Skip to content

Category: Uncategorized

Published on

Much has been written about boxing, concussions, and brain damage, but this is the first time I've read about mixed martial art fighters also having such problems. But it makes sense. From Medscape:

Fight Exposure Linked to Reduced Brain Volume

The more boxers and martial arts practitioners experience head trauma, the more likely they are to have lower brain volume, particularly caudate and thalamus volume, according to a new study. Lower brain volume in these fighters correlated with reduced processing speed, the study also found.

These results "suggest that greater exposure to head trauma is related to detectable brain structural and performance deficits in active fighters," the authors, led by Charles Bernick, MD, Lou Ruvo Center for Brain Health, Cleveland Clinic, Las Vegas, Nevada, conclude.

The analysis included 224 adults, aged 18 to 44 years, who were participants in the Professional Fighters Brain Health Study, a longitudinal cohort study of boxers and mixed martial arts (MMA) fighters. The participants included 93 boxers and 131 MMA fighters.The length of professional fighting in this group ranged from 0 to 24 years, with a mean of 4 years. The number of professional fights ranged from 0 to 101, with a mean of 10 fights.

The study also included a control group of 22 age- and education-matched participants with no history of head trauma who did not play a sport associated with head injuries from high school onward.Participants were assessed at baseline and then annually for 4 years. Researchers measured cognitive function with a computer-based battery consisting of tests of  verbal memory, processing speed, and other functions. They used MRI to assess brain volumes.

The study found that increasing exposure to head trauma, as measured by the number of professional fights or years of professional fighting, was generally associated with lower brain structural volumes, particularly subcortical structures. The most consistent relationship between exposure variables and brain volume was seen in the thalamus and caudate. 

The thalamus acts as a "gateway" to the cortex and when affected can influence many neurologic functions, said the authors. It and the caudate are vulnerable to volumetric loss through several mechanisms. Rotational movement of the head brought on by punches in boxing or MMA can result in diffuse axonal injury in white matter tracts, they note.

For the most part, brain structure volumes were lower for boxers than MMA fighters or controls. This could be due to several factors, the authors write. "Perhaps the most obvious explanation is that boxers get hit in the head more. In addition to trying to concuss (ie, knock out) their opponent, MMA fighters can utilise other combat skills such as wrestling and jiu jitsu to win their match by submission without causing a concussion."

The study also found that processing speed was correlated with reduced volume in several cortical and subcortical structures. Reduction in processing speed, said the authors, is consistent with repeated concussions and is considered a clinical component of chronic traumatic encephalopathy.

Published on

Essential oils - a whole new exciting area of research, with possible uses in animal and human health, and as an alternative to antibiotics. From The Atlantic:

Essential Oils Might Be the New Antibiotics

Faced with increasingly drug-resistant bacteria, scientists and farmers are now looking to plant extracts to keep people and animals healthy.

Essential oils often evoke thoughts of scented candles and day spas, but their benefits beyond relaxation are less well-known. Essential oils are ultimately just plant extracts—and those are used in countless cleaning and personal-care products, and are the main ingredient in some pest-control products and some over-the-counter medications, like Vick’s VapoRub and some lice sprays. They’re used in the food industry because of their preservative potency against food-borne pathogens—thanks to their antimicrobial, antibacterial, and antifungal properties. Various oils have also been shown to effectively treat a wide range of common health issues such as nausea and migraines, and a rapidly growing body of research is finding that they are powerful enough to kill human cancer cells of the breast, colon, mouth, skin, and more.

A handful of promising, real-life studies have been conducted with humans and other animals, though most of the research in that realm thus far has been conducted in the lab. More controlled trials will be required before some of these applications  will be available to the public, but meanwhile, scientists have turned up exciting results in another area of use: countering the growing antibiotic-resistance crisis.

As Cari Romm previously reported in The Atlantic, livestock consume up to 80 percent of the antibiotics used in the U.S., and the amount actually jumped by 16 percent between 2009 and 2012, according to a recent FDA report. This rampant use of the drugs has led to “superbugs” that are becoming increasingly resistant to the antibiotics that are used to treat not just farm animals, but humans as well. In fact, almost 70 percent of the antibiotics given to these animals are classified as “medically important” for humans...While the drugs are, of course, sometimes necessary to treat infections in livestock, the real reasons they’re overused are to speed up growth and to compensate for the cramped, unsanitary living conditions the animals endure. 

