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Published on Leave a comment on Proton Pump Inhibitors Linked to Dementia

A new study has confirmed an association between proton pump inhibitors (PPIs) — drugs that treat heartburn, peptic ulcers, and other acid-related disorders of the upper gastrointestinal tract — and increased risk for dementia in older patients. An earlier study by the same researchers found the same link between PPI use and dementia risk. The drugs work by lowering the amount of acid produced by the stomach. PPIs are among the most frequently prescribed drugs, and include omeprazole (Losec), esomeprazole (Nexium), lansoprazole (Prevacid), and the over-the-counter medication Olex.

The U.S. Food and Drug Administration have warned people to take them for the shortest period possible, namely a few weeks, and only for serious acid reflux, ulcers, or stomach bleeding. Other problems linked to long-term use are: fractures, pneumonia, increased rates of C. difficile, low magnesium levels, and chronic kidney disease. From Science Daily:

Proton pump inhibitors may be associated with increased risk of Dementia

The use of proton pump inhibitors, the popular medications used to treat gastroesophageal reflux and peptic ulcers, may be associated with an increased risk of dementia in a study using data from a large German health insurer, according to an article published online by JAMA Neurology.  The use of proton pump inhibitors (PPIs) has increased among older patients and PPIs are among the most frequently used classes of drugs.

Britta Haenisch, Ph.D., of the German Center for Neurodegenerative Diseases, Bonn, Germany, and coauthors examined the association between the use of PPIs and the risk of dementia using data from 2004 to 2011 on inpatient and outpatient diagnoses and drug prescriptions. Regular PPI use was at least one PPI prescription in each quarter of an 18-month interval.

The study population included 218,493 individuals 75 or older before 144,814 individuals were excluded, leaving 73,679 individuals included in the final analysis. The authors identified 29,510 patients who developed dementia during the study period. Regular users of PPIs (2,950 patients, mostly female and average age nearly 84) had a 44 percent increased risk of dementia compared with those (70,729 patients, mostly female and average age 83) not receiving PPI medication, according to the results.

"The present study can only provide a statistical association between PPI use and risk of dementia. The possible underlying causal biological mechanism has to be explored in future studies. 

Published on

 Last fall a study came out that estimated that annually about 3.3 million deaths throughout the world were caused from air pollution. But a study was presented Friday at the American Association for the Advancement of Science (AAAS) that gave a much higher estimate of annual air pollution deaths: 5.5 million. A horrifying number. And yet... governments, companies, and people resist  measures to cut air pollution. Why? It costs money. And also many people are too poor (e.g., China and India) to use cleaner sources of heating and cooking fuel - so they are damaging their own health in their own homes. From Science Daily:

Poor air quality kills 5.5 million worldwide annually

New research shows that more than 5.5 million people die prematurely every year due to household and outdoor air pollution. More than half of deaths occur in two of the world's fastest growing economies, China and India.

Power plants, industrial manufacturing, vehicle exhaust and burning coal and wood all release small particles into the air that are dangerous to a person's health. New research, presented today at the 2016 annual meeting of the American Association for the Advancement of Science (AAAS), found that despite efforts to limit future emissions, the number of premature deaths linked to air pollution will climb over the next two decades unless more aggressive targets are set.

"Air pollution is the fourth highest risk factor for death globally and by far the leading environmental risk factor for disease," said Michael Brauer, a professor at the University of British Columbia's School of Population and Public Health in Vancouver, Canada. "Reducing air pollution is an incredibly efficient way to improve the health of a population."

For the AAAS meeting, researchers from Canada, the United States, China and India assembled estimates of air pollution levels in China and India and calculated the impact on health. Their analysis shows that the two countries account for 55 per cent of the deaths caused by air pollution worldwide. About 1.6 million people died of air pollution in China and 1.4 million died in India in 2013.

In China, burning coal is the biggest contributor to poor air quality. Qiao Ma, a PhD student at the School of Environment, Tsinghua University in Beijing, China, found that outdoor air pollution from coal alone caused an estimated 366,000 deaths in China in 2013....In India, a major contributor to poor air quality is the practice of burning wood, dung and similar sources of biomass for cooking and heating. Millions of families, among the poorest in India, are regularly exposed to high levels of particulate matter in their own homes.

