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GaryMrMets
02-05-2002, 12:49 PM
http://aolsvc.health.medscapehealth.aol.com/cx/viewarticle/210316

Article Level: Advanced
Brewing a New View of Caffeine

from WebMD Health

Maxine Rock, Medical Writer

Food experts, who have warned that the caffeine in coffee may cause everything from cardiovascular disease to cancer, are changing their tune. They now say moderate caffeine intake is safe, so people can relax and indulge in several daily cups of coffee or tea.

Nutrition scientists who convened last fall at a meeting of the American Dietetic Association (ADA) noted that new studies--plus a review of existing work--show caffeine has no harmful effect on the human body. Earlier reports linking caffeine to breast cancer, high blood pressure, osteoporosis, and other diseases, they say, may have been hasty or based on too-small studies.

Moderation = 3 Cups a Day

The United States Food and Drug Administration (FDA) and the National Institutes of Health (NIH), two of the most respected US watchdog agencies, have declared caffeine safe. Even the American Medical Association (AMA) says coffee and tea drinkers "probably need have no concern for their health relative to their caffeine consumption" as long as the intake is moderate.

Moderate coffee intake is generally defined as 3 cups a day. That delivers 300 milligrams (mg) of caffeine, since an 8-ounce cup usually holds about 100 mg. The same size cup of tea holds some 40 mg of caffeine. Many soft drinks contain about 24 mg of caffeine, and chocolate ranges from 6 mg in an 8-ounce cup of cocoa to 26 mg in 1 ounce of baker's chocolate. Many processed foods also have small amounts of caffeine added to enhance flavor.

Coffee Craze Spurred Investigation

Caffeine is a natural substance found in at least 60 plants. Coffee beans were originally consumed as food in Africa, and tea was invented in China, allegedly when leaves drifted into a pot of boiling water and created a delicious liquid. Chocolate drinks were used by the Aztec emperor Montezuma in the early 1500s to welcome Spanish explorers, and caffeinated soft drinks became the rage in America in the 1880s. These treats quickly spread around the world, and caffeine has been a dietary staple ever since.

Scientists in the United States began taking a close look at caffeine in the late 1980s, when specialty coffees and neighborhood "coffee bars" spurred consumption. A variety of studies suggested that coffee drinkers might be more prone to heart disease and hypertension, and one small study done in 1988 alarmingly suggested that 1-2 cups of coffee a day might make it harder for women to conceive. Although follow-up studies have not supported this conclusion, this led to a myriad of myths about caffeine, including suggestions that it is bad for children and pregnant women and that it can become addictive.

No Such Thing as a Coffee Addict

"Caffeine is not a drug, and you can't get addicted to it," says Edith Howard Hogan, a Washington, DC, expert in nutrition who is a national spokesperson for the ADA. "Caffeine doesn't build up in the bloodstream, and doesn't stay in the body for long. You can get dependent on having a cup of coffee, and feel unhappy if you don't get it, but that's very different from addiction. An addict needs more and more of a substance, and very often that substance is harmful to the body. People don't crave more caffeine, and in reasonable amounts it's perfectly safe."

Hogan notes that misconceptions about caffeine and coffee consumption hurt nutrition researchers, because people get fed up with confusing reports and tend to disregard important information when it does surface. "Scientists and the media need to do a better job of telling consumers when information is based on preliminary studies and when something comes out that really is important," she says. "Sometimes it's hard to tell the difference."

Setting the Record Straight

Lately, scientists have been scrambling to set the record straight about caffeine. Larger studies looking at breast cancer and fibrocystic breast disease have found no evidence to implicate caffeine, prompting the American Cancer Society to declare, "There is no indication that caffeine, a natural component of both coffee and tea, is a risk factor in human cancer."

The Centers for Disease Control and Prevention (CDC) in Atlanta, in a joint study with Harvard University, found coffee was safe for pregnant women and for those wishing to conceive. The Association of Women's Health, Obstetric & Neonatal Nurses says moderate intake of caffeine isn't a factor in miscarriages, birth defects, low birth weight, or breast feeding. Caffeine can spur some increase in calcium loss, say the nurses.

