October 30, 2006
More benefits found for turmeric
Turmeric, an Asian spice that is the source of the compound curcumin, has recently been shown to help prevent both rheumatoid arthritis and osteoporosis, in addition to many other benefits previously found. The finding was published online on October 30, 2006 in the American College of Rheumatology journal Arthritis and Rheumatism.
In research funded by the National Institutes of Health (NIH), Janet L. Funk, MD of the University of Arizona College of Medicine and Barbara N. Timmermann, PhD of the Arizona Center for Phytomedicine Research tested a whole extract of turmeric root, the essential oils contained in turmeric, and an oil-depleted extract containing the major curcuminoids found in turmeric in an animal model of rheumatoid arthritis. Of the three extracts, the one containing the major curcuminoids, which was the most similar to commercially available turmeric supplements, proved to be the most effective by completely inhibiting the onset of the disease. Additionally, the extract was found to block the pathway affecting bone resorption, suggesting that turmeric could help prevent osteoporosis.
Dr Funk and her colleagues discovered that the curcuminoid-containing extract prevented the activation of a transcription factor known as nuclear factor kappa-beta (NF-KB). NF-KB activation enhances the production of inflammatory proteins that have a destructive effect on joint tissue. The finding, which is the first documentation of turmeric's mechanism of action against arthritis in a living organism, shows that the extract works via the same mechanism as some pharmaceuticals currently being developed to treat arthritis, and also indicates that turmeric or curcumin could be of use in the prevention of other inflammatory conditions such as asthma and inflammatory bowel disease.
Dr Funk has initiated another study, also funded by the NIH, to explore turmeric's effect on bone loss during perimenopause.
October 27, 2006
Diet may fail to provide enough folate for a third of pregnant women
A report published in the November, 2006 issue of the Journal of Nutrition concluded that the diet of a third of pregnant and lactating women may not be meeting their requirements for the B vitamin folate, even after mandatory folic acid fortification of grain products in North America.
Deborah L. O'Connor and her colleagues at the University of Toronto's Department of Nutritional Sciences analyzed three day weighed food records from 61 women in their thirty-sixth week of pregnancy and at their fourth and sixteenth weeks of lactation. Daily folate intake was calculated as microgram per day dietary folate equivalents (DFEs) to take into account the difference in bioavailability between synthetic folic acid used in fortification and folate that naturally occurs in food (supplemental folic acid has a 70 percent greater bioavailability than food folate.)
The average dietary folate equivalent intake during pregnancy was 562 micrograms per day. Thirty-six percent of the women had folate intakes from their diet that were below the estimated average requirement during pregnancy of 520 micrograms per day, and 32 percent of lactating women were below the estimated average requirement of 450 micrograms per day. When the researchers analyzed the data by doubling the current level of fortification, the prevalence of inadequacy was reduced to 3 percent.
"At mandated levels of folic acid fortification of the food supply, many pregnant and lactating Canadians are not likely to meet their dietary requirements for folate," the authors conclude. "Given the role of folate in the prevention of neural tube defect, health care professionals need to continue to use recommended tools of improving the folate intakes of lactating women capable of becoming pregnant, including educating them about foods rich in folate and encouraging the use of a folic acid-containing supplement."
October 25, 2006
Remember to eat your veggies . . . or, eat your veggies to remember
A report published in the October 24, 2006 issue of the American Academy of Neurology journal Neurology revealed the finding of researchers at Rush University Medical Center in Chicago that eating vegetables may help slow the decline in cognitive function associated with aging.
In a study funded by the National Institute on Aging, Martha Clare Morris, ScD of the Rush Institute for Healthy Aging and colleagues evaluated food frequency questionnaires completed by 3,718 Chicago residents aged 65 and older. Participants completed at least two of three cognitive function tests conducted at the beginning of the study and at three and six years.
The researchers discovered that vegetable, but not fruit consumption was associated with a reduced rate of cognitive decline. Green leafy vegetables were found to have the strongest association, and older individuals appeared to benefit the most.
"Compared to people who consumed less than one serving of vegetables a day, people who ate at least 2.8 servings of vegetables a day saw their rate of cognitive change slow by roughly 40 percent," Dr Morris stated. "This decrease is equivalent to about five years of younger age."
