Friday, 17 June 2011
Thursday, 16 June 2011
WATCH TV and DIE EARLY
TV time tied to diabetes, death
NEW YORK
Thursday, June 16, 2011
PEOPLE who spend more hours in front of the television are at greater risk of dying, or developing diabetes and heart disease, with even two hours of television a day having a marked effect, according to a US study.!
Every day, US residents spend an average of 5 hours watching television, while Australians and some Europeans log 3.5 to 4 hours a day, said researchers led by Frank Hu, at the Harvard School of Public Health.!
"The message is simple. Cutting back on TV watching is an important way to reduce sedentary behaviors and decrease risk of diabetes and heart disease," Hu said.!
"The combination of a sedentary lifestyle, unhealthy diet and obesity creates a 'perfect breeding ground' for type 2 diabetes and heart disease."!
Many studies have found a strong link to obesity. A 2007 report found that more TV time was associated with higher blood pressure in obese children.!
Another study that same year found that overweight children who watch food advertisements tend to double their food intake.!
For the new study, published in the Journal of the American Medical Association, Hu and his team reviewed eight studies examining the link between TV time and diseases, that in total followed more than 200,000 people, for an average of 7 to 10 years.!
Hu and his colleagues found that for every two hours of daily television that people watched, their risk of diabetes increased by 20 per cent. Reuters!
NEW YORK
Thursday, June 16, 2011
PEOPLE who spend more hours in front of the television are at greater risk of dying, or developing diabetes and heart disease, with even two hours of television a day having a marked effect, according to a US study.!
Every day, US residents spend an average of 5 hours watching television, while Australians and some Europeans log 3.5 to 4 hours a day, said researchers led by Frank Hu, at the Harvard School of Public Health.!
"The message is simple. Cutting back on TV watching is an important way to reduce sedentary behaviors and decrease risk of diabetes and heart disease," Hu said.!
"The combination of a sedentary lifestyle, unhealthy diet and obesity creates a 'perfect breeding ground' for type 2 diabetes and heart disease."!
Many studies have found a strong link to obesity. A 2007 report found that more TV time was associated with higher blood pressure in obese children.!
Another study that same year found that overweight children who watch food advertisements tend to double their food intake.!
For the new study, published in the Journal of the American Medical Association, Hu and his team reviewed eight studies examining the link between TV time and diseases, that in total followed more than 200,000 people, for an average of 7 to 10 years.!
Hu and his colleagues found that for every two hours of daily television that people watched, their risk of diabetes increased by 20 per cent. Reuters!
Sunday, 5 June 2011
Ghost Writers of Medical Articles
The Haunting of Medical Journals: How Ghostwriting Sold “HRT”
Adriane J. Fugh-Berman*
Department of Physiology and Biophysics, Georgetown University Medical Center, Washington, D.C., United States of America
Citation: Fugh-Berman AJ (2010) The Haunting of Medical Journals: How Ghostwriting Sold “HRT”. PLoS Med 7(9): e1000335. doi:10.1371/journal.pmed.1000335
Published: September 7, 2010
Funding: The author received no specific funding for this article.
Competing interests: Dr. Fugh-Berman was a paid expert witness on behalf of plaintiffs in the litigation referred to in this paper. She was not paid for any part of researching or writing this paper. Dr. Fugh-Berman directs PharmedOut, a Georgetown University-based project founded with public money from the Attorney General Consumer and Prescriber Grant program and currently supported by individual donations.
Summary Points
Some 1500 documents revealed in litigation provide unprecedented insights into how pharmaceutical companies promote drugs, including the use of vendors to produce ghostwritten manuscripts and place them into medical journals.
Dozens of ghostwritten reviews and commentaries published in medical journals and supplements were used to promote unproven benefits and downplay harms of menopausal hormone therapy (HT), and to cast raloxifene and other competing therapies in a negative light.
Specifically, the pharmaceutical company Wyeth used ghostwritten articles to mitigate the perceived risks of breast cancer associated with HT, to defend the unsupported cardiovascular “benefits” of HT, and to promote off-label, unproven uses of HT such as the prevention of dementia, Parkinson's disease, vision problems, and wrinkles.