In the last 50 years, North America, Western Europe and Japan have made massive strides to combat pollution by using cleaner fuels, more efficient vehicles, limiting coal burning and putting restrictions on electric power plants and factories. 

Additional facts about air pollution: - World Health Organization (WHO) air quality guidelines set daily particulate matter at 25 micrograms per cubic metre. - At this time of year, Beijing and New Delhi will see daily levels at or above 300 micrograms per cubic meter metre; 1,200 per cent higher than WHO guidelines..... - According to the Global Burden of Disease study, air pollution causes more deaths than other risk factors like malnutrition, obesity, alcohol and drug abuse, and unsafe sex.... - Cardiovascular disease accounts for the majority of deaths from air pollution with additional impacts from lung cancer, chronic obstructive pulmonary disease (COPD) and respiratory infections. Video: https://youtu.be/Kwoqa84npsU 

Published on Leave a comment on More On Rethinking Cancer Screening

The following is an excellent commentary by Dr. John Mandrola regarding an important British Medical Journal article that I posted about earlier (see Rethinking Cancer Screening). He has a highly regarded web-site and also frequently posts on Medscape. His view is that cancer screening "may be one of Medicine’s largest reversals. A reversal happens when something (testing or treatment) doctors did, and patients accepted, turned out to be non-beneficial." (www.drjohnm.org)

I can't overstate how big a reversal this is in medicine - it's huge, a paradigm change in the making. The reason for this is that studies show that overall death rates are basically the same in screened vs non-screened for mammography, colon, prostate, and lung cancer screening. This means our view of how cancer grows and spreads may have to be reexamined and changed. One possibility suggested by Dr. H. Gilbert Welch is that aggressive cancer is already "a systemic disease by the time it's detectable" (Oct. 28, 2015 post).  From Medscape:

In Cancer Screening, Why Not Tell the Truth?

The problem: cancer screening has not worked. Recent reviews of the evidence show that current-day screening techniques do not save lives. Worse, in many cases, these good-intentioned searches bring harm to previously healthy people.

I realize this sounds shocking. It did to me, too. Millions of women and men have had their breasts squished, veins poked, lungs irradiated, and bowels invaded in the name of "health" maintenance. I've been scolded for forgoing PSA tests and colonoscopy — "you should know better, John."....Anecdotes, however compelling, are not evidence. When you pull up a chair, open your computer, take a breath, suspend past beliefs, and look for the evidence that screening saves lives, it simply isn't there.

One reason that this many people (doctors and patients alike) have been misled about screening has been our collective attachment to the belief that if screening lowers disease-specific death rates, that would translate to lower overall mortality. That is: breast, lung, and colon cancer are bad diseases, so it makes sense that lowering death from those three types of cancer would extend life. It is not so.

In a comprehensive review of the literature[1] published in the BMJ, Drs Vinay Prasad (Oregon Health Sciences University, Portland) and David Newman (School of Medicine at Mount Sinai, New York), along with journalist Jeanne Lenzer, find that disease-specific mortality is a lousy surrogate for overall mortality. They report that when a screening technique does lower disease-specific death rates, which is both uncommon and of modest degree, there are no differences in overall mortality.

The authors cite three reasons why cancer screening might not reduce overall mortality:

  • Screening trials were underpowered to detect differences. I'm no statistician, but doesn't the fact that a trial requires millions of subjects to show a difference, mean there is little, if any, difference?
  • "Downstream effects of screening may negate any disease-specific gains." My translation: harm. Dr Peter Gøtzsche (Nordic Cochrane Center, Copenhagen) wrote in a commentary[2] that "screening always causes harm. Sometimes it also leads to benefits, and sometimes these benefits outweigh the harms." To understand harm resulting from screening, one need only to consider that a prostate biopsy entails sticking a needle through the rectum, or that some drugs used to treat breast cancer damage the heart.
  • Screening might not reduce overall mortality because of "off-target deaths." An illustration of this point is provided by a cohort study[3]that found a possible increased risk of suicide and cardiovascular death in men in the year after being diagnosed with prostate cancer. People die — of all sorts of causes, not just cancer.

