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Published on Leave a comment on Cut Back or Avoid High Fructose Corn Syrup During Pregnancy

Another reason to cut back on soda and highly processed foods. Research in mice and women showed that a high-fructose diet during pregnancy may cause defects in the placenta and restrict fetal growth. But the advice in the article was disturbing - rather than giving a drug (allopurinol) to pregnant women with high fructose levels (which is what the researchers suggest), why not focus on giving them nutrition advice and strongly encourage them to avoid or cut back on high fructose products? Especially foods containing high fructose corn syrup (HFCS), such as soda and highly processed desserts.

Nutrition and why it's important should be discussed extensively with pregnant women, starting with the first prenatal care visit. Good advice is to read food labels and avoid products that list fructose, high-fructose corn syrup, or corn syrup solids. One easy first step would be to stop drinking soda and sweet drinks and juices. The researchers admit: "One of the best ways to ensure healthy maternal and fetal outcomes is by eating natural foods." Natural foods and good nutrition, not drugs, should be the focus. From Science Daily:

High-fructose diet during pregnancy may harm placenta, restrict fetal growth

Consuming a high-fructose diet during pregnancy may cause defects in the placenta and restrict fetal growth, potentially increasing a baby's risk for metabolic health problems later in life, according to research in mice and people by a team at Washington University School of Medicine in St. Louis.

However, giving the mice allopurinol, a generic drug frequently prescribed to treat gout and kidney stones, appears to mitigate the negative maternal and fetal effects. The findings suggest it may be possible to devise a prenatal screening test and treatment plan for pregnant women with high fructose levels. The study is available online in Scientific Reports, a journal affiliated with Nature Publishing Group.

Fructose, a sugar occurring naturally in fruits and honey, has been popular for decades among food manufacturers who process it into high-fructose corn syrup used to sweeten food and beverages. In fact, researchers have reported that the refined sugar accounts for more than half of all sweeteners used in the U.S. food-supply chain. And in recent years, there's growing concern that fructose in processed foods and sugary drinks may be linked to diabetes and obesity. "Since the early 1970s, we've been eating more fructose than we should," said Kelle H. Moley, MD,.....This study shows potentially negative effects of a high-fructose diet during pregnancy." 

Fructose is processed differently than other sugars such as glucose, which the body converts into energy. Instead, fructose is broken down by liver cells that turn the sugar into a form of fat known as triglycerides while also driving high levels of uric acid, a normal waste product found in urine and stool. Too much uric acid can create metabolic mayhem resulting in obesity, type 2 diabetes and other health conditions.

Studying mice, the researchers found elevated uric acid and triglycerides in otherwise healthy mice who were fed a high-fructose diet during pregnancy. Additionally, the mice developed smaller fetuses and larger placentas than those fed standard rodent chow.

Maternal health also may suffer. Metabolic problems caused by high levels of uric acid and fat increase a woman's risk of developing pregnancy complications such as preeclampsia -- a potentially serious condition in pregnancy often marked by high blood pressure, swelling and high protein levels in the urine -- and gestational diabetes, Moley said.

To assess the relevance of the mouse data in pregnant women, the researchers examined the association between fructose and placental uric acid levels in a small controlled group of 18 women who underwent scheduled cesarean sections. The women had no disorders that would have caused elevated uric acid. "We found a correlation suggesting similar maternal and fetal effects occur in humans," Moley said.

Published on Leave a comment on Medical Error Is the Third Leading Cause of Death In the US

The title of the article says it all.  The authors of this report calculate that 9.5% of deaths in the US or 251,454 deaths annually (which equates to nearly 700 deaths a day) are due to medical errors. Others have pointed out that the number of severe patient injuries resulting from medical errors are also overlooked, with some estimates saying that this number could be as high as 40 times the death rate.From Medscape:

Medical Error Is Third Leading Cause of Death in US

Medical error is the third leading cause of death in the United States, after heart disease and cancer, according to findings published today in BMJ. As such, medical errors should be a top priority for research and resources, say authors Martin Makary, MD, MPH, professor of surgery, and research fellow Michael Daniel, from Johns Hopkins University School of Medicine in Baltimore, Maryland.