Dr Morris added that the lack of benefit found for fruit was unanticipated. "It may be due to vegetables containing high amounts of vitamin E, which helps lower the risk of cognitive decline," she explained. "Vegetables, but not fruits, are also typically consumed with added fats such as salad dressings, and fats increase the absorption of vitamin E. Still, further study is required to understand why fruit is not associated with cognitive change."
October 23, 2006
JAMA review concludes fish benefits outweigh risks
The October 18, 2006 issue of the Journal of the American Medical Association published the conclusion of Dariush Mozaffarian, MD and Eric B. Rimm, MD of Harvard School of Public Health that any risks associated with eating fish are far outweighed by the benefits of consuming them.
For their review, the authors selected reports published through April of 2006 which evaluated the effects of fish or fish oil on cardiovascular risk, methylmercury and fish oil's effect on early neurodevelopment, mercury's risks in adults, and the health impact of dioxins and polychlorinated biphenyls (PCBs) contained in fish.
The duo found that consuming one to two servings fish per week containing up to 250 milligrams per day of the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) reduced the risk of coronary heart disease death by 36 percent, and lowered all-cause mortality during the periods studied by 17 percent.
Because DHA benefits the infant brain, fish and shellfish are recommended for pregnant of nursing mothers, however, fish that have high levels of methylmercury such as swordfish and albacore tuna should be avoided because mercury adversely affects early neurodevelopment at low levels. The effects of the methylmercury in adults is uncertain, but could decrease some of fish's cardiovascular benefits.
A summary of the amount of omega-3 fatty acids, mercury, PCBs and dioxins in fish and other foods was included in the report. "Levels of dioxins and PCBs in fish are low, and potential carcinogenic and other effects are outweighed by potential benefits of fish intake and should have little impact on choices or consumption of seafood," the authors write.
"Overall, for major health outcomes among adults, the benefits of eating fish greatly outweigh the risks," Dr Mozaffarian stated. "Somehow this evidence has been lost on the public."
October 16, 2006
Rate of living theory gets old
At the American Physiological Society conference, "Comparative Physiology 2006: Integrating Diversity," held October 8 to 11 in Virginia Beach, Lobke Vaanholt of the University of Groningen, The Netherlands called into question the validity of the rate of living theory. The theory holds that every organism has a set amount of expendable energy during their lives, and that death ensues once that energy has been expended.
Dr Vaanholt and colleagues studied 200 "runner" mice who enjoy exercising by using the running wheels in their cages. In their experiment, half of the mice were given access to running wheels, while the remainder were not. An additional 100 regular laboratory mice were also provided access to a running wheel. Sixty mice from each group were followed throughout their nearly three year life span, during which running activity and body mass were periodically measured.
Although the rate of living theory would predict that running mice who had access to exercise and expended 25 percent more energy would have died sooner than the other runner group, the team found no difference in their life spans. Both groups of runner mice lived 90 days less than the regular mice. "The shorter life span cannot, therefore, be explained by a difference in metabolism," Dr Vaanholt commented.
In another experiment, 40 mice from each group were analyzed for energy expenditure, body composition and heart and liver antioxidant enzyme levels at 2, 10, 18 and 26 months. Although higher antioxidant levels were expected to be found in the mice that expended more energy, no difference was found between the groups.
Further research will explore whether other body tissues produce additional antioxidants to help lower the increased oxidative stress caused by greater activity and may examine whether other mechanisms are involved.
October 13, 2006
More benefits found for Mediterranean diet
As if enough benefits haven't already been found for adopting the Mediterranean diet, researchers at Columbia University Medical Center have discovered a link between consuming the diet and a reduction in the risk of Alzheimer's disease. The Mediterranean diet is high in fruit, legumes, vegetables, cereals, fish, and olive oil, contains a moderate amount of alcohol, and provides small amounts of meat and dairy products. The research was published online on October 9, 2006 in the Archives of Neurology.
Nikolaos Scarmeas, MD, and colleagues analyzed the diets of 194 adults with Alzheimer's disease and 1,790 individuals without dementia. Questionnaires concerning dietary intake over the previous year were used to score adherence to the Mediterranean diet on a scale of 0 to 9.
