Sleeping over 8 hours a day associated with greater risk of stroke

People who sleep for more than eight hours a day have an increased risk of stroke, according to a study by the University of Cambridge - and this risk doubles for older people who persistently sleep longer than average. However, the researchers say it is unclear why this association exists and call for further research to explore the link.

Previous studies have already suggested a possible association between sleep and risk of stroke, but today's study, published in the journal Neurology, is the first to provide detailed information about the British population and to examine the relationship between a change in sleep duration over time and subsequent stroke risk.

Researchers from the Department of Public Health and Primary Care at the University of Cambridge followed just under 10,000 people aged 42-81 years of age from the European Prospective Investigation into Cancer (EPIC)-Norfolk cohort over 9.5 years. During 1998-2000 and then again four years later, they asked the cohort how many hours on average they slept in a day and whether they generally slept well.

Almost seven out of ten participants reported sleeping between six and eight hours a day, whilst one in ten reported sleeping for over eight hours a day. Participants who slept for less than six hours or more than eight hours were more likely to be older, women and less active.

Over the almost ten year period of the study, 346 participants suffered a stroke, either non-fatal or fatal stroke. After adjusting for various factors including age and sex, the researchers found that people who slept longer than eight hours a day were at a 46% greater risk of stroke than average. People who slept less than six hours a day were at an 18% increased risk, but the small number of people falling in this category meant the association was not statistically significant.

Participants who reported persistently long sleep - in other words, they reported sleeping over eight hours when asked at both points of the study - were at double the risk of stroke compared to those with persistently average sleep duration (between six and eight hours a day). This risk was even greater for those whose reported sleep increased from short to long over the four years - their risk was close to four times that of people who maintained an average sleep duration.

In addition to studying the EPIC-Norfolk cohort, the researchers carried out a study of combined data from 11 other studies related to identify the association between sleep duration and patterns of stroke risk. Their final analysis, including 560,000 participants from seven countries, supported the findings from the EPIC-Norfolk cohort study.

Yue Leng, PhD candidate at the University of Cambridge, says: "It's apparent both from our own participants and the wealth of international data that there's a link between sleeping longer than average and a greater risk of stroke. What is far less clear, however, is the direction of this link, whether longer sleep is a symptom, an early marker or a cause of cardiovascular problems."

While older people have less work and fewer social demands and therefore often have the option of sleeping longer, previous research has shown that in fact, they tend to sleep on average for shorter periods.

The researchers say it is unclear yet why the link between sleep and stroke risk should exist. Lack of sleep has been linked with factors such as disrupted metabolism and raised levels of the 'stress hormone' cortisol, all of which may lead to higher blood pressure and increased stroke risk. However, the current study suggests that the association between longer sleep duration and higher risk of stroke was independent of normal risk factors for cardiovascular disease.

Professor Kay-Tee Khaw, senior author on the study, adds: "We need to understand the reasons behind the link between sleep and stroke risk. What is happening in the body that causes this link? With further research, we may find that excessive sleep proves to be an early indicator of increased stroke risk, particularly among older people."

The numbers are in: As many as 2 in 3 smokers will die from their habit

A large Australian study of more than 200,000 people has provided independent confirmation that up to two in every three smokers will die from their habit if they continue to smoke.

The research, published today in the international journal BMC Medicine, is the first evidence from a broad cross-section of the population to show the smoking-related death toll is as high as two thirds.

"We knew smoking was bad but we now have direct independent evidence that confirms the disturbing findings that have been emerging internationally, said lead author Professor Emily Banks, Scientific Director of the Sax Institute's 45 and Up Study and a researcher at the Australian National University.

"Even with the very low rates of smoking that we have in Australia we found that smokers have around three-fold the risk of premature death of those who have never smoked. We also found smokers will die an estimated 10 years earlier than non-smokers."

Until relatively recently it was thought that about half of smokers would die of a smoking-related illness, but newer studies in UK women, British doctors and Amercian Cancer Society volunteers have put the figure much higher, at up to 67%.

"We have been able to show exactly the same result in a very large population-wide sample," Professor Banks said.

The research is the result of a four-year analysis of health outcomes from more than 200,000 men and women participating in the Sax Institute's 45 and Up Study ? the largest longitudinal study of healthy ageing in the Southern Hemisphere.

Australia has one of the lowest smoking rates in the world - at 13% of the population ? and is an international leader on plain cigarette packaging. "But our findings are an important reminder that the war on tobacco is not yet won, and tobacco control efforts must go on," Professor Banks said.

