content/abstract/163/9/1053

New study counters previous research linking intake of dietary fat with increased risk of dementia

Previous studies suggesting that fat may be involved in the development of dementia and Alzheimer’s disease have been contradicted by a new study involving over 5,000 elderly people over a period of six years. The study found no correlation between fat and cholesterol intake and risk of dementia, and no evidence for a reduction in risk for those taking cholesterol lowering medication.

[2399] Engelhart, M. J., Geerlings M. I., Ruitenberg A., van Swieten J. C., Hofman A., Witteman J. C. M., et al.
(2002).  Diet and risk of dementia: Does fat matter?.
Neurology. 59(12), 1915 - 1921.

http://www.eurekalert.org/pub_releases/2002-12/aaon-nsc121602.php

Cholesterol not a risk factor for Alzheimer's

Previously, the long-running, large-scale Framingham study found people with elevated levels of homocysteine in the blood had nearly double the risk of developing Alzheimer’s disease (AD). The study now clarifies the inconclusive results from previous studies regarding whether plasma cholesterol levels are associated with increased risk of Alzheimer disease (AD). They found that, after adjustment for age, sex, APOE genotype, smoking, body mass index, coronary heart disease, and diabetes, there was no significant association between AD risk and cholesterol level.

Tan, Z.S., Seshadri, S., Beiser, A., Wilson, P.W.F., Kiel, D.P., Tocco, M., D'Agostino, R.B. & Wolf, P.A. 2003. Plasma Total Cholesterol Level as a Risk Factor for Alzheimer Disease: The Framingham Study. Archives of Internal Medicine, 163, 1053-1057.
http://archinte.ama-assn.org/cgi/content/abstract/163/9/1053

New study counters previous research linking intake of dietary fat with increased risk of dementia

Previous studies suggesting that fat may be involved in the development of dementia and Alzheimer’s disease have been contradicted by a new study involving over 5,000 elderly people over a period of six years. The study found no correlation between fat and cholesterol intake and risk of dementia, and no evidence for a reduction in risk for those taking cholesterol lowering medication.

Engelhart, M.J., Geerlings, M.I., Ruitenberg, A., van Swieten, J.C., Hofman, A., Witteman, J.C.M. & Breteler, M.M.B. 2002. Diet and risk of dementia: Does fat matter?: The Rotterdam Study. Neurology, 59, 1915-1921.

http://www.eurekalert.org/pub_releases/2002-12/aaon-nsc121602.php

High calorie consumption associated with higher risk of Alzheimer’s in those genetically disposed to Alzheimer’s

980 elderly individuals without Alzheimer’s participated in a four-year study to investigate whether there was any link between caloric intake and Alzheimer’s. During the course of the study, 242 patients developed Alzheimer’s, and 28% tested positive for the APOE epsilon 4 gene. Participants were divided into four groups depending on how many calories they consumed daily. 263 of the participants tested positive for the APOE epsilon 4 gene, and among them, those who consumed the most calories had a 2.3 times greater chance of developing Alzheimer’s compared to those who ate the fewest calories. For those without the ApoE e gene, calorie and fat intake were not associated with a greater risk of Alzheimer’s.

[2405] Luchsinger, J. A., Tang M-X., Shea S., & Mayeux R.
(2002).  Caloric Intake and the Risk of Alzheimer Disease.
Arch Neurol. 59(8), 1258 - 1263.

http://www.eurekalert.org/pub_releases/2002-08/jota-cmc081202.php

High blood pressure and cholesterol are risk factors for Alzheimer's disease

A large-scale Finnish study following 1449 men and women over 21 years found that raised systolic blood pressure and high serum cholesterol concentration, particularly in combination, in midlife, increase the risk of Alzheimer's disease in later life. Raised diastolic blood pressure had no significant effect.

The study was reported in the British Medical Journal. http://www.bmj.com/cgi/content/full/322/7300/1447

Cholesterol bad for brain too

An analysis of data on 1037 older women who had participated in a clinical trial of hormone replacement therapy found that high cholesterol levels increase the risk of cognitive impairment. It is speculated that, in addition to clogging arteries, and possibly leading to vascular changes in the brain, cholesterol may promote the clumping of a protein called beta-amyloid, which is believed to damage the brain in Alzheimer’s disease patients.

