Monday, September 8, 2014

1 in 10 global cardiovascular deaths due to high sodium intake

The World Health Organization recommend that adults should consume less than 2 g of sodium per day. But a new study finds that sodium intake above this recommendation accounts for almost 1 in 10 cardiovascular deaths globally each year.
Researchers estimate that 1 in 10 cardiovascular deaths each year are attributable to sodium intake above the WHO recommendations of 2 g per day.
The research team, led by Dr. Dariush Mozaffarian of the Friedman School of Nutrition Science and Policy at Tufts University in Medford, MA, recently published their findings in The New England Journal of Medicine.
Sodium is an element that occurs naturally in most foods, such as table salt, milk, beets and celery. It is also added in high amounts to processed foods, including bread and processed meats.
Too much dietary sodium can increase blood pressure, and high blood pressure is a major risk factor for cardiovascular diseases, such as heart disease and stroke.
"However," says Dr. Mozaffarian, "the effects of excess sodium intake on cardiovascular diseases globally by age, sex, and nation had not been well established."

Excess sodium intake attributable to 1.65 million cardiovascular deaths worldwide

To gain a better insight into how excess dietary sodium influences cardiovascular health on a global scale, the research team analyzed data from 205 surveys of sodium intake representing approximately 75% of the world's adult population.
They also assessed global nutrition data in order to see how sodium intake varies by sex, age and country. Furthermore, they conducted pooled meta-analyses to measure the effects of sodium on blood pressure, and separately, the effects of blood pressure on cardiovascular diseases.
The team's findings were applied to current global rates of cardiovascular diseases, and they used this information to estimate how many deaths are caused by sodium intake above 2 g per day.
Results of the study revealed that the average worldwide sodium intake in 2010 was 3.95 g per day - almost double the daily recommendation set by the World Health Organization (WHO).
All worldwide regions had sodium intakes above the WHO recommendation. These ranged from 2.18 g per day in sub-Saharan Africa to 5.51 g per day in Central Asia.
This excess sodium intake was attributable to 1.65 million cardiovascular-related deaths worldwide - the equivalent to 1 in 10 deaths from cardiovascular causes.
The researchers found that 4 out of 5 global deaths attributable to excess sodium intake occurred in low- and middle-income countries.

How is the US affected by sodium intake?

The average daily sodium intake in the US was almost 80% higher than the WHO recommendation, at 3.6 g, and significantly higher than the 2.3 g per day intake recommended by the federal government's Dietary Guidelines for Americans.
In addition, the researchers found that daily sodium intake above 2 g accounts for around 58,000 cardiovascular-related deaths in the US each year.
Commenting on the results, study author John Powles, of the department of public health and primary care at the University of Cambridge in the UK, says:
"These new findings inform the need for strong policies to reduce dietary sodium in the United States and across the world."
From their meta-analyses, the researchers found that reducing sodium intake lowered blood pressure in all adults, particularly among blacks, older adults and those who already had high blood pressure.
"Programs to reduce sodium intake could provide a practical and cost-effective means for reducing premature deaths in adults around the world," adds Powles.
The team notes that their study is subject to some limitations. For example, estimates of sodium intake were based on urine samples, which could have underestimated actual sodium consumption.
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Memories of error 'improve our learning speed'

Researchers at Johns Hopkins Medicine in Baltimore, MD, think they have discovered why people learn an identical task faster on subsequent attempts. Publishing their findings in Science Express, the team says our memories of error are the key to faster learning.
illustration of brain activity
The scientific name for the small differences between our expectations of an action and the reality of that action is "prediction errors."
The researchers note that when people perform a task - such as opening a door - their brains make comparisons of how the door moved with how they expected the door to move. This information is calculated in a way that allows the person to perform the task more efficiently next time.
The scientific name for the small differences between our expectations of an action and the reality of that action is "prediction errors." We learn prediction errors in a largely unconscious way.
To further investigate how the brain learns prediction errors, the researchers devised an experiment involving a joystick and a pair of dots on a screen.
The participants were told to guide a blue dot toward a red dot on the screen using the joystick. However, the participants were unable to see the joystick that they were holding, and the blue dot could also be programmed by the researchers to move in an off-kilter way.
To overcome the off-kilter movement of the dot, the participants were required to compensate their joystick movements accordingly. Typically, after a few attempts, they would adjust their movements to guide the blue dot to its target.
The researchers observed that the participants responded more quickly to small errors that pushed them consistently in one direction than to larger errors that were less consistent.
David Herzfeld, a graduate student in Shadmehr's laboratory who led the study, explains: "They learned to give the frequent errors more weight as learning cues, while discounting those that seemed like flukes."
Reza Shadmehr, PhD, a professor in the Department of Biomedical Engineering at Johns Hopkins, compares the experiment to his proficiency as a tennis player.
"I'm much better in my second 5 minutes of playing tennis than in my first 5 minutes," he says, "and I always assumed that was because my muscles had warmed up. But now I wonder if warming up is really a chance for our brains to re-experience error."

