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Author: Sima

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Try standing on one leg with your eyes open, Can you do it for longer than 20 seconds? From Science Daily:

Ability to balance on one leg may reflect brain health, stroke risk

Struggling to stand on one leg for less than 20 seconds was linked to an increased risk for stroke, small blood vessel damage in the brain, and reduced cognitive function in otherwise healthy people, a study has shown. One-legged standing time may be a simple test used to measure early signs of abnormalities in the brain associated with cognitive decline, cerebral small vessel disease and stroke.

The study consisted of 841 women and 546 men, average age of 67. To measure one-leg standing time, participants stood with their eyes open and raised one leg. The maximum time for keeping the leg raised was 60 seconds. Participants performed this examination twice and the better of the two times was used in the study analysis. Cerebral small vessel disease was evaluated using brain magnetic resonance imaging.

Researchers found that the inability to balance on one leg for longer than 20 seconds was associated with cerebral small vessel disease, namely small infarctions without symptoms such as lacunar infarction and microbleeds. They noted that: 34.5 percent of those with more than two lacunar infarction lesions had trouble balancing, 16 percent of those with one lacunar infarction lesion had trouble balancing, 30 percent of those with more than two microbleed lesions had trouble balancing, 15.3 percent one microbleed lesion had trouble balancing.

Overall, those with cerebral diseases were older, had high blood pressure and had thicker carotid arteries than those who did not have cerebral small vessel disease. However, after adjustment for these covariates, people with more microbleeds and lacunar infarctions in the brain had shorter one-legged standing times. Short one-legged standing times were also independently linked with lower cognitive scores.

Small vessel disease occurs due to microangiopathy of arterioles in the brain, making these arteries less flexible, which can interfere with blood flow. Small vessel disease typically increases with age. Loss of motor coordination, including balance, as well as cognitive impairment has been suggested to represent subclinical brain damage. Tabara and colleagues also found a strong link between struggling to stand on one leg and increased age, with marked shorter one-leg standing time in patients age 60 and over.

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Interesting, but it is currently unknown why this occurs. From Science Daily:

People with blood groups A, B and AB at higher risk of type 2 diabetes than group O

A study of more than 80,000 women has uncovered different risks of developing type 2 diabetes associated with different blood groups, with the biggest difference a 35 percent increased risk of type 2 diabetes found in those with group B, Rhesus factor positive blood compared with the universal donor group O, Rhesus factor negative.

While previous studies have investigated the links between blood group and stroke (finding an increased risk for group AB versus group O), those on blood groups and their link with diabetes have been small and thus underpowered and unable to provide definitive results. In this new research, Fagherazzi and colleagues took data from 82,104 women from the large prospective E3N cohort in France followed between 1990 and 2008. The objective of this study was to evaluate the relationship of ABO blood type (A, B, AB and O), Rhesus factor (positive or negative) and a combination of the two (ABO×Rhesus) with type 2 diabetes (T2D).

The results showed that, compared with women with group O blood, women with group A were 10% more likely to develop T2D, and those with group B 21% more likely (both statistically significant). The AB group was 17% more likely to develop T2D, but this result was not statistically significant. When looking solely at R+ versus R- women, neither group was at increased risk of developing T2D compared with the other.

The authors then combined ABO group and Rhesus group and compared each possible combination with O negative (O-), which is known as the universal donor group because since it contains none of the A. B, or Rhesus antigens, blood from people in this group can be successfully donated to any other group (without rejection).Compared with O- women, the highest increased risk of developing T2D was found in B+ (35% increased risk), followed by AB+ (26%), A- (22%), A+ (17%). The results for O-, B-, and AB- groups were not statistically significant.

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This is part 3 of a 4 part series by Katherine H.  Courage. It's a good description of what goes on at a lab that does state of the art genetic analysis of microbes making up the human microbiome (the community of microbes that are part of us). These analyses (especially of fecal samples) are done for the American Gut Project which anyone can participate in (go to americangut.org for more information about this crowd-sourced project). From NPR News:

Behind The Scenes At The Lab That Fingerprints Microbiomes

The gut microbiome may soon reveal important answers to questions about our health. But those answers aren't yet easy to spot or quick to obtain.The week after I mailed off my family's microbial samples to be analyzed for the American Gut Project, I followed them down the road from my home to the University of Colorado, Boulder. They — and I — came to a massive, futuristic science complex there. Daniel McDonald, a doctoral student studying quantitative biology and computer science, greeted me and brought me up to the workspace, where rows of researchers worked on computers outside of a small lab room.

 Inside the lab, where the sealed samples were received, a lone technician sorted through new arrivals, snipping off intentionally fouled swab heads. Each sample kit contains two cotton swabs. One swab head goes directly to the freezers for safe keeping (in case the first sample doesn't provide clear results or for the near future, when sequencing technology is better). The other gets dissolved in a solution so its contents can be carefully analyzed for genetic traces of microbes.

Just down the hall is one of the lab's boxed-in robots, charged with loading samples into individual wells on a tray that will later get fed through the sequencers. The task might seem mundane for such a high-tech tool, but the bot works much faster and more accurately than a human lab helper can.

Still, this is where some of the work can be slow going. The team must wait for hundreds of fecal, oral or skin samples to process together. A single sample could go through the full analysis process in a week, but it would cost thousands of dollars, Rob Knight, a co-founder of the project, estimates, rather than the $99 members of the study pay. For the project to be cost-effective for participants, the research team must wait to collect large groups of samples and analyze them together.

This robot in the Knight lab can handle many samples simultaneously. To avoid contamination, the lab only processes the same kind of samples at the same time together (fecal with fecal, skin with skin and pet with pet). Credit: Katherine Harmon Courage for NPR

Most of the human microbiome is uncharted territory because many of the microbes that live in our guts can't be grown easily in the lab. Oxygen is toxic to them. Using the tools of genetics to probe the human microbiome has already uncovered many new species, each of which has a full genome of its own.

We're still far from getting quick full genomes from each of the inhabitants. Instead, scientists rely on microbes' telltale 16S gene, a marker that helps identify bacteria from one another. Finding the base pairs —the As, Cs, Ts and Gs — for this gene can help scientists sort out which species are present.This is where a nifty machine that performs PCR (polymerase chain reaction) comes in. It makes thousands of copies of the genetic material so that the pattern in the genetic code is easier for the sequencers to find.

These sequencers are located on a lower floor of the building in a room that smells a bit like a photography darkroom. Here, each tray of samples takes about 20 hours to process. On a nearby screen, I see a readout of bright genetic points against a dark background, which looks more like a telescopic image of a night sky than the code to microbial life from someone's stomach.

Deciphering this code is just the first step in understanding what is going on in the jungle of your gut. Like many things in biology, it is not just the organisms present — plants, animals or bacteria — but how these organisms interact that is important.

The dynamics among the characters make a play — not just the cast.For instance, research has shown that many of us are walking around with E. coli in our guts but show no ill effects. In much the same way that weeds or hungry insects might not harm a thriving field or forest but could wreak havoc on an unbalanced ecosystem, we depend on a healthful mix of good microbes to keep the bad ones from taking over.

And to see what our intestinal forests are composed of, we need more than just a few points of genetic data. So after the sequencer spits out the genetic code it has assembled, the data needs to get turned back into intelligible (or at least semi-intelligible) patterns.

To do this, our microbial code gets run through a supercomputer nicknamed Compy, which hums safely in the building's basement beyond two sets of doors and a sticky, dust-collecting floor mat. When I meet her, Compy is busy crunching away on base pairs with her 1,000 processors...The research group is testing using new software to analyze and display these many layers of information.

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Avoid unnecessary ultrasounds because there is an effect on the fetus, even if it's just a temporary effect. Medical associations warn against getting ultrasounds during pregnancy without a real reason. From The Atlantic:

FDA Warning: Stay Away From 'Keepsake' Ultrasounds

The medically unnecessary scans peddled by businesses—often set up in malls and administered by people with no healthcare training—may pose a health risk to both fetus and mother.

Despite repeated warnings by the Food and Drug Administration over the years, commercial ultrasound businesses—often set up in shopping malls and run by untrained technicians—continue to offer their services to expectant parents. And consumers, despite the FDA’s pleas, continue to pay for them, shelling out hundreds of dollars for photos or videos of their developing fetus (and fueling a thriving Etsy niche, where ultrasound images can be turned into ultrasound cufflinks, pillows, cake toppers, and truly unsettling night lights.)

Earlier today, the agency issued the latest of a long line of alerts against non-medical ultrasounds and heartbeat monitors, reminding consumers that “both are prescription devices designed to be used by trained healthcare professionals … only when there is a medical need, based on a prescription,” and that “the FDA strongly discourages their use for creating fetal keepsake images and videos.”

Ultrasounds, which use sound waves to produce an image, are considered a safe and valuable diagnostic tool during pregnancy, when they can provide information on the fetus' age, sex, and overall health. But “ultrasound can heat tissues slightly, and in some cases, it can also produce very small bubbles in some tissues,” FDA biomedical engineer Shahram Vaezy said in the alert. Because the long-term effects of the heating are unknown, these gratuitous ultrasounds, which provide no medical information, may pose a small but unecessary risk to both mother and fetus—compounded by the fact that their duration, and the qualifications of the people administering them, aren't subject to regulation.... (Researchers have recently focused on ultrasound as a possible method of male contraception, noting that it dramatically lowers sperm count when applied to the testicles.)

Several medical groups have also come out against commercial ultrasounds over the years, including the American Medical Association, the American College of Obstetricians and Gynecologists, the American College of Radiology, the American Institute of Ultrasound in Medicine, and the American Pregnancy Association.

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Feeling younger than your chronological age is good! From Science Daily:

Feeling younger than actual age meant lower early death rate for older people, study finds

Turns out, feeling younger than your actual age might be good for you. Older people who felt three or more years younger than their chronological age had a lower death rate compared with those who felt their age or who felt more than one year older than their actual age, researchers found.

Self-perceived age can reflect assessments of health, physical limitation and well-being in later life, and many older people feel younger than their actual age, according background information in the report. Authors Isla Rippon, M.Sc., and Andrew Steptoe, D.Sc., of the University College London, examined the relationship between self-perceived age and mortality.

The authors used data from a study on aging and included 6,489 individuals, whose average chronological age was 65.8 years but whose average self-perceived age was 56.8 years. Most of the adults (69.6 percent) felt three or more years younger than their actual age, while 25.6 percent had a self-perceived age close to their real age and 4.8 percent felt more than a year older than their chronological age.

Mortality rates during an average follow-up of 99 months were 14.3 percent in adults who felt younger, 18.5 percent in those who felt about their actual age and 24.6 percent in those adults who felt older, according to the study results. The relationship between self-perceived age and cardiovascular death was strong but there was no association between self-perceived age and cancer death.

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More research is needed, but looking at the "microbial signature" of a criminal definitely has potential. From Science (American Association for the Advancement of Science):

Bacteria on pubic hair could be used to identify rapists

When it comes to identifying a rapist, one of the main pieces of evidence police analyze are pubic hairs found at the crime scene. But most of these hairs are missing their roots and thus don’t harbor enough DNA for a proper match. Now, a new study suggests there may be a better way to finger the criminal: Look at the bacteria he left behind.

In addition to hair, police have relied heavily on semen samples to identify potential rapists, notes Silvana Tridico, a forensic biologist at Murdoch University in Perth, Australia. But criminals have gotten wise to genetic testing, she says, and are increasingly wearing condoms, which they take with them after assaults. She hoped to find a way to get around this problem by comparing bacteria that are present in the pubic hairs of the victim and suspects and then creating a microbial fingerprint that could nail the culprit.

Tridico and colleagues asked seven individuals—two of whom were living together—to collect their scalp and pubic hair for 5 months. The researchers then analyzed these samples in the lab, looking for bacterial populations present after 2 and 5 months. The scalp hair showed that 50 different varieties of microbes in males and 55 in females are found in this part of the body, but many of the microbes that were found were not specific to the individual carrying them. The pubic hair bacteria, however, turned out to be more distinct; in addition, each individual’s “personal” pubic bacteria stayed roughly the same during the 5 months. More kinds of bacteria live in these hairs: approximately 73 in males and 76 in females. A larger combination of different bacteria means it is more likely for people to carry a unique microbial signature on them, Tridico says.

Although each person’s pubic hair bacteria were distinct, the couple who were living together had greater similarity of bacteria on their pubic hairs at 5 months than detected after 2 months. The couple later revealed that they had sexual intercourse 18 hours before the collection of their hairs, the researchers report online today in Investigative Genetics.

Because the study included only one couple who were living together and only seven participants in total, the results are “far from conclusive,” Tridico cautions. However, the findings are encouraging, she says, and show that “it may be possible to differentiate between individuals on the basis of their bacteria.”

Max Houck, a lead forensic scientist at Consolidated Forensic Laboratory, a government organization based in Washington, D.C., agrees. But he also points out that it might be more difficult to use this method if there has been previous sexual contact between the victim and the subject, in the case of abusive ex-spouses, for example. “Human pubic hairs could be of potentially significant use in cases where the victim and subject have not had previous sexual contact.”

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This was so ridiculous that I couldn't resist - Male idiot Theory! More examples are in the original study published in the BMJ or British Medical Journal (e,g., the man who shot himself in the head with a “spy pen” weapon to show his friend that it was real). Please note: every Christmas the BMJ publishes research whose premises are a bit off kilter. From Science Daily:

Study supports the theory that men are idiots

Sex differences in risk seeking behaviour, emergency hospital admissions, and mortality are well documented. Males are more likely to be admitted to an emergency department after accidental injuries, more likely to be admitted with a sporting injury, and more likely to be involved in a fatal road traffic collision.

However, little is known about sex differences in idiotic risk-taking behaviour. So researchers in north east England decided to test "male idiot theory" (MIT) that many of the differences in risk seeking behaviour may be explained by the observation that men are idiots and idiots do stupid things.

They reviewed data on idiotic behaviours demonstrated by winners of the Darwin Award over a 20 year period (1995 to 2014), noting the sex of the winner. To qualify, nominees must improve the gene pool by eliminating themselves from the human race using astonishingly stupid methods.

Worthy candidates include a man stealing a ride home by hitching a shopping trolley to the back of a train, only to be dragged two miles to his death before the train was able to stop; and the terrorist who posted a letter bomb with insufficient postage stamps and who, on its return, unthinkingly opened his own letter.

Of these 318 cases, 282 Darwin Awards were awarded to males, and just 36 awards given to females. Males thus made up 88.7% of Darwin Award winners, and this sex difference is highly statistically significant, say the authors. This finding is entirely consistent with male idiot theory (MIT) and supports the hypothesis that men are idiots and idiots do stupid things.

However, this study has limitations, add the authors. For example, women may be more likely to nominate men for a Darwin Award or the sex difference may reflect differences in alcohol use between men and women. Despite this, it is puzzling that males are willing to take such unnecessary risks -- simply as a rite of passage, in pursuit of male social esteem, or solely in exchange for "bragging rights," say the authors.

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Bottom line: view the games as fun and a way to pass some time, but nothing more. From the Atlantic:

The Myth of the Brain Game

Over the past decade, digital brain-training games have emerged as the newest way to sharpen memory skills. They’re often touted as having a wide range of benefits, from helping people remember names and childhood stories to possibly staving off dementia and Alzheimer's disease.

In October, Stanford University’s Center for Longevity and the Max Planck Institute for Human Development in Berlin asked a group of more than 70 neuroscientists, cognitive psychologists, and academics to share their views on these games. “There is little evidence that playing brain games improves underlying broad cognitive abilities, or that it enables one to better navigate a complex realm of everyday life,” the group wrote in a consensus report.

The validity of brain games has been a point of debate ever since the first iterations of them launched in the early 2000s. What’s notable about the Stanford/Max Planck report is its deliberation and scope, offering insight collected over the course of a year from experts based at 40 institutions in six different countries.

The report questions the “pernicious,” “exaggerated,” and “misleading” claims made by brain-game manufacturers and stresses that wide-reaching positive results are “elusive.” The signatories don’t call out any specific types of brain-training software, but their language is often damning. “Many scientists cringe at exuberant advertisements claiming improvements in the speed and efficiency of cognitive processing and dramatic gains in ‘intelligence,’” they write.

Brain training is projected to be a $3 billion industry by 2015. Its target demographic is vast, from kids lagging behind in school to seniors who’d love to be able to remember things more efficiently. Most people, in fact, would appreciate the opportunity to feel like they’re getting the most out of their brains, and when a particular product is advertised as being both educational and backed by science, it can be hard to resist.

That there’s a need for scientists to issue a signed letter like this one only goes to show how popular brain games are and to what extent experts feel the public may have been seduced by the promise that they’re endorsed by science. The letter is both a word of caution to the public and the signatories’ way of distancing themselves from the commercial products. 

In 2013, two researchers at the University of Oslo and University College London conducted a meta-analysis of 23 different brain-training studies. What they saw was what every skeptic has seemed to notice. “Memory training programs appear to produce short-term, specific training effects that do not generalize,” they wrote. That is, training with games helped people get better at the games they were playing, but not much else.

Brain games aren’t a complete waste of time. They provide mental stimulation, the kind that doctors advise the elderly to get from crosswords and other mind games. They are fun, engaging, even competitive. They show how we can train the brain to get better at a task with repeated practice. But these are fairly obvious results given what we know about the brain's plasticity. 

All that said, the things that do help shape a healthy brain are the things that have been tried and tested for years. Physical fitness forces more blood to flow into the brain, allowing for more neural connections. So exercise works, as does conventional training in reading and language skills for children with reading-comprehension and oral language difficulties.

Also helpful are curiosity and engagement with the world around us, and the body’s lifelong subconscious effort to keep the brain active. The report's summary is perhaps the biggest indictment of any pop-a-pill brain-game philosophy. “The promise of a magic bullet detracts from the best evidence to date,” they wrote. “Cognitive health in old age reflects the long-term effects of healthy, engaged lifestyles.”

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Children spending time outside (more than 14 hours a week) have lower rates of nearsightedness, even if they spend a lot of time reading. From Science Daily:

Scientists study effects of sunlight to reduce number of nearsighted kids

Kids who spend more time outside are less likely to need glasses for nearsightedness – but scientists don’t know why. Researchers are now looking more closely at physical changes in the eye influenced by outdoor light exposure in the hopes of reducing cases of myopia, which affects one-third of the American population.

Despite what many parents may think, kids who spend a lot of time reading or squinting at tiny electronic screens aren't more likely to become nearsighted than kids who don't. However, that risk is only reduced if the child spends plenty of quality time outside. The "outdoor effect" on nearsightedness, or myopia, is a longstanding observation backed by both scientific and anecdotal evidence. It's so compelling that some nations in Asia, which have among the highest myopia rates in the world, have increased the amount of daily outdoor time for children in the hopes of reducing the need for glasses.

But so far, no one has defined exactly what it is about being outside that seems to offer a protective effect against the condition, which causes distant objects to appear blurry.

"Data suggest that a child who is genetically predisposed to myopia are three times less likely to need glasses if they spend more than 14 hours a week outdoors," says optometrist Donald Mutti, OD, PhD, of The Ohio State University College of Optometry. "But we don't really know what makes outdoor time so special. If we knew, we could change how we approach myopia."

Supported by a pilot grant from Ohio State's Center for Clinical and Translational Science (CCTS), Mutti is now focusing his research on the variables he feels have the most potential: invisible ultraviolet B rays (UVB) and vitamin D, and visible bright light and dopamine."Between the ages of five and nine, a child's eye is still growing. Sometimes this growth causes the distance between the lens and retina to lengthen, leading to nearsightedness," explained Mutti. "We think these different types of outdoor light may help preserve the proper shape and length of the eye during that growth period."

UVB light is invisible to the human eye, but triggers several cellular functions in the body, including the production of vitamin D. Vitamin D is thought to support the function of the smooth muscle tissue found around the lens in the eye. This muscle not only helps focus light on the retina, but may also maintain the proper eye shape and length between the lens and the retina, something that can become distorted during the rapid growth of a child's eye.

Some studies, including one by Mutti, show that people with myopia have lower blood levels of vitamin D -- indicating that they have spent less time outdoors, with possible negative effects on the eye..."We don't know if vitamin D is simply a proxy for measuring outdoor time, or if it is actually exerting a biological effect on how the eye works and develops," said Mutti.

There's another part of sunlight that could help prevent myopia: exposure to visible bright light. Even on a cloudy day, visible light outdoors is at least 10 times brighter than the light indoors.When exposed to outdoor light, specialized cells in the retina help control how big or little the pupil dilates to let more or less light in. The cells connect to others that release dopamine -- an important neurotransmitter in the eye and brain. Previous research suggests that dopamine also slows down the growth of the eye, but there isn't technology currently available that can measure dopamine release in the eye directly.

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Great news for coffee lovers, especially for those drinking 3 to 5 cups daily! From Medical Daily:

Drinking Coffee Can Lower Alzheimer's Risk By 20%, All It Takes Is 3 Cups A Day

As if you weren’t already drinking a lot of coffee, a review of several studies has found drinking three to five cups a day could reduce risk of Alzheimer’s disease by 20 percent.

The research was presented at the 2014 Alzheimer Europe Annual Congress, and found that people who drank coffee regularly — all you lifers out there — were less likely to develop the debilitating disease. Alzheimer’s, perhaps the worst type of dementia, is a progressive disease that works slowly, first making it difficult to remember newly learned things, and later on making it difficult to remember early memories and family member’s faces, while also causing hallucinations. The biggest risk factor for the disease is being over 65 years old.

Roughly 83 percent of American adults drink coffee, according to the National Coffee Association. What many of these Americans don’t know, however, is that inside that cup of Joe is a wealth of polyphenols, which you probably know as antioxidants. These antioxidants — researchers said they’re the same ones found in the Mediterranean diet — prevent the formation of a hallmark of Alzheimer’s disease known as amyloid plaques and neurofibrillary tangles, the study found. They also reduce inflammation and deterioration of brain cells, particularly in the areas of the brain (the hippocampus and cortex) responsible for memory.

Along with prevention of Alzheimer’s, coffee has been linked to a reduced risk of liver cancer and other liver conditions, a lower risk of type 2 diabetes; it prevents eye damage and Parkinson’s disease; and even boosts endurance. But even then, drinking too much isn’t good, either. As the researchers noted, three to five cups is optimal; anything over that, and you might find yourself with some problems.