Friday, November 30, 2018
Falls are more likely when you've had a bad night sleep
- Just one night of disturbed sleep means you are less capable to control posture and balance the day after
- A single bad night sleep decreases your chance of controlling posture according to researchers at the University of Warwick, who have used state of the art sensors to monitor sleep and balance
- Implications could be that older people who have had a bad night sleep are the most at risk of a fall
- Innovative solutions of how to prevent imminent falls can now be researched
Disturbances during sleep decreases capability to control posture and balance according to researchers from the Department of Engineering and Warwick Medical School at the University of Warwick who have an article published today in Scientific Reports.
This is the first study demonstrating the relationship between disrupted sleep and the reduced capability to control posture and balance, and it could pave the way to new interventions to prevent falls in later life, should the results be confirmed by other studies on older adults.
The research shows that fragmented and disrupted sleep leads to acute balance deficit.
The study was conducted by the School of Engineering in collaboration with Warwick Medical School at the University of Warwick.
A sample of healthy adults underwent sleep and balance assessment over two consecutive days, in order to determine the links between day-to-day variations in sleep quality and balance.
State-of-the-art wearable sensors were used for in-home sleep monitoring and balance testing. These findings are relevant to pave the way to the design of fall prevention programs in populations and settings where normal sleep is frequently disrupted, such as older people and hospital wards.
Dr Leandro Pecchia, team leader of the research from the School of Engineering at the University of Warwick says:
"We all have direct experience of this. When we do not sleep well, we may feel a little dizzy and our capability to control our posture and balance is somehow diminished. When we are fit and in good health, our body is able to adapt and we develop a strategy to keep our balance, avoiding falls and incidents. This ability is reduced with ageing or when there are other concomitant conditions that may compromise our ability to adapt."
Prof Francesco Cappuccio, Head of the Sleep, Health & Society programme at the University of Warwick's medical school, explains:
"The results obtained in healthy normal volunteers are surprising, given the ability at younger ages to compensate for such acute and short-lived sleep disruptions. We would expect more dramatic effects when these experiments be replicated in older people, whose vulnerability to sleep disruption, postural hypotension and risk of falls is much greater".
Dr Lenadro Pecchia continues:
"These results could contribute to the understanding of in-hospital falls. Hospitalised older patients find themselves in a frail condition, sleeping in an unfamiliar environment, with unusual nocturnal light and noises from other patients and nurses, and perhaps being administered more than one drug. Waking-up to go to the toilet can be more challenging than we can imagine. Having a nurse for each bed is not practical in the modern NHS and not well accepted by many older people. We need to learn how to use available technology to detect early the changes in sleep so that we can design personalised interventions that may avoid falls in the next day. One of the problems in fall prevention is that we know a frail subject will fall, but it is very difficult to predict when. Our study is first step towards finding a solution."
Night owls may have a higher risk of suffering from heart disease and type 2 diabetes than early risers
In the first ever international review of studies analysing whether being an early riser or a night owl can influence your health, researchers have uncovered a growing body of evidence indicating an increased risk of ill health in people with an evening preference as they have more erratic eating patterns and consume more unhealthy foods.
The findings have been reported in Advances in Nutrition today (Friday 30 November)
The human body runs on a 24-hour cycle which is regulated by our internal clock, which is known as a circadian rhythm, or chronotype. This internal clock regulates many physical functions, such as telling you when to eat, sleep and wake. An individual's chronotype leads to people having a natural preference towards waking early or going to bed late.
The researchers found increasing evidence emerging from studies linking conditions such as heart disease and type 2 diabetes to people with the evening chronotype - a natural preference for evenings.
People who go to bed later tend to have unhealthier diets, consuming more alcohol, sugars, caffeinated drinks and fast food than early risers. They consistently report more erratic eating patterns as they miss breakfast and eat later in the day. Their diet contains less grains, rye and vegetables and they eat fewer, but larger, meals. They also report higher levels of consumption of caffeinated beverages, sugar and snacks, than those with a morning preference, who eat slightly more fruit and vegetables per day. This potentially explains why night owls have a higher risk of suffering from chronic disease.
Eating late in the day was also found to be linked to an increased risk of type 2 diabetes because the circadian rhythm influences the way glucose is metabolised in in the body.
Glucose levels should naturally decline throughout the day and reach their lowest point at night. However, as night owls often eat shortly before bed, their glucose levels are increased when they are about to sleep. This could negatively affect metabolism as their body isn't following its normal biological process.
One study showed that people with an evening preference were 2.5 times more likely to have type 2 diabetes than those with a morning preference.
This also impacts on people who work shifts - particularly rotating shifts - as they are constantly adjusting their body clock to fit with their working hours. The researchers found that this reduces their sensitivity to insulin and affects their glucose tolerance, putting them at greater risk of developing type 2 diabetes.
The review also uncovered interesting trends:
- People's preferences to rising early and going to bed later change at varying points in the life cycle. The morning chronotype is more common in children and can appear when a baby is just three-weeks old. This changes during childhood. While over 90% of two-year-olds have a morning preference, this declines to 58% by the age of six, and shifts further towards an evening preference during puberty. This evening preference continues until an adult reaches their early 50's and they then begin to revert back to a morning preference.
- Ethnicity and society can also influence your chronotype. For example, studies have revealed that Germans are more likely to have an evening preference in comparison to Indians and Slovakians. There can also be differences between people living in urban and rural areas in the same country.
- Another study noted that being exposed to daylight influenced sleep. Every additional hour spent outdoors was associated with 30 minutes of 'advance sleep' and that the noise, ambient lighting and crowding of urban environments can make people in some areas more likely to have a morning or evening preference.
- The researchers also found evidence that night owls would accumulate 'sleep debt' during the working week and would sleep longer at weekends to compensate for this, whereas early birds had smaller differences in their sleeping patterns across the week.
Dr Almoosawi, a Research Fellow in Northumbria's Brain, Performance and Nutrition Research Centre, explained: "We have found that your genes, ethnicity and gender determine the likelihood of you being a morning or evening type. In adulthood, being an evening chronotype is associated with greater risk of heart disease and type 2 diabetes, and this may be potentially due to the poorer eating behaviour and diet of people with evening chronotype. Our review also found that people who have a poorer control of their diabetes are more likely to be evening types.
"The review has highlighted a major gap in our understanding as to how our biological clock affects food intake in infants, children and the elderly. While most infants synchronise their body clock to that of their mothers, as they reach six-years of age, we observe that a large proportion begin to show signs of developing an evening chronotype. Whether physiological changes, school timings or social schedules determine this change, we do not know.
Dr Almoosawi added: "In teenagers, we also find that evening chronotype is related to more erratic eating behaviour and poorer diet. This could have important implications to health in adulthood as most dietary habits are established in adolescence."
The review team have called for more studies in the general population that define people's body clock and how this relates in the long-term to their dietary habits and health.
Dr Leonidas G Karagounis of Nestle Health Science, said: "Scientific evidence is providing increasing insight into the relationship between your chronotype, diet and cardiometabolic health. Overall, cross-sectional studies suggest that an evening chronotype is associated with lower intake of fruits and vegetables, and higher intake of energy drinks, alcoholic, sugary and caffeinated beverages, as well as higher energy intake from fat.
"Further research on the best methods to assess an individual's chronotype and how this may affect their long-term cardiometabolic health can potentially guide the development of health promotion strategies aimed at preventing and treating chronic diseases based on an individual's chronotype."
Light pollution may cause insomnia in older adults
A new study is the first population-based investigation to report a significant association between artificial, outdoor light exposure at night and insomnia, as indicated by older adults' use of hypnotic drugs.
Results show that increasing nighttime levels of artificial, outdoor light exposure, stratified by quartile, were associated with an increased prevalence of hypnotic prescriptions and daily dose intake. Furthermore, older adults exposed to higher levels of artificial, outdoor light at night were more likely to use hypnotic drugs for longer periods or higher daily dosages.