The team discovered that close adherence to the Mediterranean diet was significantly associated with a reduced incidence of Alzheimer's disease. Alzheimer's disease risk among the participants decreased by 19 to 24 percent for each diet score point. Adjusted analysis determined that participants in the top third of diet scores had a 68 percent lower risk of Alzheimer's disease, and those in the middle third, a 53 percent lower risk than subjects in the bottom third. The association remained valid when the researchers considered whether the subjects had vascular disease such as stroke, heart disease and diabetes that have been linked with an increased risk of developing dementia, raising the question whether the diet may reduce Alzheimer's disease risk by affecting other factors.
"When we considered vascular risk factors in our models, the association between the Mediterranean diet and Alzheimer's disease did not change," the authors observed.
"This could be the result of either other biological mechanisms (oxidative or inflammatory) being implicated or measurement error of the vascular variables," they conclude.
October 11, 2006
Low thyroid hormone levels linked to longer life
The American Physiological Society's Comparative Physiology 2006: Integrating Diversity conference was the site of a poster session on October 9, 2006 in which Mario Pinto of City College of New York presented the finding that rodents who live longer have lower levels of the thyroid hormone T4.
Mario Pinto and Rochelle Buffenstein compared the thyroid hormone levels of mice, guinea pigs, Damara mole-rats, and naked role-rats, who can live up to 3 1/2, 6, 15 and 28 years, respectively. The blood tests were performed when the animals were at a comparable point in their life spans.
The researchers found that although T3, or triiodothyronine levels in all four species were similar, the longer-lived rodents had significantly lower levels of T4, or thyroxine, which converts to T3 in the presence of iodine. Triiodothyronine is the key hormone that regulates metabolism. Mice, whose life spans are the shortest of the four rodents compared, had T4 levels that were twice as high as those of the Damara mole-rats, and three times as high as the naked mole rats.
The study's results provide support to the theory that a more rapid metabolism is associated with a shorter life span.
"Thyroid hormones are key regulators of metabolism and have been widely implicated to influence longevity," the authors write. "Mice strains that exhibit extended longevity tend to have lower thyroid hormone concentrations than shorter living strains. Significant declines in thyroid hormone correlate well with enhanced maximum lifespan."
"These hormone concentration differences correlate with maximum species lifespan and suggest an important regulatory role of thyroid hormone in longevity," they conclude.
October 9, 2006
Osteoarthritis may signify accelerated biological aging
There may be something to the saying that aches and pains are a part of growing older. According to report scheduled to appear in the November, 2006 issue of the Annals of the Rheumatic Diseases, osteoarthritis may be a sign of rapid biological aging. Biological aging is an assessment of the rate of aging of the individual as determined by various biomarker measurements, in contrast with chronological aging, measured in years lived.
Researchers at St Thomas' Hospital in London studied 1,086 predominantly female twins between the ages of 31 and 79 for the current investigation. Both hands of the participants were x-rayed to look for osteoarthritis, and blood samples were analyzed to assess biological aging as reflected by telomere shortening in leukocyte (white blood cell) DNA. Telomeres are caps found at the tips of chromosomes that shorten with time or with insufficient repair of free radical damage. Short telomeres have been associated with a number of age-related diseases in humans.
All of the participants who were found to have hand osteoarthritis were over the age of 50. While decreasing white blood cell telomere lengths were associated with advancing chronological age among all participants, in the 160 people with radiographic evidence of osteoarthritis, telomere length was significantly shorter than in those who did not have the disease, signifying increased biological aging. The amount of telomere shortening observed in the subjects with arthritis was equivalent to that accumulated over 11 years in healthy individuals, and was also associated with severity of the disease.
"Loss in leucocyte telomere length is associated with mild radiographic hand osteoarthritis and increases with disease severity, suggesting potential shared mechanisms between osteoarthritis and aging, and implicating acquired factors, such as oxidative stress and low-level chronic inflammation, in both conditions," the authors conclude.
October 6, 2006
Progesterone protects trauma victims from brain injury-induced disability
An article published online on October 4, 2006 in the Annals of Emergency Medicine reported the conclusion of researchers at Emory University that administering the hormone progesterone to trauma victims following brain injury may reduce the risk of death and the degree of disability.
The finding was the result of a phase II clinical trial following a three-year pilot study called Progesterone for Traumatic brain injury--Experimental Clinical Treatment (ProTECT). To qualify as a subject, prospective participants had to reach Grady Memorial Hospital in Atlanta within 11 hours of a moderate to severe blunt traumatic brain injury (TBI), which typically occurs during a car accident or a fall. Due to the patients' cognitive impairment, family members or representatives provided consent for the subjects' participation.
