Category Archives: Complex Health

How does poor sleep affect our ability to learn? Study investigates

Most of us know that a good night’s sleep is key for happiness and productivity, and that conversely, a night of poor sleep can have negative effects on our performance during the day. But a new study manages to find precisely the brain area responsible for learning new skills and shows how it can be affected by poor sleep quality.

A team of researchers from the University of Zurich (UZH) and the Swiss Federal Institute of Technology (ETH) in Zurich, both in Switzerland, set out to examine the effect of a disturbed deep sleep phase on the brain’s ability to learn new things.

More specifically, the new study – published in the journal Nature Communications – looks at the brain’s ability to change and adapt in response to the stimuli that it receives from the environment, or neuroplasticity, in the motor cortex and how it is affected by deep sleep.

The motor cortex is the brain area responsible for developing and controlling motor skills, and the deep sleep phase – also called slow-wave sleep – is key for memory formation and processing, as well as for helping the brain to restore itself after a day of activity.

Vegetables improve psychological health in just 2 weeks

Fruits and vegetables are a pivotal part of a healthful diet, but their benefits are not limited to physical health. New research finds that increasing fruit and vegetable consumption may improve psychological well-being in as little as 2 weeks.

Study leader Dr. Tamlin Conner, of the Department of Psychology at the University of Otago in New Zealand, and colleagues found that young adults who were given extra fruits and vegetables each day for 14 days ate more of the produce and experienced a boost in motivation and vitality.

The researchers recently reported their findings in the journal PLOS One.

According to the United States Department of Agriculture, adults should aim to consume around two cups of fruits and around two to three cups of vegetables daily.

One cup of fruits is the equivalent to half a grapefruit or a large orange, and one cup of vegetables is proportionate to one large red pepper or a large, baked sweet potato.

As part of a healthful diet, fruits and vegetables can help reduce the risk of obesity, type 2 diabetes, heart disease, stroke, and some types of cancer.

In recent years, studies have suggested that fruit and vegetable intake may also improve mental health. For their study, Dr. Conner and team set out to investigate this association further.

Marijuana’s popularity in the US is on the rise

Marijuana’s popularity among American adults is on the rise — and use of the recreational drug is expected to continue to increase, according to several surveys.

The increase in popularity, along with more permissive attitudes toward marijuana use, may be due in part to its changing legalization status in many parts of the country, experts say.

Forty-five percent of adults in the U.S. have used marijuana at least once in their lives, according to a Gallup poll released in mid-July — the all-time highest percentage in the 48-year history of Gallup asking Americans this question. [25 Odd Facts About Marijuana]

Trying marijuana at least once as an adult isn’t the same as being a user of the drug, but the percentage of current smokers is on the rise as well: The same Gallup poll revealed that 12 percent of U.S. adults — 1 in 8 — said they use marijuana, up from 7 percent in 2013.

Meanwhile, data from two large national surveys done by the federal government also finds increasing rates of marijuana use among adults. (Gallup does its poll by telephone interviews, while federal surveys conduct face-to-face interviews. An in-person interview could possibly influence results because marijuana is still illegal in most states and people may be hesitant to admit they use it.)

One of these large surveys, published in 2015 in JAMA Psychiatry, found that the prevalence of marijuana use in the United States more than doubled over a decade. After interviewing about 36,000 people, ages 18 and older, the researchers found that the percentage of adults who reported using marijuana in the past year jumped from 4.1 percent in 2001–2002 to 9.5 percent in 2012-2013.

The data showed that marijuana use was increasing in males and females in many age groups, although it was increasing a little faster in young adults, ages 18 to 29, and in males, said Deborah Hasin, one of the study authors and a professor of epidemiology at Columbia University’s Mailman School of Public Health in New York City. The rates of use were also increasing among middle-age and older adults, she said.

But the trends in increasing use appear to be limited to adults: Marijuana use is not increasing among teenagers, Hasin said. Two major studies have shown that marijuana use has been relatively stable in adolescents over the last few years, she said.

The top four reasons people give for using marijuana are to relax, to relieve pain, to have fun and to help them be social, according to a survey by Yahoo News/Marist College done in March.Unwinding and fitting in may explain why many people decide to smoke pot, but what are some reasons for its rising popularity among adults?

One explanation is the growing perception that marijuana has few risks, Hasin told Live Science. In the 1960s and ’70s, scare tactics were used to discourage young people from smoking pot, and there was a perception that marijuana could lead to a person becoming addicted to heroin, she said.

These days, teens and adults increasingly see marijuana as a natural substance that’s basically safe, Hasin said. However, one of the known risks of immediate use of the drug is impaired driving ability, she said.

Many people probably consider smoking marijuana as less likely to lead to drug dependence than using other illegal substances. But many of the studies that concluded marijuana may be less addictive than other drugs were done 25 years ago when marijuana was less potent than it is now, Hasin said.

And not only are tetrahydrocannabinol (THC) concentrations, marijuana’s main psychoactive ingredient, higher now than in the past, but people may be using these more potent forms in different ways, such as vaping or consuming them as edibles. Researchers don’t truly know yet how higherpotencies and newer delivery methods will affect marijuana use disorders, Hasin said.

The changing legal status of marijuana in many states may also be responsible for shifting attitudes toward its use and perceived dangers. Twenty-nine states have passed medical marijuana laws, and voters in eight states have approved limited recreational use in adults, Hasin said. [3 More States Legalize Recreational Use of Marijuana: How the Map Looks Now]

There is some evidence from states that have passed medical marijuana laws that shows faster increases in overall marijuana use in adults, compared with states without medical marijuana laws, Hasin said.

Data from California and Colorado, two early adopters of medical marijuana laws, has shown that increased availability of marijuana has led to more overall acceptability of marijuana use, in general, as well increasing perceptions of the drug’s safety, Hasin said. All of these factors seem to increase recreational use of marijuana by adults within these two states, she said.

Marijuana’s popularity can also be explained by a simpler factor: Many people find the drug enjoyable to use. [7 Ways Marijuana May Affect the Brain]

When a person gets high, marijuana has the same effect on the release of the brain chemical dopamine as other psychoactive substances, such as cocaine or heroin, said Francesca Filbey, the director of Cognitive Neuroscience Research in Addictive Disorders at the Center for BrainHealth at the University of Texas at Dallas.

THC binds to cannabinoid receptors, which are found all over the brain, Filbey told Live Science. When THC binds to the receptors, it stimulates the increased release of dopamine, which activates the brain’s reward system and contributes to marijuana’s pleasurable effects, she said.

But marijuana doesn’t only affect areas of the brain involved in feeling good. THC can also attach to receptors in the brain that play a role in modulating other types of behavior, Filbey said. It works like volume control, “turning down” areas of the brain that influence memory, concentration, decision-making, movement and pain perception, she said.

Does Talcum Powder Cause Ovarian Cancer?

Some people may sprinkle on powder after showering and never think much of it. But recent court cases have shined a spotlight on the possible link between women’s regular use of talcum powder on their genitals and an increased risk of developing ovarian cancer.

Yesterday (Aug. 21), a jury in Los Angeles ordered Johnson & Johnson to pay a record $417 million to a woman who claims that the company’s baby powder led to her ovarian cancer. The woman, Eva Echeverria, said in the lawsuit that she developed ovarian cancer as a “proximate result of the unreasonably dangerous and defective nature of talcum powder,” according to the Associated Press. (Johnson & Johnson’s baby powder is made from talcum powder or talc, which is a mineral made up of magnesium, silicon and oxygen.)

In a case that was settled in February, a jury determined that the family of a 62-year-old Alabama woman, who died from ovarian cancer in 2015 after decades of using talcum powder for feminine hygiene, was entitled to $72 million in damages from Johnson & Johnson. The company did not inform customers of the potential dangers of its powders despite being aware of the possible health risks, the jury ruled, according to The Washington Post.

In an earlier case against the same manufacturer, a jury in 2013 found Johnson & Johnson guilty of negligence for not warning women of the risk of ovarian cancer linked to the daily use of the company’s talc-based powders. However, the jury in this case did not award the woman who developed the cancer any monetary damages.

Although these lawsuits have resulted in more publicity about a potential connection between women’s use of talcum powder as a feminine hygiene product, the suggestion of a possible association has been raised in scientific circles for more than 30 years. (Such use means applying powders directly on women’s’ genitals, or on sanitary napkins, tampons, underwear or diaphragms.)