Whether farmers choose to use it or not, there is a strong alternative on the horizon. Numerous recent studies—including several done by the USDA—have shown great promise in using essential oils as an alternative to antibiotics in livestock. One of their studies, published in October 2014 in the journal Poultry Science, found that chickens who consumed feed with added oregano oil had a 59 percent lower mortality rate due to ascites, a common infection in poultry, than untreated chickens. Other research, from a 2011 issue of BMC Proceedings, showed that adding a combination of plant extracts—from oregano, cinnamon, and chili peppers—actually changed the gene expression of treated chickens, resulting in weight gain as well as protection against an injected intestinal infection.

Researchers have also directly compared the effects of commonly used antibiotics with those of various essential oils. One such study, from the March 2012 issue of the Journal of Animal Science, found that rosemary and oregano oils resulted in the same amount of growth in chickens as the antibiotic avilamycin, and that the oils killed bacteria, too. Additional findings have shown that essential oils help reduce salmonella in chickens, and another study found that a blend of several oils can limit the spread of salmonella among animals. One of the co-authors of that study, Dr. Charles Hofacre, a professor at the University of Georgia’s College of Veterinary Medicine, says it’s such a new area of research that they don’t yet know exactly how the essential oils work, but “there is some strong evidence that they are functioning by both an antibacterial action in the intestine and also some have an effect to stimulate the intestinal cells ability to recover from disease more quickly–either by local immunity or helping keep the intestinal cells themselves healthier.”

Of course, there is also a dire need for alternatives to antibiotics for the direct treatment of infections in humans and animals, not only for illness prevention and growth-boosting in livestock. Research investigating the use of essential oils in humans has produced encouraging results, but such studies have been small and surprisingly rare, especially given the demonstrated success of their use in livestock. An Italian study found that a combination of thyme and clove essential oils was just as effective in treating bacterial vaginosis as the usual antibiotic treatment, and results of a study by U.S. researchers show that staph-infected wounds healed faster when they were treated with vapors of tea-tree oil than with conventional methods. Research published in December 2013 reported that a hand gel made with lemongrass oil was effective in reducing MRSA on the skin of human volunteers...

In the lab, scientists have been testing all kinds of combinations of essential oils and antibiotics, and they’re repeatedly finding that the oils—used on their own and in combination with some common antibiotics—can fight numerous pathogens, including antibiotic-resistant strains of E. coli, Staphylococcus aureus (which causes staph infection), and other common types of bacteria. Results consistently show that combining essential oils and antibiotics significantly lowers the amount of antibiotic required to do the job. For example, two recent studies showed that lavender and cinnamon essential oils killed E. coli, and when combined with the antibiotic piperacillin, the oils reversed the resistance of the E. coli bacteria to the antibiotic. Another recent study found that basil oil and rosemary oil were both effective in inhibiting the growth of 60 strains of E. coli retrieved from hospital patients. Other research has produced similar results for many other essential oils, both alone and in combination with antibiotics. Researchers believe that one mechanism by which the oils work is by weakening the cell wall of resistant bacteria, thereby damaging or killing the cells while also allowing the antibiotic in.

Gay explains that “phytonutrients” or “phytochemicals” are chemical compounds derived from plants that have a range of health benefits, “including promoting tumor killing and increased resistance to infectious diseases, and they have been used as health-promoting agents by many cultures for several millennia.” Their potency isn’t surprising when you consider that the plant compounds that make up essential oils exist in the first place to help plants protect themselves from infection, endure temperature variations, heal from damage, and repel pests. 

Back on the farms, some are already putting essential oils into practice. “There are a number of companies that are currently selling plant extracts as feed additive, and large integrated producers are also adding feed additives to their rations to enhance the health of animals, especially their intestinal health, during their production cycle,” Gay says. No one seems willing to readily offer that information, though—and they don’t have to. One farmer who has talked publicly about using essential oils is Scott Sechler, owner of Bell & Evans Farms, a high-end producer of antibiotic-free poultry. Back in 2012, he told the New York Times about his use of oregano oil and cinnamon to fight infection on his farms, which now number about 140 with a total of 9 million chickens at any given time.

Published on

I bet eating fresh blueberries daily instead of blueberry powder would not only be more delicious, but also have even more health benefits. From Science Daily:

Blueberries may help reduce blood pