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

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1.4 billion risk disease from lack of exercise: WHO

PARIS - More than 1.4 billion adults are putting themselves at heightened risk of deadly diseases by not getting enough exercise, doctors are warning, with global activity levels virtually unchanged in nearly two decades. 

With richer nations enjoying an increasingly comfortable, sedentary lifestyle, a study by the World Health Organization said a third of women and a quarter of men worldwide are in the firing line for killer conditions such as heart disease, diabetes and cancer unless they up their physical activity. 

"Insufficient physical activity is a leading risk factor for non-communicable diseases, and has a negative effect on mental health and quality of life," said the study of world exercise levels published Wednesday by The Lancet Global Health Journal. 

The WHO recommends each adult do at least 150 minutes "moderate-intensity" exercise -- such as brisk walking, swimming or gentle cycling -- each week, or 75 minutes "vigorous-intensity" activity -- such as running or team sports. 

The study tracked activity levels of 1.9 million people in 168 countries across the world during 2016. 

Researchers found there had been no improvement in physical activity levels since 2001, despite numerous public health initiatives extolling the benefits of exercise.

More than a quarter of the world's adults (1.4 billion people) were insufficiently active, according to the data. 

"We definitely haven't done enough" to encourage people to exercise, the WHO's Regina Guthold, lead study author, told AFP. 

"We have seen basically no progress."

The study authors highlighted several worrying trends, including a stark divide in exercise rates between poor and rich nations, and between men and women. 

WEALTH, GENDER GAPS 

Levels of insufficient activity to guard off non-communicable killers, including dementia and cardiovascular diseases, are more than twice as high in high-income countries compared to developing nations.

Guthold said the link between the lifestyle in wealthier nations -- more time indoors, longer office hours, more easily accessible high-calorie foods -- and lower exercise levels, was part of a "clear pattern" of poorer health coming with urbanization. 

"As countries urbanize, people who used to be, say, farmers, and got a lot of physical activity through their work all of a sudden live in an urban environment where they might be without work or move to a sedentary job, so societies need to compensate," she said.

In four countries -- Kuwait, American Samoa, Saudi Arabia and Iraq -- more than half of adults were classified as insufficiently active.

In Kuwait, an oil-flush gulf state where temperatures regularly top 45 Celsius (113 Fahrenheit), a whopping two-thirds (67 percent) of adults weren't exercising enough.

Melody Ding of the University of Sydney, who worked on the paper, said there were a variety of reasons why some countries were more active than others, including "biological, psychosocial, institutional, cultural and environmental barriers". 

"I consider one of the biggest barriers being our environment -- physical activity has been engineered out of life, with desk-based jobs replacing labor jobs, lifts replacing stairs, cars replacing active travel," she told AFP. 

"Technological advancement has made our life more convenient but also less active." 

Women still lag behind men in nearly every region of the world, with the gender exercise gap highest in Bangladesh, Eritrea, India, Iraq and the Philippines, the study found. 

"In these settings, women are often expected to be at home, take care of the children, manage the household and so sometimes don't always have time to exercise," said Guthold. 

One bright spot on the global exercise map was southeast Asia, where women were equally as active as men in the only region where inactivity has decreased since 2001.

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Low-carb diet linked to elevated mortality risk: study

PARIS, France - Middle-aged people who get roughly half their daily calories from carbohydrates live several years longer on average than those with low-carb diets, researchers reported Friday.

The findings, published in The Lancet, challenge a trend in Europe and North America toward so-called Paleo diets that shun carbohydrates in favor of animal protein and fat.

Proponents of these "Stone Age" diets argue that the rapid shift 10,000 years ago -- with the advent of agriculture -- to grains, dairy and legumes has not allowed the human body enough time to adapt to these high-carb foods.

For the study, under 40 percent of energy intake from carbohydrates qualifies as a low-carb regimen, though many such diets reduce the share to 20 percent or less. 

At the other extreme, a 70 percent or higher share of carbohydrates -- such as pasta, rice, cakes, sugary drinks -- can also reduce longevity, but by far less, the scientists found.

"Low-carb diets that replace carbohydrates with protein or fat are gaining widespread popularity as a health and weight loss strategy," said lead author Sara Seidelmann, a researcher at Brigham and Women's Hospital in Boston.

"However, our data suggests that animal-based low carbohydrate diets might be associated with shorter overall lifespan and should be discouraged."

Replacing meat with plant-based fats (such as avocados and nuts) and proteins (such as soy products and lentils) reduces the risk of mortality, Seidelmann and her team found.

The optimal balance of food groups for longevity remains hotly debated. 

Many studies have concluded that eating carbohydrates in moderation -- 45 to 55 percent calories -- is best, but others report improved short-term, cardio-metabolic health with high-protein, high-fat diets.

Measures of metabolic health include blood pressure, good and bad cholesterol, and blood sugar levels.