It’s a controversial topic because manufacturers claim there is no causal connection between talc use and ovarian cancer, and researchhas demonstrated conflicting results. [5 Things Women Should Know About Ovarian Cancer]

The American Cancer Society has weighed in on the available science, and said that the “findings have been mixed.” Some studies report a slightly increased risk of ovarian cancer among women who have regularly used talcum powder in their genital areas, while other studies have found no increased risk, the society said.

Based on limited evidence, the International Agency for Research on Cancer, which is part of the World Health Organization, has designated women’s use of talc on their genitals as “possibly carcinogenic to humans.”

Some, but not all powders, such as baby powders and body powders, contain talc, a mineral that may help prevent odor, moisture and chafing when applied to the skin. Before the 1970s, talc products may have contained asbestos, now a known carcinogen, but since then, talcum powders are required by law to be asbestos-free.

Cornstarch-based powders, which have no talc in them, are considered safe for women to use on the genital area and have no known link with any female cancers. And there’s no evidence that sprinkling talc-based powders on other parts of a woman’s body, such as on her feet or her back, influences ovarian cancer risk.

Arguing for strong evidence

Dr. Daniel Cramer, a professor of obstetrics, gynecology and reproductive biology at Harvard Medical School and director of the OB/GYN Epidemiology Center at Brigham and Women’s Hospital in Boston, conducted one of the earliest studies to suggest a link between genital talc use in women and cancer of the ovaries. That research was published in 1982.

Since then, Cramer’s studies have been among those finding a link between women’s regular use of talc and an increased risk of ovarian cancer.

In his opinion, there is strong evidence from about two-dozen epidemiological studies for a significant association between genital talc use and ovarian cancer, Cramer told Live Science. These studies have found that regular talc use may increase a woman’s overall risk of ovarian cancer by about 30 percent, Cramer said.

It has been only in more recent studies that a dose-response effect has been observed in premenopausal women, especially nonsmokers and women who are heavier, and in postmenopausal women who used hormone therapy, Cramer said. A dose-response means that a woman’s risk for ovarian cancer appeared to increase the longer she used talc on her genitals or the more applications she had used over time, he explained.

One factor that has been hard for researchers to quantify is how much talc each woman uses in each application, and how much of it gets into the vagina, Cramer told Live Science. [5 Myths About Women’s Bodies]

Talc is a potent inflammatory agent, and chronic inflammation may predispose a person to cancer, said Cramer, who served as an expert witness in one of the recent court cases and provided written testimony in another. He said that pathologists who have examined tissue from the ovaries of cancer patients under a microscope have found that there is talc in the tissue. The mineral has also been found in women who don’t have ovarian cancer; talc can be found in tissue from lymph nodes in women who have used talcum powder on their genitals.

The exact mechanism by which talc may promote the development of ovarian cancer in women is not known. But Cramer said he suspects that when talc is applied to the genitals, the mineral’s particles can get into the vagina and eventually make their way into the upper genital tract, where the ovaries are located. Once there, talc can induce a potent inflammatory response and probably disrupt the immune system, he said.

Hormones, such as estrogen, may also play a role in the development of ovarian cancer in some women who use talc, but more studies are needed to tease out this effect, Cramer said.

Focus on other risks

Not everyone who examines the research on talc and ovarian cancer draws a conclusion similar to Cramer’s.

The scientific evidence for a link between women’s use of talcum powder and ovarian cancer is not that strong, said Dr. Sarah Temkin, an associate professor of gynecological oncology at the Johns Hopkins School of Medicine in Baltimore. Two newer prospective studies have failed to show any difference in ovarian cancer risk between women who used talc on their genitals and those who never did so, she said.

The older studies that suggested an increased risk tended to be case-control studies, which are open to more bias because they involve asking women to recall their use of powder after they have been diagnosed with cancer, Temkin said.

She said she does not think the evidence is strong enough to warrant forcing manufacturers to place a warning label on talcum powder to alert women to a possible health risk from using the product.

Ovarian cancer is a rare disease, and two well-established risk factors for it are a family history of ovarian cancer and a family history of breast cancer, Temkin told Live Science. Scientists have known about these two links for decades, and even so, health providers may miss the opportunity to inform women who have these risk factors about opportunities for genetic counseling, she said.

It’s also known that women who have used birth control pills for at least five years may reduce their risk for developing ovarian cancer by about 50 percent compared with women who have never used such oral contraceptives, Temkin added. [7 Surprising Facts About the Pill]

She typically does not ask her ovarian cancer patients about their talc use when taking a medical history, Temkin said, and women don’t usually ask her many questions about it. However, with news stories about recent court verdicts making headlines, two or three women have inquired about the use of talc, she said.