But accurate, transparent information about errors is not captured on death certificates, which are the documents the Centers for Disease Control and Prevention (CDC) uses for ranking causes of death and setting health priorities. Death certificates depend on International Classification of Diseases (ICD) codes for cause of death, so causes such as human and system errors are not recorded on them. And it's not just the US. According to the World Health Organization, 117 countries code their mortality statistics using the ICD system as the primary health status indicator.

The authors call for better reporting to help capture the scale of the problem and create strategies for reducing it....."Top-ranked causes of death as reported by the CDC inform our country's research funding and public health priorities," Dr Makary said in an university press release. "Right now, cancer and heart disease get a ton of attention, but since medical errors don't appear on the list, the problem doesn't get the funding and attention it deserves."

The researchers examined four studies that analyzed medical death rate data from 2000 to 2008. Then, using hospital admission rates from 2013, they extrapolated that, based on 35,416,020 hospitalizations, 251,454 deaths stemmed from a medical error.That number of deaths translates to 9.5% of all deaths each year in the US — and puts medical error above the previous third-leading cause, respiratory disease. In 2013, 611,105 people died of heart disease, 584,881 died of cancer, and 149,205 died of chronic respiratory disease, according to the CDC

The authors suggest several changes, including making errors more visible so their effects can be understood.....Another is changing death certificates to include not just the cause of death, but an extra field asking whether a preventable complication stemming from the patient's care contributed to the death.The authors also suggest that hospitals carry out a rapid and efficient independent investigation into deaths to determine whether error played a role. A root cause analysis approach would help while offering the protection of anonymity, they say. Standardized data collection and reporting are also needed to build an accurate national picture of the problem.

 

Jim Rickert, MD, an orthopedist in Bedford, Indiana, and president of the Society for Patient Centered Orthopedics, toldMedscape Medical News he was not surprised the errors came in at number 3 and that even those calculations don't tell the whole story."That doesn't even include doctors' offices and ambulatory care centers," he notes. "That's only inpatient hospitalization resulting in errors." ...."It's public pressure that brings about change. Hospitals have no incentive to publicize errors; neither do doctors or any other provider," he said.

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Published on 1 Comment on Coal-tar Sealcoats Used on Driveways and Pavements Are More Toxic Than Suspected

The title says it all: coal-tar sealcoats used on drIveways and pavement are far more toxic than earlier suspected. The asphalt sealcoats are also toxic, but the coal-tar ones are far worse - so if you must use one, go with asphalt sealcoats. Or...better yet, skip either product and avoid breathing in toxic PAHs (polycyclic aromatic hydrocarbons). From Science Daily:

Coal-tar based sealcoats on driveways, parking lots far more toxic than suspected

The pavement sealcoat products used widely around the nation on thousands of asphalt driveways and parking lots are significantly more toxic and mutagenic than previously suspected, according to a new paper published this week by researchers from Oregon State University. Of particular concern are the sealcoat products based on use of coal tar emulsions, experts say. Studies done with zebrafish -- an animal model that closely resembles human reaction to toxic chemicals -- showed developmental toxicity to embryos.

Sealcoats are products often sprayed or brushed on asphalt pavements to improve their appearance and extend their lifespan. Products based on coal tar are most commonly used east of the U.S. continental divide, and those based on asphalt most common west of the divide. The primary concern in sealcoats are polycyclic aromatic hydrocarbons, or PAHs, which are common products of any type of combustion, and have been shown to be toxic to birds, fish, amphibians, plants and mammals, including humans.

The OSU program studying PAHs....can identify and analyze more than 150 types of PAH compounds. It found some PAHs in coal tar sealcoats that were 30 times more toxic than one of the most common PAH compounds that was studied previously in these products by the U.S. Geological Survey. The OSU study also showed that new PAH compounds found in coal tar sealcoats had a carcinogenic risk that was 4 percent to 40 percent higher than any study had previously showed. Among the worst offenders were a group of 11 "high molecular weight" PAH derivative compounds, of which no analysis had previously been reported.