Let's also be clear that this one paper is not an outlier. A group of Stanford researchers performed a systematic review and meta-analyses[4] of randomized trials of screening tests for 19 diseases (39 tests) where mortality is a common outcome. They found reductions in disease-specific mortality were uncommon and reductions in overall mortality were rare or nonexistent.

Drs Archie Bleyer and H Gilbert Welch (St Charles Health System, Central Oregon, Portland) reviewed Surveillance, Epidemiology, and End Results (SEER) data from 1976 through 2008 and concluded that "screening mammography has only marginally reduced the rate at which women present with advanced cancer and that overdiagnosis may account for nearly a third of all new breast cancer cases."[5] Likewise, a Cochrane Database Systematic review[6] of eight trials and 600,000 women did not find an effect of screening on either breast cancer mortality or all-cause mortality. This evidence caused the Swiss medical board to abolish screening mammography.[7]

These are the data. It's now clear to me that mass cancer screening does not save lives. But I'm still trying to understand how this practice became entrenched as public-health gospel. It has to be more than fear. Dr Gerd Gigerenzer (Max Planck Institute, Berlin, Germany)...He pointed to language and the ability of words to persuade. Instead of saying "early detection," advocates might use the term "prevention." This, Dr Gigerenzer says, wrongly suggests screening reduces the odds of getting cancer. Doesn't looking for cancer increase the odds of getting the diagnosis of cancer?

Gigerenzer noted two other ways language is used to emphasize screening benefits over harms: -The reporting of benefits in relative, not absolute terms. - The equating of increases in 5-year survival rates with decreases in mortality. I would add to this list of word misuse, the practice of referring to women sent to mammography screening as patients. They are not patients; they are well people. Dr Gigerenzer agreed with the commonsense notion that overall mortality should be reported along with cancer-specific mortality. His editorial included a fact box on breast cancer early detection using mammography provided by the Harding Center for Risk Literacy. I challenge you to tell me why such text boxes should not be shown to people before they undergo screening,

The first action healthcare experts should take is to spread the word that there is nothing about the mass screening of healthy people for cancer that equates to health maintenance. Embrace clear language. Saying or implying that screening saves lives when there are no data to support it and lots to refute it undermines trust in the medical profession.

The second action healthcare experts should take is to stop wasting money on screening. If the evidence shows no difference in overall mortality, why pay for it? I'm not naive to the fact that use of clear language will decrease the number of billable procedures. I am not saying this will be easy. One first move that would be less painful would be to get rid of quality measures or incentives that promote screening.

I want to be clear; I'm not saying all cancer screening is worthless. People at higher baseline risk for cancer, such as those with a family history of cancer or environmental exposures, might derive more benefit than harm from screening. Prasad, Lenzer, and Newman say this group of patients would be a good place to spend future research dollars. That sounds reasonable. I also acknowledge that some people, even when presented with the evidence, will want to proceed with screening. We can argue about who should pay for non–evidence-based medical procedures.

Published on Leave a comment on Some Have Pain From Electromagnetic Fields

 For years I have heard anecdotal stories about some people who sensed electromagnetic fields and were bothered by them. Many considered such stories a little woo-woo....but now comes this study on rats that was based on people with nerve injuries, who have weird sensations and pain from electromagnetic fields of power lines, cell towers, and cell phones on roam. The nerve injured rats had pain from electromagnetic fields similar to what people with nerve-injuries (such as post amputation) report. From Science Daily:

Energy from cellphone towers amplify pain in amputees

For years, retired Maj. David Underwood has noticed that whenever he drove under power lines and around other electromagnetic fields, he would feel a buzz in what remained of his arm. When traveling by car through Texas' open spaces, the buzz often became more powerful. "When roaming on a cellphone in the car kicked in, the pain almost felt like having my arm blown off again," said Underwood, an Iraq War veteran who was injured by an improvised explosive device (IED). His injuries have resulted in 35 surgeries and the amputation of his left arm.... "I didn't notice the power lines, cellphones on roam or other electromagnetic fields until I first felt them in my arm."

