Nation World

Fatty foods affect memory and exercise

By Tara Parker-Pope
Eating fatty food appears to take an almost immediate toll on both short-term memory and exercise performance, according to new research on rats and people.
It’s already known that long-term consumption of a high-fat diet is associated with weight gain, heart disease and declines in cognitive function. But the new research shows how indulging in fatty foods over the course of a few days can affect the brain and body long before the extra pounds show up.

To determine the effect of a fatty diet on memory and muscle performance, researchers studied 32 rats that were fed low-fat rat chow and trained for two months to complete a challenging maze. The maze included eight different paths that ended with a treat of sweetened condensed milk. The goal was for the rat to find each treat without doubling back into a corridor where it had already been. The maze was wiped down with alcohol, so the rat had to rely on memory rather than sense of smell.
All of the rats studied had mastered the maze, finding at least six or seven of the eight treats before making a mistake. Some rats even found all eight on the first try.

Then half the rats were switched to high-fat rat chow (comprising 55 percent fat), while the remaining rats stayed on their regular chow (which had 7.5 percent fat). After four days, the rats eating the fatty chow began to falter on the maze test — all of them did worse than when they were on their regular chow. On average, the rats on the fatty diet found only five treats before making a mistake. The rats who stayed with their regular food continued the same high level of performance on the maze, finding six or more treats before making a mistake. Half of the rats had also been trained to run on a treadmill. After only a few days on the high-fat diet, the rats performed 30 percent worse on the treadmill. After five days of testing, the treadmill performance of the rats eating fatty foods had declined by half. The study results appear in The Faseb Journal, which is the journal of the Federation of American Societies for Experimental Biology.

“We expected to see changes, but maybe not so dramatic and not in such a short space of time,’’ said Andrew Murray, the study’s lead author and a lecturer in physiology at Cambridge University in Britain. “It was really striking how quickly these effects happened.’’

Although the human data aren’t yet published, the researchers have also performed similar studies of high-fat diets in healthy young men who then performed exercise and cognitive tests. Dr. Murray said he is still reviewing the data, but the short-term effect of a fatty diet on humans appears to be similar to that found in the rat studies.
It’s not clear why fatty foods would cause a short-term decline in cognitive function. One theory is that a high-fat diet can trigger insulin resistance, which means the body becomes less efficient at using the glucose, or blood sugar, so important to brain function.

Fatty foods appear to have a short-term effect on exercise performance because the body reacts to high fat content in the blood by releasing certain proteins that essentially make the metabolism less efficient. “It’s thought to be a protective mechanism to get rid of excess fat,’’ Dr. Murray said. “But it was making muscles less efficient at using oxygen and fuel to make the energy needed to run.’’


Patients are reminded of aspirin’s risks

Nytimes-Cheap, ubiquitous aspirin has long been known for health benefits from basic pain relief to heart attack prevention. But after a new study this week provided tantalising evidence suggesting that aspirin might increase survival chances for colorectal cancer patients, experts were quick to warn that the drug, a medicine cabinet staple, also had its risks.
“If I were on a desert island, one of the drugs I would choose to have with me, hands down, maybe No. 1, is aspirin,” said Dr. John A. Baron, a professor of medicine at Dartmouth Medical School. “It’s a fascinating, wonderful drug, a great drug. But it is a real drug, and it has side effects.”

Both Dr. Baron and other medical experts cautioned against starting a daily regimen of aspirin without consulting a physician, because of the risks of gastrointestinal bleeding, and the potential risk for hemorrhagic strokes, or bleeding in the brain.
“Aspirin is a drug that been with us a little over 100 years, and we continue to learn impressive and important things about its potential benefits,” said Dr. Otis Brawley, medical director of the American Cancer Society. “But it is a double-edged sword.”
The study found that patients with colorectal cancer who were regular aspirin users had a much better chance of surviving than non-users, and were almost one-third less likely to die of the disease, while those who began using aspirin for the first time after the diagnosis cut their risk of dying by almost half.

Earlier studies had shown that people who took aspirin regularly were less likely to develop tumors of the colon, but the new study, published in The Journal of the American Medical Association, is the first to have found that patients who had colorectal cancer and took aspirin survived longer.

The new study was not a controlled clinical trial, where patients are randomly assigned to receive either a particular treatment or a placebo. That kind of study is considered the gold standard for determining clinical recommendations in medicine, but it is also far more expensive and cumbersome. Observational studies, like this new one, can be weaker or misleading
One clinical trial is under way in Asia, where the National Cancer Center of Singapore is enrolling 2,660 patients with nonmetastatic disease in Hong Kong, India, Indonesia and Singapore, who will continue their treatment and be randomly assigned to either get aspirin or a placebo daily for up to three years, according to the National Cancer Institute Web site.

