| Antioxidants Articles
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Antioxidants in Fruits and Vegetables May Decrease Stroke Risk
Sufficient blood levels of carotenoids, a family of antioxidants in fruits and vegetables, might reduce the risk of ischemic stroke, according to a study published today in the rapid access issue of Stroke: Journal of the American Heart Association.
An ischemic stroke is caused by a blood clot and is the most common type of stroke.
Fruit and vegetable intake has long been associated with a lower risk of ischemic stroke, said study author Jing Ma, M.D., Ph.D., assistant professor of medicine, Brigham and Women's Hospital, Harvard Medical School, Boston. Researchers investigated which antioxidants in fruits and vegetables might have this positive effect.
The Physicians' Health Study involved 22,071 U.S. male physicians, 68 percent of whom provided blood samples at the start of the study in 1982. Among the 15,000 who didn't have cardiovascular disease at the beginning of the study, 297 had an ischemic stroke during the study's 13-year follow-up.
Analyzing blood samples among stroke patients, researchers measured levels of antioxidants, including carotenoids (vitamin A family, including alpha-carotene, beta-carotene, lycopene, lutein and beta-cryptoxanthin) and tocopherols (vitamin E). They then compared their findings to the blood levels of an equal number of men who did not have stroke.
They found that men who were in the lowest 20 percent quintile (bottom fifth) for carotenoid levels of alpha-carotene, beta-carotene and lycopene had the highest risk of ischemic stroke.
Men who were above the second through fifth quintiles were at a 40 percent lower risk of developing ischemic stroke during the 13 years than men in the lowest quintile, Ma said.
Once blood levels moved beyond that 20 percent threshold of carotene, the stroke protection benefit did not seem to increase with higher levels, Ma said.
The carotenoid level could have been the result of these men eating fruits and vegetables or taking antioxidant supplements.
The observational study shows an association between fruit and vegetable intake and stroke risk, but did not prove that eating fruits and vegetables caused the lower risk.
The results of this study support a diet high in fruits and vegetables to reduce ischemic stroke risk, she said.
Co-authors are A. Elizabeth Hak, M.D., Ph.D.; Calpurnyia B. Powell, B.S.; Hannia Campos, Ph.D.; J. Michael Gaziano, M.D.; Walter Willett, M.D., Dr.P.H.; and Meir J. Stampfer, M.D., Dr.P.H.NR04-1264 (Stroke/Ma)
Genes in the Brain Begin to Deteriorate, As Early as Age 40
Harvard University researchers found that 20 genes critical for learning and memory begin to decline in function as early as age 40, pointing the way for further research aimed at tackling the mental infirmities that come with growing old.
The Harvard work, released yesterday in the online edition of Nature, is the first major study to use a "genetic signature" to study brain-function decline in normal aging.
A genetic signature is a recent scientific innovation that measures the activity level of thousands of genes -- determining which are working hard, which are minimally active, and which are idle in controlling the production of proteins, which are the main actors in all microscopic bodily functions, including work performed by the brain.
The researchers studied well-preserved brain tissue from 30 people, aged 26 to 106 at the time of death. The changes they found occurred in a wide variety of genes, with functions that range from regulating sleep to metabolizing fat. But most interesting was a marked decline in function among 20 genes involved in learning, memory and the plasticity, or flexibility, of brain function. As the subjects aged, these genes became damaged, reducing their effectiveness. "Some genes begin to decline much earlier than expected, as early as the early 40s," says senior author Bruce Yanker, a professor of neurology and neuroscience at Harvard Medical School and Children's Hospital in Boston.
The Harvard researchers believe the damage is caused by exposure to toxins, including unstable molecules called free radicals. Free radicals are created both by the body's own energy-producing processes and by exposure to environmental hazards. Antioxidants such as vitamins C and E are believed to protect the body against the ravages of free radicals. Antioxidants could, in theory, help the brain protect itself from age-related damage, Dr. Yanker says, but there's still no proof that it would work.
In the older brain samples, the researchers found that genes whose job is to protect and repair neurons from damage had been working overtime. That compensatory activity may delay the effects of the damage, and could explain damage to cognitive function often doesn't show up until later in life, and why some individuals retain their intellectual acumen longer than others. The effectiveness of the compensatory activity "may be a function of genetics, and lifestyle, probably a combination of both," Dr. Yanker says.