Given the growing evidence that ghostwriting has been used to promote HT and other highly promoted drugs, the medical profession must take steps to ensure that prescribers renounce participation in ghostwriting, and to ensure that unscrupulous relationships between industry and academia are avoided rather than courted.
Adriane J. Fugh-Berman*
Department of Physiology and Biophysics, Georgetown University Medical Center, Washington, D.C., United States of America
Citation: Fugh-Berman AJ (2010) The Haunting of Medical Journals: How Ghostwriting Sold “HRT”. PLoS Med 7(9): e1000335. doi:10.1371/journal.pmed.1000335
Published: September 7, 2010
Funding: The author received no specific funding for this article.
Competing interests: Dr. Fugh-Berman was a paid expert witness on behalf of plaintiffs in the litigation referred to in this paper. She was not paid for any part of researching or writing this paper. Dr. Fugh-Berman directs PharmedOut, a Georgetown University-based project founded with public money from the Attorney General Consumer and Prescriber Grant program and currently supported by individual donations.
Summary Points
Some 1500 documents revealed in litigation provide unprecedented insights into how pharmaceutical companies promote drugs, including the use of vendors to produce ghostwritten manuscripts and place them into medical journals.
Dozens of ghostwritten reviews and commentaries published in medical journals and supplements were used to promote unproven benefits and downplay harms of menopausal hormone therapy (HT), and to cast raloxifene and other competing therapies in a negative light.
Specifically, the pharmaceutical company Wyeth used ghostwritten articles to mitigate the perceived risks of breast cancer associated with HT, to defend the unsupported cardiovascular “benefits” of HT, and to promote off-label, unproven uses of HT such as the prevention of dementia, Parkinson's disease, vision problems, and wrinkles.
Given the growing evidence that ghostwriting has been used to promote HT and other highly promoted drugs, the medical profession must take steps to ensure that prescribers renounce participation in ghostwriting, and to ensure that unscrupulous relationships between industry and academia are avoided rather than courted.
The New Controversy Calcium Intake
Researchers found that patients who underwent bariatric surgery appear to have a 2.3-fold increased risk for fracture compared with the general population. The finding from the final analysis is higher than the 1.8-fold increased fracture risk reported 2 years ago in this study population.
This photo of Minnesota is courtesy of TripAdvisor
But the study was done in Minnesota, so the population would be predominantly White or European descent, a group susceptible to osteoporosis and Fractures
But this study said, osteoporosis was not the reason for the fractures, but something else that was in the bone metabolism or structure that increased the fractures. They suggest calcium and vitamin D optimization ..
Measures to optimize bone health
Kennel said the link between bone health and bariatric surgery is not a new issue. However, “the problem is that lately we see evidence in the literature that people who are trying to get enough vitamin D and calcium still show signs that their bones are changing in a negative way,” he said at the press conference.
Of note, patients who developed fractures did not necessarily develop osteoporosis, the researchers said.
“We need to start looking at the skeleton as one of the key issues for long-term follow-up [of bariatric surgery],” Kennel said. Clinicians may also need to consider other measures to improve post-surgery bone health, such as proper calcium and vitamin D nutrition and fall prevention, he added.
But a study from New Zealand throws some light on Calcium and Vitamin D supplementation, it increases your rate of Heart Attacks..
For women the choice has been broken bones or broken hearts?
A new study from New Zealand now extends the increased cardiovascular risk (CVR) linked to calcium supplements to include people who are also taking vitamin D. The study, published in the British Medical Journal this past month by Dr. Mark Bolland from the University of Auckland, New Zealand, observed that the combination of calcium and vitamin D — popular supplements taken by millions of patients to reduce the risk of bone fractures — may be associated with a20% increased risk of both MI and stroke.
