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Published on Leave a comment on Acetaminophen Is A Common Cause Of Liver Injury and Liver Failure

A recent article discussed the large assortment of medications (both prescription and non-prescription) that are linked to liver injury, commonly known as "Drug-induced liver injury" (DILI). While it occurs rarely (fewer than 10 in 10,000 persons who take the drug in question), many medications can result in liver injury - especially if taken in too large doses and for too long. The scary part is that 46% of people with acute liver failure in the U.S have the liver damage from acetaminophen. Acetaminophen is the main cause of drug induced liver injury and liver failure in the U.S. Acetaminophen is found not just in Tylenol, but in many non-prescription drugs - thus it is easy to take too large a dose. The liver helps remove toxins - thus we need to take good care of it. From Science Daily:

Acetaminophen, supplements and other medications may trigger drug-induced liver injury

More than 1,000 medications, with acetaminophen being the most common, have been associated with drug-induced liver injury (DILI). Diagnosis can be challenging due to the multitude of contributing factors, and timely recognition and clinical response may mean the difference between recovery and acute liver failure or even death. DILI affects an estimated fewer than 10 people in every 10,000 exposed persons. The condition is dose-dependent or an adverse reaction to a medication, dietary supplement or other substance. 

"The liver helps remove toxins, which makes it especially vulnerable to injury from either short-term intake above recommended levels or long-term usage that allows toxins to build up," Collins-Yoder said. "Recognizing the clinical signs and symptoms is crucial to prompt treatment and effective patient care." Depending on the contributing factors and the level of damage to the liver, patients with mild and moderate signs and symptoms may recover normal liver function after the triggering substance is identified and use is discontinued. Other patients may experience more severe damage, progressing to acute liver failure.

About 46 percent of persons with acute liver failure in the United States have liver damage associated with acetaminophen, making it the most common cause of DILI. Since acetaminophen is often an ingredient in over-the-counter and prescription pain medications, patients may take higher doses than needed. A more infrequent type of DILI is triggered by an adverse reaction to prescription medications, herbal dietary supplements or other substances, including: nonsteroidal anti-inflammatory drugs (NSAIDs), including ibuprofen, naproxen and others; antibiotics and antiviral agencies, such as amoxicillin-clavulanate, sulfamethoxazole-trimethoprim and nitrofurantoin; antileptic agents, such as volproic acid and carbamazepine; statins; novel anticoagulants; proton pump inhibitors; methotrexate; azathioprine; sulfasalazine; herbal and dietary supplements.

Published on Leave a comment on Air Pollution Linked To Strokes

Study after study finds negative health effects from air pollution, such as heart disease (here, here, and here). Now two more studies found that living in areas with high air pollution is linked to a higher stroke risk. One study (done in Japan) found an increase of ischemic stroke on the same day as exposure to high levels of air pollution, while the other (done in London, UK) found a higher risk of death after stroke (especially ischemic strokes) in patients who live in areas of high air pollution. This was especially pronounced with exposure to smaller or fine particulate matter (PM2.5)- which is found in high quantities in vehicle exhaust fumes.

It is thought that the fine particles in the air (PM2.5) contribute to the development of potentially fatal diseases various ways - by causing chronic inflammation, and also because they slip past the body's defenses and can be absorbed deep into the lungs and bloodstream. They are not sneezed or coughed out the way larger natural particles, like airborne soil and sand, are removed from the body's airways. What can be done? Other studies have found that when air pollution is reduced, than the risk of death is reduced. So yes, pollution controls on vehicles such as trucks and buses are good. And just think how much air pollution will be reduced when electric vehicles replace current gas powered cars and trucks. From Medscape:

Air Pollution Linked to Higher Stroke Mortality

More evidence showing that living in areas with high levels of air pollution is linked to a higher stroke risk has come from two new studies. Both studies are published online in the journal Stroke. The first, from the United Kingdom, shows a higher risk for death after a stroke in patients who live in areas of high air pollution, and the other, a Japanese study, suggests a higher risk for a new stroke the same day as exposure to high levels of air pollution.

