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Books: White Doctors, Black Subjects: Abuse Disguised as Research
By DENISE GRADY, The New York Times, January 23, 2007
The most notorious medical experiment in American history was surely the Tuskegee syphilis study, in which 400 black men with syphilis were left untreated for 40 years, from 1932 until 1972, so government doctors could study the course of the disease. The experiment ended only because a journalist exposed it, igniting a firestorm of public outrage over its racism and cruelty. By then, as many as 100 of the men had already died of syphilis.
Tuskegee was just part of a pattern of experimental abuse, one of many shameful chapters in what Harriet A. Washington calls “the long, unhappy history of medical research with black Americans.”
Ms. Washington, a journalist and research scholar in ethics, writes in “Medical Apartheid” that this history has left blacks with an ugly legacy of distrust for research and even treatment, and that it is a lingering stain on the history of medicine.
She does not oppose medical research or blacks’ inclusion in it. On the contrary, she calls research “utterly essential,” and blacks’ participation necessary. “African-Americans,” she writes, “desperately need the medical advantages and revelations that only ethical, essentially therapeutic research initiatives can give them.”
But first, she argues, the air must be cleared. She is certainly the one to do it. She has unearthed an enormous amount of shocking information and shaped it into a riveting, carefully documented book.
Blacks have been forced to undergo painful, risky experimental surgery, dosed with radiation and singled out for experiments aimed at finding brain abnormalities linked to violence. They have been falsely assumed to feel pain less than whites and to require higher X-ray doses for a readable film.
One of the worst offenders was James Marion Sims, a 19th-century surgeon who has been venerated as a selfless benefactor of women for devising ways to repair severe vaginal injuries that can occur in childbirth.
Sims honed his skills by performing scores of painful operations on the genitals of black slaves. His early attempts so often failed that he operated on one young woman 30 times. The women had to be held down during the excruciating operations. Though ether was available, Sims refused to use it, insisting it was not needed. But when he had refined the surgery enough to offer it to white women, he always gave them ether.
To the question of whether it is fair to judge people like Sims by the ethical standards of a later era, Ms. Washington replies that he violated the ethical codes of his own day.
Reprehensible behavior continued into the 20th century. Often, the so-called research performed on blacks had the trappings of science but was meaningless, poorly designed and based on specious theories. People must have known better, but apparently chose not to think about it.
“In the South,” Ms. Washington writes, “rendering black women infertile without their knowledge during other surgery was so common that the procedure was called a ‘Mississippi appendectomy.’ ” But the same was true in the North, as recently as the 1970s, when unnecessary hysterectomies were often done on poor black and Puerto Rican women to give doctors in training a chance to practice their skills.
Some of Ms. Washington’s arguments are less convincing than others. She questions the “significance” of two black men’s being selected as the first subjects to test the AbioCor artificial heart in 2001 and 2002. But was it significant?
Since two of the first six subjects were black, she notes that they made up 33 percent of the test subjects, “almost three times their representation in the population,” and suggests that blacks were used disproportionately to test a device that, if ever approved, would probably be too expensive for most minorities. Ultimately, 14 people tested the AbioCor, but she never gives the complete racial breakdown. From her account, it’s hard to figure out what was going on.
In another venture onto thin ice, Ms. Washington calls for “more exhaustive studies” of an experimental AIDS vaccine that initially appeared to protect blacks and Asians, but not whites. But when the data were closely analyzed, the first finding did not hold up: the vaccine did not work for anybody. Even so, Ms. Washington implies that the vaccine did have promise for minorities but was abandoned purely because it did not help whites. If there is evidence to justify sinking more money into this vaccine, she does not provide it.
But this is an important book. The disgraceful history it details is a reminder that people in power have always been capable of exploiting those they regard as “other,” and of finding ways to rationalize the most atrocious abuse. The victims are declared defective, violent, hypersexed or a drain on the community. The medical tinkering is for their own good, and the greater good of society.