By contrast, the study showed that sealcoats based on asphalt, more commonly used in the West, were still toxic, but far less than those based on coal tar. Use of coal tar sealcoats, which are a byproduct of the coal coking process, is most common in the Midwest and East..... "And if a decision is made to use sealcoats, we concluded that the products based on asphalt are significantly less toxic than those based on coal tar."

A 2011 report from the USGS outlined how PAH compounds from sealcoat products can find their way into soils, storm waters, ponds, streams, lakes, and even house dust, as the compounds are tracked by foot, abraded by car tires, washed by rain and volatilize into the air. They reported that the house dust in residences adjacent to pavement that had been treated with a coal tar-based sealcoat had PAH concentrations 25 times higher than those normally found in house dust. Some states and many municipalities around the nation have already banned the use of coal tar-based sealcoats, due to the human, wildlife and environmental health concerns. In the European Union, use of coal tar-based sealcoats is limited or banned.

Published on Leave a comment on Diet May Affect Body’s Biological Age

This study found that people with high red meat intake, combined with low fruit and vegetable intake and a poor overall diet (which was found most frequently in males of low socioeconomic status) had biological markers indicating accelerated aging and poor renal function (early indicators of chronic kidney disease). Bottom line: eat less red meat, more whole grains, more fruits and vegetables for your health. From Medical Xpress:

Too much red meat and too few vegetables may increase your body's biological age

A diet containing too much red meat and not enough fruit and vegetables could increase your body's 'biological age' and contribute to health problems. Research led by the University of Glasgow and published today in Aging, has found that a moderate increase in serum phosphate levels caused by red meat consumption, combined with a poor overall diet, increases biological age (miles on the clock) in contrast to chronological age (years of age).
The study, which looked at participants from the most deprived to the least deprived in the NHS Greater Glasgow Health Board area, also demonstrates that deprived males were the worst affected.

Data from the study suggests that accelerated biological ageing, and dietary derived phosphate levels among the most deprived males, were directly related to the frequency of red meat consumption. Researchers believe that excess red meat particularly affects this group because of their poor diet and "sub-optimal fruit and vegetable intake".
The research, led by the Institute of Cancer Sciences in collaboration with the Karolinska Institutet (Stockholm, Sweden), also found that high phosphate levels in deprived males correlated with reduced kidney function and even underlying mild to moderate chronic kidney disease.

Phosphate is naturally present in basic foodstuffs, including meats, fish, eggs, dairy products and vegetables. Intestinal absorption of naturally occurring phosphate is minimally regulated, as absorption is efficient, hence high supplementation results in markedly elevated levels of serum phosphate, which can have adverse health consequences. Indeed high phosphate levels, as a consequence of dietary intake, have already been linked to higher all-cause and cardiovascular mortality risk, premature vascular ageing and kidney disease.

The researchers observed significant relationships between serum phosphate and biological age markers, including DNA content and telomere length. (Original study.)

Published on Leave a comment on Eat A Chocolate Bar Daily For Health?

Image result for dark chocolate  Another yes to daily chocolate consumption -  a 3.5 oz. chocolate bar a day! This study looked at 1,153 people aged 18-69 years old and found an inverse relationship between daily chocolate consumption and levels of insulin and liver enzymes. This suggests that chocolate consumption may improve liver enzymes and protect against insulin resistance (risk factors for cardiometabolic disorders such as diabetes, heart disease, or stroke). From Science Daily:

Eating chocolate each day could reduce heart disease, diabetes risk

A new study published in the British Journal of Nutrition appears to back up the adage that a little of what you fancy does you good. Including a small amount of chocolate each day could help prevent diabetes and insulin resistance. That's one of the research findings from the Luxembourg Institute of Health (LIH), the University of Warwick Medical School, the University of South Australia and the University of Maine.