A significant amount of controversy erupted last year when Bolland and colleagues reported on a meta-analysis of patients taking calcium alone compared to placebo, or people taking calcium/vitamin D combination compared with people taking vitamin D alone, and described a significant increase in myocardial infarction risk. This observation was at odds with a Women’s Health Initiative (WHI) study which had shown no adverse CVR in women taking this combination of supplements, as compared with those randomized to placebo.
As Dr. Russo and I have reported recently in this blog, Vitamin D is enjoying a wave of popularity as a CVR prevention strategy. This effect clearly was not seen in this analysis. As the authors pointed out, “This doesn’t rule out that possibility [that vitamin D may be protective], but what we’re saying here is that the calcium effect seems to be dominant when you give the two together.” I don’t think we are at the point where we need to tell patients to stop taking all dietary supplemental calcium. It seems prudent to recommend increased dietary calcium for patients with osteoporosis and recommend supplements to patients who are unable to get their dietary calcium intake. After all, suggestions that dietary calcium carries these same risks are not out there. In the end, I think that the most important recommendation at this point is to prompt physicians and patients to discuss the risks and other options for osteoporosis management/prevention. Please remember that there are other studies showing that the use of calcium and vitamin D with bisphosphonates for osteoporosis have been so far reassuring and appear safe from a cardiovascular standpoint. Clearly further studies are needed, and the debate remains ongoing.
Any correlation to the fact that the study was done in New Zealand where the calcium intake from dairy products may alredy be high?
The authors state that the effect of calcium overrides that of the addition of vitamin D, does it give us the idea that vitamin D increases calcium absorption and in new Zealand they are being overdosed with Calcium?
Obviously there is no blanket recommendations and there is more tricks to this than just calcium dosage
How much calcium?
In what form?
When to take it?
Gender and race differences?
Quality of calcium? Where it comes from?
This news is of great importance and I am sure you are going to hear more about it…
Saturday, 4 June 2011
BILINGUALISM IS GOOD FOR YOUR BRAIN
FROM THE NEW YORK TIMES
Q. Bilingualism used to be considered a negative thing — at least in the United States. Is it still?
A. Until about the 1960s, the conventional wisdom was that bilingualism was a disadvantage. Some of this was xenophobia. Thanks to science, we now know that the opposite is true.
Q. Many immigrants choose not to teach their children their native language. Is this a good thing?
A. I’m asked about this all the time. People e-mail me and say, “I’m getting married to someone from another culture, what should we do with the children?” I always say, “You’re sitting on a potential gift.”
There are two major reasons people should pass their heritage language onto children. First, it connects children to their ancestors. The second is my research: Bilingualism is good for you. It makes brains stronger. It is brain exercise.
A cognitive neuroscientist, Ellen Bialystok has spent almost 40 years learning about how bilingualism sharpens the mind. Her good news: Among other benefits, the regular use of two languages appears to delay the onset of Alzheimer’s disease symptoms.
Wednesday, 1 June 2011
For Those With Diabetes, Older Drugs Are Often Best
From the New York Times 27th May 2011
WHEN it comes to prescription drugs, newer is not necessarily better. And that’s especially true when treating diabetes.
One in 10 Americans has Type 2 diabetes. If the trend continues, one in three will suffer from the disease by the year 2050, according to the federal Centers for Disease Control and Prevention.
Most Type 2 diabetes patients take one or more drugs to control blood sugar. They spent an estimated $12.5 billion on medication in 2007, twice the amount spent in 2001, according to a study by the University of Chicago. (That figure does not including drugs that diabetics are often prescribed for related health conditions, like high blood pressure and high cholesterol.)
Why the increase? More diagnosed patients, more drugs per patient and an onslaught of expensive new drugs, according to Dr. G. Caleb Alexander, assistant professor of medicine at the University of Chicago and lead author of the study. Since 1995, several new classes of diabetes medications have come on the market. Diabetes drugs are important to the pharmaceutical industry, more lucrative than drugs for many other chronic diseases, Dr. Alexander noted in an interview.
Simply put, many of these drugs help the body produce less glucose or more insulin, the hormone that shuttles glucose into cells for use as energy, or they increase the body’s sensitivity to its own insulin.
Patients and health care professionals have long hoped that as pharmaceutical companies found ways to help the body lower blood sugar, they would produce safer and more efficient alternatives to older medications. But a true breakthrough doesn’t seem to have happened yet.
A report released in March by the federal Agency for Healthcare Research and Quality and conducted by researchers at Johns Hopkins University reviewed data from 166 studies to evaluate the effectiveness and risks of various diabetes medicines. The researchers concluded that drugs that have been around for years are more effective at lowering blood sugar and often work with fewer side effects than the newest drugs. And because so many older drugs now are available as generics, they often cost just a fraction of the price of newer brand-name drugs.
Low-cost treatment is imperative to turning back the diabetes epidemic, said Dr. Wendy L. Bennett, assistant professor of medicine at Johns Hopkins University School of Medicine and the lead author of the A.H.R.Q. study. Experts estimate that only 25 percent of diabetic patients are getting the treatment they need, and expense is a big reason. Even well-insured patients may reel when confronted with the $6,000 a year it takes on average to manage the disease (not counting the costs of such complications as heart disease, stroke, and liver and kidney damage).
Becoming educated is the most important thing a person with diabetes can do to help stem the cost of medications as well as avoid complications, said Dr. Bennett. Here, three crucial things you should know.
Step 1: Fight diabetes with lifestyle changes.
Cost: Free or low cost.
If you are pre-diabetic or recently diagnosed, you may be able to dodge the expense of drug treatment with exercise and a better diet and by quitting smoking. None of this has to cost a fortune, and in any event healthier foods and, if necessary, a gym membership or other exercise program are well worth the investment. Even if you are taking medication, these lifestyle changes can help the medicine work better and longer.
For more information go to www.cdc.gov/diabetes and the Web site for the American Diabetes Association, www.diabetes.org.
Step 2: If you need to begin taking a drug to control blood sugar, start with metformin, the most common and one of the least expensive diabetes drugs.
Cost: $36 for 100 pills (500 milligrams); usually taken twice a day. Prices may be even lower at Wal-Mart, Target and other discount pharmacies.
Metformin almost always works as a first-line drug, except for patients suffering from severe kidney disease, said Dr. Bennett. What’s more, metformin generally does not cause hypoglycemia, a common and dangerous side affect of many diabetes drugs.
It also does not seem to cause weight gain, as some other diabetes drugs do, said Dr. Bennett. “The last thing you want if you’ve been diagnosed with diabetes is additional weight,” she added.
A study published in Consumer Reports Health in February 2009 also found that older, less expensive diabetes drugs were just as effective as the new ones. Better yet, they have established safety records, while some newer diabetes drugs have been found to increase cardiovascular and other health risks.
“The expensive drugs are third- and fourth-line drugs,” said Dr. Marvin Lipman, chief medical adviser for Consumer Reports Health and a practicing endocrinologist in Westchester County, N.Y. “If you don’t get results with the less expensive drugs, you go to those. But you shouldn’t start there.”
Avoid: Certain newer diabetes drugs have been associated with heart failure and other risks.
Avandia, for example, has been linked to an increased risk of heart attacks. In September 2010, after years of debate, the Food and Drug Administration severely restricted Avandia’s availability, allowing it to be prescribed only to patients in a special program who had not responded to other drugs and were taking the medicine under a doctor’s strict supervision. This month the agency expanded those restrictions to include related drugs Avandamet and Avandaryl, which also contain rosiglitazone, the active agent in Avandia.
Step 3: Choose combination drugs from among inexpensive generics.
Cost: Glimepiride, $13 for 100 pills (1 milligram). Glipizide, $64 for 100 pills (5 milligrams).
Most diabetics will have to eventually take more than one drug to keep blood sugar under control. The good news here from the Johns Hopkins study is that inexpensive metformin is also quite effective in combination with other generics, such as glimepiride and glipizide.