If an association between talc use and ovarian cancer risk exists, it is very small, Temkin said. “There are other risk factors for ovarian cancer that are better to focus on than talc,” she said.

Eclipse Watchers’ Plane Crashes on Return Trip

A small plane carrying four people who were returning from an eclipse-watching trip crashed just short of an airport in northern California.

No one was hurt in the crash, which occurred Monday evening (Aug. 21) about a mile short of an airport in Byron, California (a town about 60 miles, or 96 kilometers, east of San Francisco), according to The Mercury News.

The pilot and three passengers were returning to the Bay Area after viewing the solar eclipse in Oregon on Monday, The Mercury News said.

The plane began to experience problems on the return trip; the pilot tried to make an emergency landing at the airport, but the plane landed in an irrigation pond close to the airport.

Officials are still investigating the cause of the crash, but it may have been a fuel shortage on the plane.

Small planes were popular vehicles for traveling to watch Monday’s solar eclipse. An airport in Madras, Oregon — a hotspot for watching the eclipse — typically gets three flights arriving per hour. But in the days leading up to the eclipse, the airport was getting one flight arriving every 3 minutes, according to CBS News. On Saturday, Aug. 19, a small plane crashed en route to Madras, killing one person.

I Used Solar Eclipse Glasses, So Why Do My Eyes Feel Funny?

After viewing the historic solar eclipse yesterday (Aug. 21), some watchers reported that their eyes felt funny, even though they wore certified eclipse glasses. But what might have caused this, and should you be concerned if it happened to you?

Experts say that if your eyes felt a little strange after the eclipse, it’s not necessarily a reason to worry. That’s because this funny feeling is not a sign of “solar retinopathy,” or damage to the eye’s retina that can occur from looking at the sun.

“The retina has no sensory nerve fibers,” so you can’t feel damage to this part of your eye, said Dr. Vincent Jerome Giovinazzo, the director of ophthalmology at Staten Island University Hospital in New York City. “If your eyes feel funny, it’s going to be [a feeling] on the surface.” [Photos: 2017 Great American Solar Eclipse]

Giovinazzo said he has already seen several patients who told him that their eyes felt funny after watching yesterday’s eclipse. In every case, the patient actually had dryness on their eyes’ outer surface from holding their eyes open too long — a condition known as exposure keratitis, Giovinazzo said.

Dr. Nathan Podoll, a spokesperson for the American Academy of Ophthalmology, agreed that eye damage after observing an eclipse would not typically show up as pain or discomfort in your eyes. Instead, people with solar retinopathy have visual symptoms. These symptoms include blurriness or blind spots in your vision, or a dark or dim spot in your central vision, Podoll said. People may notice these symptoms within 4 to 6 hours of the viewing event, Podoll said, or the symptoms could appear the next day.

Looking at the sun without proper eye protection — even for a few seconds — is dangerous and can cause solar retinopathy. But if you used authentic, certified eclipse glasses to view yesterday’s eclipse, and the glasses’ filters were intact, then you won’t have damage to your eyes, Giovinazzo said.

Still, “if you have any concern about the health of your eyes,” you should see an eye doctor, Podoll said.

Depression: Causes, Symptoms and Treatments

Depression, or major depressive disorder, is a mental health condition marked by an overwhelming feeling of sadness, isolation and despair that affects how a person thinks, feels and functions. The condition may significantly interfere with a person’s daily life and may prompt thoughts of suicide. Depression isn’t the same as sadness, loneliness or grief caused by a challenging life experience, such as the death of a loved one.

In 2015, an estimated 16.1 million U.S. adults (aged 18 or older), or 6.7 percent of the adult population, had at least one major depressive episode, or experienced depressive symptoms, in the past year, making this condition one of the most common mental disorders in the United States, according to the National Institute of Mental Health (NIMH).

Depression can affect people of all ages, races and socioeconomic classes, and can strike at any time. The condition is found in twice as many women as men, according to the NIMH.

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In a recently published report from the Centers for Disease Control and Prevention, researchers found that women between 40 and 59 have the highest rate of depression (12.3 percent) of any group based on age and gender in the United States.