Data of 1,153 people aged 18-69 years old who were part of the Observation of Cardiovascular Risk in Luxembourg (ORISCAV-LUX) study were analysed. It was found that those who ate 100 g of chocolate a day -- equivalent to a bar -- had reduced insulin resistance and improved liver enzymes. Insulin sensitivity is a well-established risk factor to cardiovascular disease.

The academics hypothesised that chocolate consumption may have a beneficial effect on insulin sensitivity and liver enzymes and therefore decided to analyse a national sample of adults, taking into account lifestyle and dietary factors, including the simultaneous consumption of tea and coffee. This is because both drinks can be high in polyphenol, the substance which may provide chocolate with its beneficial cardiometabolic effects.

More than 80% of participants claimed to eat an average of 24.8 g of chocolate a day. The study also found that those who claimed to eat chocolate were younger, more physically active and had higher levels of education than those who claimed not to eat chocolate on a daily basis. Dr Ala'a Alkerwi, the Principal Investigator of the study at LIH said: "It is also possible that chocolate consumption may represent an overall marker for a cluster of favourable socio-demographic profiles, healthier lifestyle behaviours and better health status. This could explain, at least in part, the observed inverse associations with insulin and liver biomarkers."

Published on Leave a comment on One Season of High School Football Results In Brain Changes

Study after study finds negative effects on the brain from playing football - here it is one season of high school football resulting in measurable brain changes. None of these players had a concussion during the season, and so the negative effects were from subconcussive head impacts or hits. Interestingly, those special helmets they wore to measure impacts showed no relationship with what the brain scans showed - so the helmets were basically useless in measuring subconcussive impacts. From Science Daily:

Head impacts from single season of high school football produce measurable change in brain cells

Repeated impacts to the heads of high school football players cause measurable changes in their brains, even when no concussion occurs, according to new research. Researchers gathered data from high school varsity players who donned specially outfitted helmets that recorded data on each head impact during practice and regular games. They then used experimental techniques to measure changes in cellular microstructure in the brains of the players before, during, and after the season.

"Our findings add to a growing body of literature demonstrating that a single season of contact sports can result in brain changes regardless of clinical findings or concussion diagnosis," said senior author Dr. Joseph Maldjian, Chief of the Neuroradiology Division and Director of the Advanced Neuroscience Imaging Research Lab, part of the Peter O'Donnell Jr. Brain Institute at UT Southwestern.

In the study, appearing in the Journal of Neurotrauma, a team of investigators at UT Southwestern, Wake Forest University Medical Center, and Children's National Medical Center evaluated about two dozen players over the course of a single football season.....During the pre-season each player had an MRI scan and participated in cognitive testing, which included memory and reaction time tests. During the season they wore sensors in their helmets that detected each impact they received. Post-season, each player had another MRI scan and another round of cognitive tests. 

Researchers then used diffusional kurtosis imaging (DKI), which measures water diffusion in biological cells, to identify changes in neural tissues. ....DKI also allowed the researchers to measure white matter abnormalities. White matter consists of fibers that connect brain cells and can speed or slow signaling between nerve cells. In order for the brain to reorganize connections, white matter must be intact and the degree of white matter damage may be one factor that limits the ability of the brain to reorganize connections following TBI.

Football has the highest concussion rate of any competitive contact sport, and there is growing concern -- reflected in the recent decrease in participation in the Pop Warner youth football program -- among parents, coaches, and physicians of youth athletes about the effects of subconcussive head impacts, those not directly resulting in a concussion diagnosis, researchers noted. Previous research has focused primarily on college football players, but recent studies have shown impact distributions for youth and high school players to be similar to those seen at the college level, with differences primarily in the highest impact magnitudes and total number of impacts, the researchers noted.

Published on Leave a comment on Endocrine Disruptors Raise the Risk of Endometriosis and Fibroids

We're surrounded by hormone disrupting chemicals (endocrine disruptors) in daily life - in plastics, personal care products, pesticides, food containers, plastic toys, etc.