Seidelmann and colleagues poured over the medical histories of nearly 15,500 men and women who were 45-64 when they enrolled -- between 1987 and 1889 -- in a health survey spread across four locations in the United States.

Participants filled out detailed questionnaires about their dietary habits -- what foods, how much, how often, etc.

Over a 25-year follow up period, more than 6,000 of the men and women died.

People who got 50-55 percent of their calories from carbohydrates outlived those with very low-carb diets, on average, by four years, and those with high-carb diets by one year.

A review of medical records for an additional 432,000 people from earlier studies yield confirmed the results, which are also in line with World Health Organization (WHO) recommendations. 

"There is nothing to be gained from long-term adherence to low-carbohydrate diets rich in fats and proteins from animal origins," said Ian Johnson, a nutrition researcher at Quadram Institute Bioscience in Norwich, England, commenting on the research, in which he did not take part. 

But carb quality, not just quantity, is crucial he added.

"Most should come from plant foods rich in dietary fibre and intact grains, rather than from sugary beverages or manufactured foods high in added sugar." 

Fibers also help maintain a healthy gut flora, now considered to be a major player in health and disease.

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Antidepressants don't work for teens, kids: study

PARIS, France - Most available antidepressants are ineffective for children and teenagers with major depression, and some may be unsafe, according to an overview of medical literature published Thursday.

Only one drug, fluoxetine, was found to work better at relieving the symptoms of depression than a look-alike placebo with no active ingredients, said the study, published in The Lancet.

Another drug, venlafaxine, was linked with an increased risk of suicidal thoughts and attempts compared with placebo and five other antidepressants, it reported.

More broadly, there is a paucity of well-designed clinical trials on the impact of these drugs on youngsters, the authors cautioned.

"The balance of risks and benefits of antidepressants for the treatment of major depression does not seem to offer a clear advantage in children and teenagers," said co-author Peng Xie from The First Affiliated Hospital of Chongqing Medical University in China.

The international team of researchers recommended that youths taking such medications be monitored closely regardless of the antidepressant chosen, particularly at the beginning of treatment.

They also called for more transparency and information sharing, lamenting in particular the lack of data at the individual level.

"We can’t be completely confident about the accuracy of the information contained in published and unpublished trials," lead author Andrea Cipriani at the University of Oxford said in a statement.

"Delay in implementing responsible data sharing policies has negative consequences for medical research and patient outcomes."

Major depressive disorder affects about 3 percent of children aged 6 to 12 years, and about 6 percent of teenagers aged 13 to 18 years.

Many clinical guidelines recommend psychological treatments as the first-line treatment for depression.

But in the United States, for example, the use of antidepressants has slowly increased between 2005 and 2012.

The proportion of US children and teenagers taking antidepressants climbed from 1.3 to 1.6 percent, and in Britain from 0.7 percent to 1.1 percent, the study showed.

Sertraline is the most widely prescribed antidepressant in the USA, and fluoxetine is the most common in Britain.

The study covered 34 clinical trials involving 5,260 participants, aged 9 to 18.

Two-thirds of the trials were funded by pharmaceutical companies.

In a comment, also in The Lancet, Jon Jureidini from the University of Adelaide in Australia questioned whether the lack of data about individual patients obscured the true number of suicidal events.

"Claims that appropriate access to such data is incompatible with intellectual property constraints and patient privacy must be strongly resisted."

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Alcoholism drug may help design HIV cure: study

PARIS - A treatment for alcoholism can reactivate dormant HIV, potentially allowing other drugs to spot and kill the virus hiding out in human immune cells, researchers said Tuesday.

The medication, called Disulfiram, draws out the AIDS-causing virus without any side effects for patients, according to a study published in The Lancet.

In people undergoing treatment for AIDS, the virus can take cover in certain cells and hide away, only to reemerge once therapy is stopped.

This latency has been one of the biggest hurdles in developing a cure.

"Waking up" the virus - and then destroying it -- is a promising strategy for ridding patients of HIV.

But other drugs which are able to rouse HIV from its dormant state are toxic to humans.

In clinical trials led by Sharon Lewin, a professor at the University of Melbourne, 30 people on antiretroviral treatment (ART) were given increasing doses of Disulfiram over a period of three days.

At the highest dose, there was evidence of slumbering HIV being stimulated, with no side effects.

"This trial clearly demonstrates that Disulfiram is not toxic and is safe to use, and could quite possibly be the game changer we need," Lewin said in a statement.

The next step will be to test Disulfiram's rousing effect in combination with a virus-killing drug.

"Waking up the virus is only the first step to eliminating it," said the study's lead author Julian Elliott, head of clinical research in the department of infectious diseases at Alfred Hospital in Melbourne, Australia.

"Now we need to work out how to get rid of the infected cell."