Dr. JoAnn E. Manson, chief of preventive medicine at Brigham and Women’s Hospital, which is affiliated with Harvard Medical School, warned about the risks of using even small doses of aspirin on a daily basis, saying that in a large women’s health study, half doses of baby aspirin were associated with a 40 percent increase in serious gastrointestinal bleeds that required transfusions
“I don’t think everyone should be running out and taking aspirin,” she said, “But there may be some patients who would benefit from it at this point; and if they talk with their doctors they may learn they’re reasonable candidates, and some of them may not be in a position to wait.”


First case of HIV linked to gorillas

(BBC News) – Gorillas have been found, for the first time, to be a source of HIV.
Previous research had shown the HIV-1 strain, the main source of human infections, with 33m cases worldwide, originated from a virus in chimpanzees.
But researchers have now discovered an HIV infection in a Cameroonian woman which is clearly linked to a gorilla strain, Nature Medicine reports.

A researcher told the BBC that, though it was a new type of HIV, current drugs might still help combat its effects.
HIV originated from a similar virus in chimpanzees called Simian Immunodeficiency Virus (SIV).
Although HIV/Aids was first recognised by scientists in the 1980s, it is thought to have first entered the human population early in the 20th Century in the region of the Democratic Republic of Congo.

The virus probably originally jumped into humans after people came into contact with infected bush meat.
SIV viruses have been reported in other primates, including gorillas.
French doctors treating the 62-year-old Cameroonian woman who was living in Paris said they initially spotted some discrepancies in routine viral load tests.
Further analysis of the HIV strain she was infected with showed it was more closely related to SIV from gorillas than HIV from humans.

She is the only person known to be infected with the new strain, but the researchers expect to find other cases.
Before moving to Paris, she had lived in a semi-urban area of Cameroon and had no contact with gorillas or bush meat, suggesting she caught the virus from someone else who was carrying the gorilla strain.
Analysis of the virus in the laboratory has confirmed that it can replicate in human cells.
Co-author Dr David Robertson, from the University of Manchester, said it was the first definitive transfer of HIV seen from a source other than a chimpanzee, and highlighted the need to monitor for the emergence of new strains.
“This demonstrates that HIV evolution is an ongoing process.

“The virus can jump from species to species, from primate to primate, and that includes us; pathogens have been with us for millions of years and routinely switch host species.”
The fact the patient had been diagnosed in France showed how human mobility can rapidly transfer a virus from one area of the world to another, he said.
Speaking to the BBC’s Wold Today programme, Dr Robertson said there was no reason to believe that existing drugs would not work on the new virus.

“If some day we do manage to develop a vaccine, there’s no reason to believe it wouldn’t work,” he said.
“There’s no reason to believe this virus will present any new problems, as it were, that we don’t already face.”
Professor Paul Sharp, from the University of Edinburgh, said the virus probably initially transferred from chimpanzees to gorillas.
He said the latest finding was interesting but perhaps not surprising.
“The medical implication is that, because this virus is not very closely related to the other three HIV-1 groups, it is not detected by conventional tests.

“So the virus could be cryptically spreading in the population.”
However, he said that he would guess it would not spread widely and become a major problem.
“Although the patient with this virus was not ill, there is no reason to believe that it will not lead to Aids,” he added.


Scientists find rare gene behind short sleepers

(AP) Scientists have discovered a gene that helps a mother and daughter stay alert on about six hours sleep a night, two hours less than the rest of their family needs.

It’s believed to be a very rare mutation, not an excuse for the rest of us who stay up too late. But the finding, published in Friday’s edition of the journal Science, offers a new lead to study how sleep affects health.
The National Institutes of Health says adults need seven hours to nine hours of sleep for good health. Regularly getting too little increases the risk of health problems, including memory impairment and a weakened immune system. A major 2006 study estimated that as many as 30 million Americans suffer chronic insomnia, and millions more have other sleep disorders, including sleep apnea.

University of California, San Francisco, researchers have long hunted genes related to how and when people sleep. In 2001, they discovered a mutation that puts its carriers’ sleep patterns out of whack: These people regularly go to bed around 7:30 p.m. and wake around 3:30 a.m.

Now the same team has found a gene involved in regulating length of sleep. In one family, the 69-year-old mother and her 44-year-old daughter typically go to bed around 10 p.m., and Mom rises around 4 and her daughter around 4:30, with no apparent ill effects. The rest of the family has typical sleep patterns.

