Some researchers do not think drug studies should use placebos. They say it makes more sense to compare new medicines to drugs already on the market. Then people would know if a new drug is any better.

“Placebo” is Latin for “I shall please.” It may contain nothing more than sugar.

Yet some people who are given a placebo experience improvements in their health. This is called the placebo effect.

Some doctors use the placebo effect in their treatments. An influential study published in nineteen fifty-five said placebo treatments made patients feel better thirty-five percent of the time.

But in two thousand one, Danish researchers reported that they had examined more than one hundred studies. They found little evidence of healing as a result of placebos.

Still, there is continued belief in the placebo effect.

A Swedish study published last year suggested that a placebo can reduce the emotional effects of unpleasant experiences. The study involved people who looked at images of dead bodies and other unpleasant pictures. The findings appeared in the journal Neuron.

The researchers said the effects in the brain were similar to those seen when placebos have been used as a pain treatment. In both cases, they said, expectations of improvement are a major influence.

But more than expectations might explain why placebos appear effective sometimes.

Researchers led by Scot Simpson at the University of Alberta, in Canada, just had a report published in the British Medical Journal. They examined twenty-one studies. These compared death rates between patients who always took their medicine and those who did not.

Even patients who took placebos had better results than those who did not follow doctor’s orders. The researchers see this finding as support for the idea of a so-called healthy adherer effect. That is, a person who takes a drug treatment as directed may also do other things to live a healthy life.

Researchers from Zogby International did a study for the American Speech-Language-Hearing Association. It involved three hundred high school students and one thousand adults. They were asked about their use of portable music devices. Some of the most popular are Apple Computer’s iPod, C.D. players and portable laptop computers.

Forty percent of students and adults said they set the sound levels, or volume, at high on their iPods. But students were two times more likely to play the music at a very loud volume. More than half of the students said they would probably not limit their listening time. And about a third said they were not likely to reduce the volume.

The study found that more than half of the students and less than forty percent of the adults had at least one kind of hearing loss. Some reported difficulty hearing parts of a discussion between two people. Others said they had to raise volume controls on a television or radio to hear it better. And, some experienced ringing in their ears or other noises.

Hearing experts say part of the problem is the listening equipment people are using. They say large earphones that cover the whole ear are probably safer than the smaller earbuds that come with most music players. Earbuds are thought to be less effective than earphones in blocking out foreign noises.

Hearing loss may not be apparent for years. But once it happens, it is permanent. About thirty million Americans have some hearing loss. One third of them lost their hearing as a result of loud noises.

Experts at the Mayo Clinic in Minnesota say any sound above ninety decibels for long periods may cause some hearing loss. But most portable music players can produce sounds up to one hundred twenty decibels.

The American Speech-Language-Hearing Association is working with manufacturers and government officials on setting rules for use of portable music devices. The group says the best way to protect your hearing is to reduce the volume, limit listening time and using earphones that block out foreign noises.

This is the VOA Special English Health Report.

Many people believe they are supposed to drink eight glasses of water a day, or about two liters. Why? Because that is what they have been told all their life. But a new report offers some different advice. Experts say people should obey their bodies; they should drink as much water as they feel like drinking.

The report says most healthy people meet their daily needs for liquid by letting thirst be their guide. The report is from the Institute of Medicine, part of the National Academies. This organization provides scientific and technical advice to the government and the public.

The report contains some general suggestions. The experts say women should get about two-point-seven liters of water daily. Men should get about three-point-seven liters. But wait — in each case, that is more than eight glasses.

There is an important difference. The report does not tell people how many glasses of water to drink. In fact, the experts say it may be impossible to know how many glasses are needed to meet these guidelines. This is because the daily water requirement can include the water content in foods.

People do not get water only by forcing themselves to drink a set number of glasses per day. People also drink fruit juices and sodas and milk. They drink coffee and tea. These all contain water. Yet some also contain caffeine. This causes the body to expel more water. But the writers of the report say this does not mean the body loses too much water.

As you might expect, the Institute of Medicine says people need to drink more water when they are physically active. The same is true of those who live in hot climates. Depending on heat and activity, people could need two times as much water as others do.

