Just a few hours a week of moderate exercise may not prevent all heart attacks, but it could make the difference in who survives one, Danish researchers say.

Over several decades, the study found that regular moderate exercisers were half as likely to die when they had a heart attack, compared to people who were sedentary.

Despite this benefit, exercise did not seem to protect heart attack survivors from dying or experiencing heart failure later on, the researchers write in the European Journal of Preventive Cardiology.

“We already know that exercise protects you from heart attack, as well as a number of other beneficial effects,” said senior author Dr. Eva Prescott of the University of Copenhagen and Bispebjerg Hospital.

“The main finding here is that among people who do get a heart attack, the ones who exercise more seem to be more likely to survive a heart attack than people who exercise less,” Prescott said by email.

“Exercise is good for you, we know that. These findings confirm that and help us understand why,” she said.

To examine the potential influence of exercise on heart attack survival, the researchers analyzed data on more than 14,000 people participating in the Copenhagen City Heart Study, none of whom had experienced a heart attack or stroke at the beginning of the study period.

Participants reported on their level of physical activity at the baseline assessment between 1976 and 1978 and researchers followed their health over the years through 2013.

Based on their leisure time physical activity at the start of the study, participants were categorized into one of three groups: sedentary, meaning they engaged in only light activity for less than two hours per week; light exercise, which meant they did two to four hours of walking or equivalent activity each week; or moderate/high exercise, which meant greater than two hours of vigorous activity like biking weekly.

Over the study period, 1,664 people had heart attacks and 425 died right away. The average age at which people had a heart attack was 71.

Among those who had a heart attack, the majority, 54 percent, were in the light exercise category - and they were 32 percent more likely to survive than people who were sedentary. People who were moderate or high exercisers were 47 percent more likely to survive.

Having been an exerciser did not guard against future heart failure for heart attack survivors, however. People who exercised were just as likely as sedentary peers to develop heart failure in the five years following a heart attack, the study also found.

The same was true for death over the longer term. Among the heart attack survivors, 83 percent died during the seven-year period following their heart attack. There was no difference in the mortality rate between people who had moderate/high levels of exercise and those who exercised less or not at all.

Nonetheless, regular exercise can help lower blood pressure, said Antonio Crisafulli, who studies exercise and heart function at the University of Cagliari in Italy.

"In short, if we have a low blood pressure, the work required to the heart is reduced,” said Crisafulli, who was not involved in the study.

Exercise is not a miracle cure and even active people may face heart attacks, Crisafulli noted, but active people are more likely to survive heart problems.

Exercise signals to the body to create more pathways to bring oxygen to the heart, Prescott added. In this way, even if an artery becomes blocked and causes a heart attack, the heart will still have other ways to get oxygen.

“Exercise is one of the best and smartest ways to keep our body healthy and to survive if something wrong happens in our cardiovascular system,” Crisafulli added.

source: Reuters Health
http://www.reuters.com/article/us-health-fitness-heart-attack-idUSKBN17M27Q

A study sheds new light on what happens in the brain when a person with alcohol use disorder, or AUD, is presented with an opportunity for “delay discounting,” namely forgoing a larger reward later in favor of a significantly smaller one sooner.

One of the questions asked in the study, published in the journal Alcohol and Alcoholism, to 17 alcohol-dependent individuals while their brain activity was monitored with functional magnetic resonance imaging, or fMRI, was: Would you rather receive 55 U.S. dollars today or 75 dollars two months from now?

In the research by psychological scientist Anita Cservenka of the Oregon State University (OSU) College of Liberal Arts and researchers at the University of California, Los Angeles, each subject read a series of 27 questions on a screen and had five seconds per question to answer via an electronic pad resting on his or her stomach.

As they lay still in the MRI tube, choosing a smaller amount of money sooner was categorized as an SS response; a larger amount later was classified as LL. On average, participants gave an SS response about two-thirds of the time, while fMRI more likely showed that he or she hadn’t activated the “cognitive control” region of the brain as much as someone with a lower level of dependency would have.

Severity of dependence appeared to negatively correlate with activity in the cognitive control regions when participants make impulsive decisions: the more dependent someone is, the less active the control part of his or her brain is.

“If you just look at the behavior of individuals, those with more severe alcohol use disorder had a trend toward steeper delay discounting,” Cservenka was quoted as saying in a news release from OSU on Monday. “How much they preferred smaller, immediate rewards was not significant, but it was a trend; the severity of the alcohol use disorder was positively associated with the wanting of smaller, immediate rewards.”