People with depression may experience a variety of symptoms, but most commonly, “a deep feeling of sadness or a marked loss of interest or pleasure in daily activities,” according to the American Psychiatric Association. Other symptoms of depression may include:

  • Irritability, agitation or restlessness
  • Lower sex drive
  • Inability to focus, concentrate or make decisions
  • Insomnia or sleeping too much
  • Change in appetite and/or weight, eating too much or too little
  • Tiredness and lack of energy
  • Unexplainable crying spells
  • Unexplainable physical symptoms such as headaches or body aches
  • Feeling hopeless or worthless
  • Withdrawal from social situations and normal activities
  • Thoughts of death or suicide

The causes of depression are not fully understood, but scientists think that an imbalance in the brain’s signaling chemicals may be responsible for the condition in many patients. However, there are several theories about what this imbalance actually is and which signaling chemicals are involved. Moreover, a variety of distressing life situations are also associated, including early childhood trauma, a job loss, the death of a loved one, financial troubles or a divorce.

Most likely, depression is caused by a combination of genetic, biological, environmental, and psychological factors, according to the NIMH.

Certain medical conditions may also trigger depression, including an underactive thyroid gland, cancer, heart disease, prolonged pain and other significant illnesses. Hormonally induced depression can arise after childbirth or at menopause as well.

Additionally, some sedatives, such as sleeping pills, and high blood pressure medications are linked to depression, according to the NIH.

To diagnose a person with depression disorder, doctors may ask patients about their family health history, mood and behavior patterns (such as eating and sleeping), and thoughts of suicide. They may also ask patients to report their depression symptoms on a printed questionnaire.

In the Diagnostic and Statistical Manual of Mental Disorders (DSM), which is a mental health guidebook for doctors published by the American Psychiatric Association, to diagnose a person with major depressive disorder, the person must show five or more of the symptoms (listed above) for at least two weeks. The person must also exhibit a depressed mood, or loss of interest or pleasure.

It must also be ruled out that the symptoms are not caused by another medical condition, such as a thyroid problem, or due to the direct effects of a drug or medication. So doctors may do a blood test, or test the thyroid to make sure it’s functioning properly, according to the Mayo Clinic.

And lastly, doctors look at whether “the symptoms cause clinically significant distress or impairment in social, occupational or other important areas of functioning,” according to the DSM.

Surveys have shown that up to half of Americans with depression don’t get medical help for their condition. Left untreated, major depression can set off a chain of social, emotional and health consequences that add to patients’ overall stress. According to the Mayo Clinic, these include alcohol or drug abuse, anxiety, social isolation and relationship conflicts, work or school difficulties, or suicide.

Depression treatment may involve psychotherapy therapy, medications, or a combination of the two.

Medication: Prescription drugs, called antidepressants, help alter mood by affecting naturally occurring brain chemicals. There are several categories of antidepressants, but doctors often start with a class of drugs called selective serotonin reuptake inhibitors (SSRIs), and may try other medications if the patient’s condition didn’t improve.

SSRIs target the brain’s serotonin, a signaling chemical (neurotransmitter) that studies have found to be involved in depression. This class of medication includes fluoxetine (commonly known as Prozac), sertraline (Zoloft), paroxetine (Paxil), escitalopram (Lexapro) and citalopram (Celexa). Side effects, which are usually temporary, include changes in sexual desire, digestive problems, headache, insomnia and nervousness.

Other classes of antidepressants include serotonin and norepinephrine reuptake inhibitors (SNRIs), Norepinephrine and dopamine reuptake inhibitors (NDRIs), Tricyclic antidepressants, and Monoamine oxidase inhibitors (MAOIs).

Medications take time — usually 2 to 4 weeks — to work, and often symptoms such as appetite, concentration problems and sleep improve before people may notice mood changes, according to the National Institute of Mental Health.

Psychotherapy: Also known as talk therapy or counseling, this treatment has been shown to help some patients with depression. Several studieshave suggested that combining psychotherapy and medication together works best for treating people with severe depression. Different types of psychotherapy include cognitive-behavioral therapy, which helps a person change negative thought patterns and replace them with healthier ones, as well as interpersonal therapy, which is designed to help someone understand and work through difficult relationships, according to the National Institute of Mental Health. Another form of psychotherapy is problem-solving therapy, which involves coming up with realistic solutions to cope with stressful situations.

