TUESDAY, Nov. 20 (HealthDay News) -- People who start a walking program for their health get more out of it by using a pedometer, a device that counts their steps, a new study shows.

"People who use pedometers increase their physical activity by about 2,000 steps a day, about a mile," said study author Dr. Dena M. Bravata, a senior research scientist at Stanford University. "They also seem to lower their blood pressure more and lose more weight."

The conclusion, reported in the Nov. 21 issue of the Journal of the American Medical Association, comes from an analysis of 26 studies with a total of 2,767 participants. Most were observational studies, which means the researchers simply watched what the volunteers did, while eight had some scientific controls.

Pedometer users in the controlled trials increased their physical activity by 2,491 steps per day more than those who didn't use the devices. The comparable increase for pedometer users in observational trials was 2,183 steps per day.

Pedometer users also had their systolic blood pressure -- the higher number -- fall by an average of 3.8 millimeters. A 2-mm reduction is associated with a 10 percent reduction in stroke mortality and a 7 percent reduction in death from blood vessel conditions, Bravata noted. And pedometer users also reduced their body-mass index by 0.4 percent -- about 2.5 pounds for a 195-pound individual.

One valuable input of pedometer use was that it seemed to increase motivation for more physical activity. "The more sedentary you were, the more likely this tool was to help you," Bravata said. "The effect on workplace interventions was not as great, because the people who participate in workplace programs are higher baseliners."

The study does have limitations, Bravata noted. Only 15 percent of the participants were men, and the average duration of the trials was 18 weeks.

But it's generally agreed that most Americans need more physical activity. Two-thirds of U.S. adults are overweight or obese, and the U.S. Centers for Disease Control and Prevention estimates that only 45 percent of Americans get enough physical activity, usually defined as at least 30 minutes a day of exercise such as walking.

One major advantage of pedometer use in an exercise program is that it caters to the American quest for numbers, said James Hill, director of the University of Colorado Center for Human Nutrition and co-founder of America on the Move, an organization dedicated to increasing physical activity.

"We published a paper in 2003 which suggested using pedometers as tools to promote physical activity," Hill said. "Until then, a pedometer was just a tool to measure activity. A pedometer puts physical activity in terms of a number. You can watch it and manage your day in terms of physical activity."

Pedometers can be simple and inexpensive or sophisticated and expensive, Hill said.

"I recommend that you invest at least $15," he said. "I'm a simple guy, and I prefer a one-button model that simply pushes you back to zero. Some models put in stride length and mileage, but the simpler kind does very well."

More information

A guide to using pedometers is offered by the U.S. National Institutes of Health.

FRIDAY, Nov. 16 (HealthDay News) -- Archaeologists say they've found one of the oldest traces ever of human chocolate consumption in pottery vessels more than 3,000 years old.

The jugs -- thought to have contained a fermented chocolate concoction -- date from 1150 B.C. and were used by Mesoamerican people in what is now Puerto Escondido, Honduras.

"It appears to have been used in a beverage, which was made from the pulp of the chocolate fruit. Later, they started to focus on the bean itself," said researcher Patrick McGovern, a senior research scientist and associate professor of anthropology at the Museum Applied Science Center for Archaeology, University of Pennsylvania Museum.

The cacao drink appears to have been fermented and was mildly alcoholic, containing about 5 percent alcohol, McGovern said. These ancient peoples apparently domesticated the cacao (chocolate) tree to produce these drinks, commonly consumed in ceremonies that marked weddings and births.

The findings were published in this week's Proceedings of the National Academy of Sciences.

While McGovern's team claimed the find represented the "earliest cacao beverages" found, not everyone agreed.

"Chocolate is incredibly old in that part of the world [Mesoamerica]," said Michael D. Coe, the emeritus professor of anthropology at Yale University and co-author of The True History of Chocolate.

Newer studies have found even older chocolate on the Pacific coast of Mexico, Coe said. "The earliest sample is 1,200 years older than what this team reports. It looks like chocolate is almost 4,000 years old in that part of the world," Coe added.