"We have shown a significantly increased risk of death after stroke in patients who had long-term exposure to high levels air pollution before their stroke occurred," senior author of the UK study, Charles Wolfe, MD.... "This was particularly pronounced for high exposure to smaller particulate matter — particles below 2.5 μm in diameter (PM2.5) — which are found in high quantities in exhaust fumes." For the study, Professor Wolfe and colleagues analyzed data from the South London Stroke Register, a population-based register covering an urban, multiethnic population.....Results showed an increased risk for death up to 5 years after stroke in patients living in areas of high air pollution.

"While this study adds to the evidence linking air pollution to cardiovascular disease, it cannot prove causality as it has an observational design," Professor Wolfe commented...."So it is difficult to say for certain that it is the air pollution that is responsible but there are many studies now that have shown similar associations," he said. He noted that the smaller particles (PM2.5) were associated with a worse effect on mortality and this correlated with biological studies that have shown a greater inflammatory effect of small particulate matter vs larger particulate matter on the vessel wall. "Our study suggests that people who have previously had an ischemic stroke, but not a hemorrhagic stroke, may be more vulnerable and at a higher risk of death to chronic, long-term exposure of PM," they conclude.

The Japanese study, by lead author Ryu Matsuo, MD, PhD, Department of Health Care Administration and Management Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan, and colleagues, looked at acute exposure to air pollution and shows a small increase in the risk of having a stroke within a day of high exposure to pollution. For the study, the researchers analyzed data on 6885 ischemic stroke patients from a multicenter hospital-based stroke registry in Japan who were previously independent and hospitalized within 24 hours of stroke onset.

Professor Wolfe said his group have conducted a similar study looking at exposure of air pollution in the year before stroke, which showed a 23% increase in stroke risk in those exposed to higher levels of PM2.5. 

Published on Leave a comment on Exposure To Harmful Chemicals During Pregnancy Shows Up In the Newborn

An important study was recently published that documents that when pregnant women are exposed to potentially harmful chemicals in the environment around them (environmental pollutants), many of these chemicals also get transferred to the fetus. Many of the 59 chemicals looked for were detected in the newborn babies' umbilical cords (thus the chemicals had crossed the placenta to the fetus during the pregnancy). Some chemicals were measured in higher levels in the umbilical cord than in the mother (as measured in her blood), while only cadmium appeared in mothers, but not in the umbilical cord (thus there was some protection for the fetus from that particular chemical).

This study did not look at the effects on the fetus and newborn from exposure to all these toxic chemicals - it just found that out of 59 chemicals tested for, the median number was 25 in maternal blood and 17 in umbilical cord blood. Eight of the 59 chemicals analyzed were detected in more than 90 percent of both the maternal and cord blood samples - and these included lead and mercury.

The researchers pointed out that no human studies have examined the developmental and reproductive health effects on the fetus and baby from being exposed to multiple chemicals simultaneously during pregnancy - which of course can have bigger risks and negative effects than being exposed to only one chemical at a time. Other studies have already shown that there are negative health effects (adverse neurodevelopmental effects) from a number of these chemicals, such as PCBs, PBDEs, Pb (lead) and Hg (mercury). Bottom line: No one really knows what these mixtures of chemicals do to the developing baby, but it is known that these chemicals have potential health risks. From Futurity:

Mom’s exposure to toxic chemicals shows up in newborn

Low-income and Latina pregnant women in a recent study had widespread exposure to environmental pollutants. In addition, many of the toxins showed up at even higher levels in their newborns. The study is the first in the United States to measure exposure to 59 toxic chemicals in pregnant women and their newborns.

“Pregnant women in the US are exposed to many harmful industrial chemicals that have been linked to premature birth, low birth weight, and birth defects, but estimates of how efficiently pollutants are transferred from mother to fetus have varied widely,” says Tracey Woodruff, professor of obstetrics, gynecology, and reproductive sciences and the Philip R. Lee Institute for Health Policy Studies at the University of California, San Francisco. “Our findings have found that many chemicals do indeed accumulate in the fetal environment and are absorbed at greater levels by fetuses than by the pregnant women themselves. This may have significant consequences for the growing fetus, since many of these chemicals are known to affect development.”

