Skip to content

Author: Sima

Published on

Research on a burning question for middle-aged men: how to control the belly fat that comes with aging? From Science Daily:

Weight training appears key to controlling belly fat

Healthy men who did 20 minutes of daily weight training had less of an increase in age-related abdominal fat compared with men who spent the same amount of time doing aerobic activities, according to a new study. Combining weight training and aerobic activity led to the most optimal results. Aerobic exercise by itself was associated with less weight gain compared with weight training.

"Because aging is associated with sarcopenia, the loss of skeletal muscle mass, relying on body weight alone is insufficient for the study of healthy aging," said lead author Rania Mekary, a researcher in HSPH's Department of Nutrition. "Measuring waist circumference is a better indicator of healthy body composition among older adults. Engaging in resistance training or, ideally, combining it with aerobic exercise could help older adults lessen abdominal fat while increasing or preserving muscle mass."

The new study was long-term with a large sample of healthy men with a wide range of BMI (body mass index). Mekary and colleagues studied the physical activity, waist circumference (in centimeters (cm)), and body weight of 10,500 healthy U.S. men aged 40 and over participating in the Health Professionals Follow-up Study between 1996 and 2008.

Their analysis included a comparison of changes in participants' activity levels over the 12-year period to see which activities had the most effect on the men's waistlines. Those who increased the amount of time spent in weight training by 20 minutes a day had less gain in their waistline (-0.67 cm) compared with men who similarly increased the amount of time they spent on moderate-to-vigorous aerobic exercise (-0.33 cm), and yard work or stair climbing (-0.16 cm). Those who increased their sedentary behaviors, such as TV watching, had a larger gain in their waistline.

Published on

Once again air pollution is linked to health problems, this time exposure during pregnancy is linked to congenital malformations (what are commonly called birth defects). From Science Daily:

Smoke signals: New evidence links air pollution to congenital defects

The health effects of air pollution are a major concern for urban populations all over the world. A new study provides new evidence linking high exposure to air pollution to an increased risk of congenital malformations. Children, the elderly, and people with impaired respiratory systems (such as asthmatics) tend to be especially sensitive to the impact of exposure to ozone, nitrogen dioxide, sulphur dioxide, and particulate matter.

A recent study by Tel Aviv University researchers provides new evidence linking high exposure to air pollution to an increased risk of congenital malformations. The nationwide study is the first to assess the association between different modes of conception-assisted reproductive technology (ART) versus spontaneous conception (SC) -- and the risks of exposure to air pollution to each.

"Our results suggest that exposure to higher levels of air pollution during pregnancy is associated with various adverse pregnancy outcomes," said Prof. Lerner-Geva. "While our study mainly followed SC infants, we also had the opportunity to assess a small sample of pregnancies that were conceived through ART, and observed a higher impact of air pollution -- particularly with regard to ozone exposure. This is clearly a uniquely susceptible population that should be further explored."

For the study, funded by the Environmental Health Fund (EHF), the research team analyzed data on 216,730 born in Israel between 1997 and 2004. Air pollution data, including, levels of sulfur dioxide (SO2), particulate matter (PM10), nitrogen oxides (NOx), and ozone (O3) were obtained from air monitoring stations for the study period. Using a geographic information system, exposure to air pollution during both the first trimester and the entire pregnancy was assessed for each woman according to her place of residence.

The researchers found that exposure to PM10 and NOX pollutants throughout full-term pregnancies were associated with an increased risk of congenital malformations, with specific defects evident in the circulatory system (from PM10 and NOX exposure) and genital organs (from NOX exposure). They also discovered that exposure to SO2 and O3 in ART pregnancies were associated, although not significantly, with a higher risk of congenital defects.

Published on

The bottom line: for better health be physically active at least is 2.5 hours of week. Note that HbA1c is a measure of glycated hemoglobin which identifies average plasma glucose concentration (and lower is better). From Medscape:

Exercise Tied to Cardiometabolic Markers in Clinic Patients 

Healthy, middle-aged outpatients who were physically active for at least 2.5 hours a week had better blood pressure and blood glucose levels than their sedentary peers in a large cross-sectional study in California. The differences were especially notable in women, in this study published online December 18, 2014 in Preventing Chronic Disease.