“Most combinations worked equally well, so when you’re adding a drug, you could choose a generic to save costs,” said Dr. Bennett. She added, however, that some drugs used with metformin might increase the risk of side effects such as hypoglycemia or weight gain. Patients should discuss each drug’s pros and cons, as well as cost, with their doctors.
Avoid: Do not start with one of the more expensive drugs in combination with metformin. In some cases, patients ultimately may need a combination of both generics and the newer drugs, but this usually becomes appropriate only after a less expensive combination has been used for some time or if the patient isn’t responding to the less expensive combination, said Dr. Bennett.
WHEN it comes to prescription drugs, newer is not necessarily better. And that’s especially true when treating diabetes.
One in 10 Americans has Type 2 diabetes. If the trend continues, one in three will suffer from the disease by the year 2050, according to the federal Centers for Disease Control and Prevention.
Most Type 2 diabetes patients take one or more drugs to control blood sugar. They spent an estimated $12.5 billion on medication in 2007, twice the amount spent in 2001, according to a study by the University of Chicago. (That figure does not including drugs that diabetics are often prescribed for related health conditions, like high blood pressure and high cholesterol.)
Why the increase? More diagnosed patients, more drugs per patient and an onslaught of expensive new drugs, according to Dr. G. Caleb Alexander, assistant professor of medicine at the University of Chicago and lead author of the study. Since 1995, several new classes of diabetes medications have come on the market. Diabetes drugs are important to the pharmaceutical industry, more lucrative than drugs for many other chronic diseases, Dr. Alexander noted in an interview.
Simply put, many of these drugs help the body produce less glucose or more insulin, the hormone that shuttles glucose into cells for use as energy, or they increase the body’s sensitivity to its own insulin.
Patients and health care professionals have long hoped that as pharmaceutical companies found ways to help the body lower blood sugar, they would produce safer and more efficient alternatives to older medications. But a true breakthrough doesn’t seem to have happened yet.
A report released in March by the federal Agency for Healthcare Research and Quality and conducted by researchers at Johns Hopkins University reviewed data from 166 studies to evaluate the effectiveness and risks of various diabetes medicines. The researchers concluded that drugs that have been around for years are more effective at lowering blood sugar and often work with fewer side effects than the newest drugs. And because so many older drugs now are available as generics, they often cost just a fraction of the price of newer brand-name drugs.
Low-cost treatment is imperative to turning back the diabetes epidemic, said Dr. Wendy L. Bennett, assistant professor of medicine at Johns Hopkins University School of Medicine and the lead author of the A.H.R.Q. study. Experts estimate that only 25 percent of diabetic patients are getting the treatment they need, and expense is a big reason. Even well-insured patients may reel when confronted with the $6,000 a year it takes on average to manage the disease (not counting the costs of such complications as heart disease, stroke, and liver and kidney damage).
Becoming educated is the most important thing a person with diabetes can do to help stem the cost of medications as well as avoid complications, said Dr. Bennett. Here, three crucial things you should know.
Step 1: Fight diabetes with lifestyle changes.
Cost: Free or low cost.
If you are pre-diabetic or recently diagnosed, you may be able to dodge the expense of drug treatment with exercise and a better diet and by quitting smoking. None of this has to cost a fortune, and in any event healthier foods and, if necessary, a gym membership or other exercise program are well worth the investment. Even if you are taking medication, these lifestyle changes can help the medicine work better and longer.
For more information go to www.cdc.gov/diabetes and the Web site for the American Diabetes Association, www.diabetes.org.
Step 2: If you need to begin taking a drug to control blood sugar, start with metformin, the most common and one of the least expensive diabetes drugs.
Cost: $36 for 100 pills (500 milligrams); usually taken twice a day. Prices may be even lower at Wal-Mart, Target and other discount pharmacies.
Metformin almost always works as a first-line drug, except for patients suffering from severe kidney disease, said Dr. Bennett. What’s more, metformin generally does not cause hypoglycemia, a common and dangerous side affect of many diabetes drugs.
It also does not seem to cause weight gain, as some other diabetes drugs do, said Dr. Bennett. “The last thing you want if you’ve been diagnosed with diabetes is additional weight,” she added.
