Thursday, July 10, 2008

How Foods Affect Brain Health, Cognitive Functions; Omega-3, Folic acid, Curcumin

The University of California, Los Angeles, issued the following news release: Scientists learn how food affects the brain. In addition to helping protect us from heart disease and cancer, a balanced diet and regular exercise can also protect the brain and ward off mental disorders.” Food is like a pharmaceutical compound that affects the brain," said Fernando Gomez-Pinilla, a UCLA professor of neurosurgery and physiological science who has spent years studying the effects of food, exercise and sleep on the brain. "Diet, exercise and sleep have the potential to alter our brain health and mental function. This raises the exciting possibility that changes in diet are a viable strategy for enhancing cognitive abilities, protecting the brain from damage and counteracting the effects of aging."Gomez-Pinilla analyzed more than 160 studies about food's affect on the brain; the results of his analysis appear in the July issue of the journal Nature Reviews Neuroscience and are available online atwww.nature.com/nrn/journal/v9/n7/abs/nrn2421.html.Omega-3 fatty acids -- found in salmon, walnuts and kiwi fruit -- provide many benefits, including improving learning and memory and helping tonight against such mental disorders as depression and mood disorders, schizophrenia, and dementia, said Gomez-Pinilla, a member of UCLA'sBrain Research Institute and Brain Injury Research Center. Synapses in the brain connect neurons and provide critical functions; much learning and memory occurs at the synapses, Gomez-Pinilla said."Omega-3 fatty acids support synaptic plasticity and seem to positively affect the expression of several molecules related to learning and memory that are found on synapses," Gomez-Pinilla said. "Omega-3 fatty acids are essential for normal brain function.” Dietary deficiency of omega-3 fatty acids in humans has been associated with increased risk of several mental disorders, including attention-deficit disorder, dyslexia, dementia, depression, bipolar disorder and schizophrenia," he said. "A deficiency of omega-3 fatty acids in rodents results in impaired learning and memory.” Children who had increased amounts of omega-3 fatty acids performed better in school, in reading and in spelling and had fewer behavioral problems, he said. Preliminary results from a study in England show that school performance improved among a group of students receiving omega-3 fatty acids. In an Australian study, 396 children between the ages 6 and 12 who were given drink with omega-3 fatty acids and other nutrients (iron, zinc, folic acid and vitamins A, B6, B12 and C) showed higher scores on tests measuring verbal intelligence and learning and memory after six months and one year than a control group of students who did not receive the nutritional drink. This study was also conducted with 394 children in Indonesia. The results showed higher test scores for boys and girls in Australia, but only for girls in Indonesia. Getting omega-3 fatty acids from food rather than from capsule supplements can be more beneficial, providing additional nutrients,Gomez-Pinilla said. Scientists are learning which omega-3 fatty acids seem to be especially important. One is docosahexaenoic acid, or DHA, which is abundant in salmon. DHA, which reduces oxidative stress and enhances synaptic plasticity and learning and memory, is the most abundant omega-3 fatty acid in cell membranes in the brain.” The brain and the body are deficient in the machinery to make DHA; ithas to come through our diet," said Gomez-Pinilla, who was born and raised in salmon-rich Chile and eats salmon three times a week, along with a balanced diet. "Omega-3 fatty acids are essential.” A healthy diet and exercise can also reduce the effect of brain injury and lead to a better recovery, he said. Recent research also supports the hypothesis that health can be passed down through generations, and a number of innovative studies point to the possibility that the effects of diet