Men and women who were consistently physically active—defined as performing moderate to vigorous activity such as brisk walking for at least 150 minutes a week, as self-reported at all three outpatient visits in a 33-month period—had lower diastolic blood pressure, glucose, and HbA1c levels than patients not reporting exercise at that level.

Moreover, on a population level, the observed associations "were comparable to those needed to reduce the risk of coronary heart disease, stroke, and diabetes," they continue. "If healthcare providers would routinely assess the physical activity of their patients and refer those who are physically inactive to effective physical-activity programs, it may reduce the burden of future chronic diseases."

They analyzed electronic records from over 622,000 adults covered by Kaiser Permanente Southern California healthcare insurance who made at least three clinic visits between April 2010 and December 2012 and were not being treated for diabetes or hypertension.

The consistently active women had systolic and diastolic blood pressures that were 4.60-mm-Hg lower and 3.28-mm-Hg lower, respectively, than inactive women. Perhaps surprisingly, somewhat active women had slightly better blood-pressure values than the more active group.

Published on

Two studies finding various forms of air pollution having effects on the developing fetus - the first one (fine particulate air pollution) to autism, and the second (outgassing of new flooring) to later breathing problems.

From Medical Xpress: Fine particulate air pollution linked with increased autism risk

Women exposed to high levels of fine particulate matter specifically during pregnancy—particularly during the third trimester—may face up to twice the risk of having a child with autism than mothers living in areas with low particulate matter, according to a new study from Harvard School of Public Health (HSPH). The greater the exposure, the greater the risk, researchers found. It was the first U.S.-wide study exploring the link between airborne particulate matter and autism.

"Our data add additional important support to the hypothesis that maternal exposure to air pollution contributes to the risk of autism spectrum disorders," said Marc Weisskopf, associate professor of environmental and occupational epidemiology and senior author of the study.... Prior studies have suggested that, in addition to genetics, exposure to airborne environmental contaminants, particularly during pregnancy and early life, may affect risk of autism. This study focused specifically on the pregnancy period.

The study population included offspring of participants living in all 50 states in Nurses' Health Study II, a cohort of more than 116,000 female U.S. nurses begun in 1989. The researchers collected data on where participants lived during their pregnancies as well as data from the U.S. Environmental Protection Agency and other sources on levels of fine particulate matter air pollution (PM2.5)—particles 2.5 microns in diameter or smaller—in locations across the U.S. The researchers identified 245 children who were diagnosed with autism spectrum disorder (ASD) and a control group of 1,522 children without ASD during the time period studied.

Exposure to PM2.5 was significantly associated with autism during pregnancy, but not before or after, the study found. And during the pregnancy, the third trimester specifically was significantly associated with an increased risk. Little association was found between air pollution from larger-sized particles (PM10-2.5) and autism.

From Science Daily: New floor covering can lead to breathing problems in babies

New flooring in the living environment of pregnant women significantly increases the risk of infants to suffer from respiratory diseases in their first year of life. This is the result of a study that demonstrates that exposure to volatile organic compounds in the months before and after birth induces breathing problems in early childhood. The scientists therefore recommend that redecoration should be avoided during pregnancy or in the first year of children’s life.

The observed health risks are caused by increased concentrations of volatile organic compounds (in short: VOCs), such as styrene or ethylbenzene, which escape from new flooring and are then absorbed through the respiratory air. "We therefore do not recommend that laminate, carpet or floor coverings be laid in the homes of pregnant women. Although the concentrations of these volatile chemicals are lower if no adhesive is used when installing the flooring, even then the concentrations are still high enough to significantly increase the risk of infants suffering from respiratory complaints in their first few months," explains Dr. Ulrich Franck from the UFZ. 

Earlier studies from Leipzig had already shown that chemicals from home renovations lead to changes in the immune system of new-born children.... According to our results, exposure to these volatile chemical compounds seems to be more critical in pregnancy than in the first year of a child's life," concludes Dr. Irina Lehmann from the UFZ, who is in charge of the LINA study on lifestyle and environmental factors and their influence on the risk of allergies in newborn babies. An analysis of the data showed that renovations after the birth of a child had a much lower impact on respiratory problems than during pregnancy.

Published on

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.

Published on

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.

Published on

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.

Published on

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.

Published on

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.

Published on

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.”