The worst abuses in this country may be a thing of the past, but history has a way of repeating itself. Ms. Washington warns that Africa and other poor regions are becoming the next venue for exploitative studies by foreign governments, universities and drug companies, which may use their citizens to develop medicines and other treatments that those nations will never be able to afford.
Study Says Tapping of Granite Could Unleash Energy Source
By ANDREW C. REVKIN, The New York Times, January 23, 2007
The United States could generate as much electricity by 2050 as that flowing today from all of the country’s nuclear power plants by developing technologies that tap heat locked in deep layers of granite, according to a new study commissioned by the Energy Department.
There are already dozens of power plants worldwide that have long exploited hot spots of geothermal energy to drive steam turbines, but they are restricted to a few areas.
The new report, published online yesterday, focuses on a process that it said could affordably harvest heat locked in deep layers of granite that exist almost everywhere on earth. The technique, called enhanced geothermal, involves drilling several holes — some two to three miles deep — into granite that has been held at chicken-roasting temperatures, around 400 degrees or more, by insulating layers of rock above.
In the right geological conditions, pressurized water can be used to widen natural mazelike arrays of cracks in the granite, creating a vast, porous subterranean reservoir.
In a typical setup, water pumped down into the reservoir through one hole absorbs heat from the rock and flows up another hole to a power plant, giving up its heat to generate steam and electricity before it is recirculated in the rock below.
There are successful plants harvesting heat from deep hot rock in Australia, Europe and Japan, the report noted, adding that studies of the technology largely stopped in the United States after a brief burst of research during the oil crises of the 1970s.
The report’s 18 authors, from academia, government and industry, said that a public investment of less than $1 billion spread over 15 years would probably be enough to overcome technical hurdles and do initial large-scale deployment of the technology.
The generating capacity by 2050 could be 100 billion watts, about 10 percent of the country’s current generating capacity.
David Keith, an expert on energy technologies at the University of Calgary who was not involved with the study, said there were significant, but surmountable, hurdles to doing such operations at large scale.
Among them, Professor Keith said, are cutting the costs of drilling deep holes and increasing the efficiency of systems that can generate electricity from relatively low-temperature source of heat like deep rock.
“There’s no question there’s a lot of heat down there,” he said. “It’s about the cost of access, and about the value of low-grade heat.”
Jefferson W. Tester, the lead author of the study and a chemical engineer at the Massachusetts Institute of Technology, said there were many new justifications for aggressively pursuing this kind of energy option.
“Back then, we weren’t worried about carbon dioxide and climate, we weren’t running short of natural gas, and now energy is a national security issue in the long run,” Dr. Tester said. “While there’s no guarantee it’s going to work, this is not an unreasonable investment and it’s a good bet on the future.”
Five New Satellites With a Mission of Finding a Source of Color in Space
By WARREN E. LEARY, The New York Times, January 23, 2007
WASHINGTON, Jan. 22 — NASA will soon launch a fleet of five spacecraft in hopes of solving the mystery of how the greenish auroras above the Earth’s poles suddenly burst into shimmering multicolor lights.
The quintet of identical satellites, NASA’s first attempt to launch so many satellites on a single rocket, will be positioned in orbits inside the magnetic field surrounding Earth to look for the origin of sudden energy outbursts that enliven the northern and southern lights.
The space probes are part of a mission called Themis, short for Time History of Events and Macroscale Interactions during Substorms, which is designed to find the trigger point of geomagnetic substorms that can spring up within minutes to brighten auroras and release bursts of potentially damaging radiation.
The Sun constantly fills space with charged particles and other radiation through solar flares or large eruptions called coronal mass ejections. The Earth’s magnetic field shields the planet from most of this solar wind by capturing these high-energy particles and channeling them around the planet, forming a tear-shaped protective bubble called the magnetosphere.
