Most people heading off to a sunny winter vacation in a foreign country know something about how to avoid a nasty case of travellers' diarrhea, but they don't know everything they should, according to a University of Alberta study.
A survey of 104 vacationers boarding flights for Mexico revealed that their general level of knowledge about the prevention of this condition was generally adequate; however, there were still some things they needed to know more about.
Of the travellers, surveyed as they boarded flights from the Calgary International Airport in March and April of 2005, more than 80 per cent knew that foods such as salad, partially cooked beef or chicken and ice cubes posed high risks for the illness. But only 47 per cent knew that chlorinated water is not always safe to drink, due to the resistance to chlorination among microorganisms such as Cryptosporidium. And while 96 per cent of the respondents knew that travellers' diarrhea could be contracted from bacteria, only 43 per cent knew that viruses could also be a cause. As well, only 55.8 per cent realized that hand-washing was an effective way to help ward off the sickness and 25 per cent of those surveyed wrongly identified fungi as sources of the diarrhea.
"The study showed that while these respondents are aware of the condition, they may not be aware of some important factors in avoiding and treating travellers' diarrhea," said Julie Johnson, lead author of the study and a PhD student in the Departments of Public Health Sciences and Agricultural, Food and Nutritional Science at the University of Alberta in Edmonton, Canada.
The study findings appear in the most recent issue of Journal of Travel Medicine.
Overall, information on travel-related disease had been sought by almost half of the study participants before they headed out on their trips, although less than one-fourth consulted with a doctor, pharmacist or nurse. One-third got information from the Internet, travel agents, family and friends. The study also showed that those people with any information at all scored higher on the survey than did those with no information on the illness.
Thursday, January 11, 2007
Wednesday, January 10, 2007
Study finds unexpected results in acid suppression between two OTC heartburn treatments
Researchers say differences can help guide appropriate medication selection
In a new study, researchers have directly compared the early therapeutic response of drugs from widely-used classes of heartburn medications, omeprazole magnesium, a proton pump inhibitor (PPI) and famotidine, a histamine-2 receptor antagonist (H2RAs), in an over-the-counter (OTC) setting. In contrast to general consensus, suggesting first day superiority of H2RAs, the results show similar acid suppression on the first day of dosing between these drugs as reported in Alimentary Pharmacology & Therapeutics.
Researchers also report evidence that with daily use, the body develops a rapid onset of tolerance to even a low dose H2RAs such as Pepcid AC®.
The findings may help physicians and consumers make better choices about which therapy to use when treating heartburn, which is caused by stomach acid flowing up into the esophagus, a condition that affects more than 50 million Americans annually.
"There have been many studies testing acid-suppression in these two classes of drugs -- PPIs and H2RAs (also known as H2-blockers or H2s) – but very few studies have compared the two types of drugs in an OTC setting where so many of these treatments are used," says Philip Miner, MD, Clinical Professor of Medicine at the University of Oklahoma and lead investigator at Oklahoma Foundation for Digestive Research.
"Because these two drugs work in fundamentally different ways to suppress acid production, we didn't expect that the PPI would work as well as the H2RAs within the first 24 hour period after treatment. In addition, while using the lower-dose H2RAs, the degree of acid suppression ability was found to significantly decrease after the first day of use. While this study measured acid suppression, it did not measure symptom relief or the speed of onset of action. However, both PPIs and H2RAs owe their clinical efficacy to their ability to suppress gastric acid secretion. This means that for people who have frequent heartburn, that is, heartburn two or more days per week, taking an over-the-counter PPI is an excellent option."
