January 24th, 2014
08:51 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.
Sunlight may lower blood pressure
Going outside and embracing the sun may come with unexpected health benefits, a new study suggests. But don't get so much direct exposure that you risk skin cancer.
Researchers looked at the benefits of radiation from the sun. Volunteers received a dose of ultraviolet-A radiation in a laboratory that was equivalent to being in the sun for 30 minutes in summertime in Southern Europe.
The study authors found that participants' blood pressure decreased, but they're not exactly sure why. It's possible that sunlight mobilizes molecules derived from nitric oxide, "so they travel from skin to blood, where they dilate blood vessels and lower blood pressure," LiveScience reports.
Study authors don't know whether blood pressure would continue dropping with multiple exposures to UVA, or if a person's age, sex or disease would affect the result.
Oldest-known living cancer is '11,000 years old'
Scientists have decoded the genome of a rare sexually-transmitted cancer that's 11,000 years old. It began in one dog and has been spreading in canines over millennia.
The cancer's DNA unveiled the origins of the disease in an ancient dog that was husky-like. That dog would have been medium-sized, with a grey-brown or black-colored straight coat, the BBC reported.
"We do not know why this particular individual gave rise to a transmissible cancer," lead researcher Elizabeth Murchison told the BBC.
"But it is fascinating to look back in time and reconstruct the identity of this ancient dog, whose genome is still alive today in the cells of the cancer that it spawned."
Fish oil may help preserve your brain cells
There's been a lot of back and forth about whether fish oil, and more generally omega-3 fatty acids, are useful tools in fighting dementia. The evidence on this subject has been mixed.
A new study argues in favor of the effectiveness of fatty acids derived from fish.
Researchers looked at omega-3 fatty acid levels in 1,111 women who were participating in the Women's Health Initiative, a larger study. They found a correlation between high levels of omega-3 fatty acids and larger overall brain volume, as well as volume of a structure called the hippocampus, which is important for memory.
It's important to note that brain volume shrinkage is a normal part of aging, Jay Pottala of the University of South Dakota in Sioux Falls and Health Diagnostic Laboratory in Richmond, Virginia, told USA Today.
"This doesn't mean their brains got bigger; it just means their brains didn't atrophy as much," he said.
But MedPage today points out that this study does not actually look at brain atrophy over time, as participants only had their brains scanned once - a serious limitation to the study. There could be other reasons for the correlation - fish oil isn't necessarily causing an effect.
Alzheimer's drugs fail in clinical trials
Alzheimer's disease researchers got some bad news this week, too: Two drugs that were intended to treat the condition failed in clinical trials.
The therapies are monoclonal antibodies, and they are called solanezumab and bapineuzumab. Neither of them were effective in slowing the loss of cognitive function in patients with mild to moderate Alzheimer's disease.
Both of these medications were supposed to promote the removal of beta-amyloid deposits in the brain, the plaques associated with Alzheimer's, according to the Los Angeles Times.
Home birth may be riskier than you think
A new study calls attention to the hazards that come along with choosing to give birth outside a hospital setting.
"Having a home birth may be like not putting your child's car seat belt on," researchers wrote in a study, as cited by NBC News.
The health and well-being of the child may be at risk because if any complications come up during a home birth, there wouldn't be the same kinds of resources to deal with them as in a hospital.
But home births have become more common in the United States, rising by nearly a third from 2004 to 2009, according to the CDC.
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.