Researchers measured polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polybrominated diphenyl ethers (PBDEs), perfluorinated compounds (PFCs), mercury, and lead, among other chemicals. These industrial pollutants are common in the environment, and in previous studies many have been detected in greater than 99 percent of US pregnant women, according to National Health and Nutrition Examination Survey (NHANES) data.

“Contrary to previous research, we found evidence that several PCBs and OCPs were often higher in umbilical cord samples than in maternal blood samples,” says Rachel Morello-Frosch,  professor of environmental science, policy and management at the University of California, Berkeley. The study also found that concentrations of mercury and certain PBDEs were often higher in umbilical cord samples than in maternal samples, and for most PFCs and lead, cord blood concentrations were generally equal to or lower than maternal concentrations, which is consistent with previous research.

Almost 80 percent of the chemicals detected in maternal blood samples were also detected in the umbilical cord blood samples, indicating that they passed through the placenta and entered the fetal environment, where they can pose a health risk to the developing baby. For those chemicals detected in at least 20 paired maternal and umbilical cord samples, 77 percent had significant correlations between maternal and umbilical cord concentrations.

The women in the study were participating in the Chemicals in Our Bodies Study, also referred to as the Maternal and Infant Environmental Exposure Project. Of the women participating in the current study, 95 percent had a combined annual household income of less than $40,000, two-thirds were Latina, and a third were born in Mexico, where they may have had less exposure to environmental toxics like the PBDEs found in flame retardants that have been widely used in the US. This demographic is often not well-represented in larger biomonitoring studies, such as NHANES, that form the basis of most of what is known about pregnant women’s exposure to environmental toxics nationally.

The study also provides a first indication of how several different classes of environmental chemicals found in a pregnant woman’s blood are also present in the newborn....From 2010 to 2011, researchers collected maternal blood samples from 77 pregnant women at Zuckerberg San Francisco General. Once they delivered their babies, researchers collected umbilical cord blood samples from 65 of these women. Of those samples tested for all 59 chemicals, the median number was 25 in maternal blood and 17 in umbilical cord blood. Eight of the 59 chemicals analyzed were detected in more than 90 percent of both the maternal and cord blood samples. 

Published on Leave a comment on Youth Football Players Have Brain Changes After One Season

Another study finding brain changes from playing tackle football - this time measurable brain changes were found in boys 8 to 13 years old after just one season of playing football. None of the boys had received a concussion diagnosis during the season. The changes in the white matter of the brain (and detected with magnetic resonance imaging (MRI) were from the cumulative subconcussive head impacts that occur in football - the result of repetitive hits to the head during games and practices.

No one knows if the brains of football players fully recover after the football season. But these findings are worrisome. Especially because last year researchers found that NFL players who had begun playing  football before age 12 had a higher risk of altered brain development, as compared to players who started later (see post). Currently nearly 3 million students participate in youth tackle football programs across the United States. Some are calling for young players to only play flag or touch football, and to only play tackle football starting with the teenage years. From Science Daily:

Brain changes seen in youth football players without concussion

Researchers have found measurable brain changes in children after a single season of playing youth football, even without a concussion diagnosis, according to a new study published online in the journal Radiology.

"Most investigators believe that concussions are bad for the brain, but what about the hundreds of head impacts during a season of football that don't lead to a clinically diagnosed concussion? We wanted to see if cumulative sub-concussive head impacts have any effects on the developing brain," said the study's lead author, Christopher T. Whitlow, M.D., Ph.D., M.H.A., associate professor and chief of neuroradiology at Wake Forest School of Medicine in Winston-Salem, N.C.