In this 14 day study, subjects were randomly assigned to one of six treatment sequences, each including three regimens: omeprazole magnesium 20.6 mg (Prilosec OTC®) once a day; famotidine 10 mg (Pepcid AC) twice a day; and famotidine 20 mg (now available over-the-counter as Maximum Strength Pepcid AC®) twice a day. 1 During the study treatment period, the amount of acid production was measured over 24-hours several times. Results indicate:
The PPI - Prilosec OTC - showed significant acid suppression on the very first day of treatment compared to baseline (Day 0) and comparable to the acid suppression of H2RAs – Pepcid AC and the medicine in Maximum Strength Pepcid AC. 1
After Day 1 of treatment, Prilosec OTC was consistently superior in acid suppression vs. the H2RAs - Pepcid AC and the medicine in Maximum Strength Pepcid AC. 1
In addition, while using the lower-dose H2RAs - Pepcid AC, the degree of acid suppression ability was found to significantly decrease after the first day of use. 1
Different medications, different mechanisms
The mechanistic activities of PPIs and H2RAs are well documented, and show that while both PPIs and H2RAs effectively reduce the amount of stomach acid, they do it in very different ways. The key point of difference happens at a cellular level in the stomach. The stomach is lined with millions of acid producing pumps. Acid producing pumps rely on three chemical signals that tell them to produce stomach acid. H2RAs are able to block one of these signals, thereby reducing the amount of acid produced and generally have a quicker onset of action than PPIs. PPIs on the other hand actually shut down the active pumps themselves. This study showed the PPI had more profound effects on stomach acid over time.
"The study results add an important aspect to the existing literature on these two medications," says Miner. "It further underscores the need for consumers to identify their needs in heartburn protection in order to select the most appropriate treatment."
In a new study, researchers have directly compared the early therapeutic response of drugs from widely-used classes of heartburn medications, omeprazole magnesium, a proton pump inhibitor (PPI) and famotidine, a histamine-2 receptor antagonist (H2RAs), in an over-the-counter (OTC) setting. In contrast to general consensus, suggesting first day superiority of H2RAs, the results show similar acid suppression on the first day of dosing between these drugs as reported in Alimentary Pharmacology & Therapeutics.
Researchers also report evidence that with daily use, the body develops a rapid onset of tolerance to even a low dose H2RAs such as Pepcid AC®.
The findings may help physicians and consumers make better choices about which therapy to use when treating heartburn, which is caused by stomach acid flowing up into the esophagus, a condition that affects more than 50 million Americans annually.
"There have been many studies testing acid-suppression in these two classes of drugs -- PPIs and H2RAs (also known as H2-blockers or H2s) – but very few studies have compared the two types of drugs in an OTC setting where so many of these treatments are used," says Philip Miner, MD, Clinical Professor of Medicine at the University of Oklahoma and lead investigator at Oklahoma Foundation for Digestive Research.
"Because these two drugs work in fundamentally different ways to suppress acid production, we didn't expect that the PPI would work as well as the H2RAs within the first 24 hour period after treatment. In addition, while using the lower-dose H2RAs, the degree of acid suppression ability was found to significantly decrease after the first day of use. While this study measured acid suppression, it did not measure symptom relief or the speed of onset of action. However, both PPIs and H2RAs owe their clinical efficacy to their ability to suppress gastric acid secretion. This means that for people who have frequent heartburn, that is, heartburn two or more days per week, taking an over-the-counter PPI is an excellent option."
In this 14 day study, subjects were randomly assigned to one of six treatment sequences, each including three regimens: omeprazole magnesium 20.6 mg (Prilosec OTC®) once a day; famotidine 10 mg (Pepcid AC) twice a day; and famotidine 20 mg (now available over-the-counter as Maximum Strength Pepcid AC®) twice a day. 1 During the study treatment period, the amount of acid production was measured over 24-hours several times. Results indicate:
The PPI - Prilosec OTC - showed significant acid suppression on the very first day of treatment compared to baseline (Day 0) and comparable to the acid suppression of H2RAs – Pepcid AC and the medicine in Maximum Strength Pepcid AC. 1
After Day 1 of treatment, Prilosec OTC was consistently superior in acid suppression vs. the H2RAs - Pepcid AC and the medicine in Maximum Strength Pepcid AC. 1
In addition, while using the lower-dose H2RAs - Pepcid AC, the degree of acid suppression ability was found to significantly decrease after the first day of use. 1
Different medications, different mechanisms
The mechanistic activities of PPIs and H2RAs are well documented, and show that while both PPIs and H2RAs effectively reduce the amount of stomach acid, they do it in very different ways. The key point of difference happens at a cellular level in the stomach. The stomach is lined with millions of acid producing pumps. Acid producing pumps rely on three chemical signals that tell them to produce stomach acid. H2RAs are able to block one of these signals, thereby reducing the amount of acid produced and generally have a quicker onset of action than PPIs. PPIs on the other hand actually shut down the active pumps themselves. This study showed the PPI had more profound effects on stomach acid over time.
