|March 2003 |
What's Hot Archive
March 31, 2003
Antioxidant supplements are associated with improved cognitive function in older women
The April 2003 American Journal of Clinical Nutrition published the findings of Harvard researchers that the combination of vitamin C and E supplements was associated with improved cognitive function in women. The researchers obtained information on supplement use beginning in 1980 from 14,968 participants in the Nurses' Health Study. From 1995 to 2000, cognitive function testing via telephone interviews was administered to the participants, who were aged 70 to 79 during this time period.
When data on vitamin C and E supplements were analyzed, it was found that current users of vitamins C and E and vitamin E alone had higher cognitive function test scores than participants who had never taken either vitamin supplement, equivalent to the vitamin users being one year younger. On tests of intermediate and delayed recalls of a ten word list, users of vitamins C and E or vitamin E alone scored higher than nonusers, and those who took vitamin E alone scored significantly higher on the verbal fluency test. Increased duration of use for both vitamins was related to increasingly higher mean test scores, although past use of vitamin E alone showed little benefit on cognitive performance. Vitamin C taken alone was not found to effect test scores.
The authors write that vitamin E may have a greater benefit on cognitive function than vitamin C because of it is fat soluble and is absorbed directly by tissue. Although the team failed to find a difference between those who took vitamin E alone and those who took both vitamins C and E, they note that vitamin E requires vitamin C for optimal metabolism, and that studies with rats have shown that alpha-tocopherol doubles its benefit on brain cell survival time when combined with vitamin C, providing support for the combination's benefit.
March 28, 2003
Antioxidant vitamin supplementation improves surgical outcome in critically ill patients
The December 2002 issue of Annals of Surgery published the results of a study which revealed that critically ill surgery patients who received the antioxidant vitamins C and E experienced reduced organ failure and spent less time in intensive care. Many critically ill patients who survive surgery develop organ failure or infection over the following weeks, which can be fatal. Antioxidants reduce the oxidative stress that has been found to be associated with acute respiratory distress syndrome and with organ failure caused by tissue injury and the activation of genes involved in inflammation.
Five hundred ninety-five critically ill patients were randomized to receive alpha-tocopherol via naso- or orogastric tube and intravenous ascorbic acid, or standard care for the duration of their stay in the intensive care unit (up to twenty-eight days). Ninety-one percent of the subjects were trauma victims. The researchers, from Harborview Medical Center in Seattle, Washington, found that patients who received the antioxidant vitamins had a lower incidence of acute respiratory distress syndrome and pneumonia than those in the standard care only group, experienced less than half the risk of multiple organ failure, spent less time receiving mechanical ventilation, and had shorter intensive care unit stays. Patients who received antioxidants also experienced a lower rate of mortality over the duration of the study than those who did not receive the vitamins.
Previous studies have shown that critically ill patients admitted to intensive care tend to have lower levels of serum ascorbate and alpha-tocopherol. The authors write that "The evidence for oxidative stress in the critically ill patient, coupled with the potential for direct oxidative tissue injury and induction of the systemic inflammatory response, provides a sound biologic rationale for antioxidant supplementation." (Nathens AB, "Randomized, Prospective Trial of Antioxidant Supplementation in Critically Ill Surgical Patients," Annals of Surgery 236:6,814-822)
March 26, 2003
Nonsteroidal antiinflammatories, H2 blockers, associated with lower non-Hodgkin's lymphoma risk
Researchers in the Netherlands have discovered an association between the use of certain drugs--nonsteroidal anti-inflammatory drugs (NSAIDs) and histamine2 (H2) blockers -with a lower risk of non-Hodgkin's lymphoma in women. Non-Hodgkin's lymphoma is a cancer of the lymphatic system that has been steadily increasing worldwide.
The researchers utilized pharmacy drug dispensation records and hospital discharge data for 300,000 Dutch subjects for the period of January 1991 through December 1998. Two hundred eleven non-Hodgkin's lymphoma cases and 800 controls without the disease were selected for analysis.
Although there were nonsignificant reductions in the risk of non-Hodgkins lymphoma associated with the use of NSAIDs, H2 blockers, cholesterol-lowering drugs and antibiotics in all patients, for women, NSAIDS and H2 blockers were associated with significant risk reduction. The reduced risk was increased with longer duration of drug use, with the exception of H2 blockers.