All this, however, does not answer one question. No one seems sure why people have the idea that good health requires eight glasses of water daily.

It may have started with a misunderstanding. In nineteen-forty-five, the National Academy of Sciences published some guidelines. Its Food and Nutrition Board said a good amount of water for most adults was two-point-five liters daily. This was based on an average of one milliliter for each calorie of food eaten.

But that was only part of what the board said. It also said that most of this amount is contained in prepared foods.This VOA Special English Health Report was written by Jerilyn Watson.

Researchers say people traveling in traffic are three times more likely to suffer a heart attack whether driving in a car, riding a bus or bicycling. They say the risk of a heart attack is greatest within an hour of being in traffic. Researchers believe the main reason is polluted air.

The findings are based on a German study of almost seven hundred people who suffered heart attacks. The patients described their activities during the four days before their heart attack. Researchers found that those who had been in traffic were three times more likely to have a heart attack within one hour, compared to those who had not been in traffic.

Most of those in the study had been traveling by car. But some had been on bicycles and others were on buses. Women, people over the age of sixty and those already at risk for heart problems were most at risk.

Research shows that people in cars and buses are exposed to ten times the amount of pollutants as people walking on the street. That is largely because they breathe in the particles and gasses released from the vehicles in front of them.

Over time, these small particles speed the buildup of a sticky substance in the blood. This can cause blockages to form in the arteries around the heart and lead to a heart attack.

Earlier studies have linked traffic, air pollution and heart disease. They found that people who live near major roads are at greater risk of dying from heart and lung problems.

Other studies have also linked heart trouble to stress, similar to the kind that people face while driving in heavy traffic. But the researchers of the latest study say they do not know whether the increased heart attack risk was the result of stress or pollution. They suggest it may be a combination of stress, noise and pollution.

The study found that traffic was linked to eight percent of heart attacks. But experts note that the overall risk of having a heart attack after being in traffic is still very low.

Annette Peters led the research. She is with the National Research Center for Environment and Health in Neuherberg, Germany. She said the research shows the need for cleaner vehicles and better city planning.

The research was done from nineteen ninety-nine to two thousand one. The study was published in the New England Journal of Medicine.

This VOA Special English Health Report was written by Cynthia Kirk. This is Gwen Outen.

People Traveling In Heavy Traffic And Polluted Air Will Increasing The Risk Of Suffering Heart Attack

Craving an afternoon snack? Take a drag on a cigarette, and your hunger will likely disappear. Smoking is the number one cause of preventable deaths in the Unites States and other developed countries, causing lung cancer, heart disease, and chronic bronchitis. But smokers are, on average, skinnier than nonsmokers. New research reveals how nicotine, the active ingredient in cigarettes, works in the brain to suppress smokers' appetites. The finding also pinpoints a new drug target for nicotine withdrawal—and weight loss.

The nicotine receptor in the brain has 15 subunits; they can combine in a multitude of ways to form different receptors with different jobs. Nicotine can bind to each combination and spur a cascade of distinct events; some lead to the addictive properties of cigarettes, others to an increase in blood pressure or a feeling of relaxation. It's long been known that nicotine causes a slump in appetite, and scientists suspected that this worked through receptors associated with reward and behavior reinforcement. After all, the brain considers both cigarettes and food to be rewards. But the new finding suggests that appetite has its own pathway.

Behavioral neuroscientist Marina Picciotto of Yale University set out to study whether activating one particular nicotine receptor, dubbed α3β4, had antidepressant effects on mice. But as postdoctoral researcher Yann Mineur was caring for the mice, which had received drugs engineered to stimulate only α3β4 receptors, he noticed a side effect: the mice were eating less.

“Before this study, we really didn't think that this type of receptor would have such a big role in the brain in food intake,” Picciotto says. She and Mineur went on to show that nicotine does, in fact, bind to α3β4 receptors, which then send a signal throughout the rest of the brain, signaling satiety. It's indistinguishable from the signal the brain propagates after eating a large meal. Mice that received the drug binding to the α3β4 receptor ate half the amount of food as untreated mice in the 2 hours following administration of the drug. Their body fat dropped 15% to 20% over 30 days, the team reports online today in Science.