A recent study done in the European Union (EU) reports on a growing body of evidence suggesting that exposures to endocrine-disrupting chemicals (EDCs), particularly phthalates and diphenyldichloroethene (DDE), contribute to the development of common reproductive disorders in women: endometriosis and uterine fibroids. A group of global EDC experts estimated the economic costs of these female reproductive disorders attributable to endocrine disrupting chemical exposures at nearly €1.5 billion ($158 billion) annually.

EDCs (like DDT and phthalates) are believed to contribute to health problems by mimicking, blocking, or otherwise interfering with the function of hormones by disrupting the signaling system the body uses to determine how cells develop and grow.

A number of studies suggest a byproduct of the pesticide DDT, a chemical known as DDE, can raise the risk of developing uterine fibroids, and that another group of chemicals called phthalates, which are found in plastic products and cosmetics, have been linked to a risk of edometriosis. Keep in mind that several other chemicals, such as PCBs, or polychlorinated biphenyls, and BPA have also been linked with female reproductive health problems. From Science Daily:

Chemical exposure linked to 1.4 billion euros in women's health care costs, study suggests

Endocrine-disrupting chemicals may contribute to reproductive health problems experienced by hundreds of thousands of women, costing European Union an estimated 1.4 billion Euros ($1.5 billion) a year in health care expenditures and lost earning potential, according to a new study. The study examined rates of uterine fibroids -- benign tumors on the uterus that can contribute to infertility and other health problems -- and an often painful condition called endometriosis where the tissue that normally lines the uterus develops elsewhere in the body. The two conditions are common, with as many as 70 percent of women affected by at least one of the disorders.

Research has linked the development of uterine fibroids and endometriosis to chemicals found in pesticides, cosmetics, toys and food containers. Past studies suggest a byproduct of the pesticide DDT, a chemical known as DDE, can raise the risk of developing uterine fibroids. Another group of chemicals called phthalates, which are found in plastic products and cosmetics, have been tied to growing risk of endometriosis.....DDT and phthalates are known endocrine-disrupting chemicals (EDCs). 

"Although these two gynecological conditions affect millions of women worldwide, we recognize that this analysis only reflects the tip of the iceberg," Trasande said. "A growing body of evidence suggests EDC exposure is linked to a broader range of female reproductive problems, including polycystic ovary syndrome, infertility and pregnancy complications. These disorders also place a significant cost burden on women, their families and society as a whole.

A news story added some extra details and background to this story. From CNN:

Common chemicals linked to endometriosis, fibroids -- and healthcare costs

Hormone-disrupting chemicals are everywhere -- in plastics, pesticides and makeup -- and two of them, phthalates and DDE, have been particularly strongly linked with common female reproductive conditions, such as fibroids. In a new study, researchers estimate that the problems caused by these two chemicals alone could cost the European Union at least 1.41 billion euros a year, the U.S. equivalent of about $1.58 billion.

DDE is a breakdown product of the insecticide DDT that, although banned in the United States in 1972 and in Europe starting in the 1970s, still lingers in the environment and enters our body through food. The main exposure to phthalates is through eating food and drink stored in plastic containers that have phthalates.....In a similar way, they relied on a study that linked higher phthalate levels in women who had been diagnosed with endometriosis compared to healthy women.

The current study is important because it focused on chemicals that have not been restricted, and in the case of DDE -- which persists in the environment -- are not able to be restricted, Birnbaum said. However, she said she was surprised the researchers did not include an analysis of chemicals such as BPA, which has also been linked to endometriosis risk."This study is kind of a wake-up to say endocrine disruptors impact the female reproductive system, and we have some evidence they are associated with an increase in endometriosis and fibroids and it costs a lot of money," Birnbaum said.

Even with all the questions that remain, and few regulations in place, "there are safe and simple steps that families and women can take to reduce exposure to endocrine-disrupting chemicals," Trasande said. "They can eat organic, reduce canned food consumption, which reduces exposure to BPA, and avoid packaged or highly processed food, which is a major route for phthalates to enter food. They can also open windows to allow chemical dust, which accumulates on the carpet and electronics, to circulate out of homes."