'Two processes happening simultaneously'

Further explaining the experience of learning a new motor task, Dr. Shadmehr says there appear to be two processes happening simultaneously. One of these is the learning of motor commands, and the other is critiquing the learning, "much the way a 'coach' behaves."
"Learning the next similar task goes faster, because the coach knows which errors are most worthy of attention. In effect, this second process leaves a memory of the errors that were experienced during the training, so the re-experience of those errors makes the learning go faster."
Daofen Chen, PhD, a program director at the National Institute of Neurological Disorders and Stroke, who co-funded the study, says that the research is a significant step toward understanding how we learn motor skills:
"The results may improve movement rehabilitation strategies for the many who have suffered strokes and other neuromotor injuries."
In the next component of the research, the team will examine which brain region is responsible for the "coaching" role in assigning different weights to various types of error.
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Exercise for the heart may also protect the mind

 It would appear that aerobic exercise may do more than just preserve our cardiovascular health - it may also keep our minds sharp as we age. This was the conclusion of a new study from Canada that found links between aerobic fitness and brain function in older adults.
The researchers, including first author Dr. Claudine Gauthier and others from the University of Montreal, report their findings in the journal Neurobiology of Aging.
Dr. Gauthier, now a post-doctoral fellow at the Max Planck Institute for Human Cognitive and Brain Sciences in Germany, explains:
"Our body's arteries stiffen with age, and the vessel hardening is believed to begin in the aorta, the main vessel coming out of the heart, before reaching the brain. Indeed, the hardening may contribute to cognitive changes that occur during a similar time frame."

Older adults with more elastic aortas performed better on mental tests

She and her fellow researchers studied a group of older adults and found the ones whose aortas were in better condition and who were aerobically fitter did better on a cognitive test:
Exercising seniors
A group of older adults who were aerobically fitter performed better on a cognitive test, researchers say.
"We therefore think that the preservation of vessel elasticity may be one of the mechanisms that enables exercise to slow cognitive aging," she adds.
They studied two groups of physically and mentally healthy participants: 31 younger people aged 18-30 and 54 older adults aged 55-75.
They were interested in comparing not only the younger to the older group, but also to make comparisons within each age group.
All participants underwent physical and mental tests. For the physical tests, they worked hard on workout machines while the researchers measured their maximum oxygen intake over 30-second periods. And for the mental test, they performed a Stroop effect task - a scientifically validated test researchers often use to measure cognitive ability.
In the Stroop effect test, the participant is shown the names of different colors, such as RED, YELLOW, BLUE, and so on, with each word printed in a color that is not the color meant by the word. Thus, RED might be printed in blue, and YELLOW might be printed in red. The participant has to shout out the color of the print and not the printed word.
The participants also underwent three MRI scans: one measured blood flow to the brain, another measured brain activity during the Stroop task, and the third measured the stiffness of the aorta. The aorta is the largest blood vessel in the body - it carries oxygen-rich blood away from the heart to the rest of the body.
The researchers found evidence of age-related declines in brain executive function, elasticity of the aorta and cardiorespiratory fitness. They also found links between vascular health and brain function, and aerobic fitness and brain function.

Method could be adapted to study links in less healthy populations

Dr. Gauthier says this is the first study to report using MRI in this way:
"It enabled us to find even subtle effects in this healthy population, which suggests that other researchers could adapt our test to study vascular-cognitive associations within less healthy and clinical populations."
She notes that although other, more complex mechanisms may also link cardiovascular fitness and the health of blood vessels in the brain, "overall these results support the hypothesis that lifestyle helps maintain the elasticity of arteries, thereby preventing downstream cerebrovascular damage and resulting in preserved cognitive abilities in later life."
Funding for the study came from a number of sources, including the Canadian Institutes for Health Research, the Canadian Foundation for Innovation, the Canadian National Sciences and Engineering Research Council, and the Ministère du développement économique, de l'innovation et de l'exportation.
Meanwhile, in another recently published study led by Stanford University, Medical News Today learned how physical activity cuts the risk of irregular heartbeat in older women. The researchers found the more physically active the women were, the lower the chance they would develop atrial fibrillation, a heart condition that causes arrhythmia.
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Will losing weight really make you happier?