Some of these particles leak through the magnetosphere and pour through the atmosphere toward the poles, colliding with air molecules and causing the atmosphere to glow in a greenish-white light. From space, these auroras glow like oval haloes encircling the north and south magnetic poles. At times, however, energy builds up within the magnetic field until it suddenly breaks loose into what is called a substorm, releasing a burst of electrical current that turns the auroras into pulsing red, purple and white colors.
Built by the Space Sciences Laboratory at the University of California, Berkeley, and Swales Aerospace of Beltsville, Md., the satellites aim to establish once and for all where in the magnetosphere substorms originate and what triggers them, said Dr. Vassilis Angelopoulos, a research physicist at the university and the chief scientist for the mission.
“For over 30 years, the source location of these explosive energy releases has been sought after with great fervor,” Dr. Angelopoulos said. “A substorm starts from a single point in space and progresses past the Moon’s orbit within minutes, so a single satellite cannot identify the substorm origin.”
Substorms are a recurring phenomenon that can pop up at any time, even during periods of low solar activity, he said. They appear as well during major storms caused by regular solar eruptions, adding to their destructive power, and a series of substorms happening by themselves can produce enough accumulated energy to cause damage, he said.
Solar storms can damage or disrupt communications and GPS navigation satellites, overload and knock out electric power grids, and pose a radiation danger to astronauts in space, experts said. “Themis is a stepping stone to explain space weather phenomenon that affects our lives,” Dr. Angelopoulos said.
Peter Harvey, project manager for the mission at the university, said the five-satellite constellation is scheduled to be launched aboard a Delta II rocket from Cape Canaveral, Fla., on Feb. 15. Observations from four of the satellites are needed to complete the $200 million mission, and the fifth spacecraft will serve as an in-orbit spare.
The dishwasher-sized satellites are to coast in Earth orbit for 10 months until they line up within Earth’s shadow like a string of beads, with two of the spacecraft positioned about one-sixth of the way to the Moon and the other two about halfway. By February 2008, they will begin collecting coordinated measurements every four days to pinpoint where and when substorms begin.
To get an added dimension to the life cycles of these substorms, the satellite measurements will be coordinated with ground-based readings from 20 observatories spread over Alaska and Canada. These northern observatories are equipped with all-sky cameras and magnetometer sensors that measure currents in near-Earth space.
Dr. Angelopoulos said he expected the satellites to observe more than 30 substorms during the mission’s lifespan and make a major contribution to understanding space physics.
“Themis is so important because the same fundamental physical process is seen around all planets, it happens on the Sun in solar flares, and in astrophysical systems such as black holes,” he said. “It’s amazing that being so close to us, here at Earth, it is not understood yet.”
Vital Signs: Consequences: Gun Ownership Linked to Higher Homicide Rates
By ERIC NAGOURNEY, The New York Times, January 23, 2007
States with the greatest number of guns in the home also have the highest rates of homicide, a new study finds.
The study, in the February issue of Social Science and Medicine, looked at gun ownership in all 50 states and then compared the results with the number of people killed over a three-year period.
The research, the authors said, “suggests that household firearms are a direct and an indirect source of firearms used to kill Americans both in their homes and on the streets.”
The researchers, led by Matthew Miller of the Harvard School of Public Health, drew on data gathered by the federal Centers for Disease Control and Prevention. In 2001, the agency surveyed more than 200,000 people and asked them, among other questions, whether they had a gun in or near the home.
In states in the highest quarter of gun ownership, the study found, the overall homicide rate was 60 percent higher than in states in the lowest quarter. The rate of homicides involving guns was more than twice as high.
Among the possible explanations for the higher homicide rates, the study said, is that states with high gun ownership tend to make it easier to buy guns. There are also more guns that can be stolen. And the presence of a gun may allow arguments and fights to turn fatal.
The researchers said they could not prove that the guns caused the increase in homicides, only that there was a link. It may be, they said, that people are more likely to buy guns in states where violence is already high. But they said that explanation did not appear to be supported by their findings.