"This study observed a significant association between the intensity of outdoor, artificial, nighttime lighting and the prevalence of insomnia as indicated by hypnotic agent prescriptions for older adults in South Korea," said Kyoung-bok Min, PhD, an associate professor in the Department of Occupational and Environmental Medicine at Seoul National University College of Medicine in South Korea. "Our results are supportive data that outdoor, artificial, nighttime light could be linked to sleep deprivation among those while inside the house."
The study results are published in the Nov. 15 issue of the Journal of Clinical Sleep Medicine.
According to the American Academy of Sleep Medicine, insomnia can involve struggling to fall asleep, having trouble maintaining sleep, or waking up too early. A variety of environmental factors, including excessive noise or light and extreme temperatures, will disrupt the sleep of most individuals.
The authors reported that the inappropriate or excessive use of artificial, outdoor light at night, referred to as "light pollution," has emerged as a novel environmental factor linked to human health. Research has shown that artificial nighttime lighting, whether indoor or outdoor, induces disruption of circadian rhythms, potentially leading to metabolic and chronic diseases, including cancer, diabetes, obesity and depression.
The study used data from the 2002-2013 National Health Insurance Service-National Sample Cohort (NHIS-NSC), a population-based cohort in South Korea. The final study sample, after excluding those with a diagnosed sleep disorder, comprised 52,027 adults who were 60 years of age or older. About 60 percent of participants were female.
Light exposure was based on satellite data provided by the National Centers for Environmental Information. The estimated light pollution level in each administrative district was matched with individuals' residential districts to determine an individual exposure level.
Usage data for two hypnotic drugs, zolpidem and triazolam, were extracted from health insurance records. About 22 percent of study participants had prescriptions for hypnotic drugs.
Min added that public health officials seem to be less concerned with light pollution than with other environmental pollutants. However, this study strengthens the potential link between light pollution and adverse health consequences.
"Given the recent scientific evidence including our results, bright outdoor lighting may be a novel risk factor for prescribing hypnotic drugs," Min said.
The authors noted that more studies and public policy initiatives are needed to define and minimize the adverse effects of light pollution on human health.
Thursday, November 29, 2018
Youth football changes nerve fibers in brain
Credit: Radiological Society of North America
MRI scans show that repetitive blows to the head result in brain changes among youth football players, according to a new study being presented today at the annual meeting of the Radiological Society of North America (RSNA).
Football has been the subject of much scrutiny in recent years due to growing concerns over the long-term consequences of repetitive head impacts. Players who show signs of concussion are typically removed from games, but many hits to the head are subconcussive--or below the threshold of a concussion--and, therefore, don't cause any immediate symptoms. There is rising concern that youth football players who experience these collisions in practices and games may be vulnerable to their effects.
"The years from age 9 to 12 are very important when it comes to brain development," said study lead author Jeongchul Kim, Ph.D., from Wake Forest School of Medicine in Winston-Salem, N.C. "The functional regions of the brain are starting to integrate with one another, and players exposed to repetitive brain injuries, even if the amount of impact is small, could be at risk."
Dr. Kim and colleagues studied the results of these collisions on youth football players using a novel MRI method that looks at the strain evident on white matter tracts--the bundles of nerve fibers that carry information between different areas of the brain.
"The focus here was on deformations of these fiber bundles," Dr. Kim said. "Changes from collisions might cause elongation or contraction of these bundles."
Twenty-six male youth football players, average age 12, underwent MRI studies before and approximately three months after the season was over. For comparison, 22 similarly aged boys who did not participate in contact sports had MRIs on the same schedule.
The MRI results showed that the football players developed changes in the corpus callosum, a critically important band of nerve fibers that connects the two halves of the brain. The primary role of the corpus callosum is to integrate cognitive, motor and sensory functions between the two sides of the brain.
There were signs of greater axial strain (contraction) in some parts of the corpus callosum, and indications of radial strain (expansion) in other parts.
"The body of the corpus callosum is a unique structure that's somewhat like a bridge connecting the left and right hemispheres of brain," Dr. Kim said. "When it's subjected to external forces, some areas will contract and others will expand, just like when a bridge is twisting in the wind."
The results suggest that repetitive subconcussive head impacts associated with participation in youth contact sports could lead to changes in the shape of the corpus callosum during this critical time of brain development. Dr. Kim cautioned, however, that more evidence is needed to confirm the findings. His group intends to continue studying the players, when possible, to see if any additional deformation occurs.
The ultimate goal of the research, Dr. Kim said, is to provide guidelines for safe football play. MRI may have a role in that process by helping to determine if and when an athlete is able to return to play after a head injury. Positron emission tomography, an imaging technique that can detect signs of inflammation in the brain, is also potentially useful in this regard, according to Dr. Kim.
"It's best to detect changes at the earliest possible time," he said.
Getting older adults to be more active
Tailoring exercise plans to elder preferences is key in helping them keep fit and stick with a training plan
Credit: Photo: Andrea Hegdahl Tiltnes, NTNU
But merely knowing that exercise yields big health gains doesn't mean much as long as a majority of the elderly are not active enough to achieve these benefits.
In two newly published studies, researchers at NTNU's Cardiac Exercise Research Group (CERG) have identified the kinds of exercise that older adults choose and who is most prone to dropping out of a training programme.
"The results could be important to help facilitate increasing activity levels in the elderly. Information about what older adults prefer enables us to tailor exercise programmes to appeal to seniors," says Line Skarsem Reitlo. Both research articles are part of her doctoral project.
70 000 exercise logs
Generation 100 is an exercise study that has been underway for five years.
More than 1500 participants between ages 70 and 77 were randomly assigned to one of two exercise groups or a control group. The participants in the two exercise groups undertook moderate or high intensity training sessions twice a week, mostly on their own.
"We read through a total of 70 000 exercise logs from the first year of the study. It turned out that the participants to a great degree managed to train at the prescribed intensity. This is important to know, because it indicates that older people do not need to be monitored to be able to train at high intensity," says Reitlo.
Reitlo is a PhD candidate in NTNU's Department of Circulation and Medical Imaging, which hosts CERG.
Participants were asked to fill out exercise logs documenting how long their workouts lasted, how hard they exercised, what activities they performed, where they exercised, and whether they were training alone or with someone.
The article, recently published in BMC Geriatrics, includes data from the exercise logs of 618 participants in the two Generation 100 exercise groups.
Build more walking trails
Walking was the most popular form of activity in both the moderate and high intensity training groups. In the moderate intensity group, walking represented more than half of the training that people undertook.
"Walking was the most popular activity in the high intensity group as well, but this group included more training in the form of cycling and jogging than participants in the moderate group. Achieving high intensity might have been easier with these types of activity for some participants," says Reitlo.
All the participants preferred training outdoors both in summer and in winter. Altogether, they did almost two-thirds of their workouts outside or in their own neighborhood.
"Their preference for the outdoors indicates that it's important to establish good training areas for our elders. Since walking is the most popular form of exercise, for example, it could be a good idea to create more recreation trails," says Reitlo.
Social, dancing women
"But a lot of seniors find other types of exercise attractive - and we also observed some gender differences. This suggests that we should offer different types of activities so that they meet the needs of as many elders as possible," she says.
One of the differences between older women and men is exercise intensity. Men tend to train with greater intensity, and a higher proportion of their workouts included jogging, cycling and cross-country skiing. Women were more likely to choose dance and walking as activities.
"We also found that older women exercise with others more often than older men do," Reitlo said. "Whereas women chose to train with others for almost 60% of the sessions, men only chose to do this 40% of the time."
Forgetful, unfit dropouts
The second article looks at what distinguishes participants who dropped out of the Generation 100 study. Only 15% of the over 1500 participants quit the programme in the first three years, which is a much lower percentage than in most previous studies with older participants.
"Dropout from exercise programmes is a challenge. But even at start-up you can pick up on which seniors may be prone to dropping out of a training programme, so that they can be followed up on and motivated a bit more," says Reitlo.
Older adults with memory loss and less education have a greater likelihood of quitting a training programme, according to the results from Generation 100. The physical fitness and activity level of the participants before the study started was also crucial.
"Individuals who were physically active for fewer than 30 minutes a day were almost twice as likely to drop out from the study within three years as those who were more physically active. Low grip strength and poor fitness are other characteristics that make elders more likely to discontinue a training programme," says Reitlo.
Low cardiorespiratory fitness could be a warning sign of future problems, even in the fit and healthy
FULL STORY
Even if you are a fit and healthy
person with no signs of any heart or blood vessel disease, low
cardiorespiratory fitness could be a warning sign of future problems,
according to a study published in the European Heart Journal today (Thursday).
Cardiorespiratory fitness refers to the ability of the blood
circulation and respiratory systems to supply adequate oxygen to muscles
during sustained physical activity. The main measure of it is VO2max --
the maximum rate of oxygen consumption during exercise that increases
with intensity.
In the study published today, 4527 fit and healthy men and women with no history of cardiovascular or lung disease, cancer or raised blood pressure, had their cardiorespiratory fitness assessed when they joined a large, population-based health study in Norway (the HUNT3 study) between 2006-2008. Wearing a face mask and a heart rate monitor, they warmed up for ten minutes on a treadmill before running faster and faster. Their oxygen intake was measured to establish their VO2max. The researchers also gathered information on tobacco use, alcohol consumption, family history of cardiovascular disease, physical activity, weight, height and waist circumference, blood pressure and cholesterol levels.
After an average follow-up time of nearly nine years, the researchers found that greater cardiorespiratory fitness was linked to a lower risk of cardiovascular disease, such as heart attacks. Only 147 participants (3.3%) were diagnosed with heart disease or died from it, or required intervention to unblock clogged arteries during this period.
"We found a strong link between greater fitness and reduced risk of a coronary event during the nine years of follow-up in a very healthy sample of adults," said Dr Bjarne Nes, a researcher at the Norwegian University of Science and Technology (NTNU). "In fact, the participants who were in the 25% of those with the highest cardiorespiratory fitness had nearly half the risk compared to those in the 25% with the lowest fitness levels."
The researchers found that, in both men and women, the risk of cardiovascular problems fell by 15% for every extra unit of measurement of cardiorespiratory fitness -- metabolic equivalents (METs). METs measure the oxygen required for the energy expended on physical activity, with one MET being the amount needed if a person is sitting quietly (3.5 mL of oxygen per kg of body weight per minute), while high exertion such as running would use about eight METs.
"This indicates that greater cardiorespiratory fitness protects against both chronic and acute heart and blood vessel problems," said Dr Nes. "Even a small increase in fitness could have a large impact on health."
The lead author of the study, Dr Jon Magne Letnes, who is a medical doctor and research fellow in the Cardiac Exercise Research Group at NTNU, said: "Our results should encourage the use of exercise as preventive medicine. A few months of regular exercise may be an efficient way of reducing the cardiovascular risk."
A strength of the study is that cardiorespiratory fitness was measured with a gold-standard maximal exercise test of peak oxygen uptake (VO2peak) -- the first to do this in a healthy sample of the general population. Previous studies that have linked fitness to disease risk in healthy populations are mainly based on self-report or less accurate estimates.
A limitation of the study is that participating in voluntary exercise testing introduces the possibility that more active people might choose to join the study, which might reduce its applicability to the general population.
In an accompanying editorial, Professor Sanjay Sharma, of St George's University of London (UK), who is medical director of the London Marathon and chair of the expert cardiology panel for the English Football Association, and Dr Aneil Malhotra, also of St George's, write: "This study adds to the current literature by demonstrating a similar benefit in an ostensibly healthy population with an incremental benefit that continues beyond 12 METS and suggests that there is no obvious upper threshold for the cardioprotective effects of exercise. Although the number of subjects is laudable, there are several points to note."
They highlight that there is an unavoidable but inherent selection bias towards participants who were motivated to take part and were probably more aware of lifestyle measures to avoid cardiovascular disease; and the participants were young and healthy, which explains the low number of cardiovascualar-related events during the follow-up period.
They conclude: "In an era where primary prevention is playing an increasingly significant role in society, this study helps highlight that improving CRF [cardiorespiratory fitness] is a pivotal factor in reducing CV [cardiovascular] risk and mortality. Regular physical activity and measures of CRF should be incorporated into clinical practice and CV risk models. All individuals should be encouraged to exercise to the minimal level recommended by the European guidelines for disease prevention, although the observations of Letnes and colleagues and several others suggest that substantially higher physical activity levels and CRF provide additional prognostic benefit. For those who are compromised due to comorbidities or functional status, there is overwhelming evidence that some physical activity is better than none."
In the study published today, 4527 fit and healthy men and women with no history of cardiovascular or lung disease, cancer or raised blood pressure, had their cardiorespiratory fitness assessed when they joined a large, population-based health study in Norway (the HUNT3 study) between 2006-2008. Wearing a face mask and a heart rate monitor, they warmed up for ten minutes on a treadmill before running faster and faster. Their oxygen intake was measured to establish their VO2max. The researchers also gathered information on tobacco use, alcohol consumption, family history of cardiovascular disease, physical activity, weight, height and waist circumference, blood pressure and cholesterol levels.
After an average follow-up time of nearly nine years, the researchers found that greater cardiorespiratory fitness was linked to a lower risk of cardiovascular disease, such as heart attacks. Only 147 participants (3.3%) were diagnosed with heart disease or died from it, or required intervention to unblock clogged arteries during this period.
"We found a strong link between greater fitness and reduced risk of a coronary event during the nine years of follow-up in a very healthy sample of adults," said Dr Bjarne Nes, a researcher at the Norwegian University of Science and Technology (NTNU). "In fact, the participants who were in the 25% of those with the highest cardiorespiratory fitness had nearly half the risk compared to those in the 25% with the lowest fitness levels."
The researchers found that, in both men and women, the risk of cardiovascular problems fell by 15% for every extra unit of measurement of cardiorespiratory fitness -- metabolic equivalents (METs). METs measure the oxygen required for the energy expended on physical activity, with one MET being the amount needed if a person is sitting quietly (3.5 mL of oxygen per kg of body weight per minute), while high exertion such as running would use about eight METs.
"This indicates that greater cardiorespiratory fitness protects against both chronic and acute heart and blood vessel problems," said Dr Nes. "Even a small increase in fitness could have a large impact on health."
The lead author of the study, Dr Jon Magne Letnes, who is a medical doctor and research fellow in the Cardiac Exercise Research Group at NTNU, said: "Our results should encourage the use of exercise as preventive medicine. A few months of regular exercise may be an efficient way of reducing the cardiovascular risk."
A strength of the study is that cardiorespiratory fitness was measured with a gold-standard maximal exercise test of peak oxygen uptake (VO2peak) -- the first to do this in a healthy sample of the general population. Previous studies that have linked fitness to disease risk in healthy populations are mainly based on self-report or less accurate estimates.
A limitation of the study is that participating in voluntary exercise testing introduces the possibility that more active people might choose to join the study, which might reduce its applicability to the general population.
In an accompanying editorial, Professor Sanjay Sharma, of St George's University of London (UK), who is medical director of the London Marathon and chair of the expert cardiology panel for the English Football Association, and Dr Aneil Malhotra, also of St George's, write: "This study adds to the current literature by demonstrating a similar benefit in an ostensibly healthy population with an incremental benefit that continues beyond 12 METS and suggests that there is no obvious upper threshold for the cardioprotective effects of exercise. Although the number of subjects is laudable, there are several points to note."
They highlight that there is an unavoidable but inherent selection bias towards participants who were motivated to take part and were probably more aware of lifestyle measures to avoid cardiovascular disease; and the participants were young and healthy, which explains the low number of cardiovascualar-related events during the follow-up period.
They conclude: "In an era where primary prevention is playing an increasingly significant role in society, this study helps highlight that improving CRF [cardiorespiratory fitness] is a pivotal factor in reducing CV [cardiovascular] risk and mortality. Regular physical activity and measures of CRF should be incorporated into clinical practice and CV risk models. All individuals should be encouraged to exercise to the minimal level recommended by the European guidelines for disease prevention, although the observations of Letnes and colleagues and several others suggest that substantially higher physical activity levels and CRF provide additional prognostic benefit. For those who are compromised due to comorbidities or functional status, there is overwhelming evidence that some physical activity is better than none."