"The study results add an important aspect to the existing literature on these two medications," says Miner. "It further underscores the need for consumers to identify their needs in heartburn protection in order to select the most appropriate treatment."
Tuesday, January 9, 2007
Milk eliminates cardiovascular health benefits of tea
Research published in the European Heart Journal has found that the protective effect that tea has on the cardiovascular system is totally wiped out by adding milk.
Tests on volunteers showed that black tea significantly improves the ability of the arteries to relax and expand, but adding milk completely blunts the effect. Supporting tests on rat aortas (aortic rings) and endothelial (lining) cells showed that tea relaxed the aortic rings by producing nitric oxide, which promotes dilation of blood vessels. But, again, adding milk blocked the effect.
The findings, by cardiologists and scientists from the Charité Hospital, Universitätsmedizin-Berlin, Germany, are bad news for tea-drinking nations like the British, who normally add milk to their beverage. The results have led the researchers to suggest that tea drinkers who customarily add milk should consider omitting it some of the time.
Their study showed that the culprit in milk is a group of proteins called caseins, which they found interacted with the tea to decrease the concentration of catechins in the beverage. Catechins are the flavonoids in tea that mainly contribute to its protection against cardiovascular disease.
Senior researcher Dr Verena Stangl, Professor of Cardiology (Molecular Atherosclerosis) at the hospital, said: “There is a broad body of evidence from experimental and clinical studies indicating that tea exerts antioxidative, anti-inflammatory and vasodilating effects, thereby protecting against cardiovascular diseases. As worldwide tea consumption is second only to that of water, its beneficial effects represent an important public health issue. But, up to now, it’s not been known whether adding milk to tea, as widely practised in the UK and some other countries, influences these protective properties. So, we decided to investigate the effects of tea, with and without milk, on endothelial function, because that is a sensitive indicator of what is happening to blood vessels.”
Sixteen healthy postmenopausal women drank either half a litre of freshly brewed black tea, black tea with 10% skimmed milk, or boiled water (as a control) on three separate occasions under the same conditions. The endothelial function of the brachial artery in the forearm was measured by high resolution ultrasound before and two hours after drinking, with measurements being taken every
15 seconds for up to two minutes a time.
Said first author Dr Mario Lorenz, a molecular biologist: “We found that, whereas drinking tea significantly increased the ability of the artery to relax and expand to accommodate increased blood flow compared with drinking water, the addition of milk completely prevents the biological effect. To extend our findings to a functional model, we determined vasodilation in rat aortic rings by exposing them to tea on its own and tea with individual milk proteins added, and got the same result.”
Milk contains a number of different proteins: by testing each one separately, the researchers found that it was the three caseins that accounted for the inhibiting effect, probably by forming complexes with tea catechins.
Said Dr Stangl: “The well-established benefits of tea have been described in many studies. Our results thus provide a possible explanation for the lack of beneficial effects of tea on the risk of heart disease in the UK, a country where milk is usually added.”
She said their findings could also have implications for cancer, against which tea has also been shown to be protective. “Since milk appears to modify the biological activities of tea ingredients, it is likely that the anti-tumour effects of tea could be affected as well. I think it is essential that we re-examine the association between tea consumption and cancer protection, to see if that is the case.”
Said Dr Lorenz: “It is important to bear in mind that green tea is almost exclusively drunk without milk. So we are talking only about those countries and regions where black tea is consumed and where milk is added. We certainly don’t want to dismiss the consumption of black tea: the results of our study merely attempt to encourage people to consider that, while the addition of milk may improve its taste, it may also lower its health-protective properties.”
Dr Stangl said that another important lesson from their research was that it was vital in nutritional studies to exclude confounding factors as far as possible. Often, the effects of a single nutritional compound or beverage such as red wine, olive oil and so on, are analysed. But, it is difficult to assign clearly the observed effects and separate them from the surrounding food matrix (such as adding milk) that may bias results. It was therefore important to collect all data accurately and include potentially confounding factors in the analysis.