Really? The Claim: Drinking Tea Reduces Stress
By ANAHAD O’CONNOR, The New York Times, January 23, 2007
THE FACTS Some call it nature’s tranquilizer, able to smooth away stress and lift the spirits. But are the stress-reducing powers of tea fact or fiction?
Although the association between tea and relaxation dates back centuries, few independent scientific studies have put that idea to the test. Much of the research has been focused only on animals. But a new study on humans suggests that it may hold only a sliver of truth.
The study was published this month in the journal Psychopharmacology and financed by the British Heart Foundation. It found that adult men who drank black tea four times a day for six weeks reacted no differently in the face of stress from men given a caffeinated placebo. But there was some indication that they were able to calm down more quickly.
The two groups in the study, consisting of about 75 men who were forced to give up their normal caffeinated beverages, were subjected to stressful social situations while their blood pressure, hormone levels and other indicators of stress were measured. All of the subjects showed the same substantial increases in those measures, with no positive effect on heart rate or blood pressure in the tea group. But those who drank tea had slightly lower levels of the stress hormone cortisol an hour later, suggesting that their levels of the hormone were returning to baseline sooner.
Whether that has any long-term benefit is unclear. Previous studies on animals have pointed to sedative effects of certain compounds in tea, but so far the evidence is weak.
THE BOTTOM LINE There is some evidence, but not much, that tea affects stress levels.
By DENISE GRADY, The New York Times, January 23, 2007
The most notorious medical experiment in American history was surely the Tuskegee syphilis study, in which 400 black men with syphilis were left untreated for 40 years, from 1932 until 1972, so government doctors could study the course of the disease. The experiment ended only because a journalist exposed it, igniting a firestorm of public outrage over its racism and cruelty. By then, as many as 100 of the men had already died of syphilis.
Tuskegee was just part of a pattern of experimental abuse, one of many shameful chapters in what Harriet A. Washington calls “the long, unhappy history of medical research with black Americans.”
Ms. Washington, a journalist and research scholar in ethics, writes in “Medical Apartheid” that this history has left blacks with an ugly legacy of distrust for research and even treatment, and that it is a lingering stain on the history of medicine.
She does not oppose medical research or blacks’ inclusion in it. On the contrary, she calls research “utterly essential,” and blacks’ participation necessary. “African-Americans,” she writes, “desperately need the medical advantages and revelations that only ethical, essentially therapeutic research initiatives can give them.”
But first, she argues, the air must be cleared. She is certainly the one to do it. She has unearthed an enormous amount of shocking information and shaped it into a riveting, carefully documented book.
Blacks have been forced to undergo painful, risky experimental surgery, dosed with radiation and singled out for experiments aimed at finding brain abnormalities linked to violence. They have been falsely assumed to feel pain less than whites and to require higher X-ray doses for a readable film.
One of the worst offenders was James Marion Sims, a 19th-century surgeon who has been venerated as a selfless benefactor of women for devising ways to repair severe vaginal injuries that can occur in childbirth.
Sims honed his skills by performing scores of painful operations on the genitals of black slaves. His early attempts so often failed that he operated on one young woman 30 times. The women had to be held down during the excruciating operations. Though ether was available, Sims refused to use it, insisting it was not needed. But when he had refined the surgery enough to offer it to white women, he always gave them ether.
To the question of whether it is fair to judge people like Sims by the ethical standards of a later era, Ms. Washington replies that he violated the ethical codes of his own day.
Reprehensible behavior continued into the 20th century. Often, the so-called research performed on blacks had the trappings of science but was meaningless, poorly designed and based on specious theories. People must have known better, but apparently chose not to think about it.
“In the South,” Ms. Washington writes, “rendering black women infertile without their knowledge during other surgery was so common that the procedure was called a ‘Mississippi appendectomy.’ ” But the same was true in the North, as recently as the 1970s, when unnecessary hysterectomies were often done on poor black and Puerto Rican women to give doctors in training a chance to practice their skills.
