August 30, 2006
NSAIDS delay prostate enlargement
An advance online report published on August 11, 2006 in the American Journal of Epidemiology found an association between daily nonsteroidal anti-inflammatory drug (NSAID) use and delayed onset of benign prostatic hyperplasia, a condition characterized by enlargement of the prostate gland which causes frequent urination and other symptoms.
Researchers at the Mayo Clinic led by epidemiologist Jenny St. Sauver, PhD followed 2,447 Caucasian men from 1990 to 2002. Participants completed questionnaires upon enrollment and every two years thereafter which provided information on the use of NSAIDs such as aspirin or ibuprofen. A subset of men participated in a medical examination that included assessment of prostate specific antigen (PSA) levels and ultrasound imaging of the prostate gland.
One-third of the men were taking NSAIDs daily at the beginning of the study. The research team found that men who used NSAIDs had a 27 percent lower age-adjusted risk of developing moderate to severe urinary symptoms compared to nonusers. Additionally, NSAID users had nearly half the risk of developing low maximum flow rate, prostate enlargement and elevated PSA than nonusers. Neither dosage nor type of NSAID used appeared to affect the association.
"The typical scenario with benign prostatic hyperplasia is that men start getting up three to five times a night to urinate, and their wives ultimately force them to go see a urologist," study coauthor and Mayo Clinic investigator Michael Lieber, MD observed. "Men also might come in if they have problems with daytime urinary frequency. All this adversely affects men's quality of life."
"Our study suggests that one potential unintended consequence of so many people in our society taking NSAIDs could be an improvement in urinary health for men," he concluded. "So, if a person's primary care doctor recommends NSAIDs for some other reason, prostate health might be an additional benefit."
August 28, 2006
Antioxidants protect dopamine-producing neurons in insect model of Parkinson's disease
A report published in the online early edition of the Proceedings of the National Academy of Sciences revealed the finding of Zhouhua Zhang of the Burnham Institute for Medical Research and colleagues that treatment with antioxidants protects cells from the effects a mutation in the PINK1 gene implicated in both inherited and sporadic cases of Parkinson's disease. Parkinson's disease is a progressive neurodegenerative movement disorder in which brain cells that produce dopamine are destroyed. The disease can be inherited, although most cases appear to arise sporadically.
By inactivating the PINK1 gene in fruit flies, Dr Zhang's team found a reduction of dopamine-producing neurons in their brains, which was prevented by adding back the human form of the gene. PINK1 inactivation also resulted in a degenerative condition in the flies' eyes.
Acting on the results of earlier in vitro research which found increased oxidative stress associated with PINK1 mutation, the researchers investigated the possibility that antioxidants could prevent the degeneration of dopaminergic neurons induced by PINK1 activation . Flies in which the antioxidant enzyme superoxide dismutase 1 was expressed were found to be protected from of dopaminergic neuron degeneration, suggesting that PINK1 inactivation in flies induces the death of neurons via an oxidative stress pathway. Addition of SOD1 protein or the antioxidant vitamin E to the flies' diets prevented degeneration of dopaminergic neurons as well as the degenerative eye condition.
Overexpression of the fly version of PINK1 resulted in reduced sensitivity to the insecticide paraquat, which has been linked to sporadic Parkinson's disease, and to hydrogen peroxide, another inducer of oxidative stress.
The results of the study indicate that antioxidants can compensate for the PINK1 gene defect in Parkinson's disease and protect dopamine-producing neurons from death in this laboratory model.
August 25, 2006
Being overweight at midlife associated with increased risk of mortality
Despite recent headlines proclaiming that being a little overweight might be good for you, the results of a study published in the August 24, 2006 New England Journal of Medicine suggest the opposite. Researchers at the National Institutes of Health found that while obesity (defined as having a body mass index, or BMI, of 30 or more) among healthy nonsmokers at age 50 is associated with two to three times the risk of death than that of healthy nonobese nonsmokers, being overweight (BMI of 25.0 to 29.9) but not obese also associated with an increased risk of dying.
The investigators examined the relationship of the risk of dying from any cause to the BMI of 527,265 men and women aged 50 to 71 upon enrollment in the National Institutes of Health-AARP Diet and Health Study. Completed questionnaires mailed to participants from 1995 to 1996 provided information on height, weight and other characteristics. Deaths over the ten year follow-up were ascertained via yearly updates to the Social Security Administration Death Master File.
There were 61,317 deaths over the follow-up period. While the risk of dying increased among those categorized as underweight (with a BMI of less than 18.5) at age 50, and decreased in men classified as overweight (while only mildly increasing in women), when current or former smokers and those with pre-existing disease upon enrollment were eliminated from the analysis, being overweight increased the risk of death by 20 to 40 percent, and the risk associated with being underweight weakened to insignificance. Obesity among this group tripled the risk of dying compared to subjects with a normal BMI of 23.5 to 24.9.
"Our findings suggest that adiposity, including overweight, is associated with an increased risk of death," the authors conclude.
August 23, 2006
Calcium and magnesium, but not dairy intake, linked with increased insulin sensitivity
A report published in the September, 2006 issue of the American Journal of Epidemiology revealed an association between increased insulin sensitivity and greater intake of calcium and magnesium. Reduced insulin sensitivity occurs in metabolic syndrome and diabetes type 2 when individuals produce adequate or even excessive insulin, but have become resistant to its effects. Although previous studies have indicated an association between dairy intake and insulin sensitivity, the current study failed to confirm this.
Researchers at the University of South Carolina in Columbia evaluated data from 1,036 men and women without diabetes enrolled in the Insulin Resistance Atherosclerosis Study. Food frequency interviews including dietary supplement doses were conducted at the beginning of the study. Insulin sensitivity was measured with an intravenous glucose tolerance test upon enrollment and after five years of follow-up.
The average daily calcium intake of the participants was 970 milligrams, and the average intake of magnesium was 403 milligrams. Seventeen percent of the participants reported using calcium supplements, and 5 percent used magnesium supplements. After adjustment for demographic factors, dairy intake was not found to be associated with insulin sensitivity, however, positive and independent associations of calcium and magnesium with insulin sensitivity were demonstrated. Magnesium appeared to increase insulin sensitivity up to a daily intake of 325 milligrams, suggesting that more than this amount may not be of further benefit for this concern, although higher doses of magnesium could be beneficial for other purposes.
Magnesium may play a role in glucose homeostasis and insulin action, and calcium supplementation has been shown to reduce fasting insulin and increase insulin sensitivity in one clinical trial of nondiabetics. The authors observe that it is important to determine the optimal intake of these minerals, because excessive doses could decrease the absorption of other minerals.
August 21, 2006
Large proportion of Americans find health care poorly coordinated, inefficient, unsafe and expensive
A survey of over 1,000 Americans conducted by The Commonwealth Fund Commission on a High Performance Health System found 42 percent reporting poorly coordinated, inefficient or unsafe health care over the previous two years. One in six respondents reported duplicate tests, and 25 percent reported unnecessary care or treatment by their physicians. Survey respondents also noted medical errors, and failure of test results to be provided to other physicians. Ninety-two percent of those queried agreed that it was important to have a medical home, defined as one physician or clinic responsible for providing and coordinating their medical care. Commonwealth Fund President Karen Davis stated, "Coordination and information are vital to improving our health care system. When care isn't coordinated there is a higher risk for unsafe care and duplicative or wasteful medical spending. This survey shows that patients place high value on having a medical home that coordinates all of a patient's care and provides better access to information and care. Unfortunately, the reality is that too many patients have short-term relationships with their physicians and rarely have easy access to their own medical records."
Additionally, 48 percent of those in middle-income families reported difficulty in paying for health care and health insurance, a concern shared by many higher income respondents. "The increasing difficulties Americans are facing paying for health care and health insurance are cause for concern," stated Commission member Dallas Salisbury. "As economic stresses related to health care rise up the income ladder we are undermining the economic security of the workforce. In addition to less affordable medical care, families will no longer be able to save as much for retirement. Rising costs also put financial stress on employers based in the United States."
August 18, 2006
Dietary change slows PSA rise
A report published in the September, 2006 issue of the journal Integrative Cancer Therapies revealed the finding of Gordon A Saxe, MD, PhD and colleagues at the Moores Cancer Center and School of Medicine at the University of California, San Diego that adopting a plant based diet and lowering stress is associated with a reduction in prostate cancer progression as indicated by prostate specific antigen (PSA) levels. PSA is a blood marker for prostate cancer whose values are used to indicate the possibility of prostate cancer as well as to track the progression of the disease following treatment.
Fourteen men with recurrent prostate cancer were instructed to consume more plant based foods such as whole grains, cruciferous and leafy green vegetables, beans and legumes and fruit, and to consume less meat, dairy products and refined carbohydrates. The patients received stress management instruction which included meditation and Tai Chi techniques. PSA levels were analyzed from the time of recurrence until the start of the study, and from the baseline of the study to its conclusion after six months.
Dr. Saxe's team found a significant decrease in PSA rise occurring from the start of the study through the six month study period. Of the ten evaluable patients, four experienced a reduction in PSA levels, and 9 had reductions in their PSA rise and PSA doubling time improvement. The median PSA doubling time increased from 11.9 months to 112.3 months following the dietary changes.
"The magnitude of effect of these findings is the strongest observed to date among dietary and nutritional interventions in this patient population," Dr. Saxe stated. "These results provide preliminary evidence that adoption of a plant-based diet, in combination with stress reduction, may attenuate disease progression and have therapeutic potential for management of recurrent prostate cancer."
August 14, 2006
Higher magnesium levels correlate with better muscle performance among older individuals
New findings from the InCHIANTI (Aging in the Chianti Area) study show that having a higher level of serum magnesium is associated with an increase in muscle performance, which commonly declines with age.
The InCHIANTI study is a prospective epidemiologic survey of 1,453 community residents of the Chianti area of Italy which sought to determine risk factors for late-life disability. In the current study, published in the August, 2006 issue of the American Journal of Clinical Nutrition, researchers in Italy and the U.S. analyzed information from 1,138 participants with data on serum magnesium levels and muscle performance as evaluated by grip strength, lower leg strength, knee extension torque, and ankle extension isometric strength.
Thirty percent of the men and women analyzed had deficient serum magnesium concentrations at less than 1.8 milligrams per deciliter. Serum magnesium levels were associated with all four measures of muscle performance, after adjustment for age, muscle area, and other factors. Participants in the top one-third of magnesium concentrations had significantly higher values for grip strength, knee extension torque and ankle extension strength than those whose values were in the lowest third third.
The importance of magnesium in energy metabolism, increased reactive species production resulting from magnesium deficiency, and a proinflammatory effect of reduced magnesium levels were submitted by the authors as possible explanations for their findings. They note that despite the ease of magnesium supplementation, a deficiency of the mineral is prevalent in Western populations. Supplementing with the mineral has been shown to benefit neuropsychiatric disorders, heart disease and cardiac arrhythmias, asthma, diabetes, and chronic fatigue. "Because magnesium supplementation is inexpensive and in general well tolerated, it should be a key consideration in older subjects at particular risk of magnesium deficiency," they write.
August 11, 2006
Antioxidants may help prevent tick-borne illnesses
In research funded by the the NIH's National Institute of Allergy and Infectious Disease, Sanjeev Sahni, PhD, of the University of Rochester Medical Center is studying the effect that antioxidant nutrients such as alpha-lipoic acid, green tea, and vitamins C and E may have on helping to prevent and treat illnesses caused by the rickettsia bacteria. Rocky Mountain spotted fever, transmitted by wood ticks or dog ticks, and typhus, transmitted by lice or fleas, are two commonly known diseases resulting from rickettsia infection. The diseases are currently treated with antibiotics.
