After a hike through the woods, people showed a decrease in self-reported rumination — or repetitive negative thought — and lower brain activity in areas linked to rumination.

Story highlights

A small study suggests a nature experience might positively influence mental well being.

People using chiropractic and acupuncture treatments don't always tell their primary care doc

Children from lower and high income families have brain structure differences

CNN  — 

Here’s the fascinating research we’re watching from around the world. CNN Health & Wellness has gauged these studies’ potential impact on our health.

Take a walk in the woods, for your brain

No need to wait until your next vacation to recharge – improving your brain chemistry could be as easy as taking a nature walk. In a study published in the Proceedings of the National Academy of Sciences journal, researchers randomly assigned 38 people to take a 90-minute walk in either a natural or urban setting near Stanford, California.

Before and after their treks, participants were evaluated by a questionnaire and brain scan, measuring activity in the prefrontal cortex. Afterward, the nature walkers showed a decrease in self-reported rumination — or repetitive negative thought — and lower brain activity in areas linked to rumination. While the study was small, it suggests a nature experience might positively influence mental well-being.

Patients aren’t honest with docs about alternative treatments

It’s not unusual for people dealing with chronic pain to seek alternative treatments. In a recent study published in the American Journal of Managed Care, nearly 60% of people surveyed reported receiving either acupuncture, chiropractic care, or both, but many patients didn’t tell their primary care doctor about the alternative treatments. In fact, 35% of acupuncture users and 42% of chiropractor users said these treatments weren’t brought up during regular doctor visits. Disclosing this care with primary care physicians can help doctors give their patients the most appropriate advice, according to the researchers.

Brain structure different among poor children

Children from lower-income families have a different brain structure than their more affluent counterparts, a new study published in JAMA Pediatrics reports. Researchers used MRI to scan the brains of about 400 kids and teenagers to access their brain development and found children from families with incomes lower than 1.5 times the poverty level had gray matter – the brain portions where important body functions are processed – that was 4% lower than the developmental normal. The gray matter difference was even worse in kids below the federal poverty line, with about 9% lower gray matter volume than normal.

The study authors say this brain structure difference helps explains why kids in poverty perform worse in school. To help kids in these populations, researchers urge officials to allocate resources to lower-income families.

Fetal deaths surpass infant deaths

The latest data from the National Center for Health Statistics is out, and for the first time, fetal deaths surpass infant deaths. Commonly called stillbirth, fetal deaths included the intrauterine death of a fetus 20 weeks old prior to delivery. 23,595 fetal deaths occurred in 2013 –or 5.96 fetal deaths per 1,000 live births. In 2012, the rate was 6.05 fetal deaths per 1,000 live births. The lack of decline in fetal mortality in

recent years, coupled with the decline in infant mortality, means more fetal deaths than infant deaths occurred in the United States. The difference is not statistically significant, says the study, but race and age were factors.

Fetal mortality is more than twice as high in non-Hispanic black women (10.53) as non-Hispanic white (4.88) or Asian or Pacific Islander (4.68) women. Fetal mortality was also high in teens under age 15. According to the study, socioeconomic conditions as well as teens’ physical immaturity may play a role in those high numbers.

40 years later, Vietnam vets still have PTSD

The effects of the Vietnam War are not over for many veterans, according to a new study published in JAMA Psychiatry. Estimates suggest that 271,000 Vietnam war-zone veterans have post-traumatic stress disorder (PTSD), characterized by symptoms such as paranoia, inability to sleep and mood changes. More than one-third of veterans also report having major depressive disorder.

This study – the National Vietnam Veterans Longitudinal Study (NVVLS) – is the first follow-up assessing Vietnam veterans since a government study from the 1980s. 1,450 veterans from the original study participated in at least one phase of research from this new study, which included completing questionnaires and phone interviews.

“The NVVLS thus fills a critical gap in our understanding of how military service 40 or more years earlier affects adjustment in later life,” researchers note. These findings also have implications about future challenges for veterans of more recent wars in Iraq and Afghanistan.

Women’s mental ability declines twice as fast as men’s

Women on the path to dementia decline mentally twice as fast as men, according to a new study. Researchers from Duke University Medical Center examined about 400 participants with mild cognitive impairment, a less serious form of dementia. Participants were mostly in their 70s, and researchers followed them for eight years. According to study author Katherine Lin, men and women at risk for Alzheimer’s disease might experience different challenges, and future research should explore the genetic or environmental factors contributing to this difference.