Four out of five subjects received intravenous progesterone, while the remainder received a placebo. After thirty days, neurologic function and disability level were rated.
Thirty percent of the placebo group died within the 30 day period, compared to 13 percent of those given progesterone. Lead author David Wright, MD, who is an assistant professor in the Department of Emergency Medicine at Emory, commented, "We found encouraging evidence that progesterone is safe in the setting of TBI, with no evidence of side effects or serious harmful events. In addition, we found a 50 percent reduction in the rate of death in the progesterone-treated group. Furthermore, we found a significant improvement in the functional outcome and level of disability among patients who were enrolled with a moderate brain injury."
The study was the first clinical trial of its kind to use progesterone with TBI patients. Researchers at Emory hope to initiate a similar clinical trial to study progesterone's effect on acute stroke patients.
October 4, 2006
Curcumin aids immune system in ridding brain of plaque
A report appearing in the October, 2006 issue of the Journal of Alzheimer's Disease described the discovery of researchers at the David Geffen School of Medicine at UCLA and the VA Greater Los Angeles Health Care System that curcumin, a compound occurring in the spice turmeric, assists the immune system in the clearance of amyloid beta in the brain. Amyloid beta is a substance that accumulates in the brains of Alzheimer's patients to form the plaques that are characteristic of the disease.
The research team used cell cultures of macrophages obtained from 3 healthy individuals and six Alzheimer's disease patients aged 65 to 84. Macrophages are innate immune system cells that patrol the body, consuming waste products. Before treatment with curcumin, macrophages derived from Alzheimer's disease patients demonstrated a lower uptake of beta amyloid than those derived from the healthy controls. Additional cultures of macrophages received no treatment. After 24 hours of treatment with a drug derived from curcumin the cells were exposed to amyloid beta.
The researchers found that curcumin-treated macrophages from three Alzheimer's disease patients demonstrated improved ingestion of amyloid beta compared to macrophages from Alzheimer's patients that did not receive the compound. Cells from healthy individuals, which effectively cleared amyloid beta, showed no change after treatment.
Study coauthor Dr Milan Fiala observed that the macrophages that improved after treatment with curcumin were from younger patients and those with less dementia. "Curcumin improved ingestion of amyloid beta by immune cells in 50 percent of patients with Alzheimer's disease. These initial findings demonstrate that curcumin may help boost the immune system of specific Alzheimer's disease patients," he stated.
"We are hopeful that these positive results in a test tube may translate to clinical use, but more studies need to be done before curcumin can be recommended," Dr Fiala added.
October 2, 2006
Aspirin combats tumor growth by inhibiting new blood vessel formation
A report published in the October, 2006 issue of The FASEB Journal (Federation of American Societies for Experimental Biology) revealed that aspirin, already recognized as being protective against some cancers due to its cyclooxygenase (Cox) enzyme inhibiting ability, has another tumor-fighting weapon in its arsenal: the ability to directly reduce angiogenesis, or the formation of new blood vessel growth. Without this ability, tumors are unable to grow.
Researchers at the University of Newcastle in England compared the effects of varying concentrations of aspirin, salicylate (the natural form of aspirin), and the selective Cox inhibitors SC560 and Celecoxib on the proliferation, viability and angiogenesis of cultured endothelial cells. They found while therapeutic concentrations of aspirin and salicylate had no effect on cell viability or proliferation, there was a significant reduction in angiogenesis. This effect was seen even at the lowest concentrations of aspirin and salicylate used, but was not observed with the selective Cox inhibitor drugs, either separately or in combination, suggesting that the the antiangiogenic effect of aspirin is via a Cox-independent mechanism.
While a very high concentration of aspirin resulted in apoptosis (programmed cell suicide) of the cells, the effect was not seen at doses approximating to systemic pharmacological concentrations. "It is clear that low therapeutic doses of aspirin have a direct inhibitory effect on the ability of endothelial cells to undergo angiogenesis and that this may contribute to the antineoplastic effects claimed for aspirin in a wide range of tissue types," the authors conclude.
Gerald Weissmann, MD, who is Editor-in-Chief of The FASEB Journal, stated, "Aspirin has always been touted as a 'wonder drug, and this study shows that we are still learning about the many actions of this amazing drug."
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