Published on Leave a comment on Beautiful Photos of Microbes

Beautiful photos of the microbes within and on us by the British scientific photographer Steve Gschmeisser. Check out his site (http://www.theworldcloseup.com/) to see photos of microbes and other images made with the very expensive SEM - a scanning electron microscope. All the photos are by Steve Gschmeisser.

E. coli bacteria in urine sample

breast cancer cells

prostate cancer cell

large intestine

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Published on 8 Comments on Health Reasons to Avoid Fragrances, Air Fresheners, Dryer Sheets

Did you ever wonder about all the consumer products that have fragrances in them and whether they are safe to use? Think of all the fragrances in personal care products and perfumes, in air fresheners, scented soaps, cleaning products, scented candles, even laundry detergents, and scented dryer sheets.

Fragrances are made up of many synthetic chemicals - with the "fragrance" in a product typically being a mixture of 50 to 300 chemicals. They are considered an important source of indoor air pollution and can have negative health effects on humans, especially developing fetuses and children. Fragrances are added to products to achieve a desired scent or mask other scents in the product. Air fresheners do not clean or freshen the air, but actually add chemicals to the air to mask other odors. Manufacturers are NOT required to disclose all the ingredients or chemicals in the products, and don't have to disclose any ingredients in any chemical mixture called "fragrance".

The few studies looking at health effects have found negative health effects, including on the lungs, respiratory effects, asthma, allergies, headaches, skin irritation, sensory irritation, hormonal effects, central nervous system effects, and inflammation. But more negative health effects are possible, especially because many of the chemicals are carcinogenic (cancer causing). We inhale the chemicals or absorb them through the skin, and from there they travel throughout the body - which is why they can be measured in the blood or urine.

Reading the studies that look at the chemicals emitted from scented products that people use every day can be overwhelming. Many of the studies specifically look at VOCs (volatile organic compounds) that the products emit, because these can affect air quality and human health. A big difficulty is that humans are exposed to mixtures of chemicals daily from many products, and the effects may take years to manifest themselves (such as cancer). 

Bottom line: avoid, avoid, avoid fragranced or scented products if possible. Do not use scented detergent or dryer sheets (not necessary), do not use air fresheners (either in the home, workplace, or car), do not use incense or scented candles (post on scented candles). Read labels. Opening windows is the best way to air out a house or apartment. Studies find that fragrances labeled "organic", "natural", "green", or "with essential oils" basically emit the same toxic chemicals into the air (view such labels as marketing or "greenwashing") - therefore avoid those also.

Air fresheners are consumer products used in homes or in restrooms that typically emit fragrances,  including incense, scented candles, aerosol liquid wick and electric diffusers, and gels. Depending on which air freshener is used (and including those labeled "all natural"), they emit varying levels of allergens and toxic air pollutants (and which can also combine to produce other pollutants - "secondary pollutants"): acetone, aldehydes, benzene, toluene, formaldehyde, terpenes, styrene, esters, phthalates (which are hormone disrupting chemicals), limonene, and also ultrafine particles. None of these toxic chemicals are listed on the product labels. Typically, a fragrance is listed simply as “fragrance,” even though each fragrance can contain hundreds of individual chemicals. Only this past year has one company (Glade) started posting online (but not on the packages) some of the many chemicals used in its scented products.  ...continue reading "Health Reasons to Avoid Fragrances, Air Fresheners, Dryer Sheets"

Published on Leave a comment on A New Tree of Life That’s Mainly Bacteria

In 1837, Charles Darwin sketched a simple tree of life (shown left) to illustrate the idea that all living things share a common ancestor. Ever since then, scientists have been adding names to the tree of life, including a massive effort of 2.3 million named species of animals, plants, fungi and microbes in 2015. A tree of life is a visual hypothesis of how scientists think species are related to one another, so it has been evolving over the years as more information is learned and species discovered.