Wednesday, November 28, 2018
People with more knowledge about benefits of physical activity may also exercise more
Most people have a poor understanding of how much physical activity is good for you, and what health benefits such activity conveys. But the better your knowledge on these topics, the more physical activity you're likely to get, according to a study published November 28, 2018 in the open-access journal PLOS ONE.
A study from Central Queensland University in Australia, led by Stephanie Schoeppe, surveyed 615 Australian adults about their physical activity as well as their level of knowledge about physical activity's health benefits and the risks of inactivity. Based on their answers, each participant was assigned a ranking in four areas: knowing that physical activity is beneficial and inactivity is harmful; knowing that specific health conditions are related to inactivity; knowing how much physical activity is recommended; and applying this knowledge to one's own risks. Participants were 24.4% male and 75.3% female, between 18 and 77 years old, with a median age of 43, and had a range of education levels and employment statuses relatively representative of the general Australian population.
While the vast majority (99.6%) of participants strongly agreed that physical activity is good for health, most were not aware of all the diseases associated with inactivity. On average, participants correctly identified 13.8 out of 22 diseases associated with a lack of physical activity. Moreover, 55.6% incorrectly answered how much physical activity is needed for health, and 80% of people failed to identify the probabilities of developing diseases without physical activity. A significant association was found between these scores on knowledge of the probabilities of inactivity-related diseases and how active a person was. Future research is needed to determine whether the results hold true equally between men and women, and whether the survey-based data correctly gauges a person's true levels of physical activity.
Schoeppe adds: "Most people know that physical activity is good for health. Few people know the specific benefits of physical activity for health, and it may be this specific knowledge that positively influences their physical activity behaviour."
Routine vitamin B12 screening may prevent irreversible nerve damage in type-2 diabetes
Patients
with type-2 diabetes, taking metformin, should have their vitamin B12 levels
assessed more regularly to avoid irreversible nerve damage, according to a new
study presented at the Society for Endocrinology annual conference in Glasgow.
The study findings suggest that earlier detection of vitamin B12 deficiency
through routine screening of all metformin-treated, type-2 diabetes patients
could reduce their risk of developing irreversible, painful and potentially
disabling nerve damage.
The
increasing incidence of type-2 diabetes is a serious health issue worldwide.
Its prevalence is associated with poor diet and unhealthy lifestyle choices,
and it is characterised by high blood glucose levels that need to be controlled
by medication. Nerve damage in the periphery (e.g. face, limbs, organs) is a
common complication of diabetes, with symptoms that range from numbness to
pain, and can lead to debilitating loss of balance and co-ordination. Metformin
is the recommended and most effective first-line drug for type-2 diabetes but
its use has also been linked to vitamin B12 deficiency, which increases the
risk of peripheral nerve damage. Despite the irreversibility of peripheral
nerve damage, no official guidelines exist on screening vitamin B12 levels in
patients treated with metformin.
In
this study, Dr Kaenat Mulla and GP colleagues at Hucknall Road Medical Centre,
Nottingham conducted an audit of vitamin B12 screening and deficiency among
female, metformin-treated, patients with type-2 diabetes at the GP practice.
The audit findings indicated that 64% of patients had not had their vitamin B12
levels checked at all, and that 9.6% of patients were deficient but only 6.4%
were being treated with vitamin B12.
Dr
Mulla states, "Current British Society of Haematology guidelines recommend
that vitamin B12 levels are checked only when there is clinical suspicion of
deficiency. However, peripheral neuropathy is irreversible and it may be too
late once symptoms have developed."
Dr
Mulla and her team now plan to extend their audit to determine how best to
treat patients found to be vitamin B12 deficient, and to provide further
evidence that all type-2 patients on metformin should have their levels checked
more regularly, for example at their annual check-up.
Dr
Mulla comments, "Our findings indicate that patients with diabetes taking
metformin should be checked more frequently and that we need to ensure
deficiencies are adequately treated to avoid irreversible nerve damage."
However, she also cautions, "Metformin remains the best treatment for
type-2 diabetes, these findings should not discourage patients from taking it,
but encourage doctors to monitor vitamin B12 levels more routinely, so any
deficiency can quickly be treated."
Women benefit from mammography screening beyond age 75
Women age 75 years and older should
continue to get screening mammograms because of the comparatively high
incidence of breast cancer found in this age group, according to a new
study being presented next week at the annual meeting of the
Radiological Society of North America (RSNA).
Guidelines on what age to stop breast cancer screening have been a
source of confusion in recent years. In 2009, the United States
Preventive Services Task Force (USPSTF) released controversial
guidelines stating there was not enough evidence to assess benefits and
harms of screening mammography in women age 75 and older. However, other
professional groups advise that women may continue to undergo
mammography screening as long as they are in good health."Ongoing debate exists regarding the age to cease screening mammography," said Stamatia V. Destounis, M.D., radiologist at Elizabeth Wende Breast Care, LLC, in Rochester, N.Y. "Our findings provide important data demonstrating that there is value in screening women over 75 because there is a considerable incidence of breast cancer."
For the study, Dr. Destounis and colleagues analyzed data from 763,256 screening mammography exams at Elizabeth Wende Breast Care between 2007 and 2017. Screening-detected cancer was diagnosed in 3,944 patients. Further analysis was performed to identify the number and type of cancers diagnosed among women 75 years of age and older.
There were 76,885 patients (10 percent) age 75 and older included in the study. The average age of the patients was 80.4. A total of 645 malignancies were diagnosed in 616 patients, for a cancer rate of 8.4 detections per 1,000 exams in this age group.
"For the relatively small percentage of our screening population that was composed of women 75 and older, the patients diagnosed in this population made up 16 percent of all patients diagnosed with screening-detected cancers," Dr. Destounis said.
Researchers also found that 82 percent of the malignancies diagnosed were invasive cancers, of which 63 percent were grade 2 or 3, which grow and spread more quickly. Ninety-eight percent of the cancers found were able to be treated surgically. Positive lymph nodes were reported at surgical excision in 7 percent of the patients. Seventeen cancers were not surgically treated due to advanced patient age or overall degraded patient health.
"Most of the tumors found in this age group were invasive, and almost all of these patients -- 98 percent -- underwent surgery," Dr. Destounis said.
Mammography plays a critical role in the early detection of breast cancer, because it can show changes in the breast up to two years before a woman or her physician can feel them, and early detection leads to better treatment options and improved survival.
Dr. Destounis advises women over 75 who are in relatively good health to continue routine screenings.
"The benefits of screening yearly after age 75 continue to outweigh any minimal risk of additional diagnostic testing," she said.
Anabolic steroids linked to higher rates of premature death in men
Men who use androgenic anabolic
steroids -- such as testosterone -- may face a higher risk of early
death and of experiencing more hospital admissions, according to a new Journal of Internal Medicine study.
For the study, 545 men who used androgenic anabolic steroids were
matched with 5,450 controls. In addition, 644 men who were sanctioned
because they refused to submit to a doping test and 6440 controls were
included as a replication cohort.
Over an average follow-up of 7.4 years, there were seven (1.3 percent) deaths among users of androgenic anabolic steroids and 23 (0.4 percent) among participants in the control group, translating to a three-times higher risk of death associated with androgenic anabolic steroids. The median annual number of hospital contacts was 0.81 in the androgenic anabolic steroid users and 0.36 in the controls. Acne, gynaecomastia, and erectile dysfunction affected more than 10 percent of the androgenic anabolic steroid users, and the prevalence of these disorders was significantly higher than in the control group. Similar results were seen in the replication cohort.
"This study has shown that anabolic steroids are associated with a range of side effects that can be directly attributed to their pharmacological activities," said lead author Dr. Henrik Horwitz, of the University of Copenhagen, in Denmark.