Dr Sahni, who is an assistant professor of Hematology/Oncology at the University of Rochester, began studying rickettsial diseases over a decade ago. His team initially used the bacteria as a model to study changes that occur in the lining of the blood vessels in response to infection. They found that the endothelial cells experience oxidative stress and produce free radicals that cause inflammation and other damage when infected with rickettsia.
By using electron microscopy to study the damage inflicted upon cells by infection, and by examining biochemical evidence of oxidative stress, Dr Sahni hypothesized that antioxidants, which reduce oxidative stress, could be protective. Previous experiments of cells infected with rickettsia that were subsequently treated with the antioxidant nutrient alpha-lipoic acid had revealed improved cellular defenses against infection.
"Our studies have the potential to identify novel therapeutic targets for a host of rickettsial diseases," Dr Sahni stated. Dr Sahni's research group is also attempting to identify which enzymes boost the effectiveness of antioxidants. Additionally, because the expression of cyclooxygenase-2 (cox-2) by infected cells results in inflammation and swelling, he believes that cox-2 inhibitors such as ibuprofen could be helpful to control the effects of the diseases.
August 9, 2006
Smokers have reduced folate in blood and oral mucosa
A report published in the the April, 2006 issue of the American Journal of Clinical Nutrition revealed the findings of researchers at Tufts University that men and women who smoke have reduced levels of folate and beta-carotene in their blood and oral mucosa. Smoking is strongly association with oral cancer and has also been linked to reduced levels of folate.
Joel Mason, MD, who is the director of the USDA Human Nutrition Research Center on Aging's Vitamins and Carcinogenesis Laboratory at Tufts, and his colleagues analyzed the diets of 56 men and women, half of whom were smokers. Folate levels were determined in blood and cheek cell samples. "Regardless of dietary intake, smokers had lower levels of folate in both blood and cheek cells, compared with non-smokers," Dr Mason reported. Additionally, the cheek cells of the smokers had more genetic aberrations associated with increased oral cancer risk.
"It's possible that diminishing folate in cells may cause the cellular milieu to change, inducing the formation of cancerous cells," Dr Mason stated. "However, based on our findings, it does not appear that folate depletion induced by smoking is a major avenue for the formation of the genetic aberrations (micronuclei) that increase risk of oral cancer. Oral micronuclei and low oral folate are each linked with smoking, but they were not related to each other in this study," he explained, although he noted that there are other pathways involving folate that were not explored.
In an additional experiment, Elizabeth Johnson, PhD found that smokers had lower levels of carotenoids in blood and cheek cells. "Although our results do not support a direct role for these nutrients in oral carcinogenesis, we uncovered some interesting relationships between smoking and nutrient distribution that deserve further exploration," she concluded.
August 7, 2006
Nearly one-fifth of FDA scientists report being asked to exclude or alter information
A survey conducted by the Union of Concerned Scientists (UCS) has found that 18.4 percent of 997 scientists surveyed at the U.S. Food and Drug Administration "have been asked, for nonscientific reasons, to inappropriately exclude or alter technical information or their conclusions in a FDA scientific document." Additionally, 40 percent of those surveyed stated that they feared retaliation for expressing safety concerns in public, and more than a third did not feel they could even express safety concerns within the agency.
In addition to the above, 61 percent of respondents knew of instances in which Department of Health and Human Services or FDA political appointees had inappropriately entered into FDA determinations or actions. Additionally, 60 percent were aware of cases "where commercial interests have inappropriately induced or attempted to induce the reversal, withdrawal or modification of FDA determinations or actions," and half of the respondents reported that nongovernmental interests such as advocacy groups had similarly attempted to induce such changes.