Until a recent study led by researchers at The University of Texas at Dallas was published online last month in PLOS ONE, there was no scientific evidence to back up the anecdotal stories of people, such as Underwood, who reported aberrant sensations and neuropathic pain around cellphone towers and other technology that produce radio-frequency electromagnetic fields.

"Our study provides evidence, for the first time, that subjects exposed to cellphone towers at low, regular levels can actually perceive pain," said Dr. Mario Romero-Ortega, senior author of the study and an associate professor of bioengineering in the University's Erik Jonsson School of Engineering and Computer Science. "Our study also points to a specific nerve pathway that may contribute to our main finding."

This is one of the first studies to look at the effects of electromagnetic fields (EMFs) in a nerve-injury model, said Romero-Ortega....There are nearly 2 million amputees in the United States, according to the Centers for Disease Control and Prevention, and many suffer from chronic pain. After interacting with Underwood, Romero-Ortega decided to study the phenomena that Underwood described.

The team hypothesized that the formation of neuromas -- inflamed peripheral nerve bundles that often form due to injury -- created an environment that may be sensitive to EMF-tissue interactions. To test this, the team randomly assigned 20 rats into two groups -- one receiving a nerve injury that simulated amputation, and the other group receiving a sham treatment. Researchers then exposed the subjects to a radiofrequency electromagnetic antenna for 10 minutes, once per week for eight weeks. The antenna delivered a power density equal to that measured at 39 meters from a local cellphone tower -- a power density that a person might encounter outside of occupational settings.

Researchers found that by the fourth week, 88 percent of subjects in the nerve-injured group demonstrated a behavioral pain response, while only one subject in the sham group exhibited pain at a single time point, and that was during the first week. After growth of neuroma and resection -- the typical treatment in humans with neuromas who are experiencing pain -- the pain responses persisted.

"Many believe that a neuroma has to be present in order to evoke pain. Our model found that electromagnetic fields evoked pain that is perceived before neuroma formation; subjects felt pain almost immediately," Romero-Ortega said....Romero-Ortega said since the research produced pain responses similar to those in anecdotal reports and a specific human case, the results "are very likely" generalizable to humans.

"There are commercially available products to block radio frequency electromagnetic energy. There are people who live in caves because they report to be hypersensitive to radiomagnetism, yet the rest of the world uses cellphones and does not have a problem. The polarization may allow people to disregard the complaints of the few as psychosomatic," he said. "In our study, the subjects with nerve injury were not capable of complex psychosomatic behavior. Their pain was a direct response to human-made radiofrequency electromagnetic energy."

At one point in the study, members of the research group showed Underwood video of subjects in the experiment and their response to radiofrequency electromagnetic fields. "It was exactly the same type of movements I would have around cellphones on roam, power lines and other electromagnetic fields," said Underwood, who has served on congressional medical committees and been exposed to some of the best doctors in the world.

Published on Leave a comment on Will the Blue Light From Device Screens Damage Our Eyes?

Now and then I hear people wondering whether the many hours we spend staring at computer, cell phone, and tablet screens is damaging our eyes. And what about fluorescent lighting (which seems to bother many people) and LED lights? After all, the blue light of all our device screens seems intense, and researchers have long known that blue light is toxic to the retina.

Recently researchers measured the blue light on various device screens and lamps (including over extended time periods) and compared it to looking at a clear blue sky in June (but not looking at the sun). They found that most devices put out less blue light than the blue sky on a clear day and all were less than international standards for blue light exposure limits. Whew...we're all OK. But don't use them for a long time at night because their bright emissionInternational Commission on Non-Ionizing Radiation Protectisuppresses melatonin (needed for sleep). From Medscape:

Blue Light From Screens, Bulbs Won't Damage Retina

Despite concerns that staring at devices putting out high amounts of the blue light wavelength could damage human retinas, a recent study finds that most devices put out less of that light than the blue sky on a clear day. "Even under extreme long-term viewing conditions, none of the low energy light bulbs, computers, tablets and mobile phones we assessed suggested cause for concern for public health," said lead author John O'Hagan, head of the Laser and Optical Radiation Dosimetry Group of Public Health England in Chilton, U.K., in an email.