on mental health can be transmitted across generations, Gomez-Pinilla said. A long-term study that included more than 100 years of birth, death, health and genealogical records for 300 Swedish families in an isolated village showed that an individual's risk for diabetes and early death increased if his or her paternal grandparents grew up in times of food abundance rather than food shortage.” Evidence indicates that what you eat can affect your grandchildren’s brain molecules and synapses," Gomez-Pinilla said. "We are trying to find the molecular basis to explain this.” Controlled meal-skipping or intermittent caloric restriction might provide health benefits, he said. Excess calories can reduce the flexibility of synapses and increase the vulnerability of cells to damage by causing the formation of free radicals. Moderate caloric restriction could protect the brain by reducing oxidative damage to cellular proteins, lipids and nucleic acids, Gomez-Pinilla said. The brain is highly susceptible to oxidative damage. Blueberries have been shown to have a strong antioxidant capacity, he noted. In contrast to the healthy effects of diets that are rich in omega-3fatty acids, diets high in trans fats and saturated fats adversely affect cognition, studies indicate. Junk food and fast food negatively affect the brain's synapses, saidGomez-Pinilla, which eats fast food less often since conducting this research. Brain synapses and several molecules related to learning and memory is adversely affected by unhealthy diets, he said. Emerging research indicates that the effects of diet on the brain, combined with the effects of exercise and a good night's sleep, can strengthen synapses and provide other cognitive benefits, he added. In Okinawa, an island in Japan where people frequently eat fish and exercise, the lifespan is one of the world's longest, and the population has a very low rate of mental disorders, Gomez-Pinilla noted. Folic acid is found in various foods, including spinach, orange juice and yeast. Adequate levels of folic acid are essential for brain function, and foliate deficiency can lead to neurological disorders such as depression and cognitive impairment. Foliate supplementation, either by itself or in conjunction with other B vitamins, has been shown to be effective in preventing cognitive decline and dementia during aging and enhancing the effects of antidepressants. The results of a recent randomized clinical trial indicate that a three-year folic acid supplementation can help reduce the age-related decline in cognitive function. In patients with major depression and schizophrenia, levels of signaling molecule known as brain-derived neurotrophic factor, or BDNF, are reduced. Antidepressants elevate BDNF levels, and most treatments for depression and schizophrenia stimulate BDNF. Here, too, omega-3fatty acids are beneficial, as is the curry spice curcumin, which has-been shown to reduce memory deficits in animal models of Alzheimer’s disease and brain trauma. BDNF is most abundant in the hippocampus and the hypothalamus -- brain areas associated with cognitive and metabolic regulation. The high consumption of curcumin in India may contribute to the low prevalence of Alzheimer's disease on the subcontinent. In humans, a mutation in a BDNF receptor has been linked to obesity and impairments in learning and memory."BDNF is reduced in the hippocampus, in various cortical areas and in the serum of patients with schizophrenia," Gomez-Pinilla said. "BDNFlevels are reduced in the plasma of patients with major depression.” Smaller food portions with the appropriate nutrients seem to be beneficial for the brain's molecules, such as BDNF, he said. Gomez-Pinilla showed in 1995 that exercise could have an effect on the brain by elevating levels of BDNF. He noted that while some people have extremely good genes, most of us are not so lucky and need a balanced diet, regular exercise and a goodnight's sleep. The National Institutes of Health’s National Institute of Neurological Disorders and Stroke funded the research