The authors postulate that because non-Hodgkin's lymphoma is often associated with immunodeficiency diseases, and some antibiotics influence immune components, this could explain the benefit of this category of drugs in decreasing risk of the disease. The preventive action of NSAIDs in cancers has been attributed to their cyclooxygenase enzyme inhibitory capacity, which may be their mechanism of action in helping to prevent non-Hodgkin's lymphoma. The use of H2 blockers may be protective of the stomach mucosa, which is the site of some lymphomas. Anti-cholesterol drugs inhibit the activation of mutated ras proteins, found in 30 percent of human tumors, which could account for the protective association found in this study, however the number of subjects taking the drugs was small, diminishing the significance of the finding. The authors state that the associations found between these drugs and a lowered risk of non-Hodgkin's lymphoma warrant larger studies to confirm their benefits.
March 24, 2003
Cranberry juice lowers heart disease risk
The 225th national meeting of the American Chemical Society was the site of the announcement by University of Scranton professor of chemistry Joe Vinson PhD, that daily consumption of cranberry juice significantly raised high density lipoprotein (HDL) by 10 percent, which provides a corresponding decrease in heart disease risk of 40 percent. The study is the first to demonstrate this benefit for cranberries in humans, although other studies have shown that the fruit helps prevent urinary tract infections and may lower gum disease and stomach ulcer risk.
Nineteen participants with elevated cholesterol received blood tests at the study's onset and each month for a period of three months. The subjects were given one eight ounce glass of cranberry juice daily for one month, followed by two glasses for the second month and three glasses per day for the concluding month of the study. The juice contained 27 percent pure cranberry juice by volume, similar to supermarket versions.
In addition to the elevation of HDL cholesterol experienced by the participants, plasma antioxidant capacity increased by as much as 121 percent after they received two or more servings of juice daily. Increased antioxidants are also associated with lower heart disease risk.
The mechanism of action in cranberries' ability to raise HDL may involve their high levels of polyphenols, which have a strong antioxidant effect. Of twenty commonly consumed fruits, cranberries have been shown to be among those with the highest levels of polyphenols.
Dr Vinson, who is the lead author of the study, stated, "This study gives consumers another reason to consider drinking cranberry juice, which has more health benefits than previously believed. People should consider drinking it with their meals, perhaps as an alternative to soda."
March 21, 2003
Curcumin protects against alcoholic liver disease
A study published in the February 2003 American Journal of Physiology-Gastrointestinal and Liver Physiology, has found that curcumin, the substance in the spice turmeric that provides its yellow color, can help prevent liver disease caused by alcohol abuse.
In previous research it had been found that inhibition of transcription factor NF-kB, which is involved in many tissues that are sensitive to alcohol, could prevent alcoholic liver disease. Acting on this finding, researchers sought to determine if curcumin could prevent the disease its ability to suppress the expression of NF-kB . Four groups of rats were provided with one of the following regimens for four weeks: fish oil plus ethanol, fish oil plus dextrose, or one of these regimens combined with curcumin.
When tissue taken from the rats' livers was examined, those from animals who received the fish oil and ethanol regimen were found to be fatty, with necrosis and inflammation. Curcumin added to this regimen reduced the degree of fatty liver and prevented inflammation and necrosis. While the fish oil and ethanol group showed increased NF-KB activity compared to that found in the livers of rats who received the fish oil plus dextrose, curcumin prevented the activation of NF-KB rats who received the spice in addition to the fish oil/ethanol diet. Curcumin's ability to suppress NF-kB was consistent with its ability to inhibit lipid peroxidation and liver injury. Proinflammatory mediators that were elevated in the livers of rats given fish oil and ethanol, such as tumor necrosis factor-alpha, interleukin 12, COX-2 and inducible nitric oxide synthase, were all found to be normalized by curcumin.
The research team, led by Amin A. Nanji of the University of Pennsylvania Medical Center in Philadelphia, is now attempting to determine whether curcumin can benefit individuals with nonalcoholic steatohepatitis.