As people are using computers and phones more often and low-energy lighting like fluorescent and LED bulbs is becoming more common, the types of light human eyes are encountering is changing, the researchers pointed out January 15 online in the journal Eye. Compared to traditional incandescent bulbs, electronic screens and low-energy light bulbs tend to emit more blue light, which has long been known to be toxic to the retina, they write.

Based on that toxicity research, the International Commission on Non-Ionizing Radiation Protection (ICNIRP) has proposed a safe exposure limit, below which blue light is unlikely to harm a viewer's eye. O'Hagan and his team measured the blue light emitted by several sources, including mobile phones, tablet computers, laptops and lamps, over time periods similar to the way people use the devices. Then they compared the emissions to the ICNIRP's exposure limits.

After comparing multiple colors on device screens, the researchers found that a white screen had the highest blue light emissions, so they used a white screen set at maximum brightness for their measurements.They also compared the blue light emissions from various devices to the levels people would encounter when looking at a clear blue sky in summertime in Chilton, in southern England, and also to an overcast winter sky in the same location.

The blue light exposure on a clear day in June was around 10 percent of the ICNIRP safe limit. A cloudy day in December produced around 3 percent of the limit. Comparing these natural exposures with light from lamps, computer screens and mobile devices like smartphones, the study team found that the artificial light produced even lower exposures than people normally encounter outdoors. That is, provided they're staring just at the sky, not directly at the sun.

 

Even considering that people may stare at computer screens for hours in the course of work or play, the study team concludes that there's no danger to the retina.They caution, however, that the amount of light that gets transmitted from the surface of the eye to the retina is age-related, so children may be more sensitive to blue light. Light sources that are comfortable for adults could be distressing for children, the authors warn.

Published on Leave a comment on BPA Free and BPA Plastic Have Similar Effects

Once again, research shows that "BPA-free" plastic does not mean it is safer than BPA plastic. Both BPA and BPS (the usual replacement for BPA) leach estrogenic chemicals into the foods and beverages, which means negative health effects when ingested. Both BPA and BPS mimic the effects of estrogen, as well as the actions of thyroid hormone. Yes, this study was done on zebrafish, but think of them as "the canaries in the mine" - if it affects them, it could affect humans also, especially developing fetuses and young children.

BPA  and BPS can leach into food, particularly under heat, from the lining of cans and from consumer products such as water bottles, baby bottles, food-storage containers, sippy cups, and plastic tableware. BPA can also be found in contact lenses, eyeglass lenses, compact discs, water-supply pipes, some cash register and ATM receipts, as well as in some dental sealants. A good way to minimize exposure to BPA , BPS, and other estrogenic chemicals is to try to avoid food and beverages in plastic containers and cans, but instead try to buy and store food in glass containers, jars, and bottles. From Science Daily:

'BPA-free' plastic accelerates embryonic development, disrupts reproductive system

Companies advertise "BPA-free" as a safer version of plastic products ranging from water bottles to sippy cups to toys. Many manufacturers stopped used Bisphenol A to strengthen plastic after animal studies linked it to early puberty and a rise in breast and prostate cancers.Yet new UCLA research demonstrates that BPS (Bisphenol S), a common replacement for BPA, speeds up embryonic development and disrupts the reproductive system.

Using a zebrafish model, Wayne and her colleagues found that exposure to low levels of BPA and BPS -- equivalent to the traces found in polluted river waters -- altered the animals' physiology at the embryonic stage in as quickly as 25 hours. "Egg hatching time accelerated, leading to the fish equivalent of premature birth," said Wayne, who is also UCLA's associate vice chancellor for research. "The embryos developed much faster than normal in the presence of BPA or BPS."

