New study: Coffee drinkers have slightly lower death rates than people who do not drink coffee
Drinking large amounts of coffee does not increase a person's risk for dying sooner than expected and may actually be protective
Philadelphia, June 17, 2008 – A new study published today in Annals of Internal Medicine has good news for coffee drinkers: Regular coffee drinking (up to 6 cups per day) is not associated with increased deaths in either men or women. In fact, both caffeinated and decaffeinated coffee consumption is associated with a somewhat smaller rate of death from heart disease.
"Coffee consumption has been linked to various beneficial and detrimental health effects, but data on its relation with death were lacking," says Esther Lopez-Garcia, PhD, the study's lead author. "Coffee consumption was not associated with a higher risk of mortality in middle-aged men and women. The possibility of a modest benefit of coffee consumption on heart disease, cancer, and other causes of death needs to be further investigated."
Women consuming two to three cups of caffeinated coffee per day had a 25 percent lower risk of death from heart disease during the follow-up period (which lasted from 1980 to 2004 and involved 84,214 women) as compared with non-consumers, and an 18 percent lower risk of death caused by something other than cancer or heart disease as compared with non-consumers during follow-up. For men, this level of consumption was associated with neither a higher nor a lower risk of death during the follow-up period (which lasted from 1986 to 2004 and involved 41,736 men).
The researchers analyzed data of 84,214 women who had participated in the Nurses' Health Study and 41,736 men who had participated in the Health Professionals Follow-up Study. To be in the current study, participants had to have been free of cancer and heart disease at the start of those larger studies.
The study participants completed questionnaires every two to four years that included questions about how frequently they drank coffee, other diet habits, smoking, and health conditions. The researchers then compared the frequency of death from any cause, death due to heart disease, and death due to cancer among people with different coffee-drinking habits.
Among women, 2,368 deaths were due to heart disease, 5,011 were due to cancer, and 3,716 were due to another cause. Among men, 2,049 deaths were due to heart disease, 2,491 were due to cancer, and 2,348 were due to another cause.
While accounting for other risk factors, such as body size, smoking, diet, and specific diseases, the researchers found that people who drank more coffee were less likely to die during the follow-up period. This was mainly because of lower risk for heart disease deaths among coffee drinkers.
The researchers found no association between coffee drinking and cancer deaths. These relationships did not seem to be related to caffeine because people who drank decaffeinated coffee also had lower death rates than people who did not drink coffee.
The editors of Annals of Internal Medicine caution that the design of the study does not make it certain that coffee decreases the chances of dying sooner than expected. Something else about coffee drinkers might be protecting them. And some measurement error in the assessment of coffee consumption is inevitable because estimated consumption came from self-reports.
The study, "The Relationship of Coffee Consumption with Mortality," was supported by National Institutes of Health research grants.
Age at puberty linked to mother's prenatal diet
A high-fat diet during pregnancy and nursing may lead to the child having an early onset of puberty and subsequent adulthood obesity, according to a new animal study. The results were presented Monday, June 16, at The Endocrine Society's 90th Annual Meeting in San Francisco.
An early first menstrual period, often used as a marker for early-onset puberty in girls is a risk factor for obesity, insulin resistance, teenage depression, and breast cancer in adulthood, said Deborah Sloboda, PhD, lead author of the study. She is a researcher at The Liggins Institute of the University of Auckland in New Zealand.
"Other research suggests that a combination of prenatal and postnatal influences in girls can affect the onset of menarche [menstruation]," Sloboda said.
She and her colleagues therefore studied how prenatal nutrition and nutrition during childhood interact to alter reproductive maturation. The study was done in rats.
The investigators fed pregnant rats a high-fat diet throughout pregnancy and lactation (breastfeeding). Control rats received a regular diet of rat chow. After weaning from their mother's milk, the offspring ate either regular chow or a high-fat diet. Onset of puberty was determined using established techniques. The researchers also evaluated the offspring as adults in regard to body fat composition and blood levels of sex hormones.
The onset of puberty was much earlier in all rats whose mothers had a high-fat diet, compared with the offspring of controls that ate a regular diet, the study showed. Controls' offspring that ate a high-fat diet after weaning also entered puberty early. The combination of a high-fat maternal diet—that is, inside the mother's womb—and a high-fat diet after birth did not make the early-onset puberty any earlier, Sloboda said.
"This might suggest that the fetal environment in high fat fed mothers plays a greater role in determining pubertal onset than childhood nutrition," she said.
Later in life, rats born to mothers fed a high-fat diet had a higher amount of body fat than controls did, even if they ate a regular diet while young.
Among the adult rats that had a maternal high-fat diet, the study showed alterations in sex hormones, including increased levels of the ovarian hormone progesterone in females.
"Maternal high-fat nutrition may influence reproductive maturation and reproductive capacity in adult offspring," Sloboda said.