[2411] Yaffe, K., Barrett-Connor E., Lin F., & Grady D.
(2002).  Serum Lipoprotein Levels, Statin Use, and Cognitive Function in Older Women.
Arch Neurol. 59(3), 378 - 384.

http://www.eurekalert.org/pub_releases/2002-03/uoc--cbf031302.php

Role of cholesterol in memory

It appears that cholesterol stimulates the nerve cells of the brain to make the connections that are essential to learning and memory, thus playing a crucial role in making sure that the brain works properly. But how does cholesterol do its job? The blood-brain barrier prevents the brain obtaining cholesterol from the blood. New research suggests that cholesterol is secreted by support cells (glial cells) within the brain. The research may lead to new strategies to cure injury- or disease-induced brain lesions, and suggests a new hypothesis concerning Alzheimer's disease.

[503] Barres, B. A., & Smith S. J.
(2001).  Neurobiology. Cholesterol--making or breaking the synapse.
Science (New York, N.Y.). 294(5545), 1296 - 1297.

http://news.bbc.co.uk/hi/english/health/newsid_1645000/1645372.stm
http://www.eurekalert.org/pub_releases/2001-11/m-brd110401.php

High blood pressure and cholesterol are risk factors for Alzheimer's disease

A large-scale Finnish study following 1449 men and women over 21 years found that raised systolic blood pressure and high serum cholesterol concentration, particularly in combination, in midlife, increase the risk of Alzheimer's disease in later life. Raised diastolic blood pressure had no significant effect.

[1448] Kivipelto, M., Helkala E-L., Laakso M. P., Hanninen T., Hallikainen M., Alhainen K., et al.
(2001).  Midlife vascular risk factors and Alzheimer's disease in later life: longitudinal, population based study.
BMJ. 322(7300), 1447 - 1451.

http://www.bmj.com/cgi/content/full/322/7300/1447

Older news items (pre-2010) brought over from the old website

Pollutants affect babies' brains

It appears that exposure to polychlorinated biphenyls (PCBs) in a mother's blood and breast milk can hinder the development of a baby's brain before and after birth. Although PCBs are now banned, these chemicals were once widely used in industry as coolants and lubricants and are still being leaked into the environment from old electrical equipment.

[591] Walkowiak, J., Wiener J. A., Fastabend A., Heinzow B., Krämer U., Schmidt E., et al.
(2001).  Environmental exposure to polychlorinated biphenyls and quality of the home environment: effects on psychodevelopment in early childhood.
Lancet. 358(9293), 1602 - 1607.

http://news.bbc.co.uk/hi/english/health/newsid_1644000/1644446.stm

PCB-laden fish may affect adult verbal memory

The dangers of PCBs (once widely used as electrical insulators and lubricants and in paints and varnishes) have long been known, and assumed to apply chiefly to children and developing fetuses. A long-term study of those who eat the PCB-laden fish from Lake Michigan suggests for the first time that high levels of PCB may cause problems learning and remembering new verbal information in adults. In particular, those with high blood PCB levels had difficulties recalling a story told just 30 minutes earlier, and were less likely than their less-exposed peers to cluster words given orally into categories based on their meaning to boost recall.

Schantz, S.L., Gasior, D.M., Polverejan, E., McCaffrey, R.J., Sweeney, A.M., Humphrey, H.E.B. & Gardiner, J.C. 2001. Impairments of Memory and Learning in Older Adults Exposed to Polychlorinated Biphenyls via Consumption of Great Lakes Fish. Environmental Health Perspectives, 109 (6), 605.

http://www.eurekalert.org/pub_releases/2001-06/UoIa-Hcot-0406101.php
http://ehpnet1.niehs.nih.gov/docs/2001/109-6/toc.html

How chronic exposure to solvents can impair the brain

Chronic occupational exposure to organic solvents, found in materials such as paints, printing and dry cleaning agents, has been linked to long-term cognitive impairment, but chronic solvent-induced encephalopathy (CSE) is still a controversial diagnosis. An imaging study of 10 CSE patients who had been exposed to solvents and had mild to severe cognitive impairment, 10 participants who had been exposed to solvents but had no CSE symptoms, and 11 participants who were not exposed to solvents and had no symptoms, has now found impairment in the frontal-striatal-thalamic (FST) circuitry of CSE patients. The disturbances are predictive of the clinical findings — impaired psychomotor speed and attention — and were also linked to exposure severity.