Over an average follow-up of 7.4 years, there were seven (1.3 percent) deaths among users of androgenic anabolic steroids and 23 (0.4 percent) among participants in the control group, translating to a three-times higher risk of death associated with androgenic anabolic steroids. The median annual number of hospital contacts was 0.81 in the androgenic anabolic steroid users and 0.36 in the controls. Acne, gynaecomastia, and erectile dysfunction affected more than 10 percent of the androgenic anabolic steroid users, and the prevalence of these disorders was significantly higher than in the control group. Similar results were seen in the replication cohort.
"This study has shown that anabolic steroids are associated with a range of side effects that can be directly attributed to their pharmacological activities," said lead author Dr. Henrik Horwitz, of the University of Copenhagen, in Denmark.
Tuesday, November 27, 2018
Why over-frying is risky
Heat-induced contaminants are the main topic in the latest BfR science magazine BfR2GO
Other topics in this issue are sources of caffeine and how much is too much; and mineral oils in cosmetics.
The science magazine BfR2GO appears twice a year in German and English and is published on the BfR website from where it can be downloaded free of charge:
https:/
https:/
Interested parties can register per e-mail for a free subscription to the magazine.
Blood pressure: Early treatment advised by US guidelines has no survival benefits Technica
When is high blood pressure dangerous? Medical associations offer
widely differing answers. In the USA, for example, patients are seen as
hypertensive much sooner than in Germany. A team working with Prof.
Karl-Heinz Ladwig of the Technical University of Munich and the
Helmholtz Zentrum München has concluded that treating patients sooner
does not reduce the risk of deadly heart disease. It could even
negatively affect their mental health.
In 2017 the American College of Cardiology added a new category to its guidelines for high blood pressure: "Stage 1 Hypertension". Under the new standards, doctors are advised to place patients in this category (130-139 mmHg / 80-89 mmHg) on treatment. For the European Society of Cardiology, that range is defined as "high normal" blood pressure, with no specific action recommended.
"The idea behind the US guidelines is to lower blood pressure as early as possible and, by presenting patients with a diagnosis, to encourage them to adopt a healthier lifestyle," explains Prof. Karl-Heinz Ladwig, a researcher at the Clinic for Psychosomatic Medicine and Psychotherapy at the TUM University Clinic rechts der Isar at the Helmholtz Zentrum München.
Motivation factor questionable
Using data from approximately 12,000 patients, Ladwig and his team assessed the situation in Germany. "We studied the 10-year risk of mortality from cardio-vascular disease (CVD) among people in the various hypertension categories in the context of the other risk factors affecting them," says Seryan Atasoy, the first author of the study, who is working as an epidemiologist at Helmholtz Zentrum München and Ludwig-Maximilians-Universität München.
In the newly created category "Stage 1 Hypertension", the CVD mortality risk was not significantly higher than among patients with normal blood pressure. "The motivation effect is questionable, too," says Karl-Heinz Ladwig. Patients in the high-risk category "Stage 2 Hypertension", where medication is recommended under both the US and the European guidelines, have a much greater risk of dying of heart disease, he explains. "At the same time, risk factors such as smoking and a lack of exercise are far more frequent in that group. That shows that many people do not change their lifestyles despite the diagnosis."
Dangerous depression Although the incidence of depression is generally lower among people with dangerously high blood pressure than in the general population, depression was significantly more common in one subset of that group: those taking medication to treat their serious hypertension. Here, depressive moods were reported by around half of all patients, as opposed to just one-third of those not receiving treatment.
"We believe that this should be seen as a labeling effect," says Ladwig. "When people are officially labeled as 'sick', that has an impact on their mental health." A previous study by Ladwig and his team showed that, in terms of mortality risk from cardio-vascular disease, depression is comparable to high cholesterol levels or obesity.
New guidelines mean more sick people "The American College of Cardiology itself has calculated that the proportion of adults diagnosed with high blood pressure will increase from 32 to 46 percent," says Karl-Heinz Ladwig. "That means 14 percent more who have to deal with the additional mental stress - although their risk of developing a potentially deadly cardio-vascular condition is not significantly higher, and despite no real expectation of extra motivation through the diagnosis." For those reasons, Ladwig believes that it would be a serious mistake to adopt the US guidelines in Europe.
Contact: Prof. Dr. Karl-Heinz Ladwig
Technical University of Munich (TUM)
Klinikum rechts der Isar
Clinic for Psychosomatic Medicine and Psychotherapy
+49 89 3187 3623
Email: ladwig@helmholtz-muenchen.de
In 2017 the American College of Cardiology added a new category to its guidelines for high blood pressure: "Stage 1 Hypertension". Under the new standards, doctors are advised to place patients in this category (130-139 mmHg / 80-89 mmHg) on treatment. For the European Society of Cardiology, that range is defined as "high normal" blood pressure, with no specific action recommended.
"The idea behind the US guidelines is to lower blood pressure as early as possible and, by presenting patients with a diagnosis, to encourage them to adopt a healthier lifestyle," explains Prof. Karl-Heinz Ladwig, a researcher at the Clinic for Psychosomatic Medicine and Psychotherapy at the TUM University Clinic rechts der Isar at the Helmholtz Zentrum München.
Motivation factor questionable
Using data from approximately 12,000 patients, Ladwig and his team assessed the situation in Germany. "We studied the 10-year risk of mortality from cardio-vascular disease (CVD) among people in the various hypertension categories in the context of the other risk factors affecting them," says Seryan Atasoy, the first author of the study, who is working as an epidemiologist at Helmholtz Zentrum München and Ludwig-Maximilians-Universität München.
In the newly created category "Stage 1 Hypertension", the CVD mortality risk was not significantly higher than among patients with normal blood pressure. "The motivation effect is questionable, too," says Karl-Heinz Ladwig. Patients in the high-risk category "Stage 2 Hypertension", where medication is recommended under both the US and the European guidelines, have a much greater risk of dying of heart disease, he explains. "At the same time, risk factors such as smoking and a lack of exercise are far more frequent in that group. That shows that many people do not change their lifestyles despite the diagnosis."
Dangerous depression Although the incidence of depression is generally lower among people with dangerously high blood pressure than in the general population, depression was significantly more common in one subset of that group: those taking medication to treat their serious hypertension. Here, depressive moods were reported by around half of all patients, as opposed to just one-third of those not receiving treatment.
"We believe that this should be seen as a labeling effect," says Ladwig. "When people are officially labeled as 'sick', that has an impact on their mental health." A previous study by Ladwig and his team showed that, in terms of mortality risk from cardio-vascular disease, depression is comparable to high cholesterol levels or obesity.
New guidelines mean more sick people "The American College of Cardiology itself has calculated that the proportion of adults diagnosed with high blood pressure will increase from 32 to 46 percent," says Karl-Heinz Ladwig. "That means 14 percent more who have to deal with the additional mental stress - although their risk of developing a potentially deadly cardio-vascular condition is not significantly higher, and despite no real expectation of extra motivation through the diagnosis." For those reasons, Ladwig believes that it would be a serious mistake to adopt the US guidelines in Europe.
###
Publication:
S. Atasoy, H. Johar, A. Peters, K.-H. Ladwig. "Association of
hypertension cut-off values with 10-year cardiovascular mortality and
clinical consequences: a real-world perspective from the prospective
MONICA/KORA study". European Heart Journal (2018). DOI:10.1093/eurheartj/ehy694 Contact: Prof. Dr. Karl-Heinz Ladwig
Technical University of Munich (TUM)
Klinikum rechts der Isar
Clinic for Psychosomatic Medicine and Psychotherapy
+49 89 3187 3623
Email: ladwig@helmholtz-muenchen.de
Playing youth football could affect brain development Radiological Society of North America
Young football players may experience a disruption in brain development after a single season of the sport, according to a new study presented today at the annual meeting of the Radiological Society of North America (RSNA).
"This research demonstrates that playing a season of contact sports may affect normal gray matter pruning in high school and youth football players," said Gowtham Krishnan Murugesan, M.S., research assistant in the Department of Radiology at UT Southwestern Medical Center in Dallas, Texas.
The brain is highly complex with an abundance of neural connections. New connections are formed, and unused connections fall away in a process called pruning. Much like cutting back dead or unnecessary branches keeps a tree healthy and helps it grow, brain pruning is necessary to healthy brain development.