She said that the team was now in the process of comparing the effects of green and black tea on vascular function. “It’s an ongoing question whether green tea, with its higher catechin content, is superior to black tea in regard to endothelial function. In addition, because of the antiatherogenic potential of tea ingredients, we want to investigate the effects of the ingredients on chronic cardiovascular processes such as the development of restenosis (re-narrowing of arteries) after catheter procedures.”
Tests on volunteers showed that black tea significantly improves the ability of the arteries to relax and expand, but adding milk completely blunts the effect. Supporting tests on rat aortas (aortic rings) and endothelial (lining) cells showed that tea relaxed the aortic rings by producing nitric oxide, which promotes dilation of blood vessels. But, again, adding milk blocked the effect.
The findings, by cardiologists and scientists from the Charité Hospital, Universitätsmedizin-Berlin, Germany, are bad news for tea-drinking nations like the British, who normally add milk to their beverage. The results have led the researchers to suggest that tea drinkers who customarily add milk should consider omitting it some of the time.
Their study showed that the culprit in milk is a group of proteins called caseins, which they found interacted with the tea to decrease the concentration of catechins in the beverage. Catechins are the flavonoids in tea that mainly contribute to its protection against cardiovascular disease.
Senior researcher Dr Verena Stangl, Professor of Cardiology (Molecular Atherosclerosis) at the hospital, said: “There is a broad body of evidence from experimental and clinical studies indicating that tea exerts antioxidative, anti-inflammatory and vasodilating effects, thereby protecting against cardiovascular diseases. As worldwide tea consumption is second only to that of water, its beneficial effects represent an important public health issue. But, up to now, it’s not been known whether adding milk to tea, as widely practised in the UK and some other countries, influences these protective properties. So, we decided to investigate the effects of tea, with and without milk, on endothelial function, because that is a sensitive indicator of what is happening to blood vessels.”
Sixteen healthy postmenopausal women drank either half a litre of freshly brewed black tea, black tea with 10% skimmed milk, or boiled water (as a control) on three separate occasions under the same conditions. The endothelial function of the brachial artery in the forearm was measured by high resolution ultrasound before and two hours after drinking, with measurements being taken every
15 seconds for up to two minutes a time.
Said first author Dr Mario Lorenz, a molecular biologist: “We found that, whereas drinking tea significantly increased the ability of the artery to relax and expand to accommodate increased blood flow compared with drinking water, the addition of milk completely prevents the biological effect. To extend our findings to a functional model, we determined vasodilation in rat aortic rings by exposing them to tea on its own and tea with individual milk proteins added, and got the same result.”
Milk contains a number of different proteins: by testing each one separately, the researchers found that it was the three caseins that accounted for the inhibiting effect, probably by forming complexes with tea catechins.
Said Dr Stangl: “The well-established benefits of tea have been described in many studies. Our results thus provide a possible explanation for the lack of beneficial effects of tea on the risk of heart disease in the UK, a country where milk is usually added.”
She said their findings could also have implications for cancer, against which tea has also been shown to be protective. “Since milk appears to modify the biological activities of tea ingredients, it is likely that the anti-tumour effects of tea could be affected as well. I think it is essential that we re-examine the association between tea consumption and cancer protection, to see if that is the case.”
Said Dr Lorenz: “It is important to bear in mind that green tea is almost exclusively drunk without milk. So we are talking only about those countries and regions where black tea is consumed and where milk is added. We certainly don’t want to dismiss the consumption of black tea: the results of our study merely attempt to encourage people to consider that, while the addition of milk may improve its taste, it may also lower its health-protective properties.”
Dr Stangl said that another important lesson from their research was that it was vital in nutritional studies to exclude confounding factors as far as possible. Often, the effects of a single nutritional compound or beverage such as red wine, olive oil and so on, are analysed. But, it is difficult to assign clearly the observed effects and separate them from the surrounding food matrix (such as adding milk) that may bias results. It was therefore important to collect all data accurately and include potentially confounding factors in the analysis.
