Extra protein boosts muscle with resistance-training, but only slightly

Extra protein from food or supplements does lead to increases in strength and muscle, but not as much as some might hope, researchers write in the British Journal of Sports Medicine. 

Presented as an infographic, the results are based on a review of data from 49 randomized controlled trials in 17 countries and more than 1,800 participants.

The upshot: supplementing protein while doing resistance training can increase strength by about 9 percent and add about a pound of muscle. The effect levels off at a certain point, after which extra protein provides no additional benefit.

“Lots of people take protein supplements with the expectation that they are going to gain lots of muscle because of the protein supplement,” said senior study author Stuart Phillips of McMaster University in Ontario, Canada.

“Supplement companies tout huge benefits,” Phillips told Reuters Health by email. “We thought it was time to do some science.”

Phillips and colleagues conducted a systematic review and meta-analysis of research published on the topic of protein supplementation and resistance training, looking at how much extra muscle men and women gained, as well as how much stronger they became.

The studies had to be at least 6 weeks long, include resistance training at least twice a week, and one group had to be given a protein supplement that didn’t have other muscle-building ingredients such as creatine or testosterone-enhancing compounds.

Ten of the studies involved people who were experienced in resistance training and 14 studies had exclusively female participants.

The team found that protein supplementation led to an increase in muscle, but not much. In addition, protein supplements were more effective in people who were already lifting weights and less effective in people over age 60.

The analysis didn’t find any differences between types of protein supplements or a distinction between getting protein from food or from supplements.

When Phillips’ team analyzed the relationship between the amount of muscle gained and total amount of dietary protein consumed, they found that gains leveled off at around 1.6 grams of protein per kilogram of body weight per day, or about 0.7 grams per pound. That is twice the recommended daily amount in most official nutrition guidelines, they note.

“Going to the gym is where most of the benefits come from,” Phillips said.

Current studies are investigating the key amino acids in protein that aid this muscle-building process, particularly leucine, and especially for adults over age 60 who may have muscle and bone loss known as sarcopenia.

“It’s a big deal to have sufficient enough quantities to stimulate muscle growth,” he added.

Future studies will focus on ways to boost muscle mass and the effect of protein supplementation in older adults, including through everyday foods such as milk and meat.

“Older adults experience age-related physiological changes that affect body weight and body composition,” said Li-Qiang Qin of Soochow University’s School of Public Health in Suzhou, China.

Qin, who wasn’t involved in the current review, has studied the effect of milk protein supplementation among older adults taking part in a resistance training program.

“Milk proteins are excellent sources of all the essential amino acids and may represent an ideal protein source to promote muscle anabolism in older adults undergoing resistance training,” Qin said.

source: news.abs-cbn.com

Vaping may boost pneumonia risk: study

PARIS, France – Vaping may help pneumonia-causing bacteria stick to cells lining the airways, likely boosting disease risk, researchers said Thursday.

A study published in the European Respiratory Journal did not directly compare vaping's effect to that of smoking tobacco cigarettes.

But the findings did suggest that users of electronic cigarettes may be at higher risk of lung infection than people who do not vape, the research team reported.

"If you choose to take up e-cigarettes... this indicates a red flag that there may be an increased susceptibility" to pneumococcal bacteria, study co-author Jonathan Grigg of the Queen Mary University of London told AFP.

Grigg and a team conducted three types of experiment. One exposed human nose lining cells to e-cigarette vapor in the lab, another involved mice inhaling vapor and then being exposed to pneumococcal bacteria, the main cause of pneumonia.

A third trial studied the nose lining of 11 e-cigarette users compared to six non-vapers.

The team noticed a sharp increase in the amount of bacteria sticking to airway cells after e-cigarette exposure. Such adhesion has previously been shown to increase susceptibility to disease.

"Some people may be vaping because they think it is totally safe, or in an attempt to quit smoking, but this study adds to growing evidence that inhaling vapor has the potential to cause adverse health effects," said Grigg.

"By contrast, other aids to quitting such as (nicotine) patches or gum do not result in airway cells being exposed to high concentrations of potentially toxic compounds."

- Less harmful? – 

Last month, a US study said vaping may increase cancer risk because it leads to DNA damage, despite containing fewer carcinogens than tobacco smoke.

That study, too, did not compare the effects of cigarette smoking directly to vaping.