March 19, 2003
NSAIDs do not increase hemorrhagic stroke risk
A population-based case-control study published in the February 2002 issue of the journal Stroke found that the use of nonaspirin nonsteroidal anti-inflammatory drugs (NSAIDs) is not associated with an increased risk intracerebral hemorrhage. One of the side effects of NSAID use is an increased risk of bleeding, and these drugs are particularly recognized to increase bleeding in the gastrointestinal tract. NSAIDs, especially aspirin are all known to decrease platelet aggregation which increases bleeding time. Intracerebral hemorrhage is one of two types of hemorrhagic stroke, which result from bleeding in the brain.
The Danish researchers analyzed government data to identify 912 cases of intracerebral hemorrhage and 9059 age and gender matched controls during the period of 1991 to 1999. Pharmaceutical drug use was determined through a prescription database. Nonaspirin prescription drug use in the 30, 60 or 90 days preceding intracranial hemorrhage was not found to be associated with increased risk of the event. When the subjects were analyzed by age, gender or a previous diagnosis of hypertension, no risk of intracranial hemorrhage was found in association with the drugs, demonstrating that this risk was not more prevalent in these subgroups.
In second study published in the same issue of Stroke, the use of all NSAIDs, including aspirin, was determined not to be a risk factor for either intracerebral or subarachnoid hemorrhage. The analysis examined 3,584 cases of stroke that occurred between 1994 and 1999 and 40,000 controls. Additionally, the study found that NSAIDs failed to offer protection against first time ischemic stroke, which is the type of stroke that occurs when blood flow in the brain is blocked by a blood clot.
These studies should reassure those taking NSAIDs that, despite the increased risk of bleeding elsewhere in the body, use of this class of drugs does not appear to increase the incidence of hemorrhagic stroke, with its high risk of death and disability.
March 17, 2003
Aspirin may lower risk of cancer of esophagus, larynx, pharynx and oral cavity
Aspirin use has been associated with a lower risk of breast, ovarian and colorectal cancer as well as a reduction in cardiovascular events and Alzheimer's disease. Now, an analysis of three studies published in the March 10 2003 issue of British Journal of Cancer has found that aspirin use is associated with a reduced incidence of cancers of the upper aerodigestive tract, which includes esophageal, oral and pharyngeal, and laryngeal cancer.
Researchers examined data from three Italian studies that was provided by questionnaires administered from 1992 to 2000 to 4400 individuals. Of this population, 965 patients with cancer of the esophagus, larynx, pharynx and oral cavity and 1779 individuals without cancer who provided information on aspirin consumption were selected for the analysis.
Aspirin use was reported in 3.8 percent of the cancer patients compared to 4.9 percent of the controls. When duration of use was looked at, those who used aspirin for more than five years experienced a further reduction in risk. More than five years having elapsed since the time aspirin was first used reduced the odds of diagnosis with this group of cancers by half.
The researchers conclude that their findings suggest that aspirin may have a beneficial effect in preventing esophageal, laryngeal, oral and pharyngeal cancers, with a significant risk reduction observed in long term use and a longer time since first-time use. They note that in colorectal and other cancers, aspirin inhibits cycloxygenase-2 which is involved with programmed cell destruction, and suggest that the same mechanism may be involved in aspirin's effects observed in the current study.
March 14, 2003
Ibuprofen appears to dissolve amyloid plaque in Alzheimer's disease
In what is being called a breakthrough study published in the March 31 2003 issue of the journal Neuroscience, researchers at the University of California, Los Angeles School of Medicine have discovered that two nonsteroidal anti-inflammatory drugs, ibuprofen and naproxen can dissolve the amyloid plaques found in the brains of Alzheimer's disease patients. An association between the class of drugs and a lower incidence of Alzheimer's disease had previously been established, but their preventive mechanism was believed to be that of their anti-inflammatory action. The presence of amyloid plaques is thought to be one of the factors responsible for brain cell dysfunction and death in Alzheimer's sufferers.
Using fibers taken from the brains of Alzheimer's patients, the researchers utilized a fluorescent chemical developed by their laboratory to mark amyloid plaques. When ibuprofen or naproxen were added, they were found to bind to the marked lesions. By observing a decrease in fluorescent areas, additional studies with synthetic amyloid revealed that administering the drugs may actually dissolve the plaques and inhibit their formation.
Earlier research by the team found that PET scans of patients injected with the fluorescent marker identified early brain lesions that had not reached the stage during which brain cells are destroyed. This technique will enable physicians to determine whether a patient will benefit from interventions such as ibuprofen or naproxen.