Although consuming 1-2 cups of coffee per day is common in our society, caffeine is considered a risk factor for osteoporosis. People with osteoporosis or at high risk for developing it should seriously consider significantly limiting caffeine intake.

May Even Have Health Benefits

Caffeine seems to be harmless as long as you use common sense and don't consume more than your body can handle. Children can also safely indulge in caffeinated beverages as the effects seem to be similar in adults and children--even those who are hyperactive seem to tolerate it well. (Humans don't develop the necessary machinery to effectively metabolize caffeine until somewhere between 6 months and 2 years, and therefore it is better to avoid caffeine in kids less then 2 years old.) Caffeine won't cause dehydration, either, because you'll probably ingest more water in the coffee and tea than you lose as a result of the caffeine.

Caffeine may even have health benefits: It does enhance motor skills, reaction time, and reasoning power, and is being investigated as an aid in dissolving kidney stones. There is even some preliminary scientific evidence suggesting a link between drinking filtered coffee and a rise in high-density lipoprotein (HDL), the "good" cholesterol.

Experts now agree that each individual should decide if drinking caffeine-containing beverages is right for them. Some people think of coffee or tea as one of life's pleasures; others are supersensitive to caffeine and say it results in heartburn, or makes them irritable. "The best advice is to go with how the caffeine reacts in you," says Hogan. "You know your body better than anyone else."

Maxine Rock is a medical writer who lives in Atlanta.

GaryMrMets
02-05-2002, 12:51 PM
http://aolsvc.health.webmd.aol.com/content/article/1671.50455?DEST=WebMD&contentSRC=aolhealthnews

February 5, 2002
Giving Coffee a Break

ByÂ* PeterÂ*Jaret
For true coffee connoisseurs, the day doesn't get started until that first cup of joe. And when the afternoon slump occurs, there's no better pick-me-up. The real news, however, is that after years of hand-wringing, scientists are admitting that coffee poses very little risk for most people, and may keep us sharp. That's no surprise to java junkies.

"If it weren't for the coffee," David Letterman once quipped, "I'd have no identifiable personality whatsoever."

That's a sentiment most coffee lovers can understand.

Treasured as it is, however, coffee has been blamed for a range of ills, from heart disease and cancer to osteoporosis. Are health dangers really lurking in our lattes?

Health experts offered reassuring words at the 1999 annual meeting of the American Dietetic Association: Drinking up to three cups of coffee a day poses no risk. What's more, coffee appears to have some surprising benefits.

False Alarms

It's easy to see why researchers take coffee seriously. One cup contains about 100 milligrams of caffeine -- enough to give infrequent coffee drinkers a potent kick, says Tony Chou, MD, a cardiologist at the University of California, San Francisco, and an authority on how coffee affects our health. Half an hour after a good strong cup, a coffee drinker's resting metabolic rate -- the number of calories burned just sitting quietly -- increases by as much as 10%. Blood pressure climbs. Heart rate accelerates. Breathing speeds up.

Researchers used to worry all that commotion was harming our hearts. But regular coffee drinkers quickly develop a tolerance to caffeine, Chou says. After a week or two, they don't get so much as a wobble in their blood pressure. Habitual coffee drinkers are no more likely to suffer from hypertension than people who never pour a cup.

Even patients with irregular heartbeats, or arrhythmia, don't seem to be troubled by caffeine, according to a study published in the Annals of Internal Medicine in January 1991. Toronto scientists reviewed five studies of people with arrhythmia. Drinking up to five cups of coffee a day, they found, didn't make anyone's heart more likely to skip a beat.

Nor does coffee appear to increase the risk of heart disease, according to a 10-year study of more than 85,000 women. In the February 1996 Journal of the American Medical Association, Harvard researchers reported that women who drank six or more cups of coffee weren't any more likely to have a heart attack than women who drank only one or two cups.