[989] van Dijk, F. J. H., Schene A. H., Heeten G D. J., Visser I., Lavini C., Booij J., et al.
(2008).  Cerebral impairment in chronic solvent-induced encephalopathy.
Annals of Neurology. 63(5), 572 - 580.

http://www.eurekalert.org/pub_releases/2008-04/w-dib041508.php

Chemical in clear plastics can impair learning

A rat study has found that low doses of the environmental contaminant bisphenol–A (BPA), widely used to make many plastics found in food storage containers (including feeding bottles for infants), inhibit estrogen–induction of synaptic connections in the hippocampus, suggesting implications for children's learning ability. Also, when the ability to make estrogen is impaired, as in old age, exposure to BPA could adversely affect hippocampal function and contribute to age–related neurodegenerative diseases such as Alzheimer's disease, in which hippocampal function is impaired. The doses were below the current U.S. Environmental Protection Agency reference daily limit for human exposure.

[740] MacLusky, N. J., Hajszan T., & Leranth C.
(2005).  The Environmental Estrogen Bisphenol A Inhibits Estradiol-Induced Hippocampal Synaptogenesis.
Environmental Health Perspectives. 113(6), 675 - 679.

http://www.eurekalert.org/pub_releases/2005-04/yu-cpi041205.php

 

Older news items (pre-2010) brought over from the old website

Iron supplements might harm infants who have enough

U.S. infant formulas typically come fortified with 12 mg/L of iron to prevent iron-deficiency anemia, although Europe generally uses a lower amount. A study of 494 Chilean children has now showed that those who received iron fortified formula in infancy at the 12 mg level used in the U.S. lagged behind those who received low-iron formula in cognitive and visual-motor development by age 10 years. While most children who received the higher level formula did not show lower scores, the 5% with the highest hemoglobin levels at 6 months showed the poorest outcome. Adversely affected children scored 11 points lower in IQ and 12 points lower in visual-motor integration. This suggests that those who are not deficient in iron are adversely affected by giving them too much. It seems likely that more than 5% of U.S. infants will have high hemoglobin levels. More research is needed to confirm this finding.

Castillo, M. & Smith, J.B. 2008. Poorer developmental outcome at 10 years with 12 mg/L iron-fortified formula in infancy. Paper presented May 5 at the Pediatric Academic Societies annual meeting in Honolulu.

http://www.eurekalert.org/pub_releases/2008-05/uom-ism043008.php

Iron-deficient infants have lower cognitive scores at 19, especially in lower socioeconomic levels

Another study has come out finding that teenagers who were iron-deficient as infants continue to lag behind their peers in cognitive test scores, with a wider gap for children at lower socioeconomic levels. The study of 185 children from an urban area in Costa Rica, found that among children from middle-class families, initial scores on cognitive tests were eight points apart, 101.2 for those with iron deficiency and 109.3 for those with sufficient iron levels, and this gap remained at eight or nine points through 19 years. However, for those in lower socio-economic classes, initial scores that were ten points apart (93.1 for iron-deficient infants and 102.8 for those with normal iron levels) had widened by 19 years to 25 points (70.4 vs. 95.3). The finding points to the snowball effect of early failure.

[1145] Lozoff, B., Jimenez E., & Smith J. B.
(2006).  Double Burden of Iron Deficiency in Infancy and Low Socioeconomic Status: A Longitudinal Analysis of Cognitive Test Scores to Age 19 Years.
Arch Pediatr Adolesc Med. 160(11), 1108 - 1113.

http://www.eurekalert.org/pub_releases/2006-11/jaaj-idi110206.php

Impact of iron deficiency in infancy continues into adolescence

A new study has found that teens who suffered iron deficiency as infants are likely to score lower on cognitive and motor tests, even if that iron deficiency was identified and treated in infancy. The study followed 191 children. Those who were diagnosed with severe, chronic iron deficiency when they were 12-23 months old and were treated with iron supplements, lagged behind their peers in both motor and mental measures. The difference, moreover, actually increased over time. The iron-deficient infants scored about six points lower on cognitive tests at age 1-2 years, and 11 points lower at age 15-18 years. The gap was even more pronounced for children of families with low socioeconomic status, lower stimulation in the home or mothers lower in IQ. For children with good iron status, family conditions did not seem to affect their cognitive test scores. The researcher stressed that the children were not generally malnourished. Moreover, it must be emphasized that these children received treatment for their iron deficiency, yet still showed continuing ill effects, pointing to the need to prevent the deficiency occurring in the first place.