Some of Ms. Washington’s arguments are less convincing than others. She questions the “significance” of two black men’s being selected as the first subjects to test the AbioCor artificial heart in 2001 and 2002. But was it significant?
Since two of the first six subjects were black, she notes that they made up 33 percent of the test subjects, “almost three times their representation in the population,” and suggests that blacks were used disproportionately to test a device that, if ever approved, would probably be too expensive for most minorities. Ultimately, 14 people tested the AbioCor, but she never gives the complete racial breakdown. From her account, it’s hard to figure out what was going on.
In another venture onto thin ice, Ms. Washington calls for “more exhaustive studies” of an experimental AIDS vaccine that initially appeared to protect blacks and Asians, but not whites. But when the data were closely analyzed, the first finding did not hold up: the vaccine did not work for anybody. Even so, Ms. Washington implies that the vaccine did have promise for minorities but was abandoned purely because it did not help whites. If there is evidence to justify sinking more money into this vaccine, she does not provide it.
But this is an important book. The disgraceful history it details is a reminder that people in power have always been capable of exploiting those they regard as “other,” and of finding ways to rationalize the most atrocious abuse. The victims are declared defective, violent, hypersexed or a drain on the community. The medical tinkering is for their own good, and the greater good of society.
The worst abuses in this country may be a thing of the past, but history has a way of repeating itself. Ms. Washington warns that Africa and other poor regions are becoming the next venue for exploitative studies by foreign governments, universities and drug companies, which may use their citizens to develop medicines and other treatments that those nations will never be able to afford.
Study Says Tapping of Granite Could Unleash Energy Source
By ANDREW C. REVKIN, The New York Times, January 23, 2007
The United States could generate as much electricity by 2050 as that flowing today from all of the country’s nuclear power plants by developing technologies that tap heat locked in deep layers of granite, according to a new study commissioned by the Energy Department.
There are already dozens of power plants worldwide that have long exploited hot spots of geothermal energy to drive steam turbines, but they are restricted to a few areas.
The new report, published online yesterday, focuses on a process that it said could affordably harvest heat locked in deep layers of granite that exist almost everywhere on earth. The technique, called enhanced geothermal, involves drilling several holes — some two to three miles deep — into granite that has been held at chicken-roasting temperatures, around 400 degrees or more, by insulating layers of rock above.
In the right geological conditions, pressurized water can be used to widen natural mazelike arrays of cracks in the granite, creating a vast, porous subterranean reservoir.
In a typical setup, water pumped down into the reservoir through one hole absorbs heat from the rock and flows up another hole to a power plant, giving up its heat to generate steam and electricity before it is recirculated in the rock below.
There are successful plants harvesting heat from deep hot rock in Australia, Europe and Japan, the report noted, adding that studies of the technology largely stopped in the United States after a brief burst of research during the oil crises of the 1970s.
The report’s 18 authors, from academia, government and industry, said that a public investment of less than $1 billion spread over 15 years would probably be enough to overcome technical hurdles and do initial large-scale deployment of the technology.
The generating capacity by 2050 could be 100 billion watts, about 10 percent of the country’s current generating capacity.
David Keith, an expert on energy technologies at the University of Calgary who was not involved with the study, said there were significant, but surmountable, hurdles to doing such operations at large scale.
Among them, Professor Keith said, are cutting the costs of drilling deep holes and increasing the efficiency of systems that can generate electricity from relatively low-temperature source of heat like deep rock.
“There’s no question there’s a lot of heat down there,” he said. “It’s about the cost of access, and about the value of low-grade heat.”
Jefferson W. Tester, the lead author of the study and a chemical engineer at the Massachusetts Institute of Technology, said there were many new justifications for aggressively pursuing this kind of energy option.
“Back then, we weren’t worried about carbon dioxide and climate, we weren’t running short of natural gas, and now energy is a national security issue in the long run,” Dr. Tester said. “While there’s no guarantee it’s going to work, this is not an unreasonable investment and it’s a good bet on the future.”