The UCLA team, which included first author Wenhui Qiu, a visiting graduate student from Shanghai University, chose to conduct the study in zebrafish because their transparent embryos make it possible to "watch" cell growth as it occurs.... In a second finding, the team discovered that the number of endocrine neurons increased up to 40 percent, suggesting that BPA overstimulates the reproductive system.... "We saw many of these same effects with BPS found in BPA-free products. BPS is not harmless."

After uncovering her first finding about BPA in 2008, Wayne immediately discarded all of the plastic food containers in her home and replaced them with glass. She and her family purchase food and drinks packaged in glass whenever possible. "Our findings are frightening and important," emphasized Wayne. "Consider it the aquatic version of the canary in the coal mine."

Finally, the researchers were surprised to find that both BPA and BPS acted partly through an estrogen system and partly through a thyroid hormone system to exert their effects. "Most people think of BPA as mimicking the effects of estrogen. But our work shows that it also mimics the actions of thyroid hormone," said Wayne. "Because of thyroid hormone's important influence on brain development during gestation, our work holds important implications for general embryonic and fetal development, including in humans."

Researchers have proposed that endocrine-disrupting chemicals may be contributing to the U.S.' rise in premature human births and early onset of puberty over the past couple of decades. "Our data support that hypothesis," said Wayne. "If BPA is impacting a wide variety of animal species, then it's likely to be affecting human health. Our study is the latest to help show this with BPA and now with BPS."

Published on Leave a comment on Childhood Antibiotic Use Disrupts Gut Microbiome

This confirms what researchers such as Dr. Martin Blaser (in his book Missing Microbes) and others (such as Drs. Sonnenburg and Sonnenburg) have been saying about antibiotic use in infants and children: that there are negative effects to the gut microbiome from antibiotic use in early childhood, and the more frequent the use, the greater the negative effects. It is because the use of antibiotics  in early childhood "disrupts the microbiome".

Penicillins appear to be less disruptive, but macrolides (e.g., Clarithromycin, azithromycin) much more disruptive - the researchers found that the gut microbiota recovered within 6–12 months after a penicillin course, but did not fully recover from a macrolide course even after 2 years . Antibiotics can be life-saving, but they absolutely should not be used casually because there are hidden costs (such as microbiome changes). From Medical Xpress:

Antibiotic use in early life disrupt normal gut microbiota development

The use of antibiotics in early childhood interferes with normal development of the intestinal microbiota, shows research conducted at the University of Helsinki. Particularly the broad-spectrum macrolide antibiotics, commonly used to treat respiratory tract infections, have adverse effects. Macrolides appear also to contribute to the development of antibiotic-resistant strains of bacteria.  ...continue reading "Childhood Antibiotic Use Disrupts Gut Microbiome"

Published on

This study found that greater intake of dietary nitrate and green leafy vegetables was associated with a 20 percent to 30 percent lower risk of primary open-angle glaucoma (POAG), which is the most common form of glaucoma. Glaucoma can lead to vision loss and even blindness (if left untreated).There is evidence that nitric oxide has a role in primary open-angle glaucoma, and that dietary intake of nitrates is beneficial. Green leafy vegetables (iceberg lettuce, romaine lettuce,  mustard, or chard, cooked spinach, and raw spinach) were found to be most beneficial, as well as kale and collard greens. Those who ate the most green leafy vegetables ate about 1.5 servings per day, versus .3 servings daily in the lowest intake group.

Dietary nitrate is predominately derived from green leafy vegetables, which contribute approximately 80% of nitrate intake. But they are found as well in other vegetables, such as beets and carrots. It should be pointed out that those who consumed the most dietary nitrate in this study also consumed more fruits and vegetables, and so also consumed more dietary carotenoids, vitamin C, vitamin E, flavonoids, folate, and vitamin A. Bottom line: try to eat fruits and vegetables daily, especially green leafy vegetables (e.g., a salad). From Science Daily:

Higher dietary nitrate, green leafy vegetable intake associated with lower risk of glaucoma

Greater intake of dietary nitrate and green leafy vegetables was associated with a 20 percent to 30 percent lower risk of primary open-angle glaucoma, according to a study published online by JAMA Ophthalmology.