Their search was limited to 11,000 of the body's 30,000 genes because those were the only genes available on the microchip used to perform the computerized search -- the best available at the time the work began two years ago. The researchers found that 4% of the 11,000 genes changed in activity with age. Some became less active, and others stepped up their activity. The changes began in the early 40s and varied widely from person to person until age 71. Over that age, the gene activity pattern was largely the same from one person to the next.
No Immediate Cures
The findings don't in themselves offer immediate cures to age-related mental decline, Dr. Yanker says, but are a "treasure trove" of information that will help researchers find the most promising avenues of study.
The research "adds to our understanding of the genetic factors that might contribute to memory loss," says Gary Small, director of the Center on Aging at the University of California, Los Angeles. He adds that the fact that the genetic changes start early "emphasizes how important it is to begin lifestyle changes early." Dr. Small is researching the effect of lifestyle changes, such as a healthy diet and exercise, on age-related declines in cognitive functions.
In his work, Dr. Small found that as little as two weeks on a program that includes exercise, stress reduction, and a healthy diet with antioxidants such as Japanese green tea, appears helpful for brain function. He found that subjects required less cerebral effort -- as measured by brain scans of neuronal activity -- to complete the same mental tasks than they did before they began the healthy program. Healthy diets are already widely believed to reduce fat buildup, which can increase the risk of strokes, Dr. Small says. But good nutrition also may have other, not yet understood effects on gene function.
Another possible approach is to try to mitigate the gene damage through medications. The Harvard researchers found that a very promising area of study is an enzyme used by the body to repair DNA damage, called oxoguanine DNA glycosylase. The enzyme was already known to the scientific community, but the Harvard researchers found that it was very effective in repairing genetic damages in brain neurons placed in a petri dish.
"If one had, for example, a drug to stimulate the activity of this enzyme, one might be able to repair the DNA" and slow the mental decline that happens with age, Dr. Yanker says.The research, funded by the National Institutes of Health and anonymous philanthropic donations, was done using a gene chip from Affymetrix Inc., of Santa Clara, Calif. The Harvard researchers are repeating the study with all 30,000 human genes on a newer chip from Affymetrix. The scientists also plan to study gene changes in people with Alzheimer's disease, and compare them to the changes found in normal aging.
THE WALL STREET JOURNAL
June 10, 2004; Page D1
Nutraceutical: Antioxidants and zinc
Indication/Goal
Evaluating age-related eye disease study (AREDS) public health impact
Source
Arch Opthalmol, November 2003;121(11):1621-4
Research
Researchers estimated the potential public health impact findings of the Age-Related Eye Disease Study (AREDS) on reducing the number of persons developing advanced macular degeneration (AMD) during the next five years in the US. The AREDS clinical trial provides estimates of AMD progression rates and of reduction in risk of developing advanced AMD when a high-dosage nutritional supplement of antioxidants and zinc is used. These results are applied to estimates of the US population at risk, to estimate the number of people who would potentially avoid advanced AMD during five years if those at risk were to take a supplement such as that used in AREDS.
Results
An estimated eight million persons at least 55 years old in the US have monocular or binocular intermediate AMD or monocular advanced AMD. They are considered to be at high risk for advanced AMD and are those for whom the AREDS formulation should be considered. Of these people, 1.3 million would develop advanced AMD if no treatment were given to reduce their risk. If all of these people at risk received supplements such as those used in AREDS, more than 300,000 (95% confidence interval, 158,000-487,000) of them would avoid advanced AMD and any associated vision loss during the next five years. If people at high risk for advanced AMD received supplements such as those suggested by AREDS results, the potential impact on public health in the US would be considerable during the next five years.
Antioxidants and Physical Performance in Elderly Persons
The Invecchiare in Chianti (InChianti) study1,2,3
Matteo Cesari, Marco Pahor, Benedetta Bartali, Antonio Cherubini, Brenda WJH Penninx, G Rhys Williams, Hal Atkinson, Antonio Martin, Jack M Guralnik and Luigi Ferrucci
1 From the Sticht Center on Aging, Wake Forest University Health Sciences, Winston-Salem, NC (MC, MP, BWJHP, and HA); the Laboratory of Clinical Epidemiology, Italian National Research Council of Aging, Geriatric Department, Florence, Italy (BB); the Department of Gerontology and Geriatrics, University of Perugia, Perugia, Italy (AC); the Pharmaceutical Research Institute, Bristol-Myers Squibb, Princeton, NJ (GRW); the Human Nutrition Research Center on Aging, Tufts University, Boston (AM); the Epidemiology, Demography, and Biometry Program, National Institute on Aging, Bethesda, MD (JMG); the Longitudinal Studies Section, Clinical Research Branch, National Institute on Aging, Baltimore (LF).
