April 11th, 2014
11:46 AM ET
Here's a roundup of five medical studies published this week that might give you new insights into your health, mind and body. Remember, correlation is not causation – so if a study finds a connection between two things, it doesn't mean that one causes the other.
Germophobes beware: Coughs and sneezes create floating clouds
The next time you hear an "achoo!" nearby, shield yourself. A new study shows people blow out gas clouds when they sneeze or cough - and these clouds propel germs further than previously thought.
Scientists at MIT studied how coughs and sneezes move in slow motion using high-speed imaging, in addition to mathematical modeling techniques and simulations. They found that coughs and sneezes have two phases: A quick, jet-like propulsion of droplets, and then a "puff" in which the droplets are suspended in a gas cloud.
When the researchers analyzed the trajectory of the expelled particles, they found that relatively large droplets in the clouds - measuring 100 micrometers in diameter - moved five times further than previous studies had shown. The smaller ones, 10 micrometers across, traveled 200 times farther.
So stop the spread of disease by covering your coughs and sneezes.
Fathers' obesity may be related to children's autism
As scientists continue to explore the potential causes of autism, a question has been raised about paternal obesity.
Researchers looked at a large sample of 92,909 children from the Norwegian Mother and Child Cohort Study. The children were between 4 and 13 years old.
Although a mother's weight was only weakly linked with autism in her child, an obese father was associated with a significant increase in risk. Children of obese fathers had a 0.27% likelihood of an autistic disorder, compared to 0.14% for children whose fathers were at a normal weight.
The general risk of an obese father having a child with autism is still small, study authors noted, but the association is worth further study.
"It would definitely be beneficial to replicate our analyses in population studies from other countries," lead researcher Dr. Pal Suren, of the Norwegian Institute of Public Health in Oslo, told HealthDay News.
Exercise may help older women’s brains
Mild cognitive impairment is a condition affecting memory and thinking that is a risk factor for Alzheimer's disease and dementia. We don't know how to prevent or cure MCI, but there is some indication that exercise may help.
A new study looked at 86 women between the ages of 70 and 80 who had probable mild cognitive impairment. The women were randomly assigned to aerobic exercise, resistance training, or balance and tone training (the control group) for 26 weeks. Researchers measured the volume of the hippocampus, a brain structure involved in memory, in participants before and after the interventions.
Those who had done aerobic exercise showed bigger hippocampal volume after the intervention, compared to the group that did balance and tone. Those who did resistance training did not show the benefit.
Strangely, those who had larger hippocampal volume also tended to score worse on a verbal learning test. This was a small study and more research is needed to explain the findings.
Cells involved in touch identified
Scientists have uncovered how cells that lie under the surface of your skin allow you to perceive details and textures. These cells are called Merkel cells.
“These experiments are the first direct proof that Merkel cells can encode touch into neural signals that transmit information to the brain about the objects in the world around us,” researcher Ellen Lumpkin said in a statement.
The work could have implications for understanding conditions in which touch sensitivity is lost. Sensitivity also declines with normal aging; at the same time, Merkel cells start disappearing in people in their early 20s.
“It’s an exciting time in our field because there are still big questions to answer, and the tools of modern neuroscience give us a way to tackle them,” Lumpkin said.
Junk food may bring on laziness - in rats
Poor eating habits may not only expand your waistline, but also make you less motivated, a new study suggests.
Researchers fed some rats a low-fat diet that was high in simple sugars and refined flour, and others a healthier diet. All rats learned that they would be able to get a bit of sugar water as a reward for pressing a lever. The number of lever presses required to access to the reward increased during the experiment.
Eventually both sets of rats tired of this exercise, but junk-food rats gave up a lot sooner than the ones who had a healthy diet. Both groups seemed to have similar energy levels, so researchers believe there's something happening in the brains of the ones eating poorly to explain the behavior difference. More research is required to find out if that's true.
Note that this research was in rats, so we don't know how it will apply to humans. Still, lead author Aaron Blaisdell told the LA Times: "Rats are a great animal model for humans because there is so much overlap in the systems that regulate appetite and metabolism."
About this blog
Get a behind-the-scenes look at the latest stories from CNN Chief Medical Correspondent, Dr. Sanjay Gupta, Senior Medical Correspondent Elizabeth Cohen and the CNN Medical Unit producers. They'll share news and views on health and medical trends - info that will help you take better care of yourself and the people you love.