A study published in Consumer Reports Health in February 2009 also found that older, less expensive diabetes drugs were just as effective as the new ones. Better yet, they have established safety records, while some newer diabetes drugs have been found to increase cardiovascular and other health risks.
“The expensive drugs are third- and fourth-line drugs,” said Dr. Marvin Lipman, chief medical adviser for Consumer Reports Health and a practicing endocrinologist in Westchester County, N.Y. “If you don’t get results with the less expensive drugs, you go to those. But you shouldn’t start there.”
Avoid: Certain newer diabetes drugs have been associated with heart failure and other risks.
Avandia, for example, has been linked to an increased risk of heart attacks. In September 2010, after years of debate, the Food and Drug Administration severely restricted Avandia’s availability, allowing it to be prescribed only to patients in a special program who had not responded to other drugs and were taking the medicine under a doctor’s strict supervision. This month the agency expanded those restrictions to include related drugs Avandamet and Avandaryl, which also contain rosiglitazone, the active agent in Avandia.
Step 3: Choose combination drugs from among inexpensive generics.
Cost: Glimepiride, $13 for 100 pills (1 milligram). Glipizide, $64 for 100 pills (5 milligrams).
Most diabetics will have to eventually take more than one drug to keep blood sugar under control. The good news here from the Johns Hopkins study is that inexpensive metformin is also quite effective in combination with other generics, such as glimepiride and glipizide.
“Most combinations worked equally well, so when you’re adding a drug, you could choose a generic to save costs,” said Dr. Bennett. She added, however, that some drugs used with metformin might increase the risk of side effects such as hypoglycemia or weight gain. Patients should discuss each drug’s pros and cons, as well as cost, with their doctors.
Avoid: Do not start with one of the more expensive drugs in combination with metformin. In some cases, patients ultimately may need a combination of both generics and the newer drugs, but this usually becomes appropriate only after a less expensive combination has been used for some time or if the patient isn’t responding to the less expensive combination, said Dr. Bennett.
Thursday, 26 May 2011
PLASTICITY OF THE BRAIN. PREVENT ALZHEIMERS
THE FOLLOWING ARTICLE APPEARED ON THE BRUNEI TIMES.
Dr Ramachandran is a specialist studying the Plasticity of the Brain and new information is coming out on the possibility of changing the wiring of the brain. I feel that Yoga uses this philosophy and I have written another blog about Plasticity and the Brain and Yoga.
Those with a family history of Alzheimers or with problems with remembering objects or who wish to prevent dementia , might try
1. reduce stress in their lives
2. try to learn the philosophy of Raja Yoga
3. Enjoy, more so, of the things you have always enjoyed. Arts Literature Music
(this note dedicated to a friend of mine from Singapore, hope she reads it)
Why learning gets tougher with age
An IT seminar for elderly people in Leipzig, Germany. Findings from a study has added new understanding to the process of ageing. Picture: EPA
CHICAGO
Thursday, May 26, 2011
THE middle-aged brain is not as nimble as it used to be because of all the stress it has endured, a study released on Tuesday showed.
US researchers said stress causes nerve cells in a part of the brain needed for learning to shrink and lose plasticity the ability to quickly form connections called synapses.
Younger animals can recover from this but older animals start losing this ability beginning in middle age.
The findings add new understanding to the process of aging, and may help explain why some people decline more quickly than others.
"We suspected that these nerve cells would be altered by age but the loss of synaptic plasticity in the context of life experience has profound implications for age-related cognitive decline," John Morrison of the Mount Sinai School of Medicine, whose study appears in the Journal of Neuroscience, said in a statement.
For the study, Morrison and colleagues studied young, middle-aged and elderly rats who were placed in a confined area for several hours, causing the release of stress hormones that bring about nerve cell changes in the prefrontal cortex a part of the brain used in learning.
The team then studied changes in a part of the nerve cells called spines that are used to form synapses.