Five New Satellites With a Mission of Finding a Source of Color in Space
By WARREN E. LEARY, The New York Times, January 23, 2007
WASHINGTON, Jan. 22 — NASA will soon launch a fleet of five spacecraft in hopes of solving the mystery of how the greenish auroras above the Earth’s poles suddenly burst into shimmering multicolor lights.
The quintet of identical satellites, NASA’s first attempt to launch so many satellites on a single rocket, will be positioned in orbits inside the magnetic field surrounding Earth to look for the origin of sudden energy outbursts that enliven the northern and southern lights.
The space probes are part of a mission called Themis, short for Time History of Events and Macroscale Interactions during Substorms, which is designed to find the trigger point of geomagnetic substorms that can spring up within minutes to brighten auroras and release bursts of potentially damaging radiation.
The Sun constantly fills space with charged particles and other radiation through solar flares or large eruptions called coronal mass ejections. The Earth’s magnetic field shields the planet from most of this solar wind by capturing these high-energy particles and channeling them around the planet, forming a tear-shaped protective bubble called the magnetosphere.
Some of these particles leak through the magnetosphere and pour through the atmosphere toward the poles, colliding with air molecules and causing the atmosphere to glow in a greenish-white light. From space, these auroras glow like oval haloes encircling the north and south magnetic poles. At times, however, energy builds up within the magnetic field until it suddenly breaks loose into what is called a substorm, releasing a burst of electrical current that turns the auroras into pulsing red, purple and white colors.
Built by the Space Sciences Laboratory at the University of California, Berkeley, and Swales Aerospace of Beltsville, Md., the satellites aim to establish once and for all where in the magnetosphere substorms originate and what triggers them, said Dr. Vassilis Angelopoulos, a research physicist at the university and the chief scientist for the mission.
“For over 30 years, the source location of these explosive energy releases has been sought after with great fervor,” Dr. Angelopoulos said. “A substorm starts from a single point in space and progresses past the Moon’s orbit within minutes, so a single satellite cannot identify the substorm origin.”
Substorms are a recurring phenomenon that can pop up at any time, even during periods of low solar activity, he said. They appear as well during major storms caused by regular solar eruptions, adding to their destructive power, and a series of substorms happening by themselves can produce enough accumulated energy to cause damage, he said.
Solar storms can damage or disrupt communications and GPS navigation satellites, overload and knock out electric power grids, and pose a radiation danger to astronauts in space, experts said. “Themis is a stepping stone to explain space weather phenomenon that affects our lives,” Dr. Angelopoulos said.
Peter Harvey, project manager for the mission at the university, said the five-satellite constellation is scheduled to be launched aboard a Delta II rocket from Cape Canaveral, Fla., on Feb. 15. Observations from four of the satellites are needed to complete the $200 million mission, and the fifth spacecraft will serve as an in-orbit spare.
The dishwasher-sized satellites are to coast in Earth orbit for 10 months until they line up within Earth’s shadow like a string of beads, with two of the spacecraft positioned about one-sixth of the way to the Moon and the other two about halfway. By February 2008, they will begin collecting coordinated measurements every four days to pinpoint where and when substorms begin.
To get an added dimension to the life cycles of these substorms, the satellite measurements will be coordinated with ground-based readings from 20 observatories spread over Alaska and Canada. These northern observatories are equipped with all-sky cameras and magnetometer sensors that measure currents in near-Earth space.
Dr. Angelopoulos said he expected the satellites to observe more than 30 substorms during the mission’s lifespan and make a major contribution to understanding space physics.
“Themis is so important because the same fundamental physical process is seen around all planets, it happens on the Sun in solar flares, and in astrophysical systems such as black holes,” he said. “It’s amazing that being so close to us, here at Earth, it is not understood yet.”