"Pruning is an essential part of brain development," Murugesan said. "By getting rid of the synapses that are no longer used, the brain becomes more efficient with aging."
The researchers set out to determine whether exposure to repetitive head impacts affects normal pruning of the brain in young football players.
For the study, 60 youth and high school football players without history of developmental, neurological or psychiatric abnormalities and no history of concussion prior to or during the season were outfitted with the Head Impact Telemetry System (HITS). HITS helmets are lined with accelerometers or sensors that measure the magnitude, location and direction of impacts to the head. Impact data from the helmets were used to calculate a risk of concussion exposure for each player.
Players were then split into two groups: high-impact players (24) and low-impact players (36), based on each player's risk of cumulative head impact exposure as determined by HITS.
Pre- and post-season resting state functional (fMRI) scans were performed on all players, and changes in power within five components the default mode network (DMN) were analyzed.
The DMN is a network of regions deep in the gray matter areas of the brain. It includes structures that activate when a person is awake and engaging in introspection or processing emotions, which are activities that are important for brain health.
The post-season results showed significant increases in power and gray matter volume in the frontal DMN in the high-impact group.
"Disruption in normal pruning has been shown to be related to weaker connections between different parts of the brain," Murugesan said. "Our study has found a significant decrease in gray matter pruning in the frontal default mode network, which is involved in higher cognitive functions, such as the planning and controlling of social behaviors."
Studies of biomechanical data from this same group of participants were conducted at Wake Forest University in Winston-Salem, N.C. Their findings showed that most head impacts occurred during practice.
"By replacing high-impact practice drills with low- or no-impact drills, the overall head-impact exposure for players can be reduced," Murugesan said.
The researchers also suggested that minor modifications to the game could also be implemented to reduce full-speed contact.
"The new National Football League kickoff rule eliminating the running start is an example," Murugesan said.
The researchers hope to conduct further study to fully understand the long-term changes in resting state brain networks and their association with neuropsychological task performance.
Cancer treatments may affect cognitive function by accelerating biological aging
Treatments for breast cancer increase patients' risks for long-term and late toxicities, including persistent fatigue, pain, and cognitive dysfunction. Certain treatments, including radiation and some chemotherapeutic drugs, work by damaging the DNA of cancer cells, but they can also cause damage to DNA of normal cells, which can contribute to accelerated biological aging.
To examine whether indicators of biological aging are related to cognitive function in breast cancer survivors, Judith E. Carroll, PhD, Associate Professor of Psychiatry, of the UCLA Cousins Center for Psychoneuroimmunology and the Semel Institute for Neuroscience and Human Behavior, and her colleagues evaluated a group of 94 women who had been treated for breast cancer three to six years earlier. The indicators of biological aging included elevated levels of DNA damage, reduced telomerase enzymatic activity, and shorter telomere length in certain blood cells. (Telomerase is an enzyme that is important for maintaining the length of telomeres, repeat sequences of DNA at the ends of chromosomes that help maintain the health of cells and serve as a marker of cell age.)
The team found that women who had previously been treated for breast cancer who had both higher DNA damage and lower telomerase activity had lower executive function scores. In addition, lower telomerase activity was associated with worse attention and motor speed. Telomere length was not related to any of the neurocognitive domains.
"These findings are important because they provide further information about what might be happening after cancer treatment that impacts cognitive decline in some individuals. This information can inform future research and may lead to new interventions to prevent these cognitive declines," said Dr. Carroll, who is also a member of the UCLA Jonsson Comprehensive Cancer Center. "The work is novel by identifying key factors in biological aging and connecting them to cognitive function, which initiates new avenues of research.
Beware of evening stress
The body's central system reacts less strongly to acute psychological stress in the evening than it does in the morning, according to research conducted at Japan's Hokkaido University.
In the study published in the journal Neuropsychopharmacology Reports, medical physiologist Yujiro Yamanaka and his colleagues recruited 27 young, healthy volunteers with normal work hours and sleep habits to find out if the "hypothalamic -pituitary-adrenal" (HPA) axis responds differently to acute psychological stress according to the time of day.
The HPA axis connects the central nervous and endocrine systems of the body. Cortisol, the primary stress hormone in humans, is released for several hours when the HPA axis is activated by a stressful event. This helps provide the body with energy in the face of a perceived need for fight or flight. Cortisol levels are also regulated by a master circadian clock in the brain, and are normally high in the morning and low in the evening.
The team first measured the diurnal rhythm of salivary cortisol levels from the volunteers to establish a baseline. The volunteers were then divided into two groups: one that was exposed to a stress test in the morning, two hours after their normal waking time, and another that was exposed to a stress test in the evening, ten hours after their normal waking time.
The test lasted for a period of 15 minutes and involved preparing and giving a presentation in front of three trained interviewers and a camera, and conducting a mental arithmetic. Saliva samples were taken half an hour before starting the test, immediately after, and at ten-minute intervals for another half hour.
The researchers found that salivary cortisol levels increased significantly in the volunteers that took the stress test in the morning while no such response was observed in those that took the test in the evening. The volunteers' heart rates on the other hand, an indicator of the sympathetic nervous system which immediately responds to stress, did not differ according to when the test was taken.
Yujiro Yamanaka commented "The body can respond to the morning stress event by activating the HPA axis and sympathetic nervous system, but it needs to respond to evening stress event by activating the sympathetic nervous system only. Our study suggests a possible vulnerability to stress in the evening. However, it is important to take into account each individual's unique biological clock and the time of day when assessing the response to stressors and preventing them."
Intermittent fasting: No advantage over conventional weight loss diets German
Feasting eight hours and then fasting the following 16 hours? Or is it even better to fast two whole days a week and then enjoy eating without regrets for the rest of the week? Intermittent fasting, also known as 16:8 diet or 5:2 diet, is trendy. Numerous popular self-help books on this topic promise weight loss without yo-yo effect as well as sustained changes in metabolism and resulting health benefits. The German Nutrition Society (DGE), on the other hand, warns that intermittent fasting is not suitable for long-term weight regulation. In addition, according to DGE, there is not enough scientific evidence on the long-term effects of this dieting method.
"There are in fact only a few smaller studies on intermittent fasting so far, but they have come up with strikingly positive effects for metabolic health," says DKFZ's Ruth Schübel. "This made us curious and we intended to find out whether these effects can also be proven in a larger patient group and over a prolonged period."
In collaboration with a team of DKFZ researchers and scientists from Heidelberg University Hospital, Schübel examined 150 overweight and obese study participants over one year as part of the HELENA study. At the start of the study, they were randomly classified in three groups: One third followed a conventional calorie restriction diet that reduced daily calorie intake by 20 percent. The second group kept to a 5:2 dietary plan that also saved 20 percent of calorie intake over the whole week. The control group followed no specific diet plan but was advised, like all other participants, to eat a well-balanced diet as recommended by DGE. Following the actual dieting phase, the investigators documented the participants' weight and health status for another 38 weeks.
The result may be as surprising as it is sobering for all followers of intermittent fasting. The HELENA researchers found that improvements in health status were the same with both dietary methods. "In participants of both group, body weight and, along with it, visceral fat, or unhealthy belly fat, were lost and extra fat in the liver reduced," Schübel reported.
The changes in body weight distribution in the study participants were exactly determined using special MRT imaging executed by Johanna Nattenmüller at Heidelberg University Hospital. The good news is: a small dieting success is already a big gain for health. Those who reduce their body weight by only five percent, lose about 20 percent of dangerous visceral fat and more than a third of fat in the liver - no matter which dietary method they have used.
The investigators also did not find any difference between the two dieting methods in any other metabolic values that were analyzed or biomarkers and gene activities under investigation.
Although the HELENA study does not confirm the euphoric expectations placed in intermittent fasting, it also shows that this method is not less beneficial than conventional weight loss diets. "In addition, for some people it seems to be easier to be very disciplined on two days instead of counting calories and limiting food every day," explained Tilman Kühn, leading scientist of the trial. "But in order to keep the new body weight, people must also permanently switch to a balanced diet following DGE recommendations", he added.