How to Protect Yourself from Cold and Flu in 2017

In 2017, Live Science is bringing our readers a monthly series on personal health goals. We’ll give you tips and tricks for reaching those goals, based on the advice we’ve gathered from the countless health experts we’ve interviewed. Each month, we’ll focus on a different goal, and the goal for September is “avoiding colds and flu.” Follow us on Facebook and Twitter to connect with other readers who are working toward these goals.

When the weather starts to cool down and you feel a nip in the air, it means that cold and flu season are just around the corner. Although there is no sure-fire way to avoid catching a cold or the flu, there are a number of things you can do to reduce your risk of these illnesses this fall and winter. On this page, we’ve rounded up the most important information from Live Science on how to help prevent cold and flu, and what to do if you get sick.

Cold and flu infections both cause similar symptoms, and they are both more common in the winter months compared to other times of the year. But these illnesses have important differences. For example:

  • Only influenza viruses cause the flu, while many different viruses can cause colds.
  • There is a vaccine to prevent the flu, while there is no vaccine to prevent the common cold.
  • Adults have an average of two to three colds a year, but only get the flu about twice a decade. Kids get colds and the flu more frequently.

Still, when you come down with the winter sniffles, you may be wondering — is this the flu, or a really bad cold? It may be hard to tell the difference based on symptoms alone, but there are some clues. Here are some ways you may be able to tell if you have a cold or the flu

According to the CDC, getting an annual flu shot is the best way to protect yourself from the flu. The flu vaccine is recommended for everyone ages 6 months and older.

Check out Live Science’s comprehensive flu shot page to learn about the types of vaccines, side effects and more.

Even more flu shot facts:

  • When’s the Best Time to Get the Flu Vaccine?
  • ‘Microneedle’ Patch Promises Painless Flu Vaccine
  • Flu Vaccine and Narcolepsy: New Findings May Explain Link
  • Flu Shots Keep Older People Out of the Hospital
  • 6 Flu Vaccine Myths

Getting a flu shot may reduce your risk of catching the flu, but it doesn’t protect you from colds. Still, there are things you can do that may lower your risk of catching colds, and provide additional protection from the flu. Here are some cold and flu prevention tips:

  1. Wash your hands often. Use soap and water, and scrub your hands for at least 20 seconds. You’d be surprised at how many people don’t wash their hands properly.
  2. If soap and water aren’t available, use alcohol-based hand sanitizerthat contains at least 60 percent alcohol.
  3. Get enough sleep. Studies have found that not getting enough sleep is linked with an increased risk of catching a cold or the flu.
  4. Exercise regularly. Working out on a regular basis may lower your risk of catching a cold, or lower your duration of cold symptoms, according to a 2010 study.
  5. Stand back: Studies have found that flu virus particles exhaled by a sick person travel at least six feet.
  6. Consider wearing a mask. If you’re taking care of a person sick with a cold or the flu, wearing a surgical mask may reduce your risk of catching the illness.

Sleep Deprived Sleepers May Be High Risk of Dementia

Consider it another strike against not getting enough sleep: A new study finds that getting too little REM sleep may be linked to a higher risk of dementia later in life.

REM, or “rapid eye movement,” sleep is one of four sleep stages, which also include two stages of light sleep and a stage of deeper sleep called slow-wave sleep. REM sleep is characterized by vivid dreams and high levels of brain activity, similar to the brain’s state when its awake. Humans typically cycle through several periods of REM sleep between the other stages of sleep each night.

In the new study, published today (Aug. 23) in the journal Neurology, researchers found that the people who developed dementia had gotten significantly less REM sleep when examined overnight years earlier compared with the people who didn’t develop cognitive problems. [Get Better Sleep in 2017]

The study does not prove that low levels of REM sleep cause dementia; rather, it shows an association between the two, said lead study author Matthew Pase, a senior research fellow at Swinburne University of Technology in Australia.

Pase offered several ideas for how REM sleep and dementia might be linked.

“On one hand, REM may help protect connections within the brain that are vulnerable to damage with aging and Alzheimer’s disease,” Pase told Live Science. “On the other hand, perhaps lower REM is caused by other potential dementia risk factors, such as heightened anxiety and stress. This requires further study.”

Doctors have long known that poor sleep can result in mental and emotional health problems. But details about which types of sleep are associated with dementia and long-term cognitive decline have been lacking. More than 10 percent of Americans over age 65 have some form of dementia, according to the Centers for Disease Control and Prevention.