Wednesday, July 9, 2008

A 10% Prevalence of Silent Stroke Found in "Healthy" Adults

About 10% of apparently healthy middle-aged adults have experienced silent cerebral infarcts (SCI), according to the latest results from the Framingham Offspring Study. Furthermore, the study found risk factors typically associated with clinical stroke, including hypertension, elevated serum homocysteine, and carotid artery disease, are also associated with midlife SCI.


The study's findings are consistent with previous community-based studies, which have estimated the prevalence of SCI between 5.8% and 17.7%, depending on age, ethnicity, presence of comorbidities, and imaging techniques.
"Our study shows that, in a middle-aged population free of clinical disease, there is a distressingly high prevalence of subclinical disease, as evidenced by these silent infarcts, which we know increase the risk of clinical stroke and cognitive impairment," study investigator Sudha Seshadri, MD, from Boston University School of Medicine, in Massachusetts, told Medscape Neurology & Neurosurgery.
"These findings also reinforce the need for clinicians to aggressively detect and manage cardiovascular risk factors, perhaps even earlier than midlife," she added.
The study is published online June 26 in Stroke.
Atrial Fibrillation Link
In addition to the prevalence data, the investigators also found that stroke risk factors, including hypertension, elevated plasma homocysteine, carotid stenosis, and increased carotid artery intimal medial thickness, are also significantly associated with silent infarcts.
Another, somewhat surprising, finding, said Dr. Seshadri, was a significant link between atrial fibrillation (AF) and SCI, with the data revealing that AF increased the risk for prevalent SCI more than 2-fold.
According to Dr. Seshadri, this finding may be an indication that AF is a simultaneous outcome, rather than a cause of SCI.
"While it is possible that tiny emboli resulting from atrial fibrillation may be causing these silent infarcts, it is probable that some of the risk factors for AF are the same as those for SCI. Therefore, it may be that atrial fibrillation is a marker for silent infarcts, rather than a cause, and that the 2 conditions are occurring together," she said.
An offshoot of the Framingham Heart Study, a longitudinal study that began in 1948 with the goal of identifying common risk factors for cardiovascular disease, the Framingham Offspring Study, which began in 1971, includes the children and children's spouses of the original cohort.
With an average age of 62 years, the current sample included 2040 offspring who attended the sixth examination (1996-1998) and underwent volumetric brain magnetic resonance imaging (MRI) in 2001 and were free of clinical stroke.
In addition, subjects were assessed using the Framingham Stroke Risk Profile (FSRP), a validated instrument that predicts 10-year probability of incident stroke and includes age, systolic blood pressure, antihypertensive therapy, diabetes mellitus, cigarette smoking, cardiovascular disease, AF, and left ventricular hypertrophy.
Subjects also underwent carotid imaging and measurement of cholesterol concentrations as well as plasma homocysteine.
Need to Follow Guidelines
Among the 10.7% of study subjects who had MRI evidence of silent infarcts, 84% had a single lesion, most commonly located in the basal ganglia (52%). One third of the lesions were subcortical, and 10% were cortical lesions.
According to the study, the aggregate FSRP score was significantly associated with prevalent SCI. Of the FRSP variables, AF, hypertension, and systolic blood pressure were all associated with an increased risk for silent infarct.
Of the variables not included in the FRSP, plasma homocysteine, carotid stenosis of 25% or greater, and increased intimal medial thickness were also associated with a higher risk for prevalent SCI. Neither age nor sex modified the effect of any of the risk factors on SCI prevalence.
The finding that there is a link between elevated homocysteine may warrant consideration of including SCI as an outcome in future studies looking at the potential benefit of vitamin supplementation.
While the study's findings are not necessarily surprising, said Dr. Seshadri, they do underscore the need to follow guidelines for the early diagnosis and prevention of hypertension and atherosclerosis and their risk factors.
Unfortunately, she said, such guidelines have not been optimally implemented for a variety of reasons. "For instance, we know that over a lifetime, 9 out of 10 people will develop hypertension. When a condition is that common it tends to be regarded as the 'norm.' But we also know that the 10% of people who do not develop high blood pressure are healthier and live longer, better-quality lives. I would argue that even though a condition is regarded as the norm it should still be treated aggressively," she said.
The study was supported by the National Heart, Lung, and Blood Institute; the National Institute on Aging; and the National Institute of Neurological Disorders and Stroke. The study authors have disclosed no relevant financial relationships.
Stroke. Published online June 26, 2008.

Wednesday, July 2, 2008

Brain Injuries Cause 1/2 of Seniors' Fall Deaths

Jun 24 07:32 AM US/EasternBy MIKE STOBBEAP Medical Writer


ATLANTA (AP) - The elderly fear breaking a hip when they fall, but a government study indicates that hitting their head can also have deadly consequences: Brain injuries account for half of all deaths from falls.


The study by the Centers for Disease Control and Prevention is the first comprehensive national look at the role brain injuries play in fatal elderly falls. It examined 16,000 deaths in 2005 that listed unintentional falls as an underlying cause of death.
CDC researchers found that slightly more than half of the deaths were attributed to brain injuries. The other deaths were due to a variety of causes including heart failure, strokes, infections and existing chronic conditions worsened by a broken hip or other injuries sustained in a fall.
"A lot of people don't think a fall is serious unless they broke a bone, they don't think it's serious unless they break a hip. They don't worry about their head," said Pat Flemming, a senior physical therapist and researcher at Vanderbilt University


Each year, one in three Americans age 65 and older fall. About 30 percent of such falls require medical treatment.
Previous CDC research showed that the U.S. death rate from falling has risen dramatically—about 55 percent—for the elderly since the 1990s. The new study highlights the role that brain injuries play in such deaths.
As people age, veins and arteries can be more easily torn during a sudden blow or jolt to the head, said Marlena Wald, a CDC epidemiologist who co-authored the study.
That can cause a fatal brain bleed. Other factors can contribute, such as the use of blood-thinners, said Judy Stevens, another CDC researcher and co-author.


