A new review of health studies shows that aerobic exercise can help brain function.
“Benefits of regular aerobic exercise for executive functioning in healthy populations” is published in Psychonomic Bulletin and Review.
A certain amount of mental deterioration is expected with advancing age. However, this may not necessarily have to be the case as particular aspects of cognitive function such as task switching, selective attention and working memory among others, all appear to benefit from aerobic exercise.
Studies in older adults reviewed by the authors consistently found that fitter individuals scored better in mental tests than their unfit peers.
In addition, intervention studies found scores in mental tests improved in participants who were assigned to an aerobic exercise regimen compared to those assigned to stretch and tone classes.
Interestingly, these results were not replicated in children or young adults. The one area where physical fitness or regular exercise was found to have an effect on cognitive function in these age groups was for memory tasks.
Both the updating of working memory and the volume of information which could be held was better in fitter individuals or those put on an aerobic exercise regime.
The authors comment that despite physical fitness not affecting all areas of cognitive function in younger people, evidence is mounting that just because they are in their prime developmentally does not mean that they cannot benefit from regular exercise.
In older generations, the evidence for improvement in cognitive function is insurmountable. The types of tests of cognitive function reviewed here are important in showing that exercise may attenuate age-related decline for specific tasks.
For example, it has been found to positively affect mental tasks relating to activities such as driving, an activity where age is often seen as a limiting factor.
The authors conclude that engagement in exercise can provide a simple means for people to optimize their cognitive function. They add that more research into the effects of exercise on young adults and children is required.
However, they say that "the indications reported thus far – that regular exercise can benefit brains even when they are in their prime developmentally – warrant more rigorous investigation, particularly in the context of society becoming increasingly sedentary."
A new study suggests that human papillomavirus (HPV) infection in women at or after menopause may represent an infection acquired years ago, and that HPV infections may exist below limits of detection after one to two years, similar to other viruses, such as varicella zoster, which can cause shingles.
The study, published in The Journal of Infectious Diseases and available online, highlights the need for additional research to better understand HPV infections and the role of HPV persistence and reactivation, particularly in women of the baby boomer generation.
In previous studies, HPV has been detected in 25 to 50 percent of young, sexually active women. In most of these cases, after two years the virus is “cleared,” or is no longer detected in samples.
Studies have shown that HPV infection peaks in young women around the age of sexual debut and begins to decline in the late 20s and 30s.
In some countries, such as in Central and South America, HPV has been shown to have a second peak around the age of menopause.
In contrast, in previous studies in the United States and Europe, HPV prevalence remains low or continues to decline with age.
Researchers, led by Patti E. Gravitt, PhD, of Johns Hopkins Bloomberg School of Public Health and Perdana University Graduate School of Medicine in Serdang, Malaysia, set out to investigate what factors influence these differences.
They compared differences in recent and lifetime sexual behaviors by age groups to investigate the presence of a cohort effect in a population of women in Baltimore.
The study included approximately 850 women aged 35-60 who were receiving routine cervical cancer screening from 2008 to 2011.
While HPV prevalence was higher among women who reported a new sexual partner within 6 months prior to study enrollment, less than 3 percent of women in the study reported having a new partner in that time.
Conversely, nearly 90 percent of HPV infections were detected in women reporting more than one lifetime sexual partner, and 77 percent were detected in women who reported five or more sexual partners in their lifetime.
“Taken together, our data raise the possibility that reactivation risk may increase around age 50 years and contribute to a larger fraction of HPV detection at older ages, compared with new acquisition,” the researchers wrote.
According to the authors, an important point this study makes is that women who had their sexual debut during and after the sexual revolution of the 1960s and 1970s have a significantly higher risk of HPV infection compared to women who did so before 1965, likely due to a higher number of sexual partners during their lifetime.
“Our historical experience with HPV and cervical neoplasia in postmenopausal women may not be very predictive of the experience of the baby boomer generation of women who are now entering the menopausal transition at a higher risk than their mothers,” Dr. Gravitt said.
In an accompanying editorial, Darron R. Brown, MD, and Bree A. Weaver, MD, of the Indiana University School of Medicine, noted that some previous studies demonstrating that HPV “clears” after two years have been based on only one or two negative screenings.
Several studies have shown that type-specific HPV can be detected again after a long period of non-detection, although whether this is due to reactivation of a low-level persistent infection or a new infection has not been established.
“Further research is needed to help better understand the natural history of HPV infection in older women and to understand the importance of HPV persistence and reactivation in all women,” they wrote.
Dr. Gravitt and her team of investigators will continue to follow the women in the study to further confirm their findings.
A more nationally representative sample of women would help determine whether the study’s findings can be generalized to the larger U.S. population.
“Long-term follow-up of previously highly exposed women who will transition through menopause in the next decade is urgently needed to accurately estimate the potential risk of postmenopausal invasive cervical cancer in the U.S. baby boom population and guide prevention strategies,” the authors wrote.
A new study appearing this week in the Journal of Neuroscience details for the first time how “mini-strokes” cause prolonged periods of brain damage and result in cognitive impairment.
These strokes, which are often imperceptible, are common in older adults and are believed to contribute to dementia.
“Our research indicates that neurons are being lost as a result of delayed processes following a mini-strokes that may differ fundamentally from those of acute ischemic events,” said Maiken Nedergaard, M.D., D.M.Sc., the lead author of the study and professor of Neurosurgery at the University of Rochester Medical Center (URMC). “This observation suggests that the therapeutic window to protect cells after these tiny strokes may extend to days and weeks after the initial injury.”