Lead researcher and professor of molecular and medical pharmacology at UCLA's David Geffen School of Medicine at UCLA, Jorge R. Barrio, stated, "We believe the UCLA observation is extremely important because early diagnosis of Alzheimer's disease now has an underlying purpose: early therapeutic intervention at the stage where brain cell degeneration is minimal. This would provide hope to patients and families by modifying outcomes. "
March 12, 2003
Niacin/lovastatin combination better than other statins at improving lipids
An investigation published in the March 15 2003 American Journal of Cardiology found that the B vitamin niacin, in combination with the cholesterol-lowering drug lovastatin, was significantly more effective at raising HDL cholesterol than the drugs atorvastatin and simvastatin given in standard doses. LDL, or low density lipoprotein is considered to be the undesirable form of cholesterol, whereas HDL, or high density lipoprotein, is associated with an improved cardiovascular profile.
The study was conducted at 29 sites throughout the United States and included 315 participants. The subjects all had LDL cholesterol levels of 160 milligrams per deciliter or greater and HDL levels lower than 45 (males) and 50 (females). Participants were randomly assigned to receive simvastatin, atorvastatin, 1000 milligrams extended release niacin plus 40 milligrams lovastatin, or 2000 milligrams extended release niacin plus 40 milligrams lovastatin. All subjects were given lower starting doses of each regimen for the first month, which were increased over the following months of the study to 40 milligrams as the final dose for all statin drugs.
At eight weeks, the dose of 1000 milligrams niacin plus 40 milligrams lovastatin as well as the 10 milligram starting dose of atorvastain had lowered LDL cholesterol by 38%. At twelve weeks, the 1000 milligram niacin 40 milligrams lovastatin combination had lowered LDL cholesterol by 42 percent compared to a 34 percent lower LDL benefit with 20 milligrams simvastatin. The niacin and lovastatin combination significantly elevated HDL compared to atorvastatin or simvastatin at all doses. In addition, niacin and lovastatin improved triglycerides, lipoprotein(a), apolipoprotein A-1 and B and HDL subfractions more than the two drugs. Liver enzyme levels were basically the same for all groups.
The superior improvement in users' lipid profiles elicited by niacin in combination with lovastatin is predicted to result in a greater reduction in coronary disease risk.
March 10, 2003
Magnesium improves exercise tolerance, quality of life, in CAD patients
In the American Journal of Cardiology's March 1 2003 issue, it was reported that magnesium given to patients with coronary artery disease improved exercise tolerance and reduced exercise-induced chest pain, while improving quality of life. Earlier studies had established a benefit for the mineral in this patient group through its ability to improve endothelial function, but its effect on clinical outcomes had not been established.
One hundred eighty-seven men and women with coronary artery disease were recruited from the United States, Israel and Austria to participate in the study. The subjects were randomized to receive magnesium citrate providing 365 milligrams magnesium per day in two doses or a placebo, for a period of six months. Participants remained on their regular medications and diet for the course of the investigation. Physical examinations were conducted at the study's onset and at six months. The examinations included exercise testing utilizing a treadmill or bicycle, blood tests, and completion of quality-of-life questionnaires.
At the study's conclusion, the group receiving magnesium had a 14% improvement in exercise duration compared to the placebo group, who experienced no change. While 21 percent of the placebo group reported chest pain induced by exercise after six months, only 8 percent of the magnesium group reported the symptom, and fewer individuals in this group were forced to discontinue their exercise test because of angina. Magnesium users reported less pain and greater improvement in their condition, contributing to an improved quality of life assessment.
This is the first trial to show that the consumption of magnesium supplements improves exercise tolerance, chest pain and quality of life in individuals challenged by coronary artery disease. The authors note that three quarters of American and Israeli participants had deficient magnesium levels, possibly the result of a western diet.
March 7, 2003
Green tea as effective as NSAID in preventing colon tumors
In research conducted by the Linus Pauling Institute at Oregon State University in Corvallis, Oregon, published in the February 2003 issue of the journal Carcinogenesis, it was found that both green tea and white tea reduced colon polyps as well as the nonsteroidal anti-inflammatory drug sulindac, and that a combination of the drug and white tea reduced polyp formation even more. Previous research has shown that sulindac can cut polyp formation by one half. The research was funded by the National Cancer Institute.
