Sunshine actually may put pep in your step and improve your thinking skills. A study by the University of Alabama at Birmingham shows that the amount of sunlight you are exposed to may boost your cognitive ability.

The study examined the seasonal role and amount of sunlight exposure (referred to as insolation) on patients’ energy levels and cognitive ability. Researchers hypothesized that greater insolation would boost both energy and mental functioning.

This was found to be very true for patients with depression. Sunlight plays a huge role in the body’s circadian (daily) rhythm. Alzheimer’s, for example, has been associated with low blood flow to the cerebrum, yet another of sunlight’s effects.

Individuals who got less sun exposure were more likely to experience an irregular circadian rhythm, similar to Seasonal Affective Disorder (SAD), also known as seasonal depression. Several studies have been conducted in the past to examine the effect of sunlight and seasonal changes on mood in people with depression, but this was the first to study the effects of both on thought processes.

"We think some of the same physiological mechanisms that affect depression also affect cognitive function,” says Shia Kent, author of the study and doctoral candidate at the School of Public Health at the University of Alabama at Birmingham. “These same hormone systems have been implicated in a number of mental disorders and cognitive disorders.”

One key to this relationship lies in the suprachiasmatic nuclei (SCN), a region of the brain responsible for processing information from the eyes and stimulating hormones.One of the SCN’s roles is to prevent the pineal gland from converting serotonin into melatonin, a hormone that triggers sleepiness.

The retina sends light information to the SCN, slowing the brain’s production of melatonin and serotonin—both associated with cognitive functioning—during the day or in a well-lit room. Without this process, the body’s natural rhythm is disrupted. Similar disruptions have been associated with sleep disorders and memory problems in otherwise healthy individuals.

Participants in the study hailed from an area of the United States known as the “stroke belt”—Arkansas, Louisiana, Tennessee, Mississippi, Alabama, Georgia, North Carolina, and South Carolina. Nearly 14,500 men and women over age 45 (44% African-American, 56% white) with no history of a stroke included in the final model were questioned using the Reasons for Geographic and Racial Differences in Stroke (REGARDS) Study.

Cognitive functioning was measured via telephone interviews, while weight, height and blood pressure were measured in-home prior to the study. Participants were then followed for the next two weeks, while researchers measured insolation (with the help of NASA satellite and ground data) and thinking ability (using questionnaires).

Solar radiation was measured eight times daily, at 3-hour intervals. Typical insolation values were 25,000-30,000 KJ/m² in late spring and early summer, and 8,000-10,000 KJ/ m² in the central U.S. Short-term and long-term memory were measured using a six-question test. Answering four or less correctly indicated impairment. 

Based on their findings, researchers reported that low sunlight exposure was a higher likelihood of cognitive impairment for subjects with depression, including those who were prone to SAD. Roughly 18% of participants with any form of depression were classified as having impaired thinking in response to lower insolation, regardless of the season.

“This is speculation,” says Kent, “but those who have cognitive impairment could be helped with sunlight."

 

Learn more about Seasonal Affective Disorder (SAD) in Healia Communities.

Middle-aged people who lack sleep are more likely to develop high blood pressure than those who get a full night’s sleep. A recent study published in the June 8th edition of Archives of Internal Medicine suggests that adults between the ages of 33 and 45 should get at least seven hours of sleep to promote healthy blood pressure levels.

The study found that each hour of sleep reduction was linked to a 37% increased likelihood for high blood pressure. High blood pressure is a risk factor for heart attack, stroke, and heart failure. It is also a primary cause of kidney failure.

High blood pressure – also called hypertension – is characterized by a systolic blood pressure reading of at least 140 mmHg or a diastolic blood pressure reading of at least 90 mmHg. Healthy blood pressure should be near 120 mmHg for systolic and 80 mmHg for diastolic.

To keep blood sugar lower, get ample sleep, avoid stressful activities, minimize sodium intake, exercise often, and eat healthfully. Share your other blood pressure minimizing tips on the Healia High Blood Pressure Online Health Community and Support Group.