Research in the journal Tobacco Control last October said a large-scale switch from tobacco to e-cigarettes would prevent millions of premature deaths by the year 2100, even assuming the gadgets are themselves not risk-free.

E-cigarettes, said to contain no tar and fewer toxins than tobacco cigarettes, were developed as a safer alternative to tobacco smoking.

But many people fear that a harmless veneer may make e-cigarettes a "gateway" for young people to lifelong nicotine addiction.

Commenting on the latest study, Peter Openshaw, an experimental medicine professor at Imperial College London, said any evidence that vaping raised lung infection risk was "only indirect".

"Although it is possible that vaping might increase susceptibility to pneumonia, the effect is likely to be lower than from smoking itself," he said via the Science Media Centre.

"This study should not be used as a reason to continue to smoke rather than vape –- the evidence to date is that e-cigarettes are far less harmful than smoking."

source: news.abs-cbn.com

3 cups of coffee a day keep the doctor away, studies say

Coffee addicts and aficionados often say drinking the bitter liquid makes life worth living, but the habit may also help them live longer, according to two major international studies Monday.

Experts cautioned, however, that the US and European reports, published in the Annals of Internal Medicine, failed to show that coffee was truly the reason that many drinkers appeared to have longer lives.

Rather, the studies were observational in nature, meaning they showed an association between coffee-drinking and a propensity toward longevity, but stopped short of proving cause and effect.

The first study, led by the International Agency for Research on Cancer (IARC) and Imperial College London, examined more than half a million people across 10 countries in Europe.

Those who drank about three cups a day tended to live longer than non-coffee drinkers, said the study, which researchers described as the largest analysis of the effects of coffee-drinking in a European population.

"We found that higher coffee consumption was associated with a lower risk of death from any cause, and specifically for circulatory diseases, and digestive diseases," said lead author Marc Gunter of the IARC, formerly at Imperial's School of Public Health.

"Importantly, these results were similar across all of the 10 European countries, with variable coffee drinking habits and customs."

The second study included more than 180,000 participants of various ethnic backgrounds in the United States.

It found benefits to longevity whether the coffee was caffeinated or decaffeinated.

Coffee drinkers had a lower risk of death due to heart disease, cancer, stroke, diabetes, and respiratory and kidney disease.

Those who drank one cup a day were 12 percent less likely to die compared to those who didn't drink coffee.

Those who drank two or three cups per day saw an even higher 18 percent reduced risk of death.

"We cannot say drinking coffee will prolong your life, but we see an association," said lead author Veronica Setiawan, an associate professor of preventive medicine at the Keck School of Medicine of University of Southern California.

"If you like to drink coffee, drink up! If you're not a coffee drinker, then you need to consider if you should start."

A revered drink

Coffee is one of the most popular drinks in the world. Some 2.25 billion cups are consumed every day.

Many prior studies have hailed the benefits of coffee-drinking, saying the beverage imparts anti-oxidants, may improve liver function and reduce inflammation.

But coffee may carry risks for some people, and pregnant woman and children are urged to avoid caffeine, which can be fatal in high doses.

A report from the IARC last year that said drinking very hot beverages -- coffee, tea or otherwise -- is one probable cause of cancer of the esophagus, the tube that runs from the throat to the stomach.

Experts urge caution

Experts who were not involved in the latest studies urged caution in interpreting the results.

For instance, the European study excluded people who had cancer, heart disease or diabetes, meaning it took a measure of people over 35 who were already generally healthy.

It also asked about coffee consumption just once, at the beginning, and did not update this figure over the span of the study, which included an average follow-up time of 16 years.

Finally, it found signs of a link between women who drank large amounts of coffee and a higher risk of cancer death, but downplayed this finding, saying it "may be spurious."

The "conclusions will not lead me to start drinking coffee or to recommend people drink more coffee as a way to lessen their risks for heart disease," said Naveed Sattar, professor of metabolic medicine at the University of Glasgow.

"I remain unconvinced that the link between coffee and heart disease represents a true cause and effect relationship and that coffee is truly protective, regardless of how large a study suggests this."

Sattar said that one downside to the research is the fact that many people stop drinking coffee -- or drink less of it -- when they are ill, a "bias is very hard to fully overcome."

David Spiegelhalter, a professor at the University of Cambridge, described the research as "huge in size and carefully done," but nevertheless unable to prove cause and effect.

"If these estimated reductions in all-cause mortality really are causal, then an extra cup of coffee every day would on average extend the life of a man by around three months, and a woman by around a month," he added.