Background
Muscle strength and physical performance in old age might be related to the oxidative damage caused by free radicals.
Objective
The objective was to assess the correlation of plasma concentrations and daily dietary intakes of antioxidants with skeletal muscle strength and physical performance in elderly persons.
Design
This study is part of the Invecchiare in Chianti (InCHIANTI) study, which was conducted in 986 Italians aged =" src="/math/ge.gif" border=065 y. Physical performance was assessed on the basis of walking speed, ability to rise from a chair, and standing balance. Knee extension strength was assessed with a hand-held dynamometer. The European Prospective Investigation into Cancer and Nutrition (EPIC) questionnaire was used to evaluate the daily dietary intakes of vitamin C, vitamin E, ß-carotene, and retinol. Plasma - and -tocopherol concentrations were measured. Adjusted linear regression analyses were used to calculate regression coefficients per SD increase in plasma concentrations and daily dietary intakes.
Results
In adjusted analyses, plasma -tocopherol was significantly correlated with knee extension (ß = 0.566, P = 0.003) and the summary physical performance score (ß = 0.044, P = 0.008). Plasma -tocopherol was associated only with knee extension strength (ß = 0.327, P = 0.04). Of the daily dietary intake measures, vitamin C and ß-carotene were significantly correlated with knee extension strength, and vitamin C was significantly associated with physical performance (ß = 0.029, P = 0.04).
Conclusions
Plasma antioxidant concentrations correlate positively with physical performance and strength. Higher dietary intakes of most antioxidants, especially vitamin C, appear to be associated with higher skeletal muscular strength in elderly persons.
American Journal of Clinical Nutrition, Vol. 79, No. 2, 289-294, February 2004
Vitamins Combat Age-Related Blindness
Hundreds of thousands of people could benefit from vitamin supplements shown to help prevent macular degeneration, a condition that is the leading cause of blindness from age 65, a study reported.
In 2001, researchers announced they had found a reduced risk of advanced age-related macular degeneration and vision loss for test subjects who had been given high-dose antioxidant supplements -- vitamins C, E and beta carotene -- as well as zinc or zinc oxide.
In Monday's report, researchers at the Johns Hopkins Medical Institutions in Baltimore tried to estimate how many people in the United States alone would benefit from increasing supplement use.
They concluded there are 8 million Americans at least 55 years old thought to be at high risk for the problem. If all the people at risk took the supplements used in the earlier study, more than 300,000 of them would avoid advanced macular degeneration and any associated vision loss during the next five years, the study said.
"If even half of the individuals at high risk for (the condition) were identified and compliant with the recommended supplement, it is likely that more than 150,000 individuals would avoid vision loss for some time," said the study published in the November issue of the Archives of Ophthalmology.
"These data suggest that the recommendation of such a supplement for these individuals should have a major impact on them as well as on the public health," the authors concluded.
In an editorial commenting on the study published in the same journal, Lee Jampol, a physician at the Northwestern University Feinberg School of Medicine in Chicago, said the supplements should be used "only in patients with intermediate or advanced age-related macular degeneration."
"What about patients who have a strong family history of macular degeneration or who for other reasons believe that they are at risk for the disease and wish to take the (supplement) formulation prior to the development" of intermediate or advances cases of the problem, he asked.
"It appears appropriate to eat a diet rich in fruits and (especially green) vegetables, to supplement with a multivitamin and to undergo periodic ophthalmic examinations for the development of" the condition, he added.
CHICAGO, Illinois (Reuters)
Duke University Study Shows Positive Results For Antioxidant Users
A multi-site cooperative study out of Duke University shows that in a group of seniors over 75 years old, "current antioxidant users had a 34%
lower risk of developing cognitive impairment compared with non-antioxidant users...and a 29% lower risk of experiencing cognitive
decline...."
American Journal of Geriatric Pharmacotherapy, Sept 2003, Vol 1, Num 1.
Title: Is antioxidant use protective of cognitive function in the community-dwelling elderly?
Antioxidants May Offer Brain Cell Protection
Alcohol damage may be averted.
Antioxidants, already widely promoted as cancer-fighters, also may help protect the brain from chronic alcohol damage. Chronic alcoholism damages parts of the brain used in learning and memory, but giving rats an antioxidant protected them from the damage, according to researchers working in the US and Spain.