According to Kühn, the study results show that it is not primarily the dietary method that matters but that it is more important to decide on a method and then follow through with it. "The same evidence is also suggested in a current study comparing low-carb and low-fat diets, that is, reducing carbohydrates versus reducing fat intake while otherwise having a balanced diet," said Kühn. In this study, participants also achieved comparable results with both methods.
The scientists' credo is therefore: "Just do it!" Body and health will benefit from weight loss in any case, as long as it is achieved by a reliable dieting method and on the basis of a well-balanced diet.
Certain dietary or nutritional supplements could improve sperm quality
These are the results of an analysis
of 28 nutritional intervention studies involving 2,900 participants and
headed by the Universitat Rovira i Virgili; these supplements may
increase male fertility
Infertility affects 15% of the world population and is recognised by the World Health Organisation as a global health problem. In recent years, studies of sperm quality in different populations from developing countries have shown a decrease that could have consequences for the survival of the human species. The decrease in sperm quality has been related to unhealthy lifestyles. Stress, the consumption of drugs, tobacco and alcohol and unhealthy diets seem to be the principal modifiable factors.
Despite the current lack of scientific evidence regarding the effect of dietary and nutritional supplements on sperm quality, many fertility clinics offer dietary recommendations and supplements before providing their patients with in-vitro fertilisation (IVF) or intracytoplasmic sperm injection (ICSI).
Recently, researchers at the Human Nutrition Unit of the Universitat Rovira i Virgili (URV) and the Pere i Virgili Health Research Institute (IISPV), which are both members of the Ciber Obn Network of the Carlos III Institute, and researchers at the Clinical Department of Human Reproduction and Infant Growth at the Universidad de Guadalajara (Mexico) have carried out the most extensive and systematic review to date of randomised clinical studies into the effects of different nutrients and dietary supplements on sperm quality and male fertility.
After qualitatively analysing the results of 28 nutritional studies involving 2900 participants, researchers have concluded that supplementing the diet with omega 3 and coenzyme Q10 (in either liquid or tablet form) can have a beneficial effect on the quantity of spermatozoids in semen. Supplementing the diet with selenium, zinc, fatty acids, omega-3 and coenzyme-Q10 is associated with an increase in spermatozoid concentration; supplementing the diet with selenium, zinc, omega-3, coenzyme-Q10 and carnitines has been associated with an improvement in sperm mobility, and finally, selenium, fatty acids, omega-3, coenzyme-Q10 and carnitines has a positive effect on the morphology of spermatozoids.
According to the researchers, their study suggests that dietary supplements have a modulating effect on sperm quality and provides an extensive and up-to-date review of the existing scientific evidence. The results suggest that certain dietary supplements can have a beneficial effect on sperm quality, although it remains to be demonstrated whether this increases the likelihood of conceiving a child naturally or through assisted reproduction techniques. The researchers believe that further studies need to be carried out with larger samples so that a more accurate conclusion can be drawn.
The results of the present study, headed by Albert Salas-Huetos, post-doctoral researcher currently at the University of Utah and Jordi Salas-Salvadó, professor and director of the Human Nutrition Unit at the URV, have been published in the November edition of the scientific journal Advances in Nutrition.
Do you have a healthy personality?
They found that the healthy personality can be described, with a high level of agreement, in terms of the 30 facets of the "big five" model of personality traits. This model organizes personality into five major factors: neuroticism, extraversion, openness to experience, agreeableness, and conscientiousness. Scientists have also identified facets for each of these factors that describe more specific kinds of behaviors. In this study, experts and laypeople agreed that a healthy personality consists of low neuroticism along with high levels of openness to feelings, warmth, positive emotions and agreeable straightforwardness.
Their findings were just published in the Journal of Personality and Social Psychology.
"We believe our results have both practical implications for the assessment of and research on health personality functioning as well as deeper implications for theories about psychological adaption and functioning," said Wiebke Bleidorn, associate professor of psychology at UC Davis, the lead author of the study. "In addition to providing a comprehensive description of a psychologically healthy individual in terms of basic traits, the profile generated and tested provides a practical assessment tool for research on health personality functioning."
The purpose of the research was to address the healthy personality question by generating an expert-consensus model of the healthy person, surveying hundreds of professional personality psychologists along with hundreds of college students from Texas and Michigan. They found a striking agreement among all of these groups in regards to what a healthy personality entails.
"People in general, no matter whether they are experts or not, seem to have quite a clear idea of what a healthy personality looks like," Bleidorn said. Big five traits associated with life outcomes
There is also a large body of research showing that the big five traits identified as neuroticism, extraversion, openness to experience, agreeableness and conscientiousness are stable, heritable, and predict life outcomes such as health, self-esteem, academic performance, marital quality, and work performance.
Using the big five as a framework and an expert-consensus approach, the researchers first attempted to generate a basic trait profile of a prototypical healthy individual. In a second step, they used data from seven independent samples of over 3,000 participants to test whether the generated healthy profile can be used to assess healthy personality functioning at the individual level. To do this, they computed a healthy personality index for each participant that indicated how similar their own individual personality profile matched the expert-generated profile for the healthy personality.
As predicted, individuals with healthy personality profiles tended to be better adjusted as indicated by higher self-esteem, self-concept clarity, and optimism. Individuals with healthy personality scores were also more likely to describe themselves as being able to resist impulses, regulate their behavior, and focus their attention. They also described themselves as being low in aggression and antisocial behavior.
The associations with measures of narcissism and psychopathy yielded a more complex picture, however. Specifically, people with healthy personalities tended to score lower in the maladaptive aspects of narcissism such as exploitativeness but relatively higher in the potentially adaptive aspects of grandiosity and self-sufficiency. In a similar vein, people with healthier personalities scored low on the maladaptive facets of psychopathy measures such as blame externalization or disinhibition but relatively higher on the more adaptive facets of these scales such as stress immunity or boldness.
Overall, these results provide initial evidence for the convergent and divergent validity of the healthy personality index, researchers said.
Saturday, November 24, 2018
What causes chronic itching and scratching
Credit: Mack et al./Trends in Immunology
"To understand itch, you have to take an integrative approach," says senior author Brian Kim (@itchdoctor), dermatologist and immunologist at Washington University School of Medicine. "We may think our immune responses end in our immune system. But the itch-scratch cycle engages the immune system with the whole body, interacting with behavior and the environment as well."
Scratching in response to itch likely evolved to keep parasites, toxins, and other irritants off our skin. But in a disorder such as eczema, a condition that causes the skin to dry out, irritation is constant. Unfortunately, scratching only exacerbates the itch.
"Generally speaking, scratching is not very helpful for long-term conditions like eczema or even short-term itches like mosquito bites," says Kim, who co-authored the review with immunology PhD student Madison Mack. "It's likely triggering more inflammation and, inadvertently, infection. But scratching is very much a reflex; it's hard to tell people not to do it."
Scratching in response to skin irritation damages the outermost skin cells, releasing signaling proteins such as cytokines that activate itch-sensory neurons in the skin. These neurons in turn produce signals that trigger inflammation and scratching behavior.
Itch may also be related to pain. Some itch and pain sensory pathways are thought to overlap in the nervous system. Some research suggests that scratching can override the itchy feeling by activating pain-sensory neurons in the spinal cord that inhibit itch neurons.
Kim's lab studies which molecules could make the best targets for chronic itch therapies. Cytokines are contenders; the cytokine IL-4 has been targeted in therapies to block a neural pathway of itch in eczema, which Kim and Mack fully characterize in their review.
"These cytokines are great targets, but whether they're the best targets, we don't really know," says Kim. "There are many forms of itch, many things that cause itch, and many itch-scratch cycles."
Kim is also interested in whether an equivalent of the itch-scratch cycle might underlie bowel disorders caused by inflammation of the gut.
"Every organ in our body, including our gut, is innervated, but we often don't understand why," says Kim. "We do know that a lot of bowel dysmotility is associated with immune responses. Our immune system may be eliciting a behavioral response in the gut in an analogous way to the itch-scratch cycle."