"So perhaps we should relax and enjoy it."

source: news.abs-cbn.com

Male brains 'overwhelmed' in multitasking test: study

PARIS - Are women really better at multi-tasking?

A study on Wednesday said a tricky brain-teaser throws off men's walking gait but leaves most women unfazed, reopening an age-old debate about mental gender differences.

On a treadmill, men -- and women over 60 -- started swinging their right arm less while grappling with a complicated language test, researchers found.

Language function and right arm swing are both thought to be controlled mainly by the brain's left hemisphere.

"Women under 60 seemed to be resistant to this effect, as they were able to perform the verbal task with no change in arm swing," said study co-author Tim Killeen, a neuroscientist from the University Hospital Balgrist in Switzerland.

"In men and older women, the verbal task appears to overwhelm the left brain to the extent that the movement of the arm on the right is reduced."

The "unexpected" findings were published in the journal Royal Society Open Science.

"We were surprised to find such a consistent gender difference in how two relatively simple behaviours -- cognitive control and arm swing -- interact with one another," Killeen told AFP.

The team had set out to study how people walk under different conditions, aiming to build a database of "normal" gait profiles for treating people with walking disorders.

They used infrared cameras to record the treadmill walking patterns of 83 healthy people, aged 18 to 80.

The participants were asked to walk -- first normally, and then while performing a verbal task called the Stroop test.

Developed in the 1930s, the test involves printing the name of a colour -- such as "red", "green" or "blue" -- in a non-matching colour, then asking a person to say the colour of the ink, not the word itself.

- Better at language? -

This is difficult, explained Killeen, as the human brain "sees" both the written word and the colour of the ink, and must reconcile the two.

During normal walking, the left and right arms swung approximately equally.

"When we added the verbal task, we observed that in men of all ages and women over 60, this symmetry broke down, with a reduction in right arm swing while the left arm carried on swinging normally," said Killeen.

Does this prove women are better multi-taskers?

"Ha ha! I think this shows that younger women may be able to resist interference of these two fairly specific behaviours," she said.

Whether this might apply to other compound activities -- such as driving and talking or walking and texting -- has yet to be shown.

It is also unclear whether a woman's ability to take the verbal brain teaser in her stride confers any advantage over men, said Killeen.

The fact that women over 60 lose the capacity may provide a clue as to its origin, the researchers said.

Brain receptors of the female hormone oestrogen may get a bigger boost in younger women, who have more of it.

"Alternatively, women are often shown to have somewhat better verbal skills than men" and may find the Stroop test easier, Killeen said by email.

"However, this does not explain why older women revert to the 'male pattern' after 60."

Previous studies have disagreed on whether women are actually better than men at doing more than one thing at the same time.

"This may be a paradigm for investigating this further -- maybe someone can finally settle this age-old question!" said Killeen.

source: news.abs-cbn.com

Sex exists to avoid disease, study shows

From an evolutionary perspective, sexual reproduction could be seen as a non-starter.

Compared to cloning, which also exists in Nature, it's a major waste of time and energy.

Think of the ungainly, preening peacock -- an easy snack for tigers and wild dogs -- strutting his stuff to impress the ladies.

Even without predators, sex and its attendant rituals can be dangerous: when stags butt heads or alpha-male lions fight for mating rights, it does not always end well.

Some animals and plants -- starfish, bananas, to name two -- reproduce asexually. Even a few birds and bees do it solo, Cole Porter be damned.

Others, like the Komodo dragon, can work it either way, though asexually produced Komodo babies -- produced by their mothers -- are not clones.

In short, without males in the picture the business of reproducing is faster and less fraught.

And yet, sex remains by far the dominant means by which the world's fauna and flora pass on genes to future generations, ensuring the survival of the species.

"One of the oldest questions in evolutionary biology is, why does sex exist?" said Stuart Auld, a biologist at the University of Stirling in Scotland.

Darwin's laws of natural selection dictate that doing it the hard way -- sex rather than cloning, in this case -- must confer some major, if hidden, advantages.

Granted, sexual reproduction fuels genetic variation, which boosts the likelihood that offspring in the wild will have the genetic makeup to thrive in an ever-changing environment.

By contrast, clones do not vary, and so if the environment deteriorates, a clonal mother will produce offspring that lack the genes they need to succeed.