Plenty of other alarms have turned out to be false. A few years back, headlines warned about a possible link between coffee and breast cancer. But in the February 1998 European Journal of Cancer Prevention, Italian researchers reported finding no link. The other worry, concerning osteoporosis, didn't hold much water either. Results of a study published in the June 1997 American Journal of Clinical Nutrition showed that bone thinning wasn't more likely in women who drank coffee.

Jogging the Brain

The bottom line: Coffee seems to be harmless for most people. And studies suggest that a cup may actually offer some impressive benefits. In the August 1999 issue of Physiology and Behavior, for instance, English researchers reported that volunteers who drank caffeinated coffee in the morning performed better than nondrinkers on tests that involved learning new information. That holds true for the elderly as well, according to a study in the January 2002 issue of Psychological Science. And a study published in International Journal of Sports Medicine in August 1999 found that attention, psychomotor skills, and long-term memory all improved during the few hours after volunteers drank caffeinated beverages.

Why? Caffeine keeps us alert not by speeding us up but by keeping us from slowing down, according to Michael Bonnet, PhD, professor of neurology at Wright State University in Ohio. Each time brain cells fire, they produce a squirt of a chemical that serves as an "off" switch that keeps neural activity in check. Caffeine, in effect, blocks the chemical -- jamming the switch so that it can't be turned down.

Caffeine also may boost levels of brain-cell calcium, a mineral we know is important in memory. In experiments reported in the October 1999 issue of Proceedings of the National Academy of Sciences, an Israeli researcher observed a calcium increase in brain cells exposed to caffeine.

Is There Any Reason Not to Love Coffee?

However, too much caffeinated coffee can cause problems, experts say. Because caffeine is a stimulant, it can aggravate sleep problems like insomnia.

If you're having trouble getting pregnant, you might want to think about laying off coffee. A few studies have linked caffeine to infertility (although others have found no association).

Finally, if you're feeling anxious or depressed, it's worth easing up on the caffeine, which can exacerbate symptoms.

Originally published Nov. 29, 1999.
Updated Jan. 24, 2002.

GaryMrMets
02-05-2002, 12:53 PM
http://aolsvc.health.webmd.aol.com/content/article/1671.52718?DEST=WebMD&contentSRC=aolhealthnews

February 5, 2002
Caffeine Sharpens the Mind
ByÂ* MichaelÂ*Smith ,Â*MD
WebMD Medical News Reviewed ByÂ*Dr. GaryÂ*Vogin

Dec. 20, 2001 -- Do you thrive in the morning and fall off as the day goes on? If so, a new study shows that a morning latte can jump start your mind all the way into the afternoon.

At least 75% of people over the age of 65 say they are "morning" people, according to researchers at the University of Arizona. But their research shows that a cup of java -- don't hold the caffeine -- may be able to turn you into an afternoon, person too.

In older people, memory is best early in the morning and then declines during the late afternoons, says lead author Lee Ryan, in a news release.

The researchers looked at 40 people over 65 and tested their memory in the morning and again in the afternoon a few days later. Each time, they drank a 12 oz. cup of coffee before going through a series of memory tests. Some drank decaffeinated coffee and some had the real thing but were not told which one they were getting.

Those who had caffeine were able to recall more items on a delayed memory test. That is, after a 20-minute delay and distraction with other tasks, those in the caffeine group were much better at recalling words presented to them.

The study appears in the January issue of Psychological Science.

In fact, those who drank decaffeinated coffee "showed a significant decline in memory performance from morning to afternoon," Ryan says. Those who drank the caffeine had no fall in their memory test scores. Ryan is an assistant professor of psychology at the University of Arizona.

The authors suggest that the fall in mental sharpness experienced by many people over 65 may be due to changes in alertness -- which is improved with caffeine.

However, Ryan and her colleagues aren't endorsing caffeine particularly. She says that other stimulants would likely produce a similar effect.