When asked whether they agreed that the "FDA routinely provides complete and accurate information to the public," and if "FDA leadership is as committed to product safety as it is to bringing products to the market," less than half of the scientists responded positively.
In addressing these results, the Union of Concerned Scientists recommends that the FDA increase accountability and transparency, and provide protection for scientists who speak out. Dr Francesca Grifo, who is the director of the UCS Scientific Integrity Program stated, "All federal scientists need protections so they can speak out when their science is is manipulated, and all federal agencies need fully functioning independent advisory committees. FDA leadership must understand and support independent science and it is up to Congress to hold them accountable."
August 4, 2006
Apple juice prevents decline in acetylcholine levels in animal model
A report published in the August, 2006 issue of the Journal of Alzheimer's Disease revealed that giving apple juice to mice bred to develop Alzheimer's-like symptoms prevented the decrease in acetylcholine that occurs when the animals are provided with a vitamin deficient, oxidative stress-promoting diet. Acetylcholine is a hormone that facilitates the transmission of signals between nerve cells. The age-related decline in acetylcholine is believed to contribute to memory and learning disorders among older individuals.
Researchers led by Thomas Shea, PhD, who is the director of University of Massachusetts Lowell Center for Cellular Neurobiology and Neurodegeneration Research, used mice lacking the ApoE gene as a model of oxidative stress. Previous research by the team revealed that supplementing these mice with apple juice concentrate protects against the oxidative damage and cognitive decline that results from a nutrient deficient and oxidative stress-promoting diet. Groups of adult and aged mice were divided to receive a standard diet, a diet deficient in folate and vitamin E (with added iron as a pro-oxidant), or the deficient diet supplemented with apple juice concentrate for one month.
Assay of acetylcholine levels in the brain's frontal cortex and hippocampus found a decline in acetylcholine among mice on the deficient diet which was prevented in the mice supplemented with apple juice concentrate. The animals who received apple juice also demonstrated better performance on maze tests used to evaluate memory and learning.
"The findings of the present study show that consumption of antioxidant-rich foods such as apples and apple juice can help reduce problems associated with memory loss," Dr Shea concluded. "We anticipate that the day may come when foods like apples, apple juice and other apple products are recommended along with the most popular Alzheimer's medications."
August 2, 2006
Curcumin-quercetin combination reduces intestinal polyps
The results of a small trial published in the August issue of Clinical Gastroenterology and Hepatology showed that consuming a supplement containing ingredients found in curry and onions helped prevent the formation of precancerous polyps of the colon among individuals genetically predisposed to develop them.
Researchers at Johns Hopkins University combined 480 milligrams curcumin, a compound found in the spice turmeric used in curries, and 20 milligrams quercetin, found in onions and other plant foods. The subjects consisted of five individuals with familial adenomatous polyposis (FAP), which is characterized by the development of hundreds of colorectal polyps, some of which become cancerous. The participants were instructed to take the supplement three times per day for six months while avoiding nonsteroidal anti-inflammatory drugs, which are currently recommended for the condition. Sigmoidoscopic examination of the lower intestine determined the number of polyps in each participant before treatment, and at three and six months.
After three months, there was a decrease in the number of polyps in four of the five patients, following which one participant dropped out of the study. At six months, all of the participants had experienced a decrease, with 60.4 percent fewer polyps and a 50.9 percent size reduction.
The researchers believe that curcumin is likelier to be the more important ingredient in the supplement. "The amount of quercetin we administered was similar to what many people consume daily; however, the amount of curcumin is many times what a person might ingest in a typical diet, since turmeric only contains on average 3 percent to 5 percent curcumin by weight," stated lead researcher Francis M. Giardiello, MD, of Johns Hopkins School of Medicine's Division of Gastroenterology.
"We believe this is the first proof of principle that these substances have significant effects in patients with FAP," he concluded.
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