In the new study, the researchers looked at more than 320 people in the U.S. whose average age was 67. These people were already part of an ongoing, larger study on heart health. The researchers collected sleep data approximately half way through the as they followed the participants for an average of 12 years. During that time, 32 people (about 10 percent) were diagnosed with some form of dementia; among those 32 people, 24 were diagnosed with Alzheimer’s disease.

The people who developed dementia spent an average of 17 percent of their sleep time in REM sleep, compared with 20 percent for those who did not develop dementia. The researchers found that for every 1-percent reduction in REM sleep, there was a 9-percent increase in the risk of dementia. The results held up even after the researchers adjusted for other factors that could affect dementia risk or poor sleep, such as heart disease, depression and medication use.

Also, the time that the people spent in stages of non-REM sleep was not associated with dementia risk, the study found. [5 Surprising Sleep Discoveries]

“The study is valuable, since it has identified inadequate REM sleep as correlating with dementia risk,” said Dr. Pinky Agarwal, a neurologist at EvergreenHealth in Washington and a professor of neurology at the University of Washington. Agarwal was not part of the study.

“The current [scientific] literature is mixed and mostly identifies inadequate ‘slow wave sleep’ [a type of deep, non-REM sleep] as a risk, but these have been much shorter-duration studies,” Agarwal told Live Science. Because REM sleep is thought to be related to how the brain processes and retains memories, the new findings make sense, she said; dementia is, in part, marked by memory problems. The research points to the need for closer follow-up to recognize signs of dementia in patients with decreased REM sleep, she added.

Indeed, Pase noted that his research group would like to understand why a lower amount of REM sleep is tied to an increased risk of dementia. He hopes to tap into a larger sample of data to examine the relationship between sleep and signs of accelerated brain aging, such as poor thinking, memory problems and loss of brain volume.

This further research might provide more information about how getting less REM sleep, or even poor sleep in general, could lead to the development of dementia, Pase said.

How Stress in Your Brain Could Lead to Stress in Your Body

The patterns in your brain may predict how your body physically reacts to stressful situations, a new study finds.

That’s important, because some people have stronger physical reactions to stress than others: Their hearts beat faster, and their blood pressure rises more, than you’d see in less “reactive” individuals, according to the study. And this “exaggerated” stress response can have negative consequences in the long run. [10 Things You Didn’t Know About the Brain]

People whose blood pressure shoots up in stressful situations are more likely to develop high blood pressure in the future, and they may also have an increased risk of death from heart disease, according to the study, published today (Aug. 23) in the Journal of the American Heart Association.

“It’s the people who show the largest stress-related cardiovascular response who are at the greatest risk for poor cardiovascular health, and understanding the brain mechanisms for this may help to reduce their risk,” senior study author Peter Gianaros, a professor of psychology at the University of Pittsburgh, said in a statement.

To study this “brain-body” relationship, the researchers performed brain scans on more than 300 adults while also monitoring their physical responses, such as blood pressure and heart rate. During the scans, the participants were asked complete mental tests that were designed to create a stressful experience. For example, the people in the study had to answer questions under strict time constraints.

Next, the researchers used artificial intelligence analyze the results. They found that the people who reacted more strongly to stress physically — in other words, the people whose blood pressure and heart rates rose higher — showed specific patterns of activity in their brains. Indeed, the A.I. reliably predicted how a person’s blood pressure and heart rate would change based on the person’s brain activity during the stress test, the researchers said.

In addition, activity in certain areas of the brain was linked to greater stress responses in the body, the researchers found. For example, heightened activity in areas of the brain that determine whether information from the world around you is threatening was linked to a greater physical response.

The study had several limitations, the researchers said. For example, the people included in the study were healthy, middle-age adults who were at low risk for heart disease, so the findings may not apply to less-healthy individuals.

In addition, the study didn’t prove that increased activity in certain parts of the brain in response to stress causes physical changes in the body; rather, the research found an association between the two.

Gianaros noted that more research is needed to explore the connections between brain activity and stress responses in the body.

“This kind of work is proof-of-concept, but it does suggest that, in the future, brain imaging might be a useful tool to identify people who are at risk for heart disease or who might be more or less suited for different kinds of interventions, specifically those that might be aimed at reducing levels of stress,” Gianaros said.