10 medical myths we should stop believing

You might assume that standard medical advice was supported by mounds of scientific research. But researchers recently discovered that nearly 400 routine practices were flatly contradicted by studies published in leading journals.

Of more than 3,000 studies published from 2003 through 2017 in JAMA and the Lancet, and from 2011 through 2017 in the New England Journal of Medicine, more than 1 in 10 amounted to a “medical reversal”: a conclusion opposite of what had been conventional wisdom among doctors.

“You come away with a sense of humility,” said Dr. Vinay Prasad of Oregon Health and Science University, who conceived of the study. “Very smart and well-intentioned people came to practice these things for many, many years. But they were wrong.”

Some of those ideas have been firmly dislodged, but not all. Now Prasad and his colleagues are trying to learn how widespread are discredited practices and ideas.

Here are 10 findings that contradict what were once widely held theories.

Peanut allergies occur whether or not a child is exposed to peanuts before age 3.

Pediatricians have counseled parents to keep babies away from peanuts for the first three years of life. As it turns out, children exposed to peanuts before they were even 1 year old have no greater risk of peanut allergies.

Fish oil does not reduce the risk of heart disease.

At one point, the notion that fish fats prevented heart trouble did seem logical. People whose diets contain a lot of fatty fish seem to have a lower incidence of heart disease. Fatty fish contains omega-3 fatty acids. Omega-3 supplements lower levels of triglycerides, and high levels of triglycerides are linked to an increased risk of heart disease. Not to mention that omega-3 fatty acids seem to reduce inflammation, a key feature of heart attacks.

But in a trial involving 12,500 people at risk for heart trouble, daily omega-3 supplements did not protect against heart disease.

A lifelike doll carried around by teenage girls will not deter pregnancies.

These dolls wail and need to be “changed” and “cuddled.” The idea was that girls would learn how much work was involved in caring for an infant. But a randomized study found that girls who were told to carry around “infant simulators” actually were slightly more likely to become pregnant than girls who did not get the dolls.

Ginkgo biloba does not protect against memory loss and dementia.

The supplement, made from the leaves of ginkgo trees, was widely used in ancient Chinese medicine and still is promoted as a way to preserve memory. A large federal study, published in 2008, definitively showed the supplement is useless for this purpose. Yet ginkgo still pulls in $249 million in sales. Did people just not get the message?

To treat emergency room patients in acute pain, a single dose of oral opioids is no better than drugs like aspirin and ibuprofen.

Yes, opioids are powerful drugs. But a clinical trial showed that much safer alternatives relieve pain just as well among emergency room patients.

Testosterone treatment does not help older men retain their memory.

Some men have low levels of testosterone and memory problems, and early studies had hinted that middle-aged men with higher testosterone levels seemed to have better preserved tissue in some parts of their brains. Older men with higher testosterone levels also seemed to do better on tests of mental functioning.

But a rigorous clinical trial showed that testosterone was no better than a sugar pill in helping older men avoid memory loss.

To protect against asthma attacks, it won’t help to keep your house free of dust mites, mice and cockroaches.

The advice from leading medical groups has been to rid your home of these pests if you or your child has asthma. The theory was that allergic reactions to them can trigger asthma attacks. But intensive pest management in homes with children sensitized to mouse allergens did nothing to reduce the frequency of their asthma attacks, researchers reported in 2017.

Step counters and calorie trackers do not help you lose weight.

In fact, the reverse is true. Among 470 dieters followed for two years, those who wore devices tracking the steps they took and calories they burned actually lost less weight than those who just followed standard advice.

Torn knee meniscus? Try physical therapy first, surgery later.

An estimated 460,000 patients in the United States get surgery each year to fix knee cartilage that tears, often because of osteoarthritis. The tear is painful, and many patients fear that if it is not surgically treated, the pain will linger.

But when patients with a torn meniscus and moderate arthritis were randomized to six months of physical therapy or surgery, both groups improved, and to the same extent.

If a pregnant woman’s water breaks prematurely, the baby does not have to be delivered immediately.

Sometimes, a few weeks before a woman’s due date, the membrane surrounding her fetus ruptures and amniotic fluid spills out. Obstetricians worried that bacteria could invade what had been a sterile environment around the fetus, causing infection. Better to deliver the baby immediately, doctors thought.