'Twofold cost of sex'

"But sex needs to be over twice as efficient as cloning to outweigh its costs," Auld told AFP.

"If sex is to be favored by natural selection, a sexual mother needs to either produce twice as many offspring as an asexual mother, or produce offspring that are twice as good."

Biologists have long agreed that the enhanced ability to fight off disease was a major advantage of the genetic changes that come with sexual reproduction.

But constructing an experiment to confirm this has always proved difficult: how do you compare the costs and benefits of sexual strategies in different species?

To get around that "apples and oranges" problem, Auld and two colleagues used an organism -- the humble waterflea -- that can reproduce both ways.

"By comparing clonal and sexual daughters from the same mothers, we found sexually produced offspring get less sick," Auld said.

The ever-present need to evade disease, it turned out, explains why sex persists in the natural world in spite of the high "costs" that come with it, he explained.

Parasites and their hosts are in a constant tug-of-war, each evolving and adapting to the other, one attacking immune defenses and the other rebuilding them.

Cloning offers fewer chances for genetic changes in the host that can rise to that challenge.

But sexual reproduction -- with a new genetic variations coming into the mix with each generation -- offers more opportunities to fight back against pathogens.

The findings were published in the British journal Proceedings of the Royal Society B.

source: news.abs-cbn.com

How much chocolate is good for you? New study finds out

New research has added to tentative evidence that eating chocolate in modest quantities may be good for the heart, its investigators said on Tuesday.

Scientists in Britain looked at data from nearly 21,000 people who filled out questionnaires about their lifestyle, and had their health monitored for more than 11 years.

Their average daily consumption was seven grams (0.25 ounces) of chocolate, ranging from none to 100g.

The top fifth of chocolate-eaters were 12 percent less likely to develop heart disease and 23 percent less likely to suffer a stroke compared to the bottom fifth of consumers, the researchers found.

The study, published in the British journal Heart, noted that most consumers of the confectionary ate milk chocolate, not dark chocolate which famously has a higher percentage of protective molecules called flavonoids.

"This may indicate that not only flavonoids, but also other compounds, possibly related to milk constituents, such as calcium and fatty acids, may provide an explanation for the observed association," it said.

The team, headed by Phyo Myint of the University of Aberdeen in Scotland, admitted the probe had limitations.

The study was observational, meaning it could not show cause and effect, merely an association which may be circumstantial.

Another question mark was to be found in "reverse causation": participants who knew they had cardiovascular problems may have followed a healthier diet and eaten less chocolate.

The team also did a review of other published studies, covering more than 130,000 people in total, and said they had found a similarly beneficial association with regular chocolate consumption.

"Cumulative evidence suggests that higher chocolate intake is associated with a lower risk of future cardiovascular events," it said.

"There does not appear to be any evidence to say that chocolate should be avoided in those who are concerned about cardiovascular risk."

A couple of squares of chocolate are around 16g, and an average bar of chocolate about 50g.

Commentators not involved in the research were cautious, noting too much chocolate can lead to weight gain, which is bad for the heart.

"You can't draw a medical conclusion from this study," said Arnaud Cocaul, a nutritionist at the Pitie Salpetriere Hospital in Paris.

"People who refrain from eating chocolate are not necessarily those who eat the most balanced diet."

Added Tim Chico, a cardiologist at the University of Sheffield in northern England: "I would not advise my patients to increase their chocolate intake based on this research, particularly if they are overweight," in remarks to Britain's Science Media Centre (SMC).

source: www.abs-cbnnews.com

Pot tied to fewer brain injury deaths: study

NEW YORK - People who use marijuana may be more likely to survive a serious head injury than people who don't, a new study suggests.

At one hospital, the death rate after traumatic brain injury was lower among people who tested positive for tetrahydrocannabinol (THC, the active ingredient in marijuana) than among people who tested negative for it, researchers found.

“This data fits with previous data showing that (THC) may be neuroprotective,” Dr. David Plurad, one of the study's authors, said in a phone interview.

Experiments in animals have found that THC may protect the brain after injury, Plurad and his colleagues write in The American Surgeon. Little is known about the specific effects of THC on brain injury in humans, however.

For the new study, the researchers reviewed data on 446 adults treated at Harbor-UCLA Medical Center in Torrance, California for traumatic brain injuries. All had been tested for THC.

Overall, approximately one in five patients tested positive for THC and one in 10 patients died after their injury.