She said that the team was now in the process of comparing the effects of green and black tea on vascular function. “It’s an ongoing question whether green tea, with its higher catechin content, is superior to black tea in regard to endothelial function. In addition, because of the antiatherogenic potential of tea ingredients, we want to investigate the effects of the ingredients on chronic cardiovascular processes such as the development of restenosis (re-narrowing of arteries) after catheter procedures.”
Study finds that caffeine cuts post-workout pain by nearly 50 percent
Although it’s too soon to recommend dropping by Starbucks before hitting the gym, a new study suggests that caffeine can help reduce the post-workout soreness that discourages some people from exercising.
In a study to be published in the February issue of The Journal of Pain, a team of University of Georgia researchers finds that moderate doses of caffeine, roughly equivalent to two cups of coffee, cut post-workout muscle pain by up to 48 percent in a small sample of volunteers.
Lead author Victor Maridakis, a researcher in the department of kinesiology at the UGA College of Education, said the findings may be particularly relevant to people new to exercise, since they tend to experience the most soreness.
“If you can use caffeine to reduce the pain, it may make it easier to transition from that first week into a much longer exercise program,” he said.
Maridakis and his colleagues studied nine female college students who were not regular caffeine users and did not engage in regular resistance training. One and two days after an exercise session that caused moderate muscle soreness, the volunteers took either caffeine or a placebo and performed two different quadriceps (thigh) exercises, one designed to produce a maximal force, the other designed to generate a sub-maximal force. Those that consumed caffeine one-hour before the maximum force test had a 48 percent reduction in pain compared to the placebo group, while those that took caffeine before the sub-maximal test reported a 26 percent reduction in pain.
Caffeine has long been known to increase alertness and endurance, and a 2003 study led by UGA professor Patrick O’Connor found that caffeine reduces thigh pain during moderate-intensity cycling. O’Connor, who along with professors Kevin McCully and the late Gary Dudley co-authored the current study, explained that caffeine likely works by blocking the body’s receptors for adenosine, a chemical released in response to inflammation.
Despite the positive findings in the study, the researchers say there are some caveats. First, the results may not be applicable to regular caffeine users, since they may be less sensitive to caffeine’s effect. The researchers chose to study women to get a definitive answer in at least one sex, but men may respond differently to caffeine. And the small sample size of nine volunteers means that the study will have to be replicated with a larger study.
O’Connor said that despite these limitations, caffeine appears to be more effective in relieving post-workout muscle pain than several commonly used drugs. Previous studies have found that the pain reliever naproxen (the active ingredient in Aleve) produced a 30 percent reduction in soreness. Aspirin produced a 25 percent reduction, and ibuprofen has produced inconsistent results.
“A lot of times what people use for muscle pain is aspirin or ibuprofen, but caffeine seems to work better than those drugs, at least among women whose daily caffeine consumption is low,” O’Connor said.
Still, the researchers recommend that people use caution when using caffeine before a workout. For some people, too much caffeine can produce side effects such as jitteriness, heart palpitations and sleep disturbances.
“It can reduce pain,” Maridakis said, “but you have to apply some common sense and not go overboard.”
In a study to be published in the February issue of The Journal of Pain, a team of University of Georgia researchers finds that moderate doses of caffeine, roughly equivalent to two cups of coffee, cut post-workout muscle pain by up to 48 percent in a small sample of volunteers.
Lead author Victor Maridakis, a researcher in the department of kinesiology at the UGA College of Education, said the findings may be particularly relevant to people new to exercise, since they tend to experience the most soreness.
“If you can use caffeine to reduce the pain, it may make it easier to transition from that first week into a much longer exercise program,” he said.
Maridakis and his colleagues studied nine female college students who were not regular caffeine users and did not engage in regular resistance training. One and two days after an exercise session that caused moderate muscle soreness, the volunteers took either caffeine or a placebo and performed two different quadriceps (thigh) exercises, one designed to produce a maximal force, the other designed to generate a sub-maximal force. Those that consumed caffeine one-hour before the maximum force test had a 48 percent reduction in pain compared to the placebo group, while those that took caffeine before the sub-maximal test reported a 26 percent reduction in pain.