Since the weight gain that comes with stopping smoking is often one deterrent for smokers to quit, Picciotto suggests that the new pathway could be targeted by pharmaceuticals to suppress appetite during the initial stages of smoking cessation. In addition, such a drug could have wider reach as an appetite suppressant to aid in weight loss, without the health hazards tied to cigarette smoke.

Neil Grunberg, a behavioral neuroscientist at the Uniformed Services University of the Health Sciences in Bethesda, Maryland, was the first to prove, through rat studies in 1982, that nicotine causes a decrease in appetite. He says the new study is a step forward in understanding the phenomenon he first observed.

“Most people had accepted that the decrease in appetite was caused through a dopamine-reward pathway and left it at that,” Grunberg says. “So I think the most important contribution of this paper is to prove that there is another whole pathway that nicotine is working through.”

Grunberg notes, however, that the study looks only at male mice. In his previous work, he has found differences in the effects of nicotine on weight between males and females. Females, he says, experience larger weight loss when they start smoking and a larger weight gain if they quit. Whether this means nicotine is working through an additional, hormone-regulated pathway in the female brain is yet to be determined.

Picciotto says her group is repeating the experiments on female mice. “We're also still trying to get back to that original question we had,” she says: “Does this also have antidepressant actions?”

The study of the placebo effect — and its opposite the nocebo effect — is published in Science Translational Medicine. The findings suggest that doctors may need to consider dealing with patients’ beliefs about the effectiveness of any treatment, as well as determining which drug might be the best for that patient.

‘Doctors shouldn’t underestimate the significant influence that patients’ negative expectations can have on outcome,’ says Professor Irene Tracey of the Centre for Functional Magnetic Resonance Imaging of the Brain at Oxford University, who led the research. ‘

For example, people with chronic pain will often have seen many doctors and tried many drugs that haven’t worked for them. They come to see the clinician with all this negative experience, not expecting to receive anything that will work for them. Doctors have almost got to work on that first before any drug will have an effect on their pain.’

The placebo effect describes the improvements seen when patients — unknowingly — are given dummy pills or sham treatments but believe it will do them good. This is a very real physiological effect; it is not just about patients ‘feeling’ better. The nocebo effect is the opposite: patients see poorer outcomes as the result of doubts about a medical treatment.

Previous studies have investigated the basis of the placebo effect, when using sugar pills or saline injections for example, and confirmed it can elicit a real response.

This new research, funded by the Medical Research Council and German research funders, goes a step further by examining how manipulating participants’ expectations can influence their response to an active drug.

The Oxford University team, along with colleagues from the University Medical Center Hamburg-Eppendorf in Germany, Cambridge University, and the Technische Universität München, set out to investigate these effects among 22 healthy adult volunteers by giving them an opioid drug and manipulating their expectations of the pain relief they might receive at different points.

The volunteers were placed in an MRI scanner and heat applied to the leg at a level where it begins to hurt — set so that each individual rated the pain at 70 on a scale of 1 to 100. An intravenous line for administration of a potent opioid drug for pain relief was also introduced.

After an initial control run, unknown to the participants, the team started giving the drug to see what effects there would be in the absence of any knowledge or expectation of treatment. The average initial pain rating of 66 went down to 55.

The volunteers were then told that the drug would start being administered, although no change was actually made and they continued receiving the opioid at the same dose. The average pain ratings dropped further to 39.

Finally, the volunteers were led to believe the drug had been stopped and cautioned that there may be a possible increase in pain. Again, the drug was still being administered in the same way with no change. Their pain intensity increased to 64. That is, the pain was as great as in the absence of any pain relief at the beginning of the experiment.

The researchers used brain imaging to confirm the participants’ reports of pain relief. MRI scans showed that the brain’s pain networks responded to different extents according to the volunteers’ expectations at each stage, and matching their reports of pain.

This showed the volunteers really did experience different levels of pain when their expectations were changed, although the administration of pain relief remained constant.