The Health Research Council of New Zealand, National Research Centre for Growth and Development, and Maurice and Phyllis Paykel Trust in New Zealand all supported this research.
Medicines derived from cannabis: a review of adverse events
Montreal, 13 June 2008 – Researchers at the McGill University Health Centre (MUHC), McGill University and the University of British Columbia (UBC) determined that medical use of cannabinoids do not cause an increase in serious adverse events, but are associated with an increase in some non-serious adverse events.
Several drugs containing compounds derived from the cannabis plant, or cannibinoids, are available for medical purposes in Canada. As the use of cannabinoid medications increases, so do concerns about their potential to cause "adverse events," or negative side effects. Dr. Mark Ware, Dr. Stan Shapiro and PhD candidate Tongtong Wang of the Research Institute of the McGill University Health Centre and McGill University, and Dr. Jean-Paul Collet of the University of British Columbia examined the nature of these potential adverse events in a study which will be published June 16 in the Canadian Medical Association Journal (CMAJ).
The study was based on the adverse events reported in 31 separate clinical studies of cannabinoid medications conducted between 1966 and 2007. Adverse events were categorized as either serious or non-serious; with serious adverse events defined as those leading to death, hospitalization or disability.
"Overall, we found an 86% increase in the rate of non-serious adverse events among the patients treated with cannabinoids compared to the patients in the control groups," said Ware, a neurosciences researcher at the Research Institute of the MUHC and assistant professor in anesthesia at McGill's Faculty of Medicine The majority of events were mild to moderate in severity.
The majority of non-serious adverse events observed affected the nervous system, mainly dizziness and drowsiness. "Cannabinoids are used as medicines because they are neurologically active, so we expected to see some side effects such as these," said Wang, a PhD candidate in epidemiology and biostatistics at McGill University.
Cannabinoids have been shown to treat chronic pain resulting from diseases such as cancer, multiple sclerosis, arthritis and fibromyalgia, and also to stimulate appetite and relieve nausea. Physicians must weigh the possible benefits of treatment against the possible side effects in an overall attempt to improve the patient's quality of life.
"We have summarized the adverse events from these studies to help educate physicians and patients about the possible risks of medical cannabinoids," said Collet, formerly at McGill's Department of Epidemiology, and now professor at University of British Columbia, senior researcher at the Child & Family Research Institute and Director of the Centre for Applied Health Research and Evaluation at British Columbia Children's Hospital. "We cannot extend these results to smoked cannabis or recreational use. That will require further research."
This study was funded by a grant from Canadian Institutes of Health Research, and by a contribution from the Fond de recherche en santé du Québec.
Nanotechnology, biomolecules and light unite to 'cook' cancer cells
DALLAS ― June 16, 2008 ― Researchers are testing a new way to kill cancer cells selectively by attaching cancer-seeking antibodies to tiny carbon tubes that heat up when exposed to near-infrared light.
Biomedical scientists at UT Southwestern Medical Center and nanotechnology experts from UT Dallas describe their experiments in a study available online and in an upcoming print issue of Proceedings of the National Academy of Sciences.
Scientists are able to use biological molecules called monoclonal antibodies that bind to cancer cells. Monoclonal antibodies can work alone or can be attached to powerful anti-cancer drugs, radionuclides or toxins to deliver a deadly payload to cancer cells.
In this study, the researchers used monoclonal antibodies that targeted specific sites on lymphoma cells to coat tiny structures called carbon nanotubes. Carbon nanotubes are very small cylinders of graphite carbon that heat up when exposed to near-infrared light. This type of light, invisible to the human eye, is used in TV remote controls to switch channels and is detected by night-vision goggles. Near-infrared light can penetrate human tissue up to about 11/2 inches.
In cultures of cancerous lymphoma cells, the antibody-coated nanotubes attached to the cells’ surfaces. When the targeted cells were then exposed to near-infrared light, the nanotubes heated up, generating enough heat to essentially “cook” the cells and kill them. Nanotubes coated with an unrelated antibody neither bound to nor killed the tumor cells.
“Using near-infrared light for the induction of hyperthermia is particularly attractive because living tissues do not strongly absorb radiation in this range,” said Dr. Ellen Vitetta, director of the Cancer Immunobiology Center at UT Southwestern and senior author of the study. “Once the carbon nanotubes have bound to the tumor cells, an external source of near-infrared light can be used to safely penetrate normal tissues and kill the tumor cells.
“Demonstrating this specific killing was the objective of this study. We have worked with targeted therapies for many years, and even when this degree of specificity can be demonstrated in a laboratory dish, there are many hurdles to translating these new therapies into clinical studies. We’re just beginning to test this in mice, and although there is no guarantee it will work, we are optimistic.”