But a clinical trial found that if obstetricians carefully monitor the fetus while waiting for labor to begin naturally, the fetus is at no greater risk for infection. And newborns left to gestate were healthier, with less respiratory distress and a lower risk of death, than those who were delivered immediately after a break.


2019 New York Times News Service

source: news.abs-cbn.com

Sex, masturbation may hamper Ebola eradication

Isolated flare-ups of Ebola may point to a higher risk of transmission via the semen of male survivors than previously thought, undermining hopes of ending West Africa's deadly outbreak by the end of the year.

The World Health Organization's advice is that all male survivors should be tested three months after the onset of symptoms and then monthly until they know they have no risk of passing on the virus through their semen, Bruce Aylward, head of the WHO's Ebola response, told a news conference.

But a forthcoming study in the New England Journal of Medicine, based on around 200 survivors, found that around half still had traces of the virus in their semen after six months, a clinician familiar with the study told Reuters.

"The old advice of three months is no longer good," the clinician said. "The number of people with persistent virus in their semen is much greater than expected."

The clinician, who was not authorised to speak about the study, added that the risk might not only be from sex but also from masturbation.

"It's not the sex that is dangerous, it's the semen that is dangerous," said Aylward, who mentioned the study during a news conference but did not give details. "How people actually get exposed, in soiled linens or whatever, is not clear."

Transmission through semen may explain why a few cases continue to occur even though the outbreak has been almost completely eradicated by an intense international effort, recently bolstered by the deployment of a trial vaccine in Guinea and Sierra Leone.

"This virus and this outbreak in particular has a nasty sting in the tail," Aylward said. "It's not finished, by a long shot."

The latest flare-up, in a village on the northern border of Sierra Leone, followed the death of a 67-year-old woman late last month, 50 days after the previous confirmed case in the region. Transmission chains are considered to have been broken after 42 days with no new infections.

However, Aylward said that sexual transmission was "obviously not a huge risk, because if it were we would have seen a lot more in the areas that were hardest hit at the beginning of this outbreak."

source: www.abs-cbnnews.com

Ebola vaccine promising in first human trials: NIH

WASHINGTON - Researchers say they are one step closer to developing an Ebola vaccine, with a Phase 1 trial showing promising results, but it will be months at the earliest before it can be used in the field.

The news comes amid the worst ever outbreak of the hemorrhagic fever, which has killed 5,500 people so far, mostly in West Africa.

Pharmaceutical companies and health agencies scramble to fast-track experimental drugs and vaccines that could help.

In the first phase of testing, all 20 healthy adults injected with a higher or lower dose of the vaccine developed antibodies needed to fight Ebola, said the National Institutes of Health (NIH), which conducted the study.

Results were published Wednesday in the New England Journal of Medicine.

"The unprecedented scale of the current Ebola outbreak in West Africa has intensified efforts to develop safe and effective vaccines," said Anthony Fauci, head of the National Institute of Allergy and Infectious Diseases, which is developing the vaccine alongside GlaxoSmithKline.

The vaccines under development "may play a role in bringing this epidemic to an end and undoubtedly will be critically important in preventing future large outbreaks," he noted.

"Based on these positive results from the first human trial of this candidate vaccine, we are continuing our accelerated plan for larger trials to determine if the vaccine is efficacious in preventing Ebola infection," he added.

But the NIAID/GSK vaccine is still a long way from being ready for use in the field.

The NIAID is "in active discussions with Liberian officials and other partners about next-stage vaccine testing in West Africa" for efficacy and safety, the NIH said, but no announcement on larger-scale trials was expected before early next year.

There is no licensed treatment or vaccine against the Ebola virus, which is transmitted through bodily fluids and has been fatal in an estimated 70 percent of cases in the current outbreak.

Antibodies within four weeks

The volunteers were injected starting in September, and each showed a positive result for Ebola antibodies in blood tests within four weeks.

The 10 volunteers in the higher-dose group developed higher antibody levels, the NIH said.

In addition, two of the lower-dose group and seven of the higher-dose group developed a kind of immune cell called CD8 T cells, which are an important part of the body's response against disease.

"We know from previous studies in non-human primates that CD8 T cells played a crucial role in protecting animals" who got the vaccine and then were exposed to Ebola, said researcher Julie Ledgerwood, the trial’s principal investigator.

None of the volunteers experienced serious side effects within the study period, though two had a brief, mild fever within the 24 hours after the injection.