About 2.4 percent of people who tested positive for THC died, compared to about 11.5 percent of those with negative THC tests.

People who tested positive for THC were about 80 percent less likely to die, compared to people with negative THC tests, researchers found after they adjusted the numbers to account for age, gender, injury severity and type.

Previous studies have also suggested that alcohol may protect the brain in traumatic brain injuries, Plurad said. Those studies did not account for the presence of THC, however.

“We included the presence of alcohol in our statistical analysis, and it didn't turn out to be as protective as the presence of the marijuana,” he said, adding that future studies examining the effects of alcohol on traumatic brain injury should account for the presence of THC.

One concern with the study, according to Plurad, is that the test for THC could not distinguish occasional from regular users. A person could test positive after having used marijuana days or even weeks before.

Given that marijuana is inexpensive and may have some medical benefits, its therapeutic effects are worth investigating further, he added.

“There's not going to be one answer, is marijuana good for you, is marijuana bad for you,” he added. “Like most things in life, and particularly medicine, it's going to be somewhere in between.”

source: www.abs-cbnnews.com

More fresh fruit deters diabetes; juice boosts risk

PARIS - Eating more whole fresh fruit, especially blueberries, grapes, apples and pears, is linked to a lower risk of type 2 diabetes, but drinking more fruit juice has the opposite effect, says a study.

British, US and Singaporean researchers pored over data from three big health investigations that took place in the United States, spanning a quarter of a century in all.

More than 187,000 nurses and other professional caregivers were enrolled.

Their health was monitored over the following years, and they regularly answered questionnaires on their eating habits, weight, smoking, physical activity and other pointers to lifestyle.

Around 6.5% of the volunteers developed diabetes during the studies.

People who ate at least two servings each week of certain whole fruits, especially blueberries, grapes and apples, reduced their risk of Type 2 diabetes by as much as 23% compared to those who ate less than one serving per month.

"Our findings provide novel evidence suggesting certain fruits may be especially beneficial for lower diabetes risk," said Qi Sun, an assistant professor of nutrition at the Harvard School of Public Health.

On the other hand, those who consumed one or more servings of fruit juice each day saw their risk of the disease increase by as much as 21%.

Swapping three servings of juice per week for whole fruits resulted in a 7% reduction in risk, although there was no such difference with strawberries and cantaloupe melon.

The paper, published on Friday by the British Medical Journal (BMJ), says further work is needed to to explore this "significant" difference.

It speculates that, even if the nutritional values of whole fruit and fruit juice are similar, the difference lies with the fact that one food is a semi-solid and the other a liquid.

"Fluids pass through the stomach to the intestine more rapidly than solids even if nutritional content is similar," says the paper.

"For example, fruit juices lead to more rapid and larger changes in serum [blood] levels of glucose and insulin than whole fruits."

The study also points to evidence that some kinds of fruit have a beneficial effect for health.

Berries and grapes, for instance, have compounds called anthocyanins which have been found to lower the risk of heart attacks.

But, say the authors, how or even whether this also applies to diabetes risks is for now unclear.

The investigation looked at data from the Nurses' Health Study, which ran from 1984-2008; the Nurses' Health Study II (1991-2009); and the Health Professionals Follow-Up Study (1986-2008).

Ten kinds of fruit were used in the questionnaire: grapes or raisins; peach, plums or apricots; prunes; bananas; cantaloupe melon; apples or pears; oranges; grapefruit; strawberries; and blueberries.

The fruit juices identified in the questionnaire were apple, orange, grapefruit and "other."

source: www.abs-cbnnews.com

Women smokers, higher risk of sudden death

Longtime women smokers are two-and-a-half times more likely to suffer sudden cardiac death than non-smokers, a researcher in Canada says.

Dr. Roopinder Sandhu, assistant professor of medicine at the University of Alberta in Edmonton, who conducted the study as a visiting scientist at Brigham and Women's Hospital in Boston, said the study involved 101,018 women who took part in the Nurses' Health Study. In 30 years of tracking, 351 cases of sudden cardiac death were reported, WebMD reported.

Sandhu and colleagues found the amount and duration of cigarette smoking was strongly associated with the women's risk of sudden cardiac death.

The study, published in the journal Circulation: Arrhythmia & Electrophysiology, found women who smoked 25 cigarettes a day or more had more than three times the risk of sudden cardiac death than women who didn't smoke.

source: upi.com