The findings are reported in the June 3rd, 2003, online issue of Proceedings of the National Academy of Science.
Antioxidants are chemicals that inhibit the oxidation of a substance to which they are added. Oxidation can stress or damage cells.
The team, led by Dr. Daniel G. Herrera of Weill Medical College of Cornell University, fed rats a liquid diet containing alcohol for six weeks. They found a 66 percent decrease in the number of new cells in crucial parts of the brain and an increase in cell death of more than 227 percent. But in rats that also received injections of the antioxidant ebselen, the damage to developing cells did not occur, the researchers said.
Those rats had the same brain characteristics as a group that received no alcohol. Alcohol also kills liver cells, and the researchers knew that this could be reduced with the use of antioxidants, Herrera said. They decided to see if the same held for the brain. The antioxidant ebselen was used because it is known to have protective effects in the liver and digestive tract and has few side effects in humans. Finding ways to improve mental function in people, particularly the elderly, might increase positive results of alcohol treatment programs, Herrera said in a statement.
Dr. Antonio Noronha, chief of the neuroscience and behavioral branch of the National Institute of Alcohol Abuse and Alcoholism, said this is the first study to show the effects of antioxidants on chronic alcohol damage. Noronha, who was not part of the research team, said similar findings have been reported in studies at the University of North Carolina, but those focused on binge drinking and used a different antioxidant. The mechanism by which alcohol damages portions of the brain is still not fully understood, he said. Oxidative stress seems to be part of it, and the antioxidants appear to be protective.
Antioxidants May Protect Against Ozone Pollution
Vitamin C and E supplements appear to provide some protection against ozone pollution in young children with asthma, suggests the results of a new study.
Researchers at the National Institute of Public Health in Mexico gave 158 asthmatic children either a placebo or 50 mg of vitamin E and 250 mg of vitamin C per day and observed them for 18 months, carrying out pulmonary function tests twice per week.
The researchers found that the supplements improved forced expiratory volume.
"Our results suggest that supplementation with antioxidants might modulate the impact of ozone exposure on the small airways of children with moderate to severe asthma," wrote the researchers.
Source: I Romieu et al., "Antioxidant Supplementation and Lung Functions Among Children with Asthma Exposed to High Levels of Air Pollutants, "American Journal of Respiratory and Critical Care Medicine 166 (September 1, 2002):703-709
Dietary Antioxidants Help Prevent Alzheimer's
A diet rich in antioxidants may help protect against Alzheimer's disease, according to the results of the Rotterdam Study involving 5,395 people aged 55 and older.
In 1990, researchers determined the participants' intakes of beta-carotene, flavonoids, vitamin C and vitamin E. During the next ten years, participants were screened for Alzheimer's disease; a neurologist, neurophysychologist and magnetic brain imaging confirmed the condition in 146 of the subjects. Compared with participants whose diets provided fewer antioxidants, those with greater vitamin C intake cut their Alzheimer's risk by nearly 30%; those with greater vitamin E intake by up to 43%.
Smokers experienced the greatest risk reduction from antioxidants. Smokers, unlike the overall study population, also reduced their Alzheimer's risk when they consumed more beta-carotene and flavonoids.
Maryanne Engelhart, M.D., director of this population-based prospective cohort study, suggests that by decreasing excess oxidation in the brain, antioxidants may prevent the DNA damage, neuron cell death and build-up of the brain-clogging substance beta-amyloid that typify Alzheimer's disease.
Journal of the American Medical Assoc.
2002 Jun 26;287:3223-9.
Reversing a long-standing anti-vitamin policy
The Journal of The American Medical Association today is advising all adults to take at
least one multivitamin pill each day.
Scientists' understanding of the benefits of vitamins has rapidly advanced, and it now appears that people who get enough vitamins may be able to prevent such common chronic illnesses as cancer,
heart disease and osteoporosis, according to Drs. Robert Fletcher and Kathleen Fairfield of Harvard University, who wrote the new guidelines.
The last time JAMA made a comprehensive review of vitamins, about 20 years ago, it concluded people of normal health shouldn't take multivitamins because they were a waste of time and money. People can get all the nutrients they need from their diet, JAMA advised, adding that only pregnant women and chronically sick people may need certain vitamins. That was at a time when knowledge about vitamins was just beginning to expand. The role that low levels of folate, or folic acid, play in neural tube defects, for instance, was not known, nor was its role as a major risk factor for heart disease.