Approximately 34 million people have died of HIV-related causes worldwide. By the end of 2014, there were an estimated 36.9 people living with HIV globally.

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Woman has baby after womb transplant in world first: Lancet

PARIS - A 36-year-old Swede has become the world's first woman to give birth after receiving a womb transplant, medical journal The Lancet said on Saturday, describing the event as a breakthrough for infertile women.

The healthy baby boy was born last month, it said. Both mother and infant are doing well.

Weighing 1.775 kilos (3.9 pounds), the baby was born by Caesarean section at 31 weeks after the mother developed pre-eclampsia, a pregnancy condition, the journal said.

The woman had a genetic condition called Rokitansky syndrome which meant she was born without a womb, although her ovaries were intact.

The surgeons said the exploit smashes through the last major barrier of female infertility -- the absence of a uterus as a result of heredity or surgical removal for medical reasons.

"Absolute uterine factor infertility is the only major type of female infertility that is still viewed as untreatable," they said in a paper published by the British journal.

The replacement organ came from a 61-year-old woman, a close family friend who had been through menopause seven years earlier. The organ was transplanted in a 10-hour operation last year.

The recipient underwent in-vitro fertilization, in which eggs were harvested from her ovaries and fertilized using sperm from her partner, and then cryogenically preserved.

A year after the transplant, a single early-stage embryo was inserted into the transplanted womb. A pregnancy test three weeks later was positive.

The womb encountered a brief episode of rejection, but this was successfully tackled by increasing a dose of corticosteroid drugs to suppress the immune system.

- A decade of research -

"Our success is based on more than 10 years of intensive animal research and surgical training by our team and opens up the possibility of treating many young females worldwide that suffer from uterine infertility," the Lancet quoted Professor Matts Braennstroem of the University of Gothenburg, who led the operation, as saying.

"What is more, we have demonstrated the feasibility of live-donor uterus transplantation, even from a post-menopausal donor."

Rokitansky syndrome -- Mayer-Rokitansky-Kuester-Hauser syndrome to give it its full name -- affects approximately one in 4,500 newborn girls, previous research has found.

The options open to women with this disorder, or who have had a hysterectomy, are adoption or having a baby through a surrogate mother.

But surrogacy is not allowed in many countries because of ethical, legal or religious reasons.

The unnamed Swede was one of nine who received a uterus from live donors under Braennstroem's programme.

Two of them had to undergo hysterectomy within a few months, either because the womb became infected or blood flow to it became clotted, the paper said.

The other seven women began menstruation during the first two to three months, and the transplanted organs remained viable during the first year after the operation.

Two other transplant attempts have been reported elsewhere, but neither resulted in a live birth.

The first, carried out in Saudi Arabia in 2000, ended in failure after three months when the uterus became necrotic and had to removed.

The second, carried out in Turkey in 2011, entailed a uterus that was transplanted from a deceased donor, resulting in pregnancies that miscarried within six weeks.

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Pollution, smoking, roads, obesity kill 4.7m Chinese a year

PARIS - Air pollution, smoking, obesity and accidents, especially on the road, kill at least 4.7 million Chinese a year and cost the country tens of billions of dollars, researchers said on Friday.

In an overview published in The Lancet, they said China had in some respects made great strides in health, boosting the average lifespan from 40 years in 1950 to 76 years in 2011 and rolling back many infectious diseases.

On the other hand, the risk of premature death and sickness from pollution, smoking, road crashes and "lifestyle" ailments is worse than before.

The trio of Chinese and US experts said China had the chance of learning from rich countries which had already been down this path, a by-product of rising prosperity.

"Many of these risks can be lowered by interventions with shown effectiveness," they said.

"China has the opportunity to avoid repetition of the full toll of preventable disease burdens suffered by high-income countries from non-communicable diseases."

The research, led by Jeffrey Koplan, a professor at Emory University in Atlanta, provides the following snapshot, which includes figures that have been published previously:

-- Air pollution: A million deaths annually are attributable to inhaling indoor smoke from solid fuels, and another 1.2 million from inhaling fine particulate matter outdoors.

The economic cost from particulate air pollution among urban dwellers was 341 billion yuan ($55 billion, 42 billion euros) in 2006, according to the paper.

-- Smoking: 1.4 million premature deaths each year, costing 41 billion yuan annually on the basis of values for 2000.

-- Road fatalities: China has more than 800,000 deaths annually from accidents, which are "mainly" accounted for by road accidents, according to the report. (Separately, the United Nations estimated 275,000 road deaths in China in 2010).

Accidents of all kinds are the leading cause of death in the 1-39 age group and cost 65 billion yuan in medical expenses alone, said the study.

-- Obesity: 363,000 fatalities each year attributable to high body-mass index, a condition linked to heart disease, diabetes and other ailments. The cost -- in 2003 -- was 21 billion yuan.

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