In addition, the scans indicated dysregulation in other regions associated with decision making and higher-order cognition. The participants showed greater activation of the brain’s reward-evaluation regions during “delayed decisions,” namely choosing the larger, later prize. Activation of those regions during delayed decisions is positively associated with alcohol dependence severity, indicating that individuals with greater dependence may need to activate those areas more to make less impulsive decisions.

While impulsivity tends to decline with age, Cservenka noted, adults with severe alcohol use disorder can show heightened levels of impulsivity compared to individuals without alcohol use problems.

The findings suggest that more effective AUD treatment could involve neuropsychological tasks designed to help patients train themselves to make more-reasoned, better-planned decisions by using cognitive control to rein in impulses.

source: Manila Bulletin
http://lifestyle.mb.com.ph/2017/04/19/alcohol-dependence-severity-related-to-impulse-control-deficiency-study/

By simulating a space mission to Mars, an international team of researchers noted that eating salty food led to greater hunger than thirst, at least in the long term. The reason seems to be a protective mechanism that conserves water in the kidneys.

Researchers from the Max Delbrûck Center for Molecular Medicine in Germany and Vanderbilt University in the city of Nashville in the United States studied the link between salt intake and drinking habits on a simulated space mission to Mars.

You may be thinking what’s the connection between Mars and salt? There isn’t one really, except perhaps that on a long trip, holding on to every drop of water is important. In fact, the advantage of this environment was that the scientists could easily monitor and measure all aspects of food, salt and water intake.

The team selected ten male volunteers who were sealed into a “spaceship” for two simulated flights to Mars. They observed the first group for 105 days and the second for 205 days. They were all given the same food, except that over periods of weeks their food had three different levels of salt content (6, 9 and 12 grams).

Unsurprisingly, they showed that eating more salt led to urine with a higher salt content and a greater quantity of urine. But this increase was not due to the fact that the volunteers were drinking more.

The researchers found that the volunteers who went from a 6-gram to 12-gram salt intake drank less, and that a mechanism conserving water in their kidneys or producing more water was triggered.

The original hypothesis—that charged sodium and chloride ions in salt took hold of water molecules and dragged them into the urine—had been ripped apart. The experiment showed that salt remained in the urine while water moved back to the kidneys and the rest of the body.

The scientists had to revise their view of urea, a product formed in muscles and the liver as a way of shedding nitrogen. Experiments on mice showed that urea accumulates in the kidneys where it neutralizes the pull of the sodium and chloride ions. But making urea requires energy, which explains why the mice on a high-salt diet had a bigger appetite. Eating salty food didn’t increase their thirst, it increased their hunger. The researchers explain in this study that urea is therefore not simply a waste product, but is a compound which binds to water and helps to keep water in the body when it gets rid of salt.

Mother Nature has found a way of holding on to water which would otherwise be carried away into the urine by salt.

People who cycle to work have a substantially lower risk of developing cancer or heart disease or dying prematurely, and governments should do all they can to encourage more active commuting, scientists said on Thursday.

In a study published in the BMJ British medical journal, the researchers found that cycling to work was linked to the most significant health benefits - including a 45 percent lower risk of developing cancer and a 46 percent lower risk of heart disease compared to non-active commuters.

Walking to work was linked to a 27 percent lower risk of developing heart disease and a 36 percent lower risk of dying from it, though it also appeared to have no effect on cancer risk or overall premature death risk, the study showed.

The research involved 264,377 people with an average age of 53 whose data forms part of the UK Biobank - a database of biological information from half a million British adults.

Since the study was observational, no firm conclusions can be drawn about cause and effect, the researchers said. Its findings could also be affected by some confounding factors, they added, including that the mode and distance of commuting was self-reported, rather than objectively measured.

However, "the findings, if causal, suggest population health may be improved by policies that increase active commuting, particularly cycling", they said.

These would include creating more cycle lanes, introducing more bike buying or hiring schemes, and providing better access for cyclists on public transport.

Lars Bo Andersen, a professor at the Western Norwegian University of Applied Sciences, who was not directly involved in the research but wrote a commentary on it in the BMJ, said its findings "are a clear call for political action on active commuting", saying this had the potential to significantly improve public health by reducing rates of chronic disease.

"A shift from cars to more active modes of travel will also decrease traffic in congested city centers and help reduce air pollution, with further benefits for health," he said.

source: Reuters Health
http://www.reuters.com/article/us-health-cycling-idUSKBN17L2ZO