Researchers hope JAMA's endorsement will encourage more people to reap health benefits of a daily multivitamin. Health experts are increasingly worried that most American adults do not consume healthy amounts of vitamins in their diet, although they may be getting enough to ward off such vitamin-deficiency disorders as scurvy, beriberi and pellagra. Almost 80 percent of Americans do not eat at least five helpings of fruits and vegetables a day, the recommended minimum amount believed to provide sufficient essential nutrients.
Humans do not make their own vitamins, except for some vitamin D, and they must get them from an outside source to prevent metabolic disorders. "It's nice to see this change in philosophy that's saying we can make public-health recommendations based on this really compelling set of data," said Dr. Jeffrey Blumberg, chief of antioxidant research at Tufts University's Jean Mayer USDA Human Nutrition Research Center on Aging. Blumberg said the JAMA recommendations underscore a growing concern among nutrition experts that the recommended daily allowances, or RDAs, for many vitamins are set too low. RDAs essentially were established to prevent symptoms of vitamin-deficiency disorders, he said. But evidence is growing that higher levels of many vitamins are necessary to achieve optimum health, he said.
The National Academy of Sciences, which sets RDAs, is revising its recommendations based on the new evidence. Even people who eat five daily servings of fruits and vegetables may not get enough of certain vitamins for optimum health, Fletcher said. Most people, for instance, cannot get the healthiest levels of folate and vitamins D and E from recommended diets, he said. "All of us grew up believing that if we ate a reasonable diet, that would take care of our vitamin needs," Fletcher said. "But the new evidence, much of it in the last couple of years, is
that vitamins also prevent the usual diseases we deal with every day - heart disease, cancer, osteoporosis and birth defects." Because foods contain thousands of vitaminlike compounds - many not yet identified - that may be important for good health, vitamin supplements should not be a substitute for a wholesome diet, Blumberg said.
Chicago Tribune
By Ronald Kotulak 6-20-02
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Raw Material Research (AMD)
Raw Materials
Antioxidants
Indication
Age-related macular degeneration (AMD)
Source
Archives of Opthalmology, 2001;119:1417-1436
Research: More than 3600 patients, aged 55-80, from 11 medical centers took one of the following supplements or placebo for an average of six years:
(1) a multi-antioxidant containing vitamin C (500 mg), vitamin E (400 IU), beta-carotene (15 mg) daily;
(2) zinc (80 mg) and copper (2 mg)
(3) a combination of the antioxidants above, plus zinc and copper
Results
Patients with the highest risk of advanced AMD experienced the greatest benefits, with the combination of antioxidants and zinc reducing the rate of visual acuity loss by 27%.
In general, the antioxidant/zinc combination reduced the overall risk of AMD by 28%. Antioxidants and zinc each reduced the risk of AMD, but their effect was greater in combination.
Raw Material Research (Asthmatics)
Raw Materials
Antioxidants
Indication
Protecting asthmatics from air pollution
Source
Archives of Environmental Health, 2001;56:242-249
Research
Researchers studied the effect of supplements containing 400 IU of vitamin E and 500 mg of vitamin C versus placebo on 17 adult asthmatics for five weeks. The subjects' lung function was measured after four weeks, using three standard tests, following ozone exposure during mild exercise on a treadmill. The experiment was then repeated after another week.
Results
After taking the antioxidants, subjects tolerated the ozone with considerably less breathing difficulty compared to placebo and, sometimes, experienced improvements in lung function.
Raw Material Research (Alzheimer’s disease)
Raw Material
Antioxidant Vitamins
Indication
Reduction in possibility of Alzheimer's disease.
Source
Age and Aging 2001;30:235-241
Research
Researchers measured levels of antioxidants and free radicals in 20 patients with Alzheimer's disease and 23 elderly people without the disease.
Results
People with Alzheimer's disease had lower blood levels of vitamins E and A and higher levels of malondialdehyde, a marker of free radicals.
Vitamins C And E Supplements Protect Lungs
Researchers have found that daily doses of vitamin C and E counteract the negative, inflammatory effect on lungs from the pollutant ozone. Previous studies have shown that even low levels of ozone have significant effects on lung function, as little as one hour after exposure. These effects have been previously studied by researchers exercising athletes indoors, under laboratory conditions.
Research teams feel that the antioxidants protect the lungs by reducing the lung's inflammatory response to the pollutants and ozone. Vitamin E and antioxidants are believed to have anticancer effects as well as heart protective benefits.
American Journal of Epidemiology, 1999
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