The severity of brain injuries isn't always immediately apparent, and some people may not lose consciousness. Wald noted a scenario seen in hospitals in which an elderly fall victim comes in alert and talking, but dies an hour or two later.
The study also found that deaths and hospitalization rates for fall-related brain injuries increased with age. Brain injuries accounted for about 8 percent of hospital stays for non-fatal falls.


There are several steps older Americans can take to try to prevent falls. Exercise can increase leg strength and balance. Glasses or other vision correction measures can help people avoid obstacles. And being careful with the use of drugs that can affect thinking and coordination—such as tranquilizers and sleeping pills—can also make a difference.
"Falls are not an inevitable consequence of aging. These head injuries are not inevitable, either," Wald said.
The research is being published in the June issue of a scientific publication, the Journal of Safety Research

Women More Likely Than Men to Have Dementia After Age 90

The University of California , Irvine, issued the following news release:Women over 90 more likely to have dementia than menIrvine, Calif. -- Women over 90 are significantly more likely to havedementia than men of the same age, according UC Irvine researchersinvolved with the 90+ Study, one of the nation's largest studies ofdementia and other health factors in the fastest-growing age demographic.The researchers reviewed an analysis of 911 people enrolled in the 90+Study. Of those, 45 percent of the women had dementia, as opposed to 28percent of the men. The analysis did not determine when the subjectsfirst experienced dementia.The 90-plus age group, or the "oldest old," is the fastest growingsegment of the population, according to the U.S. Census. While there arecurrently nearly 2 million nonagenarians in the U.S. alone, that numberis projected to increase to 10 to 12 million by the middle of thecentury, raising concerns that the current health care system may not beable to accommodate this population."Our findings show that more will need to be done to provide adequateresources to care for the increasing number of very old people withdementia," said Maria Corrada, a UC Irvine epidemiologist and studycorresponding author.The study appears in the July 2 online issue of Neurology, the medicaljournal of the American Academy of Neurology.Research has shown that dementia prevalence for both men and womenincreases from age 65 to 85. The frequency of dementia increases withage from less than 2 percent for the 65-69-year-olds, to 5 percent forthe 75-79-year-olds and to more than 20 percent for the 85-89-year-olds.The UC Irvine study, conducted in Laguna Woods, Calif., is among the fewto look at dementia in people over age 90. It found that the likelihoodof having dementia doubled every five years in women after reaching 90,but not in men. The results also showed that women with a highereducation appeared to be as much as 45 percent less likely to havedementia compared to women with less education.With women comprising three-quarters of the 90-plus population, thestudy raises questions why these women nonagenarians are more likely tohave dementia than men."Our findings provide valuable information toward further inquiries intodementia, such as if oldest-old men can live as long with dementia asoldest-old women do, or whether in this age group women develop dementiaat a higher rate than men," Corrada said.Dementia, a progressive brain dysfunction, leads to a graduallyincreasing restriction of daily activities. The most well-known type ofdementia is Alzheimer's disease. Symptoms of dementia include memoryloss, cognitive disorientation and behavioral changes. Dementia affectsnot only patients but also those surrounding them, as most patientsrequire long-term care.Study co-authors are Dr. Claudia Kawas and Daniel Berlau from UC Irvine,Ron Brookmeyer from Johns Hopkins University, and Annlia Paganini-Hillof USC. The study was supported by the National Institutes of Health andthe Nichols Chair in Clinical Neuroscience.About the 90+ Study: Initiated in 2003, the 90+ Study performs clinical,pathological and genetic research in people 90 or older, the fastest-growing segment of the population. With a cohort of 1,100 participants,the 90+ team has assembled one of the largest prospective studies ofoldest old subjects in the world. Results obtained thus far haveprovided researchers across the globe with valuable information aboutaging. The study, run through the Clinic for Aging Research andEducation in Laguna Woods, Calif., is directed by Dr. Claudia Kawas, theNichols Chair in Clinical Neuroscience.