(Press-News.org) SAN FRANCISCO-- Memory improves in older, overweight women after they lose weight by dieting, and their brain activity actually changes in the regions of the brain that are important for memory tasks, a new study finds. The results were presented today at The Endocrine Society's 95th Annual Meeting in San Francisco.
"Our findings suggest that obesity-associated impairments in memory function are reversible, adding incentive for weight loss," said lead author Andreas Pettersson, MD, a PhD student at Umea University, Umea, Sweden.
Previous research has shown that obese people have impaired episodic memory, the memory of events that happen throughout one's life.
Pettersson and co-workers performed their study to determine whether weight loss would improve memory and whether improved memory correlated with changes in relevant brain activity. A special type of brain imaging called functional magnetic resonance imaging (functional MRI) allowed them to see brain activity while the subjects performed a memory test.
The researchers randomly assigned 20 overweight, postmenopausal women (average age, 61) to one of two healthy weight loss diets for six months. Nine women used the Paleolithic diet, also called the Caveman diet, which was composed of 30 percent protein; 30 percent carbohydrates, or "carbs"; and 40 percent unsaturated fats. The other 11 women followed the Nordic Nutrition Recommendations of a diet containing 15 percent protein, 55 percent carbs and 30 percent fats.
Before and after the diet, the investigators measured the women's body mass index (BMI, a measure of weight and height) and body fat composition. They also tested the subjects' episodic memory by instructing them to memorize unknown pairs of faces and names presented on a screen during functional MRI. The name for this process of creating new memory is "encoding." Later, the women again saw the facial images along with three letters. Their memory retrieval task, during functional MRI, was to indicate the correct letter that corresponded to the first letter of the name linked to the face.
Because the two dietary groups did not differ in body measurements and functional MRI data, their data were combined and analyzed as one group. The group's average BMI decreased from 32.1 before the diet to 29.2 (below the cutoff for obesity) after six months of dieting, and their average weight dropped from 188.9 pounds (85 kilograms) to 171.3 pounds (77.1 kilograms), the authors reported. This study was part of a larger, diet-focused study funded by the Swedish Research Council and the Swedish Heart-Lung Foundation.
Memory performance improved after weight loss, and Pettersson said the brain-activity pattern during memory testing reflected this improvement. After weight loss, brain activity reportedly increased during memory encoding in the brain regions that are important for identification and matching of faces. In addition, brain activity decreased after weight loss in the regions that are associated with retrieval of episodic memories, which Pettersson said indicates more efficient retrieval.
"The altered brain activity after weight loss suggests that the brain becomes more active while storing new memories and therefore needs fewer brain resources to recollect stored information," he said.
###
Founded in 1916, The Endocrine Society is the world's oldest, largest and most active organization devoted to research on hormones and the clinical practice of endocrinology. Today, The Endocrine Society's membership consists of over 16,000 scientists, physicians, educators, nurses and students in more than 100 countries. Society members represent all basic, applied and clinical interests in endocrinology. The Endocrine Society is based in Chevy Chase, Maryland. To learn more about the Society and the field of endocrinology, visit our site at http://www.endocrine.org. Follow us on Twitter.
Weight loss improves memory and alters brain activity in overweight women
2013-06-17
ELSE PRESS RELEASES FROM THIS DATE:
Being overweight linked to excess stress hormones after eating
2013-06-17
SAN FRANCISCO-- Overweight and obese men secrete greater amounts of stress hormones after eating, which may make them more susceptible to disease, a new observational study finds. The results will be presented Saturday at The Endocrine Society's 95th Annual Meeting in San Francisco.
Excess weight and obesity are a global health problem, and medical researchers are seeking different approaches to reduce the burden of disease. One way to do this is by identifying differences in hormonal regulation between overweight and lean people in response to various situations, including ...
The Rett Syndrome protein surrenders some of its secrets
2013-06-17
Discovery of a mutant gene responsible for a disease is a milestone, but for most conditions, it may be only a first step towards a treatment or cure. Understanding Rett Syndrome, an autism spectrum disorder, is further complicated by the fact that the implicated gene controls a suite of other genes. Two papers, published in today's Nature Neuroscience and Nature, reveal key steps in how mutations in the gene for methyl CpG-binding protein (MECP2) cause the condition. The Rett Syndrome Research Trust (RSRT) funded this work with generous support from partners Rett Syndrome ...