The research team studied 25 male youth football players between the ages of 8 and 13. Head impact data were recorded using the Head Impact Telemetry System (HITs), which has been used in other studies of high school and collegiate football to assess the frequency and severity of helmet impacts....The study participants underwent pre- and post-season evaluation with multimodal neuroimaging, including diffusion tensor imaging (DTI) of the brain. DTI is an advanced MRI technique, which identifies microstructural changes in the brain's white matter. 

The brain's white matter is composed of millions of nerve fibers called axons that act like communication cables connecting various regions of the brain. Diffusion tensor imaging produces a measurement, called fractional anisotropy (FA), of the movement of water molecules in the brain and along axons. In healthy white matter, the direction of water movement is fairly uniform and measures high in FA. When water movement is more random, FA values decrease, which has been associated with brain abnormalities in some studies.

The results showed a significant relationship between head impacts and decreased FA in specific white matter tracts and tract terminals, where white and gray matters meet. "We found that these young players who experienced more cumulative head impact exposure had more changes in brain white matter, specifically decreased FA, in specific parts of the brain," Dr. Whitlow said. "These decreases in FA caught our attention, because similar changes in FA have been reported in the setting of mild TBI."

It is important to note that none of the players had any signs or symptoms of concussion."We do not know if there are important functional changes related to these findings, or if these effects will be associated with any negative long-term outcomes," Dr. Whitlow said. "Football is a physical sport, and players may have many physical changes after a season of play that completely resolve. These changes in the brain may also simply resolve with little consequence. However, more research is needed to understand the meaning of these changes to the long-term health of our youngest athletes." [Original study]

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Published on 2 Comments on Pesticide Residues In Honey and Other Foods

I've been thinking a lot about pesticides in foods and pesticides in honey since the recent post about untreated lawns and bees. Research finds that untreated lawns (no pesticides of any kind) with their diversity of flowering weeds or "spontaneous flowering plants" (such as clover and dandelions) are actually great pollen and nectar sources for bees. In other words, untreated lawns are great bee habitats! We think of conventional farms as using a lot of pesticides, but that is also true of suburbia with its obsession with "perfect lawns" and gardens, with no weeds allowed. According to U.S. Fish and Wildlife Service: Up to ten times more pesticides per acre are used on suburban lawns than on conventional farms! Perhaps it's time to view clover and other "spontaneous flowering plants" as beneficial wildflowers providing food for bees, and not undesirable weeds that need eradicating with pesticides.

Thus these recent articles about pesticide residues in foods, including honey, caught my eye. Notice that conventional foods have pesticide residues, but not organic foods (or they may have much lower pesticide residues, typically due to contamination from neighboring farms). Honey is tricky - there may be pesticide residues because bees fly to pesticide contaminated areas, and also beekeepers may use pesticides for pest control when caring for their bees and bee hives. The most uncontaminated honey would be from organic beekeepers located in pristine areas, with no industry, farming, or treated lawns nearby, and who do not buy "wax starter comb". Bees forage for nectar and pollen within 2 miles from the bee hive, but may fly up to 7 miles from the bee hive. As an article in Scientific Reports pointed out: "Any agrochemical applied anywhere within a colony's extensive reach can end up back in the hive."

Note that no one knows what the long-term health effects are of ingesting foods daily with low levels of mixtures of pesticides (chronic exposure), and also of ingesting endocrine disruptors. A "cocktail effect" may occur from combined traces of different pesticides - the chemicals may be more toxic when combined than alone. We just don't know. The FDA just started testing for glyphosate residues (glyphosate is the active ingredient in Roundup) in 2016 - and this is the most heavily used pesticide in the world! Currently nearly 300 million pounds of glyphosate are applied each year on U.S. farms. Now add in all the other ways we're exposed to pesticides - both indoors and outdoors  lawns, gardens, farms), even on our treated pets. Something to think about.

