Nancy Shute

We all know ancestors give us our hair color, but the roots of gray hair have been less clear. Is it genetics, or stress?

Marie Antoinette supposedly went completely white the night before they lopped off her head. And our presidents seem to go gray much faster than those of us with less weighty roles.

It turns out you can blame Mom and Dad, at least a bit. Scientists say they've identified the first gene for gray hair.

The earlier a child with autism can be identified and get treatment the better, child development specialists say. So there's been a push to have pediatricians give all toddlers screening tests for autism during well child visits.

But the influential U.S. Preventive Services Task Force said Tuesday that there's not yet enough evidence to show that screening all children delivers measurable benefits, a decision sure to frustrate or anger many in the autism community.

The odds of getting Alzheimer's disease or other forms of dementia are declining for people who are more educated and avoiding heart disease, a study finds. The results suggest that people may have some control over their risk of dementia as they age.

This isn't the first study to find that the incidence of dementia is waning, but it may be the best so far. Researchers looked at 30 years of records from more than 5,000 people in the famed Framingham Heart Study, which has closely tracked the health of volunteers in Framingham, Mass.

If you fall off a curb, bop your head and go to the ER to make sure you're OK, there's a good chance you'll be trundled off for a CT scan.

That might sound comforting, but people with injuries minor enough that they get sent home are increasingly being given computed tomography scans, a study finds. That's despite efforts to reduce the unnecessary use of CTs, which use radiation and increase the lifetime risk of cancer.

Smoking is the #1 cause of premature death and preventable illness in the United States. And since one-third of Medicaid participants smoke, compared to 17 percent of the general population, you'd think the states would be all about helping people in their Medicaid programs to quit.

But just 10 percent of Medicaid participants who smoke are getting medication to help them quit, according to a study published Tuesday in the journal Health Affairs. That's 830,000 people in 2013.

Although many people know someone who has abused prescription opioids, people still think of opioid abuse as a criminal justice issue more than a health problem, a study finds.

Illegal drug dealing is mentioned most frequently in news stories as the cause of prescription painkiller abuse, and two-thirds of abusers are shown as being actively involved in crimes, according to an analysis by researchers at Johns Hopkins Bloomberg School of Public Health.

The number of people newly diagnosed with diabetes continues to decline after decades of increases that transformed what was once a disease of the old into a public health crisis that affects even children.

That's not to say the crisis is over; 1.4 million people were diagnosed with diabetes in 2014, according to numbers released Tuesday by the Centers for Disease Control and Prevention. That's down from 1.7 million new cases in 2009, the fifth straight year of decline.

Two years ago my mom fell at home and ended up being admitted to the ICU with four broken ribs and internal injuries. She was lucky. After two weeks in the hospital and a few more in a rehab unit she was back home, using her new blue walker to get around.

We live in a society where sex is often touted as the secret sauce that keeps a relationship tasty. So more sex must be better for you and your romantic partner, right?

Well, for established couples, having sex once a week hits the sweet spot for happiness and well-being, a study finds. This is either great news or tragic, depending on how you're feeling about your sex life.

It turns out that psychologists are working hard to figure out whether more sex makes us happier.

Almost 20 percent of the people in low-income communities who die of colon cancer could have been saved with early screening. And those premature deaths take a toll on communities that can least bear it.

Lower-income communities in the United States face $6.4 billion in lost wages and productivity because of premature deaths due to colon cancer, according to researchers at the Centers for Disease Control and Prevention.

In September, we reported on a charming little study that found people who feel blue after watching sad videos have a harder time perceiving colors on the blue-yellow axis.

Now the researchers may be feeling blue themselves. On Thursday they retracted their study, saying that errors in how they structured the experiment skewed the results.

Women shouldn't drink when they're pregnant — absolutely no alcohol at all, according to the American Academy of Pediatrics. But it's been getting a lot of pushback about that edict.

After we reported on it last week, the comment stream exploded with hundreds of people arguing over whether moderate drinking in pregnancy is safe.

Sure, you know you're not supposed to drink while pregnant. But what about those glasses of wine you had before you found out? Is a little OK in the third trimester? Or when you're anxious and can't sleep?

Those are the kinds of questions that women keep asking about pregnancy and alcohol. And science has not been a huge help in providing answers, though that's getting better.

Almost half of teenagers have sex before they graduate from high school. And many high schoolers drink. But drinking can make that first sexual experience less than what a girl might hope, and poses risks for the future, too.

Researchers asked 228 women ages 18 to 20 about their sexual experiences and drinking habits.

One-quarter of the young women had been drinking at the time of their first sexual intercourse, which happened when they were 16, on average.