The research was supported by the National Heart Foundation of Australia in collaboration with major 45 and Up Study partner Cancer Council NSW and was conducted by a national and international team. It also found that compared with non-smokers, smoking just 10 cigarettes a day doubles the risk of dying and smoking a pack a day increases the risk four- to five-fold.

The NSW Heart Foundation's CEO, Kerry Doyle, said the Australian Government was on the right path in driving down smoking rates through initiatives like tax increases and plain packaging.

"Higher tobacco prices have been shown to be the most effective intervention available to governments to reduce demand for tobacco. With smoking being a major cause of cardiovascular disease, including heart attack, stroke and peripheral vascular disease the more deterrents people have between them and smoking, the better," Ms Doyle said.

Scott Walsberger, Tobacco Control Manager at Cancer Council NSW, said the research results highlighted an important message for smokers: "It's never too late to quit ? no matter what your age, or how much you smoke."

Marine oil supplement has positive effects on post-exercise muscle damage

An Indiana University study has revealed that there may be a greater connection between mussels and muscles than previously thought.

The study, by kinesiology professor Timothy Mickleborough at the IU School of Public Health-Bloomington, found that taking a pre-exercise supplement of the omega-3 PCSO-524, a marine oil lipid derived from the New Zealand green-lipped mussel, has significant positive effects on post-exercise muscle damage.

The pharmaceutical name of the supplement is Lyprinol, or Omega XL in the United States, and it has previously been used to effectively reduce the effects of osteoarthritis, rheumatoid arthritis, inflammatory bowel disease and exercise-induced asthma. Pharmalink International LTD, which funded the study, develops it.

Mickleborough said his initial study of this particular marine oil supplement led him to further test its healing properties on other parts of the body.

"I've worked with Pharmalink before when they approached me to do a study with this particular oil and its effects on exercise-induced asthma and respiratory inflammation," Mickleborough said. "I thought if it can be used as an anti-inflammatory for lungs, perhaps it could reverse muscle inflammation as well."

For the study, lead author Mickleborough and his colleagues tested 32 "untrained male subjects" -- men who exercise less than three times a week for less than 30 minutes at a time -- who would elicit a greater muscle response than an athlete who is used to regular muscle damage. The subjects were randomly given either the marine oil supplement or a placebo for 26 days before a muscle-damaging exercise session and for 96 hours afterwards.

The exercise session consisted of running at fairly high intensity for 20 minutes downhill on a treadmill. The body's reaction to the muscle-damaging exercise regimen was tested immediately, and at 24, 48, 72 and 96 hours post-workout.

The men who were given the PCSO-524 marine oil supplement exhibited less muscle soreness, less muscle pain, less strength loss, less fatigue and even less inflammatory proteins evident in their bloodstreams. Overall, they experienced less bodily stress after their workout in comparison to the subjects who were given the placebo.

For people who are looking to start exercising again, or even for those who engage in intense workouts regularly, this discovery can have a variety of positive effects on how their bodies react to muscle damage, Mickleborough said.

"It might have positive implications for triathletes if they're doing several different types of exercises, and it could potentially help diminish soreness in multisport, recreational athletes as well," he said. "Essentially, for anyone who is engaging in unaccustomed exercise, it's a nice product."

Mickleborough's study "The effects PCSO-524®, a patented marine oil lipid and omega-3 PUFA blend derived from the New Zealand green lipped mussel (Perna canaliculus), on indirect markers of muscle damage and inflammation after muscle damaging exercise in untrained men: a randomized, placebo controlled trial" is featured in the Feb. 2015 issue of the Journal of the International Society of Sports Nutrition.

'Walking Football' (Soccer) = Good Health

The new sporting craze of 'Walking Football' may enable people to continue playing football into their 60s and 70s while reaping a multitude of health benefits, according to Aston University researchers.

The sport was created in 2011 to help keep older players involved in football for longer and from hanging up their boots before they need to. Games are played at a slower pace to reduce the threat of pain, discomfort and injury, with players briskly walking through matches. Across the country, new Walking Football clubs and groups are setting up every week as its popularity rockets.

Although it is known that regular football, including 11-a-side and 5-a-side versions of the sport, has considerable health benefits such as reducing the risk of cardiovascular disease and improving blood pressure, little research has been done into the impact of Walking Football.

Aston University researcher, Peter Reddy, felt compelled to conduct a study into the sport to discover just how healthy it is. The investigation will assess two groups of men and women over the age of 48 playing Walking Football once a week for 12 weeks. Participants will be regularly assessed to measure changes in their postural balance, blood pressure and resting heart rate, cholesterol, blood sugar and bone density -- all indicators of general good health.

