obesity

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

Overweight and obese elderly have smaller brains

Analysis of brain scans from 94 people in their 70s who were still "cognitively normal" five years after the scan has revealed that people with higher body mass indexes had smaller brains on average, with the frontal and temporal lobes particularly affected (specifically, in the frontal lobes, anterior cingulate gyrus, hippocampus, and thalamus, in obese people, and in the basal ganglia and corona radiate of the overweight). The brains of the 51 overweight people were, on average, 6% smaller than those of the normal-weight participants, and those of the 14 obese people were 8% smaller. To put it in more comprehensible, and dramatic terms: "The brains of overweight people looked eight years older than the brains of those who were lean, and 16 years older in obese people." However, overall brain volume did not differ between overweight and obese persons. As yet unpublished research by the same researchers indicates that exercise protects these same brain regions: "The most strenuous kind of exercise can save about the same amount of brain tissue that is lost in the obese."

Thompson, P. M., Raji, C. A., Ho, A. J., Parikshak, N. N., Becker, J. T., Lopez, O. L., … Toga, A. W. (2010). Brain structure and obesity. Human Brain Mapping, 31(3), 353-364. Retrieved from http://dx.doi.org/10.1002/hbm.20870

http://www.newscientist.com/article/mg20327222.400-expanding-waistlines-may-cause-shrinking-brains.htm

Obesity surgery can lead to memory loss

A review of the literature has found that weight loss surgery such as gastric bypass surgery, can lead to a vitamin deficiency that can cause memory loss and confusion, inability to coordinate movement, and other problems. Wernicke encephalopathy affects the brain and nervous system when the body doesn’t get enough vitamin B1 (thiamine). The study found that the syndrome occurs most often in people who have frequent vomiting after the surgery, and usually occurs within one to three months after the surgery.

Singh, S. & Kumar, A. 2007. Wernicke encephalopathy after obesity surgery: A systematic review. Neurology, 68, 807-811.

http://www.eurekalert.org/pub_releases/2007-03/aaon-osc030607.php

High BMI tied to poorer cognitive function in middle-aged adults

A study of 2,223 healthy French men and women aged 32—62 found that a higher body mass index (BMI) was associated with lower scores on a word-recall task.

Cournot, M., Marquie, J. C., Ansiau, D., Martinaud, C., Fonds, H., Ferrieres, J., & Ruidavets, J. B. (2006). Relation between body mass index and cognitive function in healthy middle-aged men and women. Neurology, 67(7), 1208-1214. Retrieved from http://www.neurology.org/cgi/content/abstract/67/7/1208

http://www.sciencedaily.com/releases/2006/10/061010023000.htm
http://www.eurekalert.org/pub_releases/2006-10/aaon-hbt100306.php

Morbid obesity in toddlers linked to low IQ

A study of 18 children and adults with early-onset morbid obesity (they weighed at least 150% of their ideal body weight before they were 4), 19 children and adults with Prader-Willi syndrome, and 24 of their normal-weight siblings, has revealed a link between morbid obesity in toddlers and lower IQ scores, cognitive delays and brain lesions similar to those seen in Alzheimer's disease patients. The links between cognitive impairments and Prader-Willi syndrome (a genetic disorder that causes people to eat nonstop and become morbidly obese at a very young age if not supervised) are well-established. But researchers were surprised to find patients with early-onset morbid obesity had an average IQ of 77, compared to an average of 63 for Prader-Willi patients and an average of 106 for the control group of siblings. Scans also revealed white-matter lesions on the brains of many of the Prader-Willi and early-onset morbidly obese patients.

Sahoo, T., Beaudet, A. L., Driscoll, D. J., Miller, J., Kranzler, J., Liu, Y., … Goldstone, A. P. (2006). Neurocognitive findings in Prader-Willi syndrome and early-onset morbid obesity. The Journal of Pediatrics, 149(2), 192-198. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/16887432

http://www.eurekalert.org/pub_releases/2006-08/uof-ssl083106.php

Fat hormone linked to learning and memory

A new study reveals why obese patients who have diabetes also may have problems with their long-term memory. Leptin — the so-called ‘fat’ hormone — doesn't cross into the brain to help regulate appetite in obese people. Leptin also acts in the hippocampus, suggesting that leptin plays a role in learning and memory. The new study supports this by demonstrating that mice navigated a maze better after they received leptin. Moreover, mice with elevated levels of amyloid-beta plaques (characteristic of Alzheimer's) were particularly sensitive to leptin.

Farr, S. A., Banks, W. A., & Morley, J. E. (2006). Effects of leptin on memory processing. Peptides, 27(6), 1420-1425. Retrieved from http://www.sciencedirect.com/science/article/pii/S0196978105004754

http://www.sciencedaily.com/releases/2006/06/060614090511.htm
http://www.eurekalert.org/pub_releases/2006-06/slu-alb061306.php

Large waist linked to poor health even when BMI healthy

Submitted by Fiona McPherson on Thu, 5 Jun 2014 - 12:44

Data from 11 different cohort studies, involving more than 600,000 people from around the world, has found that:

Obesity linked to inflammation & impaired brain function

Submitted by Fiona McPherson on Thu, 5 Jun 2014 - 11:53

A mouse study has found that obese mice had high levels of interleukin 1 in both their blood and their brains, and this was associated with:

high levels of inflammation,
low levels of a biochemical important to synapse function, and
impaired cognitive function.

Moreover, when fat was removed from the obese mice, interleukin levels dropped dramatically, and cognitive performance improved.

Putting obese mice on an exercise program had a similar effect, even though they didn’t lose weight — but they gained muscle and lost fat.

Larger belly linked to memory problems in people with HIV

A study involving 130 HIV-positive people has found that memory impairment was associated with a significantly larger waistline.

Some 40% of participants (average age 46) had impaired cognition. This group had an average waist circumference of 39 inches, compared to 35 inches for those without such problems. Memory impairment was also linked to diabetes in those older than 55 (15% of those with memory problems had diabetes compared to only 3% of those without memory problems).

Obesity linked to better cognition in post-menopausal women

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.

Cognitive impairment in obese improved by surgery

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.

Metabolic syndrome linked to memory loss in older people

The new label of ‘metabolic syndrome’ applies to those having three or more of the following risk factors: high blood pressure, excess belly fat, higher than normal triglycerides, high blood sugar and low high-density lipoprotein (HDL) cholesterol (the "good" cholesterol). Metabolic syndrome has been linked to increased risk of heart attack.

Steep cholesterol decline in older women linked to Alzheimer's risk

Research into the link, if any, between cholesterol and dementia, has been somewhat contradictory. A very long-running Swedish study may explain why. The study, involving 1,462 women aged 38-60 in 1968, has found that cholesterol measured in middle or old age showed no link to dementia, but there was a connection between dementia and the rate of decline in cholesterol level.

Obesity and body shape linked to poorer brain function in older women

A very large study of older women has found that although there was a small downward trend in cognitive function (as measured by the MMSE) with increasing obesity, this trend was almost entirely driven by those with a waist-hip ratio below 0.78 — that is, for women who carry excess weight around their hips, known as pear shapes (as opposed to carrying it around the waist, called apple shapes).