A number of Kellogg and Nestle brand muesli cereals were among those tested in the following research. Muesli is a breakfast cereal of rolled oats, perhaps other grains, dried fruit, and nuts.  ...continue reading "Pesticide Residues In Honey and Other Foods"

Published on Leave a comment on Lower Lead Levels With Iron Fortified Foods

Lead exposure is a big problem for children throughout the United States and the rest of the world - whether lead from plumbing, lead paint, lead solder, and even from nearby mining. There are no safe levels of lead in children (best is zero) because it is a neurotoxicant - thus it can permanently lower IQ scores as well as other neurological effects. More lead gets absorbed if the person also has an iron deficiency than if the person has normal iron levels.

This study found that simply eating iron fortified biscuits daily lowered lead levels (and improved iron levels) in children during a several month period. Two types of iron supplements were tested, and it was found that sodium iron EDTA (which is commonly added to foods) worked better than iron sulphate. The CDC (Centers for Disease Control) recommend eating foods high in calcium, iron, and vitamin C to lower iron absorption. From Science Daily:

Iron supplements in the fight against lead

Lead is a toxic heavy metal that was added to gasoline for use in cars until as recently as 25 years ago. It is particularly harmful to the developing brains of infants, children and teenagers, and the damage it does is irreversible. The situation becomes significantly worse if people are exposed to a high level of lead at the same time as they are suffering from iron deficiency. In the small intestine, lead and iron bind to the same transport protein, which absorbs the metals into the bloodstream. If someone consumes too little iron with their food, the transporter increases its activity, and can carry lead into the bloodstream instead, leading to increased levels of the toxic heavy metal in the body and brain.

A team of researchers led by ETH professor Michael B. Zimmermann from the Laboratory of Human Nutrition have now shown in a study that fortifying food with iron produces a striking reduction in blood lead concentration in children exposed to high levels of the metal. This is the result of a trial involving over 450 children carried out by Zimmermann's former doctoral student Raschida Bouhouch and colleagues in southern Morocco.....Mining in the surrounding area meant that children of preschool and school age were exposed to an increased quantity of lead. At the same time, the level of iron in their blood was relatively low, placing them in a high-risk group.

Depending on their weight, the children were given several white-flour biscuits on a daily basis for a period of four and a half months. The biscuits were fortified with different iron preparations: some received biscuits containing a specific quantity of iron sulphate, while others received biscuits with sodium iron EDTA or sodium EDTA without iron. To test the effect of the iron supplements, some children received only placebo biscuits containing no additional iron. EDTA, which stands for ethylene diamine tetraacetic acid, forms stable complexes with iron, aiding its uptake into the bloodstream from the intestines, but it is not absorbed itself. EDTA can also bind to lead in the intestines, reducing its absorption....Sodium iron EDTA has already been used for iron fortification in foodstuffs for many years.

The researchers measured the children's blood lead concentration and iron status before and after the trial, as well as conducting tests to determine how well the children could solve cognitive tasks. The researchers were delighted to find that the biscuits fortified with iron did indeed reduce the level of lead in the blood -- specifically, by a third with sodium iron EDTA complexes and by a quarter with EDTA and iron sulphate.

Before the study began, the children's blood contained on average 4.3 micrograms of lead per decilitre. Biscuits with added sodium iron EDTA facilitated a reduction in blood lead concentration to 2.9 micrograms per decilitre. The biscuits also brought about an improvement in the children's iron status. On the other hand, the reduction in lead concentration had no effect on cognitive performance, as the researchers discovered during the corresponding tests. Although, contrary to the researchers' expectations, the children's blood lead concentration before supplementation with iron was in line with the worldwide average at 4.3 micrograms per decilitre of blood, it was still possible to achieve a considerable reduction by administering the biscuits.  

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Published on 1 Comment on Some More Benefits of Eating Chocolate

Image result for dark chocolate Great news for chocolate lovers! A review of 19 good studies (studies with people randomly assigned to different conditions) found that chocolate (whether from cocoa products, chocolate, or cocoa beverages), overall had beneficial effects on cardiometabolic health, and that it may improve lipid metabolism, and reduce inflammation and insulin resistance. This held for both men and women. The main assumption is that it is the flavanols in chocolate that has the beneficial effects on health.