Caffeine has long been known to increase alertness and endurance, and a 2003 study led by UGA professor Patrick O’Connor found that caffeine reduces thigh pain during moderate-intensity cycling. O’Connor, who along with professors Kevin McCully and the late Gary Dudley co-authored the current study, explained that caffeine likely works by blocking the body’s receptors for adenosine, a chemical released in response to inflammation.
Despite the positive findings in the study, the researchers say there are some caveats. First, the results may not be applicable to regular caffeine users, since they may be less sensitive to caffeine’s effect. The researchers chose to study women to get a definitive answer in at least one sex, but men may respond differently to caffeine. And the small sample size of nine volunteers means that the study will have to be replicated with a larger study.
O’Connor said that despite these limitations, caffeine appears to be more effective in relieving post-workout muscle pain than several commonly used drugs. Previous studies have found that the pain reliever naproxen (the active ingredient in Aleve) produced a 30 percent reduction in soreness. Aspirin produced a 25 percent reduction, and ibuprofen has produced inconsistent results.
“A lot of times what people use for muscle pain is aspirin or ibuprofen, but caffeine seems to work better than those drugs, at least among women whose daily caffeine consumption is low,” O’Connor said.
Still, the researchers recommend that people use caution when using caffeine before a workout. For some people, too much caffeine can produce side effects such as jitteriness, heart palpitations and sleep disturbances.
“It can reduce pain,” Maridakis said, “but you have to apply some common sense and not go overboard.”
Monday, January 8, 2007
MRI of the ankle changes patient treatment and improves referring physician confidence in diagnosis
MR imaging can make a dramatic difference in the management of patients with ankle pain, changing treatment in about one-third of the patients, a new study finds.
The study, of 91 patients, found that MR changed the management plans of 35% of patients, said Philip W.P. Bearcroft, MD, of Cambridge University Hospitals in England. "This is itself is significant, but more significant is the fact that before an MRI was done, 65 of the 91 patients were scheduled to undergo surgery. After an MRI was done, nine of those patients were treated nonsurgically," Dr. Bearcroft said.
Dr. Bearcroft and his colleagues conducted the study in conjunction with an orthopedic foot and ankle surgeon at a regional teaching hospital. The surgeon noted his proposed treatment plan for each patient before and after an MR examination. The surgeon also noted the potential diagnoses for each injury. Before an MR examination was done, the surgeon indicated an average 2.3 possible diagnoses per patient. "After MRI was performed, the number of diagnoses per patient was reduced to 1.2," said Dr. Bearcroft. MRI increased the referring physician's confidence in his diagnoses, Dr. Bearcroft said. "In 66% of the MRI examinations performed, the referring surgeon felt that his understanding of the patient's disease had either depended upon or had been substantially improved by MRI," he added.
"This study is a bit different than the traditional radiological study," Dr. Bearcroft said. "Most studies relate to improving technique or look at the accuracy and predictive value of imaging techniques. This one was designed to determine if we really make a difference to the referring physician and the patient," he said.
The study, of 91 patients, found that MR changed the management plans of 35% of patients, said Philip W.P. Bearcroft, MD, of Cambridge University Hospitals in England. "This is itself is significant, but more significant is the fact that before an MRI was done, 65 of the 91 patients were scheduled to undergo surgery. After an MRI was done, nine of those patients were treated nonsurgically," Dr. Bearcroft said.
Dr. Bearcroft and his colleagues conducted the study in conjunction with an orthopedic foot and ankle surgeon at a regional teaching hospital. The surgeon noted his proposed treatment plan for each patient before and after an MR examination. The surgeon also noted the potential diagnoses for each injury. Before an MR examination was done, the surgeon indicated an average 2.3 possible diagnoses per patient. "After MRI was performed, the number of diagnoses per patient was reduced to 1.2," said Dr. Bearcroft. MRI increased the referring physician's confidence in his diagnoses, Dr. Bearcroft said. "In 66% of the MRI examinations performed, the referring surgeon felt that his understanding of the patient's disease had either depended upon or had been substantially improved by MRI," he added.