The use of carbon nanotubes to destroy cancer cells with heat is being explored by several research groups, but the new study is the first to show that both the antibody and the carbon nanotubes retained their physical properties and their functional abilities ― binding to and killing only the targeted cells. This was true even when the antibody-nanotube complex was placed in a setting designed to mimic conditions inside the human body.
Biomedical applications of nanoparticles are increasingly attracting the attention of basic and clinical scientists. There are, however, challenges to successfully developing nanomedical reagents. One is the potential that a new nanomaterial may damage healthy cells and organisms. This requires that the effects of nanomedical reagents on cells and organisms be thoroughly studied to determine whether the reagents are inherently toxic.
“There are rational approaches to detecting and minimizing the potential for nonspecific toxicity of the nanoparticles developed in our studies,” said Dr. Rockford Draper, leader of the team from UT Dallas and a professor of molecular and cell biology.
Other researchers from UT Southwestern involved in the research were lead authors Pavitra Chakravarty, a graduate student in biomedical engineering, and Dr. Radu Marches, assistant professor in the Cancer Immunobiology Center. Authors from UT Dallas' Alan G. MacDiarmid NanoTech Institute were Dr. Inga Musselman, Dr. Paul Pantano and graduate student Pooja Bajaj. Two undergraduate students in UT Southwestern’s Summer Undergraduate Research Fellowship program ― Austin Swafford from UT Dallas and Neil Zimmerman from the Massachusetts Institute of Technology ― also participated.
The research was supported by the Cancer Immunobiology Center at UT Southwestern, the Robert A. Welch Foundation, the Department of Defense and the Center for Applied Biology at UT Dallas.
Dr. Vitetta is a co-inventor on a patent describing the techniques outlined in the study.
Visit to learn more about UT Southwestern’s clinical services in cancer.
Type and severity of combat wounds in Iraq war have changed over time
The transition in Iraq from maneuver warfare to insurgency warfare is associated with changes in the type and severity of injuries treated by surgical units of the U.S. Marine Corps, according to a report in the June issue of Archives of Surgery, one of the JAMA/Archives journals. In the second, insurgent phase of the war, injuries have been more severe, transport times longer, more injuries have occurred per individual and more soldiers have been killed in action or died of their wounds.
"Operation Iraqi Freedom is an ongoing conflict that has changed dramatically since the initial invasion," the authors write as background information in the article. "Following the maneuver warfare that resulted in the capture of Baghdad, Iraq, in April 2003, firm U.S. military bases have been established throughout the country to support the Iraqi government and to fight insurgencies." During the first phase of warfare (March and April 2003), the Forward Resuscitative Surgery System—a small mobile surgery team of eight personnel that treated soldiers' injuries —moved 11 times as the battlefield changed. In the second phase of the war, from March 2004 to February 2005, medical support for U.S. forces has remained stationary.
Stacy A. Brethauer, M.D., of Cleveland Clinic, and colleagues analyzed records from combat trauma databases for 338 casualties treated during the first phase of the war (maneuver) and 895 treated in the second phase (insurgency). When comparing those injured in phase II with those injured in phase I, the authors found that:
* More major injuries occurred per patient (2.4 vs. 1.6)
* More individuals sustained fragment wounds (61 percent vs. 48 percent) but fewer were injured by gunshots (33 percent vs. 43 percent)
* Critically injured U.S. casualties took longer to reach the surgical unit (a median or midpoint time of 59 minutes vs. 30 minutes)
* The percentage of individuals killed in action before reaching the surgical unit increased (20.2 percent from 13.5 percent)
* The percentage of patients who died of their wounds after evaluation by a physician also increased, from 0.88 percent to 5.5 percent
In the second phase of the war, the use of improvised explosive devices by insurgents has resulted in more fragment wounds and a higher percentage of critically injured patients arriving to the surgical unit. "A higher percentage of patients arriving at the Forward Resuscitative Surgery System are undergoing surgery, and these patients have more injuries and undergo more procedures than casualties during Operation Iraqi Freedom I," the authors write. The higher percentage of surgeries is due to an increase in the number of wounds per patient, the severity of these wounds and the stationary nature of the surgical unit, they note.
"The nature of the current conflict in Iraq should influence the way that casualties are managed and entered into the medical system," the authors conclude. "Only with continued data collection and careful attention to the many variables involved will we be able to make definitive statements regarding optimal trauma care in Iraq."
(Arch Surg. 2008;143[6]:564-569. Available pre-embargo to the media at
HIV screening found cost-effective in older adults
DURHAM, NC – Recent studies suggest that large numbers of Americans remain sexually active well into their 60's, 70's and even 80's. But researchers at Duke University Medical Center say seniors may be overlooked as possible carriers of the AIDS virus, and based on a new study, they are recommending screening for most adults ages 55 to75 as a sensible, cost-effective way to prolong life and decrease the spread of the disease.