What causes asthma? Plus, the best sunscreens for you, how a gene may prevent Alzheimer’s, and more health news

Understanding what causes asthma can help you better manage its causes and triggers.

Whether you, your child or another loved one has asthma, you can feel more in control by knowing your options for reducing asthma symptoms and managing its underlying causes.

Asthma is a chronic condition that causes swelling and inflammation in the airway tissues. This leads to a narrowing of your airways, making it more difficult to breathe, according to the Asthma and Allergy Foundation of America (AAFA).

About 1 in 13 people in the United States have asthma.

In a major change from its longstanding advice, an influential medical panel now recommends that women start mammography screening for breast cancer at age 40.

The new guidance, from the U.S. Preventive Services Task Force, says women at average risk of breast cancer should start having mammograms, every other year, when they turn 40. For years, the recommendation had been to start at age 50 -- though women in their 40s were advised to talk with their doctor and choose what was best for them.

The change, published as a draft recommendation on May 9, brings the task force guidance more in line with what other medical groups advise.

While newborns are only screened for about 60 treatable conditions, there are hundreds of genetic disorders that have targeted treatments.

Now, a national survey of experts in rare diseases found the vast majority support DNA sequencing in healthy newborns.

Testing, surveillance and treatment options exist for over 600 genetic conditions. This includes a growing number of devastating childhood diseases that now have targeted treatments that sometimes offer permanent cures.

“Early identification of infants who are at risk for genetic disorders can be lifesaving and screening has the potential to improve health care disparities for affected children,” said lead author Dr. Nina Gold, a medical geneticist at Massachusetts General Hospital for Children, in Boston.

The influence of Neanderthals is evident right in the center of the faces of modern humans.

New research finds that genetic material inherited from Neanderthals affects nose shape. A particular gene made the nose taller from top to bottom.

This may have been necessary as ancient humans adapted to colder climates.

“In the last 15 years since the Neanderthal genome has been sequenced, we have been able to learn that our own ancestors apparently interbred with Neanderthals, leaving us with little bits of their DNA,” said co-corresponding author Dr. Kaustubh Adhikari. He is from the University College London (UCL) Genetics, Evolution & Environment and The Open University, in England.

The U.S. Food and Drug Administration on Thursday finalized the elimination of certain restrictions that prevented healthy gay and bisexual men from donating blood.

Instead of requiring men who have sex with men or the women who have sex with them to abstain for sexual contact for three months, the FDA has created an individual risk assessment for all donors.

These questions are meant to reduce the risk of transfusion-transmitted HIV.

"The FDA has worked diligently to evaluate our policies and ensure we had the scientific evidence to support individual risk assessment for donor eligibility while maintaining appropriate safeguards to protect recipients of blood products."

It’s easy to keep your skin safer in the summer sun if you have the right sunscreen.

UCLA Health offers some tips for picking the best type and SPF level.

Getting sunburned just five times in a lifetime doubles the risk of getting melanoma, the most serious skin cancer, so making sure you’re protected is worth the effort, the experts at UCLA Health said in a news release.

Types of sunscreens can be divided into two categories: mineral and chemical. Each type has its pros and cons.

Mineral sunscreen sits on the skin’s surface. It physically blocks ultraviolet (UV) light before those rays can penetrate the skin.

Researchers have discovered a genetic mutation that should actively protect people from Alzheimer’s, thanks to a man belonging to a Colombian family known to be susceptible to the degenerative brain disease.

Based on his family's genetics, this unnamed patient should have started showing signs of Alzheimer’s in his 40s.

“They start getting impaired at age 44. By 49, they have dementia, By 60, they are dead,” said co-researcher Dr. Joseph Arboleda-Velasquez, an associate scientist at Mass Eye and Ear, a research institute with Mass General Brigham in Boston.

But this man showed no signs of cognitive decline by age 67, Arboleda-Velasquez said.

Mobile phone use for making or receiving calls was significantly associated with a higher risk for new-onset hypertension, according to a study published online May 4 in the European Heart Journal: Digital Health.

Ziliang Ye, from Southern Medical University in Guangzhou, China, and colleagues examined associations of mobile phone use for making or receiving calls and use frequency with new-onset hypertension in the general population. The analysis included data (median follow-up, 12.0 years) from 212,046 participants in the U.K. Biobank without prior hypertension.

The researchers found that compared with mobile phone nonusers, a significantly higher risk for new-onset hypertension was seen in mobile phone users (hazard ratio [HR], 1.07).