From Medical Xpress: Cocoa compound linked to some cardiovascular biomarker improvements

To the tantalizing delight of chocolate lovers everywhere, a number of recent studies employing various methods have suggested that compounds in cocoa called flavanols could benefit cardiovascular health. Now a systematic review and meta-analysis of 19 randomized controlled trials (RCTs) of cocoa consumption reveals some further pieces of supporting evidence..... "We found that cocoa flavanol intake may reduce dyslipidemia (elevated triglycerides), insulin resistance and systemic inflammation, which are all major subclinical risk factors for cardiometabolic diseases."

Liu noted some limitations in the trials. All studies were small and of short duration, not all of the biomarkers tracked in these studies changed for the better, and none of the studies were designed to test directly whether cocoa flavanol consumption leads to reduced cases of heart attacks or type 2 diabetes. But taking into account some of these heterogeneities across studies, the team's meta-analysis summarizing data from 19 trials found potential beneficial effects of flavanol-rich cocoa on cardiometabolic health. There were small-to-modest but statistically significant improvements among those who ate flavanol-rich cocoa product vs. those who did not.

The greatest effects were seen among trial volunteers who ate between 200 and 600 milligrams of flavanols a day (based on their cocoa consumption). They saw significant declines in blood glucose and insulin, as well as another indicator of insulin resistance called HOMA-IR. They also saw an increase in HDL, or "good," cholesterol. Those consuming higher doses saw some of the insulin resistance benefits and a drop in triglycerides, but not a significant increase in HDL. Those with lower doses of flavanols only saw a significant HDL benefit. 

In general, Lin said, where there were benefits they were evident for both women and men and didn't depend on what physical form the flavanol-rich cocoa product was consumed in —dark chocolate vs. a beverage, for example.

Published on Leave a comment on Mediterranean Diet and Caffeine Linked to Lower Risk of Macular Degeneration

One of the dreaded afflictions of getting older is age-related macular degeneration (AMD), which is a leading cause of vision loss in Americans 60 years and older. It has no cure. Thus this study finding that eating a Mediterranean diet, and especially lots of fruit, was associated with a lower risk of macular degeneration was welcome news. They also found a protective effect from drinking caffeinated beverages - about 78 mg of caffeine per day (about one cup of coffee or one shot of espresso). A Mediterranean diet stresses eating fruits, vegetables, nuts, whole grains, legumes, fish, seeds, and olive oil. From Science Daily:

Fruit-rich Mediterranean diet with antioxidants may cut age-related macular degeneration risk by more than a third

People who closely follow the Mediterranean diet -- especially by eating fruit -- may be more than a third less likely to develop age-related macular degeneration, a leading cause of blindness, according to a study presented at AAO 2016, the 120th annual meeting of the American Academy of Ophthalmology. The study is the first to identify that caffeine may be especially protective against AMD.

Many studies have confirmed the health benefits of the Mediterranean diet, which emphasizes eating fruits, vegetables, whole grains, legumes, nuts, healthy fats and fish, and limiting red meat and butter. The diet has been shown to improve heart health and reduced risk of cancer, but there has been little research on whether its benefits can extend to eye disease. To determine this, researchers studied a Portuguese population to see whether adherence to the diet impacted people's risk of AMD. Their findings revealed a significant reduction in risk in those who ate a Mediterranean diet most frequently, and particularly among those who consumed more fruit and caffeine.

Researchers at the University of Coimbra in Portugal studied 883 people age 55 or older in the central region of the country between 2013 and 2015. Of those, 449 had AMD in its early stages before vision loss, and 434 did not have AMD. Researchers assessed their diets based on a questionnaire asking how often they ate foods associated with the Mediterranean diet. The more they ate foods associated with the diet, the higher the score, from 0-9. Those who closely followed the diet scored a 6 or greater. Their findings were as follows:

Higher diet adherence scores meant lower AMD risk Of those who did not closely follow the diet (scored below a 6), 50 percent had AMD. Of those who did closely follow the diet (scored 6 or above), only 39 percent had AMD. This represents a 35 percent lower risk compared to those who did not adhere to the diet.