The vaccine uses a modified chimpanzee cold virus to deliver segments of genetic material from the Ebola virus.

The genetic material cannot spread in the body like the virus does, but can still prompt the antibody response.

The version tested at NIH contains material from two species of Ebola -- the Zaire species, responsible for the outbreak in West Africa, and another called Sudan Ebola.

"This work is encouraging and another significant contribution to efforts to tackle the Ebola crisis," said Dr Jeremy Farrar, Director of the Wellcome Trust.

The White House also congratulated the vaccine researchers.

"We congratulate Drs Francis Collins and Tony Fauci and their teams at the National Institutes of Health on the first published results from Phase 1 clinical trials of a promising Ebola vaccine candidate," a White House statement said, adding that President Barack Obama would visit the NIH next week.

A second version of the vaccine, aimed at blocking just Zaire Ebola, also began human testing in October, at the University of Maryland.

Another experimental vaccine that has shown promising results in primates is the Canadian VSV-EBOV, licensed by US firm NewLink Genetics. It is also in early stages of human testing.

source: www.abs-cbnnews.com

Baby's HIV 'cure not a fluke,' US researchers say

WASHINGTON - A little girl who was treated for HIV shortly after birth still shows no sign of infection at age three, suggesting her apparent cure was not a fluke, US researchers said Wednesday.

The story of the first child known to have been cured of HIV through early treatment with powerful doses of antiretroviral drugs -- what researchers call "sustained remission" rather than a cure -- was initially announced in March when she was two and a half.

A handful of HIV-infected adults around the world have been described in medical literature as newly free of the disease, most famously Timothy Brown, also known as "the Berlin patient," who was given a bone marrow transplant for leukemia that wiped out his HIV as well.

But no easy method has emerged to eradicate the three-decade-old human immunodeficiency virus that infects 34 million people globally and is responsible for 1.8 million deaths each year.

The girl's updated case report in the New England Journal of Medicine also sought to answer questions raised by outside experts over whether she was ever really infected, by describing DNA and RNA tests that were positive for HIV just over a day after birth.

The child was given antiretroviral drugs until the age of age 18 months and, after a year and half without treatment, no sign of the disease has returned, the article said.

"Our findings suggest that this child's remission is not a mere fluke but the likely result of aggressive and very early therapy that may have prevented the virus from taking a hold in the child's immune cells," said lead author Deborah Persaud, a virologist and pediatric HIV expert at the Johns Hopkins Children's Center.

The child's mother gave birth to her prematurely, about a month early, and had not received any prenatal care. She was unaware that she was HIV positive until she was tested at the Mississippi hospital where she delivered.

The newborn also tested positive for HIV, and the high level found in her blood suggested that she had become infected with human immunodeficiency virus while in the womb, researchers said.

She also showed signs of HIV in blood tests at 19 days of age, data that "support the authors' perspective that the infant was truly infected," said an accompanying editorial by Scott Hammer, a leading HIV scientists at Columbia University Medical Center.

"The big question, of course, is, 'Is the child cured of HIV infection?' The best answer at this moment is a definitive 'maybe,'" he wrote.

A longer term follow up of the child is needed, he said, cautioning that her case may be "unique," even as it shows a proof of principle that may lead to more rigorous studies down the road.

The child was given antiretroviral drugs for the first 15-18 months of her life, when she was lost to follow up.

Her mother brought her back to doctors at 23 months of age, saying she had last given her anti-HIV medication at age 18 months.

"This happened almost by accident," said Anthony Fauci, director of the National Institute for Allergy and Infectious Diseases.

"It wasn't that the doctor said 'let's stop the therapy.' This is not recommended for home use," he told AFP.

Tests at 23 months were negative for HIV, and by the time the child reached 30 months of age, tests still showed no sign of HIV or HIV antibodies, said the study.

"We're thrilled that the child remains off medication and has no detectable virus replicating," said pediatrician Hannah Gay of the University of Mississippi Medical Center.

"We've continued to follow the child, obviously, and she continues to do very well," said Gay, who first treated her.

"There is no sign of the return of HIV, and we will continue to follow her for the long term."

The girl's medical team believes the reason for her success was the early intervention, and they hope to investigate whether treating other infected infants within hours or days of birth could show similar outcomes.

A US-government funded study is set to begin in low and middle income countries in 2014 that would test the method in HIV-infected newborns on a wider scale, Fauci said.

source: www.abs-cbnnews.com