When they looked under a microscope, they saw changes in the spines of the young rats, showing they were able to adapt to the stressful experience. There were few changes in the spines in middle-aged rats and none in the oldest rats.
The findings suggest aging causes a significant loss in the brain's ability to respond to stress, something that is crucial to learning, Morrison said.
"The prefrontal cortex is constantly 'rewiring' in response to life experiences," Morrison said.
But he said the aged brain has already suffered significant loss of these nerve spines and the ones that remain are less able to respond in situations that require rewiring.
"The aged animal essentially loses its capacity for experience-induced plasticity," Morrison, who is 58, said in a telephone interview.
He was surprised by the findings at first and now finds them a bit sobering.
"I wouldn't want to try to learn a language," Morrison said. "People can do it in a partial way but nothing like a child can do it."
But you do not lose everything while aging, he said.
"One of the great stories about aging is you don't lose expertise. You are not losing the very stable synapses and circuits," Morrison said.
He said the findings point to a new approach in the search for treatments that protect the brain from age-related declines, such as in Alzheimer's disease.
"If we really want to understand Alzheimer's disease and deal with it effectively, we have to prevent it. And preventing it will require very early intervention," he said.
Dr Ramachandran is a specialist studying the Plasticity of the Brain and new information is coming out on the possibility of changing the wiring of the brain. I feel that Yoga uses this philosophy and I have written another blog about Plasticity and the Brain and Yoga.
Those with a family history of Alzheimers or with problems with remembering objects or who wish to prevent dementia , might try
1. reduce stress in their lives
2. try to learn the philosophy of Raja Yoga
3. Enjoy, more so, of the things you have always enjoyed. Arts Literature Music
(this note dedicated to a friend of mine from Singapore, hope she reads it)
Why learning gets tougher with age
An IT seminar for elderly people in Leipzig, Germany. Findings from a study has added new understanding to the process of ageing. Picture: EPA
CHICAGO
Thursday, May 26, 2011
THE middle-aged brain is not as nimble as it used to be because of all the stress it has endured, a study released on Tuesday showed.
US researchers said stress causes nerve cells in a part of the brain needed for learning to shrink and lose plasticity the ability to quickly form connections called synapses.
Younger animals can recover from this but older animals start losing this ability beginning in middle age.
The findings add new understanding to the process of aging, and may help explain why some people decline more quickly than others.
"We suspected that these nerve cells would be altered by age but the loss of synaptic plasticity in the context of life experience has profound implications for age-related cognitive decline," John Morrison of the Mount Sinai School of Medicine, whose study appears in the Journal of Neuroscience, said in a statement.
For the study, Morrison and colleagues studied young, middle-aged and elderly rats who were placed in a confined area for several hours, causing the release of stress hormones that bring about nerve cell changes in the prefrontal cortex a part of the brain used in learning.
The team then studied changes in a part of the nerve cells called spines that are used to form synapses.
When they looked under a microscope, they saw changes in the spines of the young rats, showing they were able to adapt to the stressful experience. There were few changes in the spines in middle-aged rats and none in the oldest rats.
The findings suggest aging causes a significant loss in the brain's ability to respond to stress, something that is crucial to learning, Morrison said.
"The prefrontal cortex is constantly 'rewiring' in response to life experiences," Morrison said.
But he said the aged brain has already suffered significant loss of these nerve spines and the ones that remain are less able to respond in situations that require rewiring.
"The aged animal essentially loses its capacity for experience-induced plasticity," Morrison, who is 58, said in a telephone interview.
He was surprised by the findings at first and now finds them a bit sobering.
"I wouldn't want to try to learn a language," Morrison said. "People can do it in a partial way but nothing like a child can do it."
But you do not lose everything while aging, he said.
"One of the great stories about aging is you don't lose expertise. You are not losing the very stable synapses and circuits," Morrison said.
He said the findings point to a new approach in the search for treatments that protect the brain from age-related declines, such as in Alzheimer's disease.
"If we really want to understand Alzheimer's disease and deal with it effectively, we have to prevent it. And preventing it will require very early intervention," he said.
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