Elevated intraocular pressure and impaired autoregulation of optic nerve blood flow are implicated in primary open-angle glaucoma (POAG; optic nerve damage from multiple possible causes that is chronic and progresses over time). Evidence suggests that nitrate or nitrite, precursors for nitric oxide, is beneficial for blood circulation. Jae H. Kang, Sc.D., of Brigham & Women's Hospital and Harvard Medical School, Boston, and colleagues evaluated the association between dietary nitrate intake, derived mainly from green leafy vegetables, and POAG. The researchers followed up participants biennially in the prospective cohorts of the Nurses' Health Study (63,893 women; 1984-2012) and the Health Professionals Follow-up Study (41,094 men; 1986-2012). Eligible participants were 40 years or older, were free of POAG, and reported eye examinations. Information on diet was updated with questionnaires.

During follow-up, 1,483 incident cases of POAG were identified. Participants were divided into quintiles (one of five groups) of dietary nitrate intake (quintile 5, approximately 240 mg/d; quintile 1, approximately 80 mg/d). The researchers found that greater intake of dietary nitrate and green leafy vegetables was associated with a 20 percent to 30 percent lower POAG risk; the association was particularly strong (40 percent-50 percent lower risk) for POAG with early paracentral visual field loss (a subtype of POAG linked to dysfunction in blood flow autoregulation). 

Published on Leave a comment on Microbes Are Circling the Earth in Air Currents and Winds

The following article is interesting because it describes how microbes are high up in the sky riding air currents and winds to circle the earth, and eventually drop down somewhere. This is one way diseases can be spread from one part of the world to another. And the study looking at how antibiotic resistant bacteria are spread in the air from cattle feedlots has implications for how antibiotic resistance is spread. From Smithsonian:

Living Bacteria Are Riding Earth's Air Currents

Considering the prevailing winds, David J. Smith figured the air samples collected atop a dormant volcano in Oregon would be full of DNA signatures from dead microorganisms from Asia and the Pacific Ocean. He didn’t expect anything could survive the journey through the harsh upper atmosphere to the research station at the Mount Bachelor Observatory, at an elevation of 9,000 feet.

But when his team got to the lab with the samples, taken from two large dust plumes in the spring of 2011, they discovered a thriving bunch of hitchhikers. More than 27 percent of the bacterial samples and more than 47 percent of the fungal samples were still alive. Ultimately, the team detected about 2,100 species of microbes, including a type of Archea that had only previously been isolated off the coast of Japan. “In my mind, that was the smoking gun,“ Smith says. Asia, as he likes to say, had sneezed on North America.

 Microbes have been found in the skies since Darwin collected windswept dust aboard the H.M.S. Beagle 1,000 miles west of Africa in the 1830s. But technologies for DNA analysis, high-altitude collection and atmospheric modeling are giving scientists a new look at crowded life high above Earth. For instance, recent research suggests that microbes are hidden players in the atmosphere, making clouds, causing rain, spreading diseases between continents and maybe even changing climates.

"I regard the atmosphere as a highway, in the most literal sense of the term," Smith says. "It enables the exchange of microorganisms between ecosystems thousands of miles apart, and to me that’s a more profound ecological consequence we still have not fully wrapped our heads around."

Airborne microbes potentially have huge impacts on our planet. Some scientists attribute a 2001 foot-and-mouth outbreak in Britain to a giant storm in north Africa that carried dust and possibly spores of the animal disease thousands of miles north only a week before the first reported cases. Bluetongue virus, which infects domestic and wild animals, was once present only in Africa. But it's found now in Great Britain, likely the result of the prevailing winds.

In west Texas, researchers from Texas Tech University collected air samples upwind and downwind of ten cattle feedlots. Antibiotic resistant microbes were 4,000 percent more prevalent in the downwind samples. .... What's clear is there are far more viable microbes in far more inhospitable places than scientists expected.