"This study is a bit different than the traditional radiological study," Dr. Bearcroft said. "Most studies relate to improving technique or look at the accuracy and predictive value of imaging techniques. This one was designed to determine if we really make a difference to the referring physician and the patient," he said.
Higher folate levels linked to reduced risk for Alzheimer's disease
Individuals who take in higher levels of the nutrient folate through both diet and supplements may have a reduced risk of developing Alzheimer's disease, according to a report in the January issue of Archives of Neurology, one of the JAMA/Archives journals.
By the year 2047, the prevalence of Alzheimer's disease is expected to quadruple, according to background information in the article. Delaying the onset of this neurodegenerative disease would significantly reduce the burden it causes. Researchers suspect that elevated levels of the amino acid homocysteine in the blood, which is linked to a higher risk for cardiovascular disease and stroke, may also increase the risk for Alzheimer's disease. Folate, vitamin B12 and vitamin B6, are important in the body's processing of homocysteine--therefore, deficiencies in these nutrients increase homocysteine levels and may contribute to cardiovascular disease, stroke and dementia.
José A. Luchsinger, M.D., Columbia University Medical Center, New York, and colleagues examined, interviewed and assessed the diets of 965 individuals without dementia between 1992 and 1994 and then followed them for an average of 6.1 years to see if they developed Alzheimer's disease. The participants had an average age of 75.8 and 70.2 percent were women, 32.6 percent African-American, 45.3 percent Hispanic and 22.1 percent white.
During the follow-up period, 192 of the participants developed Alzheimer's disease. When the individuals were divided into four groups based on the total level of folate they took in through food and supplements and the analysis was adjusted for patient characteristics, comorbid diseases and B12 and B6 intake, the risk of Alzheimer's disease was lower in the groups with higher intake. Neither dietary folate nor supplements alone were significantly linked to Alzheimer's disease risk; only the two in combination appeared to produce an effect. Levels of the vitamins B12 and B6 were not associated with Alzheimer's disease risk.
Higher folate intake was modestly correlated with lower homocysteine levels, "indirectly suggesting that a lower homocysteine level is a potential mechanism for the association between higher folate intake and a lower Alzheimer's disease risk," the authors write.
Definitive conclusions about the role of folate in the development of Alzheimer's disease cannot yet be made, they continue. The findings of this study are in contrast to those of some other research, and other compounds (such as hormones) perceived to reduce the risk for dementia in observational studies did not do so in randomized trials. "Thus, the decision to increase folate intake to prevent Alzheimer's disease should await clinical trials," they conclude.
By the year 2047, the prevalence of Alzheimer's disease is expected to quadruple, according to background information in the article. Delaying the onset of this neurodegenerative disease would significantly reduce the burden it causes. Researchers suspect that elevated levels of the amino acid homocysteine in the blood, which is linked to a higher risk for cardiovascular disease and stroke, may also increase the risk for Alzheimer's disease. Folate, vitamin B12 and vitamin B6, are important in the body's processing of homocysteine--therefore, deficiencies in these nutrients increase homocysteine levels and may contribute to cardiovascular disease, stroke and dementia.
José A. Luchsinger, M.D., Columbia University Medical Center, New York, and colleagues examined, interviewed and assessed the diets of 965 individuals without dementia between 1992 and 1994 and then followed them for an average of 6.1 years to see if they developed Alzheimer's disease. The participants had an average age of 75.8 and 70.2 percent were women, 32.6 percent African-American, 45.3 percent Hispanic and 22.1 percent white.
During the follow-up period, 192 of the participants developed Alzheimer's disease. When the individuals were divided into four groups based on the total level of folate they took in through food and supplements and the analysis was adjusted for patient characteristics, comorbid diseases and B12 and B6 intake, the risk of Alzheimer's disease was lower in the groups with higher intake. Neither dietary folate nor supplements alone were significantly linked to Alzheimer's disease risk; only the two in combination appeared to produce an effect. Levels of the vitamins B12 and B6 were not associated with Alzheimer's disease risk.