Although physical health is significantly improved by weight loss, the effects of losing weight on mental health are less clear, according to a new study by University College London researchers in the UK.
fat woman and thin woman back to back
"People should not expect weight loss to instantly improve all aspects of life," say the researchers.
The study, which is published in the journal PLOS ONE, looked at 1,979 overweight and obese people in the UK.
It found that people who lost 5% or more of their original weight over 4 years showed significantly improved physical health. However, these people were more likely to report low mood than participants who stayed within their initial weight.
In the study, 14% of the participants lost at least 5% of their body weight - the mean weight loss was 6.8 kg per person.
Adjusting their results to take into account serious health issues and major life events that might cause weight loss and depressed mood, the researchers calculated that the participants who lost weight were 52% more likely to report symptoms of depression.
Lead author Dr. Sarah Jackson, of University College London's Epidemiology and Public Health department, says:
"We do not want to discourage anyone from trying to lose weight, which has tremendous physical benefits, but people should not expect weight loss to instantly improve all aspects of life."
She adds that "aspirational advertising by diet brands" may set unrealistic expectations about weight loss by offering what appear to be instant life improvements. Dr. Jackson advises that people should be realistic about weight loss and be prepared for the challenges:
"Resisting the ever-present temptations of unhealthy food in modern society takes a mental toll, as it requires considerable willpower and may involve missing out on some enjoyable activities. Anyone who has ever been on a diet would understand how this could affect well-being.
However, mood may improve once target weight is reached, and the focus is on weight maintenance. Our data only covered a 4-year period so it would be interesting to see how mood changes once people settle into their lower weight."
She also says that health care professionals should monitor both the physical and mental health of patients when recommending weight loss and offer ongoing support as needed.

What were the study's limitations?

Although the researchers attempted to factor in major life events that could confound results, such as bereavement, which is known to be associated with both weight loss and depression, they acknowledge that data on this was limited.
The bereavement data only covered parents and spouses during the study, and did not take into account deaths of children, close friends or non-marital partners, or the deaths of parents or spouses shortly before the study commenced.
Another major life event that the study did not have data for that could have caused weight loss and depression was job loss.
The study participants were predominantly white, older adults. It is possible, therefore, that the effects of weight loss might be different among different ethnic groups or younger adults.
Also, the researchers admit problems with the measure of well-being used in the study, explaining:
"The use of an arbitrary, unvalidated threshold to indicate low levels of well-being is also problematic, and we observed some differences in results when well-being data were analyzed continuously, so these results should be interpreted with caution."
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Baldness cured with bone marrow disease drug in alopecia areata patients

Alopecia areata causes hair loss for more than 6.5 million people in the US. Now, researchers have discovered that a drug already approved by the Food and Drug Administration for treatment of a rare bone marrow disease - ruxolitinib - could restore hair growth in these patients.
alopecia areata drug
Researchers found that a drug used to treat a rare bone marrow disease - ruxolitinib - restored the hair of patients with alopecia areata within a few months.
Image credit: Columbia University Medical Center
The research team, led by Dr. Raphael Clynes and Angela M. Christiano of Columbia University Medical Center (CUMC), recently published the initial findings of their ongoing clinical trial in the journalNature Medicine.
"We've only begun testing the drug in patients, but if the drug continues to be successful and safe, it will have a dramatic positive impact on the lives of people with this disease," says Dr. Clynes.
Alopecia areata is a disease whereby the immune system attacks hair follicles - the parts of the skin from which hair grows. The majority of people with this disease experience bald patches over their head, face and body, although the condition can cause total hair loss in some cases.
It is unclear exactly what causes the disease, but this latest study may shed some light, as well as offer a potential treatment.

FDA-approved drugs 'fully restored hair in mice within 12 weeks'

Four years ago, the CUMC team conducted a study of more than 1,000 patients with alopecia areata. Their findings indicated that hair follicles send a "danger signal" to immune cells, which encourages them to launch an attack on the follicles.
The researchers investigated this further by studying mice with the disease. By tracing the danger signal backwards, they identified a certain set of T cells responsible for attacking hair follicles.
Through further research into cells of both mice and patients with the disease, the team pinpointed several immune pathways through which these T cells launch their attack. These pathways, the researchers say, can be targeted by a class of drugs known as JAK inhibitors.
The researchers tested two JAK inhibitors already approved by the Food and Drug Administration (FDA) - ruxolitinib (approved for the treatment of myelofibrosis, a rare bone marrow disease) and tofacitinib (approved for the treatment of rheumatoid arthritis) - on mice with alopecia areata that had severe hair loss from the disease.
These drugs, the researchers say, fully restored the rodents' hair within 12 weeks. Furthermore, this hair regrowth lasted for months after treatment had ceased.