Sweetened drinks pose greater diabetes risk than other sugary foods
"These findings might help guide recommendations on important food sources of fructose in the prevention and management of diabetes," said Dr. John Sievenpiper, the study's lead author and a researcher in the Clinical Nutrition and Risk Factor Modification Centre of St. Michael's Hospital in Toronto, Canada. "But the level of evidence is low and more high quality studies are needed."
The role of sugars in the development of diabetes and heart disease attracts widespread debate and increasing evidence suggests that fructose could be particularly harmful to health.
Fructose occurs naturally in a range of foods, including whole fruits and vegetables, natural fruit juices and honey. It is also added to foods, such as soft drinks, breakfast cereals, baked goods, sweets, and desserts as 'free sugars'.
Current dietary guidelines recommend reducing free sugars, especially fructose from sweetened beverages, but it is unclear whether this holds for all food sources of these sugars.
So researchers based at St. Michael's and the University of Toronto in Canada analysed the results of 155 studies that assessed the effect of different food sources of fructose sugars on blood glucose levels in people with and without diabetes monitored for up to 12 weeks.
Results were based on four study designs: substitution (comparing sugars with other carbohydrates), addition (energy from sugars added to diet), subtraction (energy from sugars removed from diet), or ad libitum (energy from sugars freely replaced).
Outcomes were glycated haemoglobin or HbA1c (amount of glucose attached to red blood cells), fasting glucose, and fasting insulin (blood glucose and insulin levels after a period of fasting).
Studies were also assessed for bias and certainty of evidence. Overall, no serious risk of bias was detected, but the certainty of evidence was low.
The results show that most foods containing fructose sugars do not have a harmful effect on blood glucose levels when these foods do not provide excess calories. However, a harmful effect was seen on fasting insulin in some studies.
Analysis of specific foods suggest that fruit and fruit juice when these foods do not provide excess calories may have beneficial effects on blood glucose and insulin control, especially in people with diabetes, whereas several foods that add excess "nutrient poor" energy to the diet, especially sweetened drinks and fruit juice, seem to have harmful effects.
The low glycaemic index (GI) of fructose compared with other carbohydrates, and higher fibre content of fruit, may help explain the improvements in blood glucose levels, by slowing down the release of sugars, say the researchers.
They point to some limitations, such as small sample sizes, short follow-up periods, and limited variety of foods in some studies. However, strengths included an in-depth search and selection process and thorough assessment of evidence quality.
As such, they conclude: "Until more information is available, public health professionals should be aware that harmful effects of fructose sugars on blood glucose seem to be mediated by energy and food source."
Orange juice, leafy greens and berries = less memory loss in men
Eating leafy greens, dark orange and red vegetables and berry fruits, and drinking orange juice may be associated with a lower risk of memory loss over time in men, according to a study published in the November 21, 2018, online issue of Neurology®, the medical journal of the American Academy of Neurology.
"One of the most important factors in this study is that we were able to research and track such a large group of men over a 20-year period of time, allowing for very telling results," said study author Changzheng Yuan, ScD, of Harvard T.H. Chan School of Public Health in Boston. "Our studies provide further evidence dietary choices can be important to maintain your brain health."
The study looked at 27,842 men with an average age of 51 who were all health professionals.
Participants filled out questionnaires about how many servings of fruits, vegetables and other foods they had each day at the beginning of the study and then every four years for 20 years. A serving of fruit is considered one cup of fruit or ½ cup of fruit juice. A serving of vegetables is considered one cup of raw vegetables or two cups of leafy greens.
Participants also took subjective tests of their thinking and memory skills at least four years before the end of the study, when they were an average age of 73. The test is designed to detect changes that people can notice in how well they are remembering things before those changes would be detected by objective cognitive tests. Changes in memory reported by the participants would be considered precursors to mild cognitive impairment. The six questions include "Do you have more trouble than usual remembering a short list of items, such as a shopping list?" and "Do you have more trouble than usual following a group conversation or a plot in a TV program due to your memory?"
A total of 55 percent of the participants had good thinking and memory skills, 38 percent had moderate skills, and 7 percent had poor thinking and memory skills.
The participants were divided into five groups based on their fruit and vegetable consumption. For vegetables, the highest group ate about six servings per day, compared to about two servings for the lowest group. For fruits, the top group ate about three servings per day, compared to half a serving for the bottom group.
The men who consumed the most vegetables were 34 percent less likely to develop poor thinking skills than the men who consumed the least amount of vegetables. A total of 6.6 percent of men in the top group developed poor cognitive function, compared to 7.9 percent of men in the bottom group.
The men who drank orange juice every day were 47 percent less likely to develop poor thinking skills than the men who drank less than one serving per month. This association was mainly observed for regular consumption of orange juice among the oldest men. A total of 6.9 percent of men who drank orange juice every day developed poor cognitive function, compared to 8.4 percent of men who drank orange juice less than once a month. This difference in risk was adjusted for age but not adjusted for other factors related to reported changes in memory.
The men who ate the most fruit each day were less likely to develop poor thinking skills, but that association was weakened after researchers adjusted for other dietary factors that could affect the results, such as consumption of vegetables, fruit juice, refined grains, legumes and dairy products.
The researchers also found that people who ate larger amounts of fruits and vegetables 20 years earlier were less likely to develop thinking and memory problems, whether or not they kept eating larger amounts of fruits and vegetables about six years before the memory test.
The study does not show that eating fruits and vegetables and drinking orange juice reduces memory loss; it only shows a relationship between them.
A limitation of the study was that participants' memory and thinking skills were not tested at the beginning of the study to see how they changed over the course of the study. However, because all participants completed professional training, they can be assumed to have started with relatively high cognitive function in early adult life. In addition, the study participants were all male health professionals such as dentists, optometrists, and veterinarians. Thus, the results may not apply to women and other groups of men.
Sleep length may affect risk of falls and fractures
Compared with women in a recent study who slept seven to eight hours each night, women who slept for less than 5 hours or more than10 hours had about a 25 percent increased odds of experiencing recurrent falls (falling at least twice in a year). In the Journal of Bone and Mineral Research analysis, poor sleep quality, insomnia, and more sleep disturbances were also associated with an increased odds of recurrent falls.
Short sleep was associated with an increased risk of all fractures, and upper limb, lower limb, and central body fractures, but not with an increased risk of hip fractures.
The analysis included 157,306 women enrolled in the Women's Health Initiative, with an average follow-up time of 7.6 years for falls and 12.0 years for fractures. The annualized rate of recurrent fall events was 10.6 percent among women reporting less than 5 hours of sleep per night, 7.0 percent among women sleeping seven to eight hours per night, and 11.8 percent among women sleeping more 10 hours per night.
"Falls are an important public health problem among older adults and lead to moderate to severe injuries. Most fractures occur because of falls, and recent evidence shows that mortality from falls in the US is increasing," said lead author Dr. Jane Cauley, of the University of Pittsburgh. "Even though falls are caused by a number of factors, our paper focuses on a novel risk factor: sleep. Results suggest that interventions aimed at improving sleep may reduce the risk of falls."
Mindfulness meditation may improve mood
In a randomized controlled trial of 134 mildly stressed, middle-aged
to older adults, participants who were assigned to a six-week
mindfulness-meditation training program experienced significantly
reduced negative affect variability--which refers to subjective distress
and includes a range of mood states such as worry, anxiety, anger,
self-criticism, and life dissatisfaction--compared with participants
assigned to a waitlist control. The effects seen in the Stress & Health study were mediated by a reduction in perceived stress.
The findings support the theory that mindfulness training facilitates a capacity to observe and experience internal reactions to stressors as they arise with acceptance and equanimity. "In turn, this impartial receptiveness buffers initial threat appraisals, and subsequently, reduces emotional reactivity, potentially leading to greater health," the authors wrote.
The findings support the theory that mindfulness training facilitates a capacity to observe and experience internal reactions to stressors as they arise with acceptance and equanimity. "In turn, this impartial receptiveness buffers initial threat appraisals, and subsequently, reduces emotional reactivity, potentially leading to greater health," the authors wrote.
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