Higher folate intake was modestly correlated with lower homocysteine levels, "indirectly suggesting that a lower homocysteine level is a potential mechanism for the association between higher folate intake and a lower Alzheimer's disease risk," the authors write.
Definitive conclusions about the role of folate in the development of Alzheimer's disease cannot yet be made, they continue. The findings of this study are in contrast to those of some other research, and other compounds (such as hormones) perceived to reduce the risk for dementia in observational studies did not do so in randomized trials. "Thus, the decision to increase folate intake to prevent Alzheimer's disease should await clinical trials," they conclude.
Wednesday, January 3, 2007
State of Childhood Asthma, United States: 1980-2005
A new report on childhood asthma released today by the Centers for Disease Control and Prevention (CDC) shows that death rates for asthma among children under age 18 have declined since 1999, while doctor visits for the condition have more than doubled over the past decade.
In 2005, nearly 9 percent of children - 6.5 million children under age 18 - were reported to currently have asthma. The percentage of children who had asthma more than doubled between 1980 and 1995, from 3.6 percent to 7.5 percent. In 2001, CDC introduced a more precise measurement of asthma and the five years since then the trend has remained stable at historically high levels.
Other highlights:
After increasing steadily between 1980 and 1998, asthma death rates among children have for the most part declined since 1999. A change in the way causes of death are coded resulted in a sizable one-year decline between 1998 and 1999, but since then the asthma death rate for children has fallen from 3.2 deaths per 1 million children under age 18 in 1999 to 2.5 deaths per 1 million in 2004.
Asthma-related visits to physician offices have increased sharply since the early 1990's, from less than 40 visits per 1,000 children under age 18 in 1990 to 89 visits per 1,000 in 2004.
Among race/ethnic groups, Puerto Rican and non-Hispanic black children were reported to have the highest percentages of asthma (19.2 and 12.7 respectively).
According to 2003 data, children with at least one asthma attack in the previous year (nearly 4 million children) missed a cumulative total of 12.8 million school days due to asthma.
Asthma-related emergency department visits for children have remained fairly stable from 1992 to 2004 (103 visits per 10,000 children in 2004 compared to 97.6 visits per 10,000 in 1992).
Among the 37 states for which data were available, the states with the highest percentage of children with asthma were: Massachusetts, Hawaii, Oklahoma, Maryland, and Rhode Island. The states with the lowest percentage of children with asthma were: Utah, California, Iowa, Tennessee, and Washington.
"The State of Childhood Asthma, United States: 1980-2005" is available at www.cdc.gov/nchs.
In 2005, nearly 9 percent of children - 6.5 million children under age 18 - were reported to currently have asthma. The percentage of children who had asthma more than doubled between 1980 and 1995, from 3.6 percent to 7.5 percent. In 2001, CDC introduced a more precise measurement of asthma and the five years since then the trend has remained stable at historically high levels.
Other highlights:
After increasing steadily between 1980 and 1998, asthma death rates among children have for the most part declined since 1999. A change in the way causes of death are coded resulted in a sizable one-year decline between 1998 and 1999, but since then the asthma death rate for children has fallen from 3.2 deaths per 1 million children under age 18 in 1999 to 2.5 deaths per 1 million in 2004.
Asthma-related visits to physician offices have increased sharply since the early 1990's, from less than 40 visits per 1,000 children under age 18 in 1990 to 89 visits per 1,000 in 2004.
Among race/ethnic groups, Puerto Rican and non-Hispanic black children were reported to have the highest percentages of asthma (19.2 and 12.7 respectively).
According to 2003 data, children with at least one asthma attack in the previous year (nearly 4 million children) missed a cumulative total of 12.8 million school days due to asthma.
Asthma-related emergency department visits for children have remained fairly stable from 1992 to 2004 (103 visits per 10,000 children in 2004 compared to 97.6 visits per 10,000 in 1992).
Among the 37 states for which data were available, the states with the highest percentage of children with asthma were: Massachusetts, Hawaii, Oklahoma, Maryland, and Rhode Island. The states with the lowest percentage of children with asthma were: Utah, California, Iowa, Tennessee, and Washington.
"The State of Childhood Asthma, United States: 1980-2005" is available at www.cdc.gov/nchs.
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