Not getting enough sleep? Get advice on the Healia Sleep Disorders Online Health Community and Support Group. Visit our Healia Sleep Disorders Quiz to challenge your knowledge about sleep.

This weekend is the start of Daylight Saving Time. Sunday, March 8 at 2am, most Americans will "spring" forward one hour (despite the fact that the recent lengthening of DST now means the "springing" actually takes place during the winter). In a previous blog post, we presented some of the health problems associated with the sudden time change and its attendant lack of sleep, and provided some tips for easing the transition into DST. We also mentioned that the adjustment can be made more easily if you regularly practice good sleep hygiene. In this article, we present some tips for good sleep hygiene that, if practiced regularly, can not only aid the transition to DST but also help you fall asleep more easily and get more restful sleep for the rest of the year.

In order to practice good sleep hygiene, researchers advise you to:

• Go to bed and get up at the same time each day, even on the weekends.
• Avoid daytime naps or limit them to one brief (15-30 minutes) mid-afternoon nap.
• Avoid drinking alcohol in the evening and do not use it to help you sleep.
• Avoid caffeinated products (coffee, tea, soda, chocolate) after mid-afternoon.
• Eliminate tobacco use, especially close to bedtime and during the night.
• Exercise regularly during the day, but avoid evening exercise.
• Avoid using the bedroom for homework, reading, business affairs, TV-watching, or exercise.
• Keep the bedroom dark, quiet, and comfortable.
• Set aside about 45 minutes or more to wind down at the end of the day before going to bed.
• Avoid stress and worrisome thoughts in the evening before sleep.

For more information about good sleep habits, read the Healia Health Guide to Excessive Sleepiness. If you have a question about methods for easing the transition to DST, Ask the Experts at Healia Health Communities.

_{Source: University of Michigan Center for Sleep Science, Principles of Sleep Hygiene. http://www.med.umich.edu/neuro/Sleeplab/patients/resources.htm#principles}

_{Photo (adapted): ***j9***, Flickr, Creative Commons}

This Sunday, March 8^th marks the beginning of Daylight Saving Time (DST), when most Americans will move their clocks ahead one hour. This is the third year in which DST will start "early" on the second Sunday in March, thanks to a Congressional bill passed in 2005 that lengthens DST by nearly a month. While the energy saving from this program is still a topic of debate, there is ample evidence that "springing forward" may have negative health consequences.

Researchers from the University of Michigan say that while for some losing an hour of sleep causes only minor sleepiness and irritability in the period immediately following the clock change, for others the effects of the switch to DST may be more serious. The good news is that some simple preparations may help reduce these negative effects for everyone.

Studies show that in the weeks following the switch to DST, work performance may suffer and there is a greater risk of car accidents while driving, especially on the Monday following the switch. Other studies indicate that heart attacks increase in frequency after the switch, which may be related to a lack of sleep.

The impact of sleep deprivation tends to manifest itself differently in children, who instead of being sleepy may become hyperactive and inattentive in the days following the switch. This can impact their ability to function in school and can lead to disruptions in their relationships with friends and family.

So what can you do to help minimize the impact DST for yourself and your family? Some experts recommend taking a nap on the day before the switch, but the nap must be brief and take place well before bedtime in order to avoid disrupting the night’s sleep. If possible, you can try to get some extra sleep for a few days leading up to and after the switch to assist with the adjustment, particularly if you are a good sleeper. Another idea is to gradually shift your sleep schedule by going to sleep and waking 15-20 minutes earlier each night for 3-4 nights preceding the changeover, which can help your body adjust to the time change. Treatments often used to prevent jet lag may also be beneficial, such as exposure to bright light upon waking or a short course of melatonin pills. Talk with your doctor to find out if such treatments might be appropriate for you.

Other suggestions for easing the transition to DST include:

• Modify your eating schedule ahead of time by having dinner one hour earlier.
• Avoid napping after the switch, particularly before bedtime.
• Keep a light schedule on the Monday after the time change and avoid operating heavy machinery.
• Eat properly, stay hydrated, and remain physically active.