Study lead author John S. Henderson, a professor of anthropology at Cornell University in Ithaca, N.Y., said that while he wasn't aware of the new data Coe cites, "it is very possible" that an older use of cacao had been found.

McGovern's team based their conclusion on finding traces of the chemical theobromine, a chemical found only in cacao plants, in pottery vessels used to hold liquids.

It is not clear what the drink looked like or how it tasted, McGovern said. But it would have had a sweet chocolate taste, he said. "Later, when the drink was being made from the bean, other things such as chilies, honey, and flowers and spices were added," he said.

Chocolate drinks made from the cacao bean were later used by the Mayans and Aztecs, McGovern noted.

Henderson said the findings pointed to the haphazard way customs developed and changed over time.

He argued that it was significant that the first use of chocolate was sourced and fermented from the plant's pulp. If this is true, then the way the Aztecs and others used chocolate, as well as the modern chocolate industry, "becomes an accident. An unintended consequence of early beer brewing," he noted.

"It makes a nice example that important developments are not self-consciously done by intended result," Henderson added.

McGovern said his team had also found the oldest known alcoholic beverage in the world. It came from China and dates from 7000 B.C., he said. The drink was made from rice, honey and hawthorn, or wild grape.

It appears that "humans are interested in finding anything that will ferment," McGovern said.

More information

For more on the history of chocolate, visit The Field Museum  .

TUESDAY, Nov. 13 (HealthDay News) -- In mice, a low-carbohydrate diet slowed prostate tumor growth, possibly because fewer carbohydrates leads to a drop in insulin production, U.S. researchers say.

"This study showed that cutting carbohydrates may slow tumor growth, at least in mice. If this is ultimately confirmed in human clinical trials, it has huge implications for prostate cancer therapy through something that all of us can controls, our diets," lead researcher Dr. Stephen Freedland, a urologist at Duke University Medical Center, said in a prepared statement.

Previous studies linked insulin and a related substance called insulin-like growth factor (IGF) with the growth of prostate tumors in mice. Freedland and his colleagues theorized that reducing levels of these substances might slow prostate tumor growth.

They compared tumor growth in mice eating either a low-carbohydrate diet; a low-fat but high-carbohydrate diet; or a Western diet high in fat and carbohydrates.

Mice fed the low-carbohydrate diet had the smallest tumor size and longest survival, the team found.

""Low-fat mice had shorter survival and large tumors , while mice on the Western diet had the worst survival and biggest tumors. In addition, though both the low-carb and low-fat mice had lower levels of insulin, only the low-carb mice had lower levels of the form of IGF capable of stimulating tumor growth," Freedland said.

The study is published in the Nov. 13 online edition of the journal Prostate.

Freedland is currently organizing a clinical trial to examine the impact of a low-carbohydrate diet on prostate tumor growth in men.

More information

The American Cancer Society has more about prostate cancer  .

WEDNESDAY, Oct. 24 (HealthDay News) -- When it comes to your lungs, a couple of drinks a day may help keep the doctor away, researchers report.

Though considerable evidence has mounted that a daily dose of alcohol helps the heart, this study suggests the same may be true for lung function -- even for smokers.

"This is the biggest study that's ever looked at the possible protective effect of alcohol involving the lung," noted study author Dr. Stanton T. Siu, chief of pulmonary medicine at Kaiser Permanente Hospital in Oakland, Calif.

"We found that that if you drank less than two glasses of alcohol per day of wine, beer, or hard liquor that you had much less likelihood of developing obstructive airways disease, which includes asthma and emphysema," he said.

"You do seem to get some benefit if you drink three to five drinks per day," added Siu. "But it wasn't as good if you drank just a little. And if you drank six or more, it actually had a bad effect. It made your lung function worse."

Siu was to present his findings Oct. 24 at the American College of Chest Physicians annual meeting, in Chicago.

Previous studies have indicated that other dietary interventions -- such as consuming vitamin D supplements -- might offer some measure of protection against developing lung health problems.