In the current study, mice bred to develop intestinal tumors were given drinking water to which was added green tea, white tea, sulindac, a combination of white tea and sulindac or plain water for twelve weeks. At the study's conclusion, the mice who received green tea had 17 tumors compared to 30 tumors in the control group. White tea further reduced polyp formation to 13, and a combination of the tea with sulindac resulted in a finding of only 6 polyps. Because NSAIDs such as sulindac can have side effects, an agent that increases the efficacy of a lower dose would be valuable.
Coauthor Gayle A Orner of Oregon State University wrote, "Tea is one of the most widely consumed beverages in the world, and recent upswings in the sales of green tea in the United States can be attributed to reports of potential health benefits against cancer and other chronic diseases. Teas exert significant protective effects in experimental animal models of skin, lung, esophageal, gastric, hepatic, small intestinal, pancreatic, colon, bladder and mammary cancer . . . These are pretty exciting results. What's especially significant is that as far as we can tell consumption of tea has none of the side-effects of NSAIDs, which can be severe, including bleeding, ulcers and even death."
March 5, 2003
B vitamin levels linked with lower rates of breast cancer
The March 5 2003 Journal of the National Cancer Institute published the results of an investigation that revealed an association between higher plasma levels of the vitamins folate and pyrixodine and a reduced risk of breast cancer. The study utilized data from the Nurses' Health Study, which enrolled 121,700 female nurses beginning in 1976.
The Harvard researchers obtained blood samples from 32,826 participants from 1989 to 1990 and analyzed them for plasma levels of folate, vitamin B6, vitamin B12 and homocysteine. Information on the participants' diets and alcohol consumption was obtained from food frequency questionnaires completed in 1980, 1984, 1986 and 1990, from which the subjects' daily nutrient intake was determined. Supplement use was updated on the biennial questionnaires, enabling the researchers to calculate average intake levels of folate, vitamin B6 (pyridoxine) and vitamin B12.
Plasma levels of the vitamins were found to correlate with reported intake. During the follow-up period, 735 cases of breast cancer were confirmed. Breast cancer patients were found to have significantly lower levels of plasma folate and B6 than women who were free of the disease. The association between plasma folate levels and lower breast cancer risk was especially strong for women who drank more than 15 grams per day of alcohol. Higher alcohol intake appeared to increase breast cancer risk only in women with low folate levels.
While plasma levels of vitamin B12 were weakly associated with a lowered risk of breast cancer, homocysteine levels were not. Homocysteine levels were, however, inversely associated with plasma folate, B6 and B12 levels.
The findings suggest that folate and B6 may be preventive against breast cancer, and that folate may be particularly important for women who consume higher amounts of alcohol.
March 4, 2003
Multivitamin supplementation reduces bacterial infections
A double-blind, placebo-controlled study published in the March 4 2003 issue of Annals of Internal Medicine concluded that taking a multivitamin supplement reduced infections and absenteeism, particularly in type 2 diabetics.
The researchers, from the University of North Carolina in Charlotte, and Wake Forest University School of Medicine in Winston-Salem, North Carolina, recruited 130 men and women aged forty-five and older, and randomly assigned them a multivitamin and mineral supplement or a placebo, to be taken daily for a one year period. The participants' nutritional status was evaluated through the use of a three day food diary that was completed at the study's onset and at six months. Approximately 18 percent of the subjects were classified as nutritionally deficient. One third of the participants were diabetic.
While 73 percent of the placebo group developed one or more infection-related illnesses during the study, 43 percent of the group receiving the multivitamin reported infections. Absenteeism in the placebo group was more than twice than that of the group that received the supplement. The effect of supplementation was most profound in diabetic participants among whom 17 percent experienced infections, compared to 93 percent of the diabetics. Eighty-nine percent of the diabetic placebo subjects reported at least one absentee day, while none of the diabetics who received the supplement reported being absent from work.
The researchers state that correction of micronutrient deficiencies is the most likely explanation for the findings. They found that diabetic participants were more likely than nondiabetics to be deficient in one or more of these nutrients. The authors recommend a large clinical trial to establish whether these findings are true not only for diabetics but for individuals with other diseases, or for those who have less than ideal nutrition.
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