The prevalence of mini-strokes, or microinfarcts, has only been recently appreciated because common imaging techniques, such as MRI, are typically not sensitive enough to detect these microscopic injuries.
Similar to severe ischemic strokes, mini-strokes are caused when blood flow is blocked to a small area of the brain, usually by particle that travelled there from another part of the body.
But unlike acute ischemic strokes – which bring about immediate symptoms such as numbness, blurry vision, and slurred speech – mini-strokes usually pass without notice. However, it is increasingly appreciated that these smaller strokes have a lasting impact on neurological function.
Microinfarcts are far more common than previously understood; it is believed that about 50 percent of individuals over the age of 60 have experienced at least one mini-stroke.
Studies have also correlated the presence of mini-strokes with the symptoms of dementia. An estimated 55 percent of individuals with mild dementia and upwards of 70 percent of individuals with more severe symptoms show evidence of past mini-strokes. This association has led researchers to believe that these mini-strokes may be key contributors to age-related cognitive decline and dementia.
Nedergaard and her colleagues were the first to develop an animal model in which the complex progression and, ultimately, the cognitive impact of mini-strokes could be observed. Her team found that, in most instances, these strokes result in a prolonged period of damage to the brain.
A small fraction of these microinfarcts unfold in a manner similar to acute strokes; cell death is immediate and the brain quickly seals off the site of the stroke and begins to “digest” the damaged tissue. However, the researchers also identified a second and far more common form of mini-stroke – which they labeled incomplete lesions – where the cell death can drag on for several weeks.
“In most microinfarcts the injury is incomplete,” said Nedergaard. “There is no scar tissue to separate the stroke site from the rest of the brain and the cells that would normally support the neurons may not function properly. As a result, the neurons at the site continue to slowly die like a smoldering fire. This suggests that, unlike acute ischemic strokes where the cell death occurs in the first 24 hours, there is a longer period in which we can medically intervene and stop the neuronal death that results from mini-strokes.”
The researchers then attempted to determine the cognitive impact of microinfarcts. Mice who were victims of mini-strokes underwent a series of experiments during which they had to recall objects or respond to certain audio cues.
The researchers observed that the mice with mini-strokes were far more likely to fail these tasks – suggesting neurological impairment – compared to healthy mice.
Are you allergic to peanuts and worried there might be some in that cookie? Now you can find out using a rather unlikely source: your cell phone.
A team of researchers from the UCLA Henry Samueli School of Engineering and Applied Science has developed a lightweight device called the iTube, which attaches to a common cell phone to detect allergens in food samples.
The iTube attachment uses the cell phone’s built-in camera, along with an accompanying smart-phone application that runs a test with the same high level of sensitivity a laboratory would.
Food allergies are an emerging public concern, affecting as many as 8 percent of young children and 2 percent of adults. Allergic reactions can be severe and even life-threatening.
And while consumer-protection laws regulate the labeling of ingredients in pre-packaged foods, cross-contaminations can still occur during processing, manufacturing and transportation.
Although several products that detect allergens in foods are currently available, they are complex and require bulky equipment, making them ill-suited for use in public settings, according to the UCLA researchers.
The iTube was developed to address these issues, said Aydogan Ozcan, leader of the research team and a UCLA associate professor of electrical engineering and bioengineering. Weighing less than two ounces, the attachment analyzes a test tube–based allergen-concentration test known as a colorimetric assay.
To test for allergens, food samples are initially ground up and mixed in a test tube with hot water and an extraction solvent; this mixture is allowed to set for several minutes.
Then, following a step-by-step procedure, the prepared sample is mixed with a series of other reactive testing liquids. The entire preparation takes roughly 20 minutes.
When the sample is ready, it is measured optically for allergen concentration through the iTube platform, using the cell phone’s camera and a smart application running on the phone.
The kit digitally converts raw images from the cell-phone camera into concentration measurements detected in the food samples. And beyond just a “yes” or “no” answer as to whether allergens are present, the test can also quantify how much of an allergen is in a sample, in parts per million.
The iTube platform can test for a variety of allergens, including peanuts, almonds, eggs, gluten and hazelnuts, Ozcan said.
The UCLA team successfully tested the iTube using commercially available cookies, analyzing the samples to determine if they had any harmful amount of peanuts, a potential allergen. Their research was recently published online in the peer-reviewed journal Lab on a Chip and will be featured in a forthcoming print issue of the journal.
Other authors of the research included graduate student and lead author Ahmet F. Coskun and undergraduate students Justin Wong, Delaram Khodadadi, Richie Nagi and Andrew Tey, all of whom are members of the Ozcan BioPhotonics Laboratory at UCLA. Ozcan is also a member of the California NanoSystems Institute at UCLA.
“We envision that this cell phone–based allergen testing platform could be very valuable, especially for parents, as well as for schools, restaurants and other public settings,” Ozcan said. “Once successfully deployed in these settings, the big amount of data – as a function of both location and time – that this platform will continuously generate would indeed be priceless for consumers, food manufacturers, policymakers and researchers, among others.”
Allergen-testing results of various food products, tagged with a time and location stamp, can be uploaded directly from cell phones to iTube servers to create a personalized testing archive, which could provide additional resources for allergic individuals around the world.
A statistical allergy database, coupled with geographic information, could be useful for future food-related policies – for example in restaurants, food production and for consumer protection, the researchers said.