Now a group of 17 researchers have sketched out a radically different tree of life. It has two main trunks—one full of bacteria and another comprised of archaea, a group of single-celled microbes that run on very different biochemistry. The eukaryotes—the domain that includes all animals, fungi, and plants—are crowded on a thin branch coming off the archaeal trunk. About half of these bacterial branches belong to a supergroup, which was discovered very recently and is currently known as the candidate phyla radiation. Within these branches are numerous species that we’re almost completely ignorant about, and they’ve never been isolated or grown in a lab (with one exception called TM7). In fact, this supergroup of bacteria and “other lineages that lack isolated representatives clearly comprise the majority of life’s current diversity,” write researchers Hug and Banfield. Wow. From Science Daily:

Wealth of unsuspected new microbes expands tree of life

Scientists have dramatically expanded the tree of life, which depicts the variety and evolution of life on Earth, to account for over a thousand new microscopic life forms discovered over the past 15 years. The expanded view finally gives bacteria and Archaea their due, showing that about two-thirds of all diversity on Earth is bacterial -- half bacteria that cannot be isolated and grown in the lab -- while nearly one-third is Archaeal.

Much of this microbial diversity remained hidden until the genome revolution allowed researchers like Banfield to search directly for their genomes in the environment, rather than trying to culture them in a lab dish. Many of the microbes cannot be isolated and cultured because they cannot live on their own: they must beg, borrow or steal stuff from other animals or microbes, either as parasites, symbiotic organisms or scavengers.

The new tree, to be published online April 11 in the new journal Nature Microbiology, reinforces once again that the life we see around us -- plants, animals, humans and other so-called eukaryotes -- represent a tiny percentage of the world's biodiversity.

"Bacteria and Archaea from major lineages completely lacking isolated representatives comprise the majority of life's diversity," said Banfield.....According to first author Laura Hug,... the more than 1,000 newly reported organisms appearing on the revised tree are from a range of environments, including a hot spring in Yellowstone National Park, a salt flat in Chile's Atacama desert, terrestrial and wetland sediments, a sparkling water geyser, meadow soil and the inside of a dolphin's mouth. All of these newly recognized organisms are known only from their genomes.

One striking aspect of the new tree of life is that a group of bacteria described as the "candidate phyla radiation" forms a very major branch. Only recognized recently, and seemingly comprised only of bacteria with symbiotic lifestyles, the candidate phyla radiation now appears to contain around half of all bacterial evolutionary diversity.

Charles Darwin first sketched a tree of life in 1837 as he sought ways of showing how plants, animals and bacteria are related to one another. The idea took root in the 19th century, with the tips of the twigs representing life on Earth today, while the branches connecting them to the trunk implied evolutionary relationships among these creatures.....Archaea were first added in 1977 after work showing that they are distinctly different from bacteria, though they are single-celled like bacteria. A tree published in 1990 by microbiologist Carl Woese was "a transformative visualization of the tree," Banfield said. With its three domains, it remains the most recognizable today.

With the increasing ease of DNA sequencing in the 2000s, Banfield and others began sequencing whole communities of organisms at once and picking out the individual groups based on their genes alone. This metagenomic sequencing revealed whole new groups of bacteria and Archaea, many of them from extreme environments, such as the toxic puddles in abandoned mines, the dirt under toxic waste sites and the human gut. Some of these had been detected before, but nothing was known about them because they wouldn't survive when isolated in a lab dish.

For the new paper, Banfield and Hug teamed up with more than a dozen other researchers who have sequenced new microbial species, gathering 1,011 previously unpublished genomes to add to already known genome sequences of organisms representing the major families of life on Earth.....The analysis, representing the total diversity among all sequenced genomes, produced a tree with branches dominated by bacteria, especially by uncultivated bacteria. A second view of the tree grouped organisms by their evolutionary distance from one another rather than current taxonomic definitions, making clear that about one-third of all biodiversity comes from bacteria, one-third from uncultivable bacteria and a bit less than one-third from Archaea and eukaryotes. (Original article and diagrams.)

This is a new and expanded view of the tree of life, with clusters of bacteria (left), uncultivable bacteria called 'candidate phyla radiation' (center, purple) and, at lower right, the Archaea and eukaryotes (green), including humans.
Credit: Graphic by Zosia Rostomian, Lawrence Berkeley National Laboratory