Ruxolitinib restored patients' hair within 4-5 months

In this latest study, the researchers report on the findings of a small, open-label clinical trial of ruxolitinib on patients with moderate-to-severe alopecia areata, defined as having more than 30% hair loss.
Early results of the trial revealed that in three of the participants, hair growth was fully restored within 4-5 months of treatment initiation. Furthermore, the T cells that attack the hair follicles were no longer present in the participants' scalps.
Dr. Clynes says that although further testing is needed to determine whether ruxolitinib can be used for patients with alopecia areata, the findings so far are "exciting news" for those with the disease.
Commenting on the team's findings, Dr. David Bickers, of the Department of Dermatology at CUMC, says:
"There are few tools in the arsenal for the treatment of alopecia areata that have any demonstrated efficacy. This is a major step forward in improving the standard of care for patients suffering from this devastating disease."

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Women who read Fifty Shades 'more likely to have unhealthy behaviors'

Mr Grey will see you now." Just these words are likely to send many women into a frenzy. The Fifty Shades novels by British author E.L. James have been a global phenomenon, selling more than 100 million copies worldwide. But although reading a book may seem harmless, a new study suggests young adult women who read these erotic novels are more likely to engage in unhealthy behaviors that are risk factors for abusive relationships.
romantic novel
Women who read Fifty Shades are more likely to have unhealthy behaviors that are risk factors for abusive relationships, according to new research.
For those of you who are unfamiliar with Fifty Shades, the story revolves around the sexual endeavors of two characters: Anastasia Steele and Christian Grey.
In the first of the series - Fifty Shades of Grey - Steele, a literature student described as "unworldly" and "innocent," meets Grey, a man who is charming, intelligent, but who has a dark, controlling side.
They then embark in a "daring, passionately physical" affair, or as lead study author Amy Bonomi of Michigan State University deems it, an abusive relationship. This continues throughout the subsequent two novels - Fifty Shades Darker andFifty Shades Freed.
According to the researchers, the erotic series "depicts pervasive violence against women, perpetuating a broader social narrative that normalizes these types of risks and behaviors in women's lives."
Is there a relationship between reading these books and unhealthy behaviors in real life? Bonomi and colleagues from The Ohio State University wanted to find out.

Fifty Shades fans 'more likely to binge drink, have abusive partners and eating disorders'

For their study, recently published in the Journal of Women's Health, the team analyzed 655 women between the ages of 18 and 24 - a time in women's lives when they are most likely to explore greater sexual intimacy in relationships, according to Bonomi.
Of these women, 122 had read all three Fifty Shades novels, 97 had read at least the first novel but not all three, and 436 had not read any part of the novels.
The team found that, compared with women who had not read any of the books, the women who had read the first novel were 25% more likely to have a partner who verbally abused them, 34% more likely to have a partner who showed stalking tendencies, and 75% more likely to have starved themselves for more than 24 hours or to have used dieting aids.
Furthermore, women who had read all three books were 65% more likely to engage in binge drinking - defined as drinking five or more drinks in one sitting on 6 days or more every month - and were 63% more likely to have had five or more sexual partners in their lifetime, compared with those who had not read any of the books.
Bonomi admits that one limitation of this study is that they were not able to determine whether these behaviors were already pre-existing among the women. But she says that even if they were, reading the books may still pose problems.
She explains:
"If women experienced adverse health behaviors such as disordered eating first, reading Fifty Shades might reaffirm those experiences and potentially aggravate related trauma.
Likewise, if they read Fifty Shades before experiencing the health behaviors seen in our study, it's possible the books influenced the onset of these behaviors."

Unhealthy behaviors 'risk factors for abusive relationships'

Bonomi notes that she is not recommending that the book should be banned, nor is she trying to dictate what books women should or should not read.
But she says it is important that women understand that the unhealthy behaviors linked to reading Fifty Shades demonstrated in this study are risk factors for engaging in violent relationships.
In an attempt to reduce these risks, Bonomi says that parents and teachers should have conversations with children from a young age about sexuality and expectations of body image and gender roles.
In addition, she believes children and young adults should be taught to be critical when it comes to watching movies, reading books or consuming other media that demonstrates violence.
"We recognize that the depiction of violence against women in and of itself is not problematic, especially if the depiction attempts to shed serious light on the problem," Bonomi adds. "The problem comes when the depiction reinforces the acceptance of the status quo, rather than challenging it."
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