Vital Signs: Consequences: Gun Ownership Linked to Higher Homicide Rates
By ERIC NAGOURNEY, The New York Times, January 23, 2007
States with the greatest number of guns in the home also have the highest rates of homicide, a new study finds.
The study, in the February issue of Social Science and Medicine, looked at gun ownership in all 50 states and then compared the results with the number of people killed over a three-year period.
The research, the authors said, “suggests that household firearms are a direct and an indirect source of firearms used to kill Americans both in their homes and on the streets.”
The researchers, led by Matthew Miller of the Harvard School of Public Health, drew on data gathered by the federal Centers for Disease Control and Prevention. In 2001, the agency surveyed more than 200,000 people and asked them, among other questions, whether they had a gun in or near the home.
In states in the highest quarter of gun ownership, the study found, the overall homicide rate was 60 percent higher than in states in the lowest quarter. The rate of homicides involving guns was more than twice as high.
Among the possible explanations for the higher homicide rates, the study said, is that states with high gun ownership tend to make it easier to buy guns. There are also more guns that can be stolen. And the presence of a gun may allow arguments and fights to turn fatal.
The researchers said they could not prove that the guns caused the increase in homicides, only that there was a link. It may be, they said, that people are more likely to buy guns in states where violence is already high. But they said that explanation did not appear to be supported by their findings.
Really? The Claim: Drinking Tea Reduces Stress
By ANAHAD O’CONNOR, The New York Times, January 23, 2007
THE FACTS Some call it nature’s tranquilizer, able to smooth away stress and lift the spirits. But are the stress-reducing powers of tea fact or fiction?
Although the association between tea and relaxation dates back centuries, few independent scientific studies have put that idea to the test. Much of the research has been focused only on animals. But a new study on humans suggests that it may hold only a sliver of truth.
The study was published this month in the journal Psychopharmacology and financed by the British Heart Foundation. It found that adult men who drank black tea four times a day for six weeks reacted no differently in the face of stress from men given a caffeinated placebo. But there was some indication that they were able to calm down more quickly.
The two groups in the study, consisting of about 75 men who were forced to give up their normal caffeinated beverages, were subjected to stressful social situations while their blood pressure, hormone levels and other indicators of stress were measured. All of the subjects showed the same substantial increases in those measures, with no positive effect on heart rate or blood pressure in the tea group. But those who drank tea had slightly lower levels of the stress hormone cortisol an hour later, suggesting that their levels of the hormone were returning to baseline sooner.
Whether that has any long-term benefit is unclear. Previous studies on animals have pointed to sedative effects of certain compounds in tea, but so far the evidence is weak.
THE BOTTOM LINE There is some evidence, but not much, that tea affects stress levels.
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no subject
Date: 2007-01-23 01:59 pm (UTC)no subject
Date: 2007-01-23 02:06 pm (UTC)Caffeine Contents:
Date: 2007-01-23 02:10 pm (UTC)Brewed coffee (8 oz) 60-120 mg
Instant coffee (8 oz) 70 mg
Decaf coffee (8 oz) 1-5 mg
Tea - black (8 oz) 45 mg
Tea - green (8 oz) 20 mg
Tea - white (8 oz) 15 mg
Coca Cola (12 oz can) 34 mg
Pepsi (12 oz can) 38 mg
Barq's Root Beer (12 oz can) 22 mg
7-up (12 oz) 0 mg
Chocolate milk (8 oz) 4 mg
Dark chocolate (1 oz) 20 mg
Milk chocolate (1 oz) 6 mg
Ben & Jerry's Coffee Fudge Frozen Yogurt (8 oz) 85 mg
From: http://coffeetea.about.com/library/blcaffeine.htm
Re: Caffeine Contents:
Date: 2007-01-23 02:45 pm (UTC)Re: Caffeine Contents:
Date: 2007-01-23 02:46 pm (UTC)I think ice cream has so much because it's coffee and chocolate, which both contain caffeine.