Drug boosts fat tissue's calorie-burning ability in lab
2013-06-17
SAN FRANCISCO-- A drug that mimics the activity of thyroid hormone significantly increases the amount of energy burned by fat tissue and promotes weight loss, an animal study of metabolism finds. The results were presented Sunday at The Endocrine Society's 95th Annual Meeting in San Francisco.
Humans and other mammals have two kinds of fat, or adipose, tissue, which are referred to by color: white or brown. White adipose tissue, or WAT, has low energy-burning capacity. Because of this, WAT is associated with weight gain and obesity, as well as other conditions related ...
Testosterone therapy improves sexual function after uterus and ovary removal
2013-06-17
SAN FRANCISCO-- High doses of testosterone significantly improve sexual function among women who have had their uterus and ovaries surgically removed, a clinical study demonstrates. The results were presented Sunday at The Endocrine Society's 95th Annual Meeting in San Francisco.
Surgical removal of the uterus, or hysterectomy, and the ovaries, which is called oophorectomy, is performed to treat various diseases, including cancer. Hysterectomy is also performed as an elective sterilization, usually among older women, and may be combined with oophorectomy if ovarian disease ...
Insulin resistance linked to weaker bones
2013-06-17
SAN FRANCISCO-- Reduced effectiveness of the hormone insulin, or insulin resistance, is associated with weakened bones, a clinical study shows. The results were presented Sunday at The Endocrine Society's 95th Annual Meeting in San Francisco.
In the United States, the incidence of diabetes is quickly mounting. Between the years of 1980 and 2011, the number of cases diagnosed jumped from about 6 million to nearly 21 million, according to statistics from the Centers for Disease Control and Prevention.
Type 2 diabetes is the result of insulin resistance, which causes cells ...
Skipping breakfast may make obese women insulin resistant
2013-06-17
SAN FRANCISCO—- Overweight women who skip breakfast experience acute, or rapid-onset, insulin resistance, a condition that, when chronic, is a risk factor for diabetes, a new study finds. The results, which were presented Sunday at The Endocrine Society's 95th Annual Meeting in San Francisco, suggest that regularly skipping breakfast over time may lead to chronic insulin resistance and thus could increase an individual's risk for type 2 diabetes.
"Our study found that acute insulin resistance developed after only one day of skipping breakfast," said the study's lead author, ...
Short-term antidepressant use, stress, high-fat diet linked to long-term weight gain
2013-06-17
SAN FRANCISCO—- Short-term use of antidepressants, combined with stress and a high-fat diet, is associated with long-term increases in body weight, a new animal study finds. The results were presented Sunday at The Endocrine Society's 95th Annual Meeting in San Francisco.
"Our study suggests that short-term exposure to stress and antidepressants, rather than a high-calorie, high-fat diet alone, leads to long-term body weight gain, accompanied with increased bone and spleen weights," said study lead author Suhyun Lee, a PhD candidate in the medical sciences at the John ...
Father's diet before conception affects offspring's body fat in mice
2013-06-17
SAN FRANCISCO—- When fathers eat a high-fat diet before conception of offspring, the male offspring have increased body weight after weaning and high body fat in midlife despite eating a low-fat diet, a new study in mice finds. The results were presented Sunday at The Endocrine Society's 95th Annual Meeting in San Francisco.
"Many researchers have studied the effects of maternal diet on the risk of obesity in their children. We found that the father's diet also affects the offspring in ways that are inherited," said the study's principal investigator, Felicia V. Nowak, ...
JCI early table of contents for June 17, 2013
2013-06-17
Scouring the genome of adenoid cystic carcinoma
Adenoid cystic carcinoma (ACC) is a slow-growing and often fatal malignancy that can occur at multiple organ site, but is most frequently found in the salivary glands. The primary treatment is surgical removal; however, the majority of patients develop metastatic disease. In this issue of the Journal of Clinical Investigation, researchers led by Andrew Futreal at the Wellcome Trust Sanger Institute in Cambridge, MA, performed a type of genetic sequencing known as whole exome sequencing of 24 ACC cases. They identified a genetic ...
Scouring the genome of adenoid cystic carcinoma
2013-06-17
Adenoid cystic carcinoma (ACC) is a slow-growing and often fatal malignancy that can occur at multiple organ site, but is most frequently found in the salivary glands. The primary treatment is surgical removal; however, the majority of patients develop metastatic disease. In this issue of the Journal of Clinical Investigation, researchers led by Andrew Futreal at the Wellcome Trust Sanger Institute in Cambridge, MA, performed a type of genetic sequencing known as whole exome sequencing of 24 ACC cases. They identified a genetic translocation that can precipitate disease ...