Published on Leave a comment on Rethinking Cancer Screening

A provocative and thought-provoking article in which the title says it all: Cancer screening has not been shown to 'save lives'. The following is from the Medscape analysis/reporting of the original British Medical Journal article and accompanying editorial ( BMJ. January 2016, Article, Editorial), and both the original and Medscape analysis are well worth reading. From Medscape:

Cancer Screening Has Not Been Shown to 'Save Lives'

Debates about cancer screening programs tend to focus on when to start, who to screen, and the frequency of screening. But some investigators are asking a far more provocative question: Do screening programs actually save lives?

We do not know the answer to that question, and would need to conduct massive clinical trials to find out, said Vinay K. Prasad, MD, MPH, assistant professor of medicine at the Oregon Health Sciences University in Portland."Proponents of cancer screening say that screening tests have been shown to save lives. What we're trying to show is that, strictly speaking, that's sort of an overstatement," he told Medscape Medical News.

In an analysis published online January 6 in the BMJ, Dr Prasad and his colleagues argue that although cancer screening might reduce cancer-specific mortality, it has not conclusively been shown to have an effect on overall mortality. The researchers go on to suggest that the harms of screening might actually contribute to overall mortality rates. These potential harms include false-positive results that lead to unnecessary biopsies or therapeutic interventions and overdiagnosis, in which treatment is delivered for a condition that is unlikely to affect patients during their natural lifespans.

"There are two chief reasons why cancer screening might reduce disease-specific mortality without significantly reducing overall mortality," the researchers write. "Firstly, studies may be underpowered to detect a small overall mortality benefit. Secondly, disease-specific mortality reductions may be offset by deaths due to the downstream effects of screening." "The bar to say that screening saves lives should be overall mortality, and we haven't met that bar," Dr Prasad told Medscape Medical News.

The rationale for cancer screening is based on the assumptions that screening will reduce deaths from cancer and that lowering cancer-specific deaths will decrease overall mortality. These assumptions remain unsupported by facts, Dr Prasad's team contends.

They illustrate this point with data from the National Lung Cancer Screening Trial (NLST). Although there was a 20% relative reduction in lung cancer deaths with low-dose CT screening, compared with chest x-ray, and a 6.7% relative reduction in overall mortality, the absolute reduction in risk for overall mortality was just 0.46%....The team also notes that "the benefit in lung cancer mortality of CT screening (estimated to avert over 12,000 lung cancer deaths in the United States annually) must be set against the 27,034 major complications (such as lung collapse, heart attack, stroke, and death) that follow a positive screening test."

The decision to undergo screening should be part of an informed discussion between the patient and clinician that takes into account personal preferences and the risks and benefits of screening. Dr Prasad explained. "Declining screening may be a reasonable and prudent choice for many people," the researchers write. "Doctors should be comfortable with whatever choice people make when they hear about all the potential benefits and the known harms," Dr Prasad added.

However, in an accompanying editorial, Gerd Gigerenzer, PhD, from the Max Planck Institute for Human Development in Berlin, argues that "rather than pouring resources into 'megatrials' with a small chance of detecting a minimal overall mortality reduction, at the additional cost of harming large numbers of patients, we should invest in transparent information in the first place." He explains that information about screening should be presented in a "fact box" that lays out the benefits and risks of mammography with numbers for how many women would be affected."It is time to change communication about cancer screening from dodgy persuasion into something straightforward," he concludes.

Richard L. Schilsky, MD, chief medical officer for the American Society of Clinical Oncology (ASCO), said that although, in general, ASCO supports cancer screening, "it's a very imperfect process....The often high variability in the natural history of many cancers has been the source of particular confusion and uncertainty surrounding screening, he noted. For example, there is little value in screening for aggressive cancers for which interventions are unlikely to make a difference in outcomes, no matter how early the disease can be detected. Conversely, "if the cancer is never going to kill you, no matter what the doctors do, then screening won't help either," he said. Additionally, there are some cancers for which treatments are sufficiently effective that they can be successfully managed whether they are diagnosed at an early or later stage. "When you consider all these factors, the number of individuals who will actually benefit from detecting a screen-detected cancer is very small," Dr Schilsky said.