Blood tests showed the women harbored a mutation in a gene named DEC2 that’s involved in regulation of circadian rhythms, the body’s clock. A check of more than 250 stored DNA samples didn’t find another carrier.
Then lead researcher Ying-Hui Fu, a neurology professor, and colleagues bred mice and fruit flies that carried the mutation. Sure enough, the flies’ activity and brain-wave measurements on the mice showed those with the mutation slept less — and the mice needed less time to recover from sleep deprivation.
The result: A model that “provides a unique opportunity” to study the effects of different amounts of sleep, Fu concluded.


Mimicking behavior may help form social bonds

HealthDay News) - If you want someone to like you, try imitating their actions, new research suggests. Capuchin monkeys playing with a wiffle ball preferred the company of researchers who mimicked their motions over researchers who didn’t, according to the study in the Aug. 14 issue of Science.
Imitation promotes social bonding, encourages strangers to become friends and underpins the formation of social groups, the study authors explained.

“Researchers have known that human beings prefer the behavior of other people who subtly imitate their gestures and other affects,” said Dr. Duane Alexander, director of the Eunice Kennedy Shriver National Institute of Child Health and Human Development, in a news release from the U.S. National Institutes of Health. “Observing how imitation promotes bonding in primates may lead to insights in disorders in which imitation and bonding is impaired, such as certain forms of autism.”
When given a ball, the capuchin monkeys, chosen because they’re known to form close social bonds, either probed it with their fingers, put in their mouths or pounded it on a surface. Each monkey was then paired with two researchers, each of whom had their own wiffle ball. One person did the same motion as the monkey they were paired with -- either probing, mouthing or pounding the ball. The other did something different, such as pounding the ball when the monkey probed it.

After the experiment, the monkeys consistently spent more time near the researcher who imitated them than with the one who did not, according to the investigators at the National Institutes of Health and two Italian research institutions.
When given the opportunity to take a small trinket from the researcher’s hand and then return it for a small food reward, the monkeys also tended to choose the person who’d imitated them.

“It has been argued that the link between behavior matching and increases in affiliation might have played an important role in human evolution by helping to maintain harmonious relationships between individuals,” wrote the authors. “We propose that the same principle also holds for other group-living primates.”


FDA warns of faulty results with blood sugar tests

(AP) - The Food and Drug Administration is warning diabetes patients that certain blood sugar tests can give inaccurate results in patients taking other medications.
Public health regulators told consumers on Friday not to use certain glucose testing strips from Roche, Abbott Laboratories and other companies in combination with dialysis and other biologic drugs. According to FDA those formulations contain non-glucose sugars, which can falsely elevate blood sugar results and increase the risk of insulin overdose.
People with the disease often have to inject insulin, which helps break down carbohydrates, because their bodies have become resistant to the protein.

Dialysis and so-called immunoglobulins are most often taken by patients with serious medical ailments, including kidney failure and rheumatoid arthritis. The biologic drugs’ labeling already warns that they can interfere with glucose monitoring tests, but FDA says the products continue to be used together despite past warnings.

Since 1997 the FDA received 13 reports of death related to the use of glucose testing strips and biologic drug formulations.
“Six of the deaths have occurred since 2008 despite FDA’s efforts to communicate the risk,” the agency said. In some cases, patients experienced brain damage, coma and confusion before death. In a letter issued Thursday, the agency urged doctors and nurses to report any suspected problems related to glucose strips.

Many of the testing strips are used in hospitals and nursing facilities, “which should instead use a laboratory assay to measure a patient’s glucose if the patient is also receiving an interfering product,” the FDA said in a statement.
Brands affected by the announcement include Roche’s Accu-Chek Comfort Curve test strips and Abbott’s Freestyle test strips.
A spokesman for North Chicago-based Abbott said the company has been working on a new version of the Freestyle that addresses the problems cited by the FDA. Abbott expects to submit a marketing application for the new product to FDA in the next 30 days.
Calls to Swiss manufacturer Roche were not immediately returned Friday evening.


Chocolate helps heart attack survivors

(AFP) – Eating chocolate can reduce heart attack survivors’ risk of dying, say researchers who followed 1,169 Swedish men and women, ages 45 to 70, from the time they were hospitalized with their first heart attack in the early 1990s.
Those who ate chocolate two or more times a week were about three times less likely to die from heart disease than those who never ate chocolate, the study found. Smaller amounts of chocolate also offered some protection, Agence France Presse reported.

The study, which appears in the September issue of the Journal of Internal Medicine, is believed to be the first to demonstrate that chocolate can help prevent death in heart attack survivors.
“Our findings support increasing evidence that chocolate is a rich source of beneficial bioactive compounds,” the researchers wrote.
Antioxidants in cocoa likely explain chocolate’s beneficial effects in heart attack survivors, study co-author Dr. Kenneth Mukamal, a researcher at Beth Israel Deaconess Medical Center in Boston, told.