Lozoff, B. 2004. Longitudinal Analysis of Cognitive and Motor Effects of Iron Deficiency in Infancy. Presented at the Pediatric Academic Societies' annual meeting in San Francisco May 3.

http://www.eurekalert.org/pub_releases/2004-05/uom-iis050404.htm

American Academy of Pediatrics information on iron intake for infants: http://aappolicy.aappublications.org/cgi/content/full/pediatrics;104/1/119

Even moderate iron deficiency affects cognitive performance

A new study involving 149 young women (aged 18 to 35, average age 21), has found that iron supplementation significantly improved attention, short-term and long-term memory, and performance on cognitive tasks in those who were deficient in iron, even if not classified as anemic. On the baseline test, women who were iron deficient but not anemic completed the tasks in the same amount of time as iron sufficient women of the same age, but they performed significantly worse. Women who were anemic both performed significantly worse and took longer, with length of time increasing with degree of anemia. However, 16 weeks of iron supplementation markedly improved both scores and time to complete the task.
While iron deficiency was once presumed to exert most of its deleterious effects only if it had reached the level of anemia, it has more recently become recognized that many organs show negative changes in functioning before there is any drop in iron hemoglobin concentration. Iron deficiency is thought to occur in 9 – 11% of women of reproductive age and 25% of pregnant women. In non-industrialized countries, the prevalence of anemia is over 40% in non-pregnant women and over 50% for pregnant women and children aged five to 14.

Murray-Kolb, L., Beard, J. & Whitfield, K. 2004. presented at Experimental Biology 2004, in the American Society of Nutritional Sciences' scientific program.

http://www.eurekalert.org/pub_releases/2004-04/foas-mid040404.php

U.N. prescribes nutrient-fortified foods

A new U.N. survey says the brainpower of many developing countries has diminished because of a shortage of the right vitamins. To fight the problem, the United Nations is prescribing artificially fortified foods: soy sauce laced with zinc, "super salt" spiked with iron, cooking oil fortified with vitamin A. The report claimed a lack of iron lowered children's IQs by an average five to seven points, while a deficiency in iodine cuts it 13 more points. The report was produced by the Micronutrient Initiative and the United Nations Children's Fund.
http://www.micronutrient.org/

Iron deficiency may affect maths achievement in children and teens

A U.S. national study of 5,398 children aged 6 to 16 found iron deficiency in 3% of the children overall, and 8.7% of girls aged 12 to 16 (7% without anemia). Average math scores for iron-deficient children with or without anemia were about six points lower than those with normal iron levels. Among adolescent girls, the difference in scores was more than eight points. Previous research has linked iron-deficiency anemia with lower developmental test scores in young children, but there is less information on older children and on iron deficiency without anemia. It is suggested that this finding may help explain why the female superiority in maths at younger ages reverses itself in adolescence.

Halterman, J.S., Kaczorowski, J.M., Aligne, C.A., Auinger, P. & Szilagyi, P.G. 2001. Iron Deficiency and Cognitive Achievement Among School-Aged Children and Adolescents in the United States. Pediatrics, 107 (6), 1381-1386.

http://www.pediatrics.org/cgi/content/abstract/107/6/1381

Anemia linked to impaired thinking in older adults

For older adults, anemia has long been linked to fatigue, muscle weakness and other physical ailments. But a new study suggests it may also be an independent risk factor for executive-function impairment. The study examined 364 women between 70 and 80 years old, of whom some 10% had mild anemia. Those with anemia were four to five times more likely to perform worst on the executive function tests.

[708] Chaves, P. H. M., Carlson M. C., Ferrucci L., Guralnik J. M., Semba R., & Fried L. P.
(2006).  Association Between Mild Anemia and Executive Function Impairment in Community-Dwelling Older Women: The Women's Health and Aging Study II.
Journal of the American Geriatrics Society. 54(9), 1429 - 1435.

http://www.eurekalert.org/pub_releases/2006-09/jhmi-aab091306.php