Fruits were especially beneficial Researchers analyzed consumption of foods and found that people who consumed higher levels of fruit were significantly less likely to have AMD. Of those who consumed 150 grams (about five ounces) or more of fruit a day: 54.5 percent did not have AMD and 45.5 percent had AMD. Overall, people who ate that much fruit or more each day were almost 15 percent less likely to have AMD, based on an odds ratio calculation.

Caffeine and antioxidants also were protective Researchers used a computer program to analyze the participants' consumption of micronutrients, according to their answers on the questionnaire. They found higher consumption of antioxidants such as caffeine, beta-carotene and vitamins C and E was protective against AMD. Of those who consumed high levels of caffeine (about 78 mg a day, or the equivalent of one shot of espresso): 54.4 percent did not have AMD and 45.1 percent had AMD....The researchers opted to look at caffeine because it is a powerful antioxidant that is known to be protective against other conditions, such as Alzheimer's disease.

Published on Leave a comment on Save Bees – Don’t Treat Lawns With Weed Killers

Image result for lawns with weeds, wikipedia Conserving native bees for their vital pollination services is of national interest. It turns out that an excellent way to save bees is to not treat lawns with herbicides (weed-killers) or any other pesticides. It turns out that lawns with "flowering weeds" (think wildflowers or flowering plant species such as dandelions and clover) are valuable nectar and pollen sources for all sorts of species of bees (and also for butterflies).

And as much research shows, pesticides (insecticides, herbicides, fungicides) have all sorts of negative health effects - on humans, pets, and wildlife (here, here, here, and here).

Chemically treated lawns are "dead zones" with an absence of normally occurring plant species. In contrast, a study found 63 different flowering plant species in 17 suburban lawns that were NOT treated with any herbicides or pesticides over the 2 year study period. The bee species they found tend to travel only short distances and so lived within close proximity of the lawns with the flowering weeds.

So do your bit for both human health and to protect bees, and don't treat lawns with chemicals. View what we now call lawn weeds as "spontaneous flowering plants" and that they are wildlife habitats. Of course using an organic fertilizer is OK, but just "mowing and leaving grass clippings" is also an excellent way to fertilize the lawn.

From The University of Massachusetts at Amherst (press release): To Help Bees, Skip Herbicides and Pesticides, Keep Lawns Naturally Diverse

Declining populations of pollinators is a major concern to ecologists because bees, butterflies and other insects play a critical role in supporting healthy ecosystems. Now a new study from urban ecologists at the University of Massachusetts Amherst suggests that when urban and suburban lawns are left untreated with herbicides, they provide a diversity of “spontaneous” flowers such as dandelions and clover that offer nectar and pollen to bees and other pollinators. 

Private lawns make up a significant part of urban lands in the United States, an estimated 50 percent of city and suburbs, say Susannah Lerman and co-author Joan Milam, an adjunct research fellow in environmental conservation. They write, “Practices that support nesting and foraging opportunities for bees could have important implications for bee conservation in suburban areas.” 

Lerman, an adjunct UMass Amherst faculty member who is also with the U.S. Forest Service, says, “We are still surprised at how many bees we found on these untreated lawns.” In this study of lawns in suburban Springfield, Mass., she and Milam found that “spontaneous lawn flowers could be viewed as supplemental floral resources and support pollinators, thereby enhancing the value of urban green spaces.”

For this study, supported by the National Science Foundation, the researchers enlisted owners of 17 lawns in suburban Springfield. Between May 2013 and September 2014, the homeowners did not apply chemical pesticides or herbicides to lawns. “We documented 63 plant species in the lawns, the majority of which were not intentionally planted,” the authors report. Lerman and Milam visited each yard six times per year for two years, collecting a total of 5,331 individual bees representing 111 species, of which 97 percent were native to North America.

Conserving native bees for their vital pollination services is of national interest, Lerman and Milam point out.....Overall, one of their main findings, say Lerman and Milam, is that “when lawns are not intensively managed, lawn flowers can serve as wildlife habitat and contribute to networks of urban green spaces.” 