The study will also look into the psychological advantages of playing Walking Football. Recent research into older males exposed to lifelong football found they had high levels of 'flow' while playing football -- a state of psychological reward and satisfaction. They also reported low levels of stress and exertion while playing, despite working hard. Peter hopes to see similarly positive results in his investigation.

Peter, a Reader in Psychology, said: "Football is a fantastically good way of staying fit and healthy. Studies have shown it can be effective in the treatment of mild to moderate hypertension and that it can produce high aerobic activity with marked improvements in fat oxidation and aerobic power. Most people who play the sport, at amateur and professional levels, give it up in their late 30s but there's no reason not to enjoy the beautiful game until well into your 60s and even 70s.

"We hope this study will establish that Walking Football has health benefits on proportionally similar lines to regular football and that older adults can happily play every week without pain or discomfort. If the data is positive, it will form a basis for local and national charities and authorities to set up and support local Walking Football groups. We want to ensure people are healthy for longer -- and that they can enjoy a kickabout at any age."

In the context of an aging society, rising levels of obesity and the growing incident of late onset diabetes, it is thought Walking Football has the potential to make a significant impact.

In the UK around 22% of men die before the age of 65, compared to 13% of women. Although physically active men have a 20 -- 30% reduced risk of premature death and 50% less chronic disease, by the age of 55-64 only 32% of men say they take the recommended half hour of exercise five times a week.

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Vitamin D deficiency linked more closely to diabetes than obesity

People who have low levels of vitamin D are more likely to have diabetes, regardless of how much they weigh, according to a new study published in the Endocrine Society's Journal of Clinical Endocrinology & Metabolism.

The results help clarify the connection between vitamin D, obesity and diabetes. According to the Society's Scientific Statement on the Non-skeletal Effects of Vitamin D, studies have found that people who have low levels of vitamin D are more likely to be obese. They also are more likely to have Type 2 diabetes, prediabetes and metabolic syndrome than people with normal vitamin D levels.

Vitamin D helps the body absorb calcium and maintain bone and muscle health. The skin naturally produces this vitamin after exposure to sunlight. People also absorb smaller amounts of the vitamin through foods, such as milk fortified with vitamin D. More than 1 billion people worldwide are estimated to have deficient levels of vitamin D due to limited sunshine exposure.

"The major strength of this study is that it compares vitamin D levels in people at a wide range of weights (from lean to morbidly obese subjects) while taking whether they had diabetes into account," said one of the study's authors, Mercedes Clemente-Postigo, MSc, of Instituto de Investigación Biomédica de Málaga (IBIMA) at Complejo Hospitalario de Málaga (Virgen de la Victoria) and Universidad de Málaga in Malaga, Spain.

The cross-sectional study compared vitamin D biomarkers in 118 participants at the university hospital Virgen de la Victoria in Malaga as well as 30 participants from the Hospital Universitari Dr. Josep Trueta in Girona, Spain. All participants were classified by their body-mass index (BMI) as well as whether they had diabetes, prediabetes or no glycemic disorders. Researchers measured levels of vitamin D in the participants' blood streams and vitamin D receptor gene expression in adipose tissue.

The analysis found that obese subjects who did not have glucose metabolism disorders had higher levels of vitamin D than diabetic subjects. Likewise, lean subjects with diabetes or another glucose metabolism disorder were more likely to have low levels of vitamin D. Vitamin D levels were directly correlated with glucose levels, but not with BMI.

"Our findings indicate that vitamin D is associated more closely with glucose metabolism than obesity," said one of the study's authors, Manuel Macías-González, PhD, of Complejo Hospitalario de Málaga (Virgen de la Victoria) and the University of Málaga. "The study suggests that vitamin D deficiency and obesity interact synergistically to heighten the risk of diabetes and other metabolic disorders. The average person may be able to reduce their risk by maintaining a healthy diet and getting enough outdoor activity."

Sauna use associated with reduced risk of cardiac, all-cause mortality

A sauna may do more than just make you sweat. A new study suggests men who engaged in frequent sauna use had reduced risks of fatal cardiovascular events and all-cause mortality, according to an article published online by JAMA Internal Medicine.

Although some studies have found sauna bathing to be associated with better cardiovascular and circulatory function, the association between regular sauna bathing and risk of sudden cardiac death (SCD) and fatal cardiovascular diseases (CVD) is not known.

Jari A. Laukkanen, M.D., Ph.D., of the University of Eastern Finland, Kuopio, and coauthors investigated the association between sauna bathing and the risk of SCD, fatal coronary heart disease (CHD), fatal CVD and all-cause mortality in a group of 2,315 middle-aged men (42 to 60 years old) from eastern Finland.