The adjustment can also be made more easily if you regularly practice good sleep hygiene. More information about this will come in about this in tomorrow’s blog. Also, firefighters would like to remind you that the switch to and from DST is a great time to check the batteries in the smoke and carbon monoxide detectors in your home.

For more information about good sleep habits, read the Healia Health Guide to Excessive Sleepiness. If you have a question about methods for easing the transition to DST, Ask the Experts at Healia Health Communities.

Related blog post: One-third of Americans Losing Sleep over Financial Concerns

_{Photo: Randy Son of Robert, Flickr, Creative Commons.}

Results of a poll released today show that one-third of Americans are losing sleep over the world economic crisis and other personal financial concerns. Chronic lack of sleep is associated with unhealthy lifestyles, poor job performance, and impaired judgment, and can negatively impact health.

The National Sleep Foundation’s Sleep in America poll surveyed 1,000 American near the end of last year about their recent sleep habits. Sixteen percent of those polled said they are losing sleep because of financial concerns, 15 percent reported losing sleep because of the state of the U.S. economy, and another 10 percent said job worries are keeping them awake.

The results also showed that in the past eight years, the number of Americans who sleep less than six hours a night jumped from 13 percent to 20 percent, and the number who reported sleeping eight hours or more dropped from 38 percent to 28 percent. Overall, the number of people reporting sleep problems has increased 13% since 2001.

According to the NSF, people who do not get enough sleep have more trouble working efficiently, which may compound stress they have about their job. Getting less sleep also makes it more difficult to exercise and eat healthy, leading to further health risks from an unhealthy lifestyle. Less sleep also makes you more than twice as likely to eat foods high in sugar and carbohydrates and to smoke cigarettes or use other types of tobacco. Not getting enough sleep may also impact leisure time, with many people reporting more difficulty having sex and engaging in their usual leisure activities, according to the NSF.

The NSF also says that lack of sleep not only endangers your health but can put you at greater risk of suffering a serious accident, such as falling asleep while driving. According to the poll, more than one-half of adults (54 percent) have driven when drowsy at least once in the past year and nearly one-third of drivers polled (28 percent) say that they have nodded off or fallen asleep while driving a vehicle.

The NSF suggests that doctors should always ask their patients about how they are sleeping in addition to the routine questions about diet and physical activity.

If you are having difficulty sleeping, you may be able to improve your sleep by practicing better "sleep hygiene." This requires you to follow a set of rules that help keep your sleeping routine regimented, including going to bed and waking up at the same time every day, avoiding naps, and using the bed for sleep and sex only (not watching TV, reading, or doing work). If you are having trouble sleeping due to your worries about the economy, talk to your doctor about ways you can improve your sleep.

For more information on good sleep hygiene and other sleep issues, read the Healia Health Guide to Excessive Sleepiness. For ways to help you deal with the stress of tough economic times, see the Healia Health Guide to Stress Management. If you want to share your own experience battling sleep problems, join the Healia Health Community for Sleep Disorders.

_{Photo: Maxintosh, Flickr, Creative Commons}

In the first study of its kind, researchers from Carnegie Mellon University report that lack of sleep can increase your odds of catching a cold. In the study, people who slept less than seven hours a night were nearly three times as likely to catch a cold as people who slept eight hours a night or more. What’s more, people with low “sleep efficiency” – who reported spending less than 92 percent of their time in bed actually asleep – were more than five times as likely to come down with a cold as those whose sleep efficiency was 98 percent or more.

The study lends credence to the idea that sleep deprivation can impair the immune system, making it harder for people to fight off infection. Other studies have suggested that lack of sleep can increase the risk of heart disease, weight gain, high blood pressure, stroke, and diabetes.