Further, “developing outreach to homeowners and lawn care companies to encourage, rather than eliminate, lawn flowers such as dandelions and clover and thin grass cover or bare spots could be a key strategy for urban bee conservation programs targeting private yards.”

Original study from the Annals of the Entomological Society of America: Bee Fauna and Floral Abundance Within Lawn-Dominated Suburban Yards in Springfield, MA

Private yards comprise a significant component of urban lands, with managed lawns representing the dominant land cover. Lawns blanket > 163,000 km2 of the United States, and 50% of urban and suburban areas. When not treated with herbicides, lawns have the capacity to support a diversity of spontaneous (e.g., not planted) flowers, with the potential to provide nectar and pollen resources for pollinators such as native bees.....We collected 5,331 individual bees, representing 111 species, and 29% of bee species reported for the state. The majority of species were native to North America (94.6%), nested in soil (73%), and solitary (48.6%).

We recorded 63 different flowering plant species in 17 lawns during 2013 and 2014. Dandelion (Taraxacum officinale) was the most widespread flower, found in all lawns in both years (Table 4). White clover (Trifolium repens), purple violet (Viola sororia), yellow wood-sorrel (Oxalis stricta), Canadian horseweed (Conyza canadensis), annual fleabane (Erigeron annuus), dwarf cinquefoil (Potentilla canadensis), and Pennsylvania smartweed (Polygonum pensylvanicum) were recorded in at least 60% of all sites for the two years (Table 4). In 2013, horseweed, hairy rock cress (Arabis hirsute), and white clover represented more than 67% of all flowers, whereas in 2014, white clover, yellow wood-sorrel, purple smartweed and purple violet were the most abundant species.

Published on Leave a comment on Dental Fillings and Mercury Levels

Many of us grew up having silver colored dental fillings (called dental amalgam) in our teeth. Dental amalgam has been used for over 150 years for the treatment of dental cavities (caries) because it is durable, easy to use, and affordable. But it is composed of about 50% elemental mercury (Hg) and so it may release a certain amount of mercury both during the time the cavity is filled and afterward with normal wear. Mercury can cause adverse health effects, such as effects on the central nervous system, kidneys, and immune system. Human mercury exposure also occurs through the consumption of mercury (MeHg) contaminated seafood.

Recently many dentists switched to the use of the composite resins, which are mercury-free alternative materials. However, these can release can release small quantities of bisphenol A (BPA) when applied and as they degrade in the mouth. BPA is an endocrine disruptor, has been found to cause various adverse health effects, including reproductive effects, and can be measured in urine. Which raised the question, do persons with composite resin fillings have elevated BPA in their bodies?

This study examined 14,703 subjects who were divided into three groups based on the number of dental surface restorations (DSR): 0, 1–8, or greater than 8. Dental surface restorations applies to fillings, and not crowns. Note that a tooth's surface can have 5 surfaces (in molars and pre-molars), so 8 filled surfaces can be fewer than 8 teeth with fillings. (It's not the number of fillings, but the surface area they occupy - so the Science Daily article title is misleading.)

They found that the more dental surface restorations a person has, the higher the levels of mercury in the blood. But they found no association between dental surface restorations and urinary BPA. These results are reassuring for those with fillings made of composite resins, but not for people with fillings of dental amalgam. Note: DSR are Dental Surface Restorations, THg is blood total mercury, IHG is inorganic mercury, and MeHg is methyl mercury (typically from seafood). From Science Daily:

Have more than eight dental fillings? It could increase the mercury levels in your blood

Dental surface restorations composed of dental amalgam, a mixture of mercury, silver, tin and other metals, significantly contribute to prolonged mercury levels in the body, according to new research from the University of Georgia's department of environmental health science in the College of Public Health.This research, which analyzed data from nearly 15,000 individuals, is the first to demonstrate a relationship between dental fillings and mercury exposure in a nationally representative population.  ...continue reading "Dental Fillings and Mercury Levels"