Results show that during a median (midpoint) follow-up of nearly 21 years, there were 190 SCDs, 281 fatal CHDs, 407 fatal CVDs and 929 deaths from all causes. Compared with men who reported one sauna bathing session per week, the risk of SCD was 22 percent lower for 2 to 3 sauna bathing sessions per week and 63 percent lower for 4 to 7 sauna sessions per week. The risk of fatal CHD events was 23 percent lower for 2 to 3 bathing sessions per week and 48 percent lower for 4 to 7 sauna sessions per week compared to once a week. CVD death also was 27 percent lower for men who took saunas 2 to 3 times a week and 50 percent lower for men who were in the sauna 4 to 7 times a week compared with men who indulged just once per week. For all-cause mortality, sauna bathing 2 to 3 times per week was associated with a 24 percent lower risk and 4 to 7 times per week with a 40 percent reduction in risk compared to only one sauna session per week.

The amount of time spent in the sauna seemed to matter too. Compared with men who spent less than 11 minutes in the sauna, the risk of SCD was 7 percent lower for sauna sessions of 11 to 19 minutes and 52 percent less for sessions lasting more than 19 minutes. Similar associations were seen for fatal CHDs and fatal CVDs but not for all-cause mortality events.

"Further studies are warranted to establish the potential mechanism that links sauna bathing and cardiovascular health," the study concludes.

Editor's Note: Health Benefits of Sauna Bathing

In a related Editor's Note, Rita F. Redberg, M.D., of the University of California, San Francisco, and editor-in-chief of JAMA Internal Medicine, writes: "Although we do not know why the men who took saunas more frequently had greater longevity (whether it is the time spent in the hot room, the relaxation time, the leisure of a life that allows for more relaxation time or the camaraderie of the sauna), clearly time spent in the sauna is time well spent."

Study finds peanut consumption in infancy prevents peanut allergy

Introduction of peanut products into the diets of infants at high risk of developing peanut allergy was safe and led to an 81 percent reduction in the subsequent development of the allergy, a clinical trial has found. The study was supported by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, and was conducted by the NIAID-funded Immune Tolerance Network (ITN). The results appear in the current online issue of the New England Journal of Medicine and were presented today at the annual meeting of the American Academy of Allergy, Asthma and Immunology.

Researchers led by Gideon Lack, M.D., of King's College London, designed a study called Learning Early About Peanut Allergy (LEAP), based on observations that Israeli children have lower rates of peanut allergy compared to Jewish children of similar ancestry residing in the United Kingdom. Unlike children in the UK, Israeli children begin consuming peanut-containing foods early in life. The study tested the hypothesis that the very low rates of peanut allergy in Israeli children were a result of high levels of peanut consumption beginning in infancy.

"Food allergies are a growing concern, not just in the United States but around the world," said NIAID Director Anthony S. Fauci, M.D. "For a study to show a benefit of this magnitude in the prevention of peanut allergy is without precedent. The results have the potential to transform how we approach food allergy prevention."

LEAP compared two strategies to prevent peanut allergy--consumption or avoidance of dietary peanut--in infants who were at high risk of developing peanut allergy because they already had egg allergy and/or severe eczema, an inflammatory skin disorder.

"The study also excluded infants showing early strong signs of having already developed peanut allergy. The safety and effectiveness of early peanut consumption in this group remains unknown and requires further study," said Dr. Lack. "Parents of infants and young children with eczema or egg allergy should consult with an allergist, pediatrician, or their general practitioner prior to feeding them peanut products."

More than 600 high-risk infants between 4 and 11 months of age were assigned randomly either to avoid peanut entirely or to regularly include at least 6 grams of peanut protein per week in their diets. The avoidance and consumption regimens were continued until 5 years of age. Participants were monitored throughout this period with recurring visits with health care professionals, in addition to completing dietary surveys by telephone.

The researchers assessed peanut allergy at 5 years of age with a supervised, oral food challenge with peanut. They found an overall 81 percent reduction of peanut allergy in children who began early, continuous consumption of peanut compared to those who avoided peanut.

"Prior to 2008, clinical practice guidelines recommended avoidance of potentially allergenic foods in the diets of young children at heightened risk for development of food allergies," said Daniel Rotrosen, M.D., director of NIAID's Division of Allergy, Immunology and Transplantation. "While recent studies showed no benefit from allergen avoidance, the LEAP study is the first to show that early introduction of dietary peanut is actually beneficial and identifies an effective approach to manage a serious public health problem."

A follow-up study called LEAP-On will ask all LEAP study participants to avoid peanut consumption for one year. These results will determine whether continuous peanut consumption is required to maintain a child's tolerance to peanut.