In the study, researchers tracked 153 healthy volunteers with an average age of 37 for two weeks, calling them daily to ask about the amount and quality of sleep they had gotten the night before. Then, the volunteers had samples containing the rhinovirus, one of the more common causes of colds, squirted inside their nose and each checked into a hotel room for five days. Afterwards, the researchers tested them for infection with the virus and for symptoms of the common cold including sneezing, sore throat, runny nose, and congestion.

While nearly 90 percent of the volunteers became infected with the virus, only 35 percent got sick. Those who had slept fitfully or for fewer hours each night were much more likely to show symptoms than those who slept soundly for eight hours or more.

Cold symptoms are caused by the reaction of the body’s immune system to infection with a cold-causing virus, not by the infection itself. If a person’s immune system mounts a defense that is equal to the infection, it can fight off the virus that person even realizing they are fighting an infection. However, when the immune system is not able to control the infection early, it must mount a much larger response to rid the body of the virus, leading to the symptoms of a cold.

The researchers suggest that sleep may “fine tune” the immune system, allowing it to mount an appropriate immune response using signaling molecules called cytokines and histamines. Lack of sleep may hamper the immune system by interfering with these molecular signals.

According to the researchers, seven to eight hours of quality sleep each night is a reasonable goal to help people maintain a healthy immune system. One important finding of the study was that tossing-and-turning had an even greater impact on the ability to fight off a cold than sleep time. You can also improve the restfulness of your sleep by practicing good sleep hygiene such as setting a regular bedtime, not watching TV in bed, and getting out of bed when for a while when you can’t seem to sleep. Engage in something relaxing for a few minutes, and then get back in bed when you feel tired.

For more information on sleep hygiene, join the Healia Health Community on Sleep Disorders, and for more about the common cold, join the Healia Health Community for Cold and Flu.


_{Photo: deeleea, Flickr, Creative Commons}

Researchers in Japan report that adults who don’t get enough sleep face an increased risk of heart disease. The study, which involved more than 1200 people who had high blood pressure, found that those who got less than 7.5 hours of sleep per night had a 68% greater chance of suffering a heart attack, stroke, or cardiac death. A subset of the study participants who got less than 7.5 hours of sleep a night and also experienced elevated overnight blood pressure had a fourfold increase in cardiovascular problems.

The findings suggest that doctors caring for patients with high blood pressure should ask them about their sleep habits, the researchers report in the Archives of Internal Medicine. The study did not address the effect of sleep time on people with normal blood pressure.

The researchers suspect that a lack of sleep leads to increased nervous system activity throughout the day, which may in turn stress the cardiovascular system. Previous research has demonstrated that inadequate sleep can contribute to conditions such as obesity and diabetes, and is also associated with risk factors for cardiovascular disease including sleep-disordered breathing and elevated overnight blood pressure.

If you have high blood pressure, you may want to talk to your doctor about ways to improve your sleep habits. You might also want to ask him or her about enrolling you in a sleep study that can examine your nighttime breathing and blood pressure. Many people who have sleep disorders such as sleep apnea or elevated overnight blood pressure have no idea they are affected.

The Healia Health Community on sleep disorders allows you to ask questions about these and other sleep problems. Find out more about heart disease and its risk factors in the Healia Health Guide to Heart Disease.

 

 

^{Photo: Brian Boulos, Flickr, Creative Commons}

Don’t forget that Daylight Savings Time is scheduled for this Sunday, March 9, 2008. To help minimize the impact of lost sleep due to the time change, the American Academy of Sleep Medicine suggests planning ahead and following a few simple tips.

• Begin to readjust your sleep schedule a few days prior to the time change by going to bed an hour earlier.
• Modify your eating schedule by having dinner one hour earlier.
• Be careful when driving or operating machinery on the day of the time change.
• Avoid napping, particularly before bedtime.
• Keep a light schedule -- such as minimizing driving and avoiding strenuous physical activity -- on the Monday after the time change.
• Eat properly, stay hydrated and remain physically active.

So remember to change your clocks, get some extra sleep, and “spring forward” this Sunday!

Daylight Savings Time sleep health