For the current study, Siu and his colleagues analyzed the health records of almost 178,000 patients living in northern California. All had undergone exams between 1964 and 1973 as members of the same local health plan.

Exam questionnaires completed at the time recorded their smoking and drinking habits, as well as their lung function histories.

According to the surveys, 61 percent said they had already experienced some kind of cardio-respiratory illness.

An almost identical percentage said they drank less than two alcoholic drinks per day, while eight percent consumed three to five drinks daily. Just over two percent said they drank six or more glasses per day. A little more than 21 percent said they consumed no alcohol at all.

As part of their exams, all the patients also underwent a range of pulmonary function tests (PFT) designed to gauge how well a person inhales, exhales and transfers oxygen from the lungs into the bloodstream.

Stacking PFT results alongside drinking rates, Siu's team found that so-called "light to moderate drinkers" -- those who did not abstain altogether but consumed less than two glasses of alcohol per day -- were the least likely to have problems with lung function.

The relationship between moderate drinking and healthy lungs appeared to hold up regardless of smoking habits or a previous experience of lung and/or heart disease.

The survey records had not broken down alcohol consumption according to type of alcohol consumed, so it's not possible to tell from this study if any category of drink is healthier for the lungs than another.

Siu said light drinking's protective effect roughly translates to a 20 percent reduction in the risk for developing lung disease. The link between alcohol use and lung health held steady across all ethnic groups, all age groups, and for both men and women, he added.

"There was a little more of a positive impact for women," Siu said, "but not a huge difference. And, in fact, when we looked at three to five drinks per day, then the men did better than the women."

A second study, also presented at this week's meeting, found that vitamins might help keep lungs healthy, too.

In this instance, a team of researchers from Bangladesh, led by Kazi S. Bennoor from the National Institutes of Diseases of Chest and Hospital, followed a group of 200 healthy smokers between the ages of 30 and 50 for two months. They divided the participants into four groups: those told to consume 10,000 IUs daily of vitamin A; those taking 500 mg daily of vitamin C; those taking 200 mg daily of vitamin E; and those taking all three of the vitamins in combination.

All the patients had smoked cigarettes for at least 11 years.

Lung performance tests were conducted at the start of the study, at the two-month mark (when all vitamin supplementation was stopped), and six months following vitamin cessation. A fifth group of 50 healthy non-smokers who took no vitamin supplementation was also similarly examined for lung function.

Although none of the smokers achieved lung health comparable to that of the non-smoking group, Bennoor's team found that vitamin supplementation did significantly improve lung function in all four smoking groups.

No one vitamin appeared to positively impact lung health any more than another, but the group taking all three vitamins seemed to derive the biggest benefit.

However, six months after going off a vitamin regimen, the lung health of all the smokers reverted back to levels that were below those seen after two months of supplementation.

It's possible that antioxidant supplementation might help improve lung function, the team speculated, but such improvements are not retained when supplementation stops.

Dr. Neil Schachter, professor of pulmonary medicine and medical director of the Respiratory Care Department at Mount Sinai Medical Center, New York City, was a bit cautious on the results of both studies.

"These are interesting studies," he said. "But, first of all, there is simply not that much literature on alcohol and lung function. So, yes, there is this thought that one or two glasses of alcohol is good for your heart and too much is not good for your health in general. And I guess their findings go along with that general statement. But, nevertheless, I'd say the jury is still out."

"On the other hand, there's a lot of literature on vitamin supplementation as it relates to chronic lung disease," Schachter added. "There is a lot of evidence that diets loaded with what are considered healthy nutrients -- fruits, grains, those kind of things -- are associated with better lung health than those that are not. But attempts to supplement diets with vitamins in order to improve lung health have not been terribly successful. And this vitamin study was very, very small."

"So, while I understand that certainly people would much rather make themselves well with diet than they would with medication, it's important to recognize that this is very hard research to do," Schachter said. "So far, the attempts to sort of pluck out the ingredients that we think are the keys ones haven't been very successful. Much more work is needed," he added.

More information

For additional information on lung disease, visit the National Lung Health Education Program  .