Professor Tracey notes that these results have been seen in a small, healthy group of volunteers, and that these are short-term, not sustained, manipulations of the participants’ beliefs about the treatment.

But she says it’s important not to underestimate the strength of the effect of such expectations on any treatment, and that clinicians need to know how to manage that.

Professor Tracey says there may also be lessons for the design of clinical trials. These are often carried out comparing a candidate drug against a dummy pill to see if there is any effect of a drug above and beyond that of the placebo.’We should control for the effect of people’s expectations on the results of any clinical trial. At the very least we should make sure we minimize any negative expectations to make sure we’re not masking true efficacy in a trial drug.’

NEW YORK (Reuters Health) – Taking the herbal supplement ginkgo biloba may help delay the onset of cognitive impairment in normal elderly adults, according to a study published online Wednesday.

However, the study also showed a higher incidence of strokes and “mini-strokes” in ginkgo users. The reasons for this are unclear and require confirmation in other studies, the investigators say.

Extracts of ginkgo biloba are among the most widely used dietary supplements. The herb is marketed as a memory enhancer, and some studies have suggested it may help improve memory and other mental functions in people with dementia.

“One of the most pressing public health problems facing our society is the rapidly growing number of people who, due to their age alone, are at high risk of developing dementia. The potential to delay or prevent this is of great importance,” study chief Dr. Hiroko H. Dodge, from the Oregon State University in Corvallis, said in a statement.

The three-year study involved 118 people age 85 and older with no memory problems. Half of them took ginkgo biloba extract three times a day and half took a placebo.

During the study, 21 people developed mild memory problems, or questionable dementia: 14 of those took the placebo and 7 of those who took the ginkgo extract. Although there was a trend favoring ginkgo, the difference between those who took ginkgo and those who took placebo was not statistically significant.

However, when the researchers took into account whether people followed directions in taking the study pills, they found that people who reliably took ginkgo had a 68 percent lower risk of developing mild memory problems than those who took the placebo.

“These results need to be clarified with larger studies, but the findings are interesting because ginkgo biloba is already widely used, readily available, and relatively inexpensive,” Dodge said.

As noted, more strokes and mini-strokes were seen in the ginkgo group. Seven people taking ginkgo had strokes, while none of those taking placebo did. “Ginkgo has been reported to cause bleeding-related complications, but the strokes in this case were due to blood clots, not excessive bleeding, and were generally not severe,” Dodge noted in a statement.

“Further studies are needed to determine whether ginkgo biloba has any benefits in preventing cognitive decline and whether it is safe,” he added.

　　NEW YORK (AP) – Pfizer Inc. said Friday it is pulling its blood pressure drug Thelin off the market and stopping all clinical trials because the drug can cause fatal liver damage.

　　Thelin is sold in the European Union, Canada, and Australia as an oral treatment for severe pulmonary arterial hypertension, or high blood pressure in the pulmonary artery. Pfizer said two patients who were taking Thelin died during a clinical trial, and a review of data from clinical studies and post-marketing reports showed a new link to liver injury.

　　Liver damage was a known side effect of Thelin and similar drugs, the company said, but the review uncovered a link to liver damage that was not tied to identifiable risk factors. It said the problem was unlikely to be detected by routine monitoring, and in some cases, the problems did not go away after patients stopped taking Thelin.

　　Pfizer said the withdrawal was voluntary and added that it has withdrawn its filing for marketing approval in the U.S.

　　Since there are other treatment options, Pfizer said the benefits of Thelin don’t outweigh the risks. It is stopping all studies of the drug, which Pfizer acquired in 2008 when it bought Encysive Pharmaceuticals Inc. Encysive had been trying to win marketing approval for Thelin since 2005, but the Food and Drug Administration said it was not effective enough. Other agencies only approved the drug for hypertension that was so debilitating that patients’ physical activity was severely limited.

　　The New York company said worldwide sales of Thelin, or sitaxsentan, totaled $44.4 million in the first nine months of 2010.

　　In afternoon trading, shares of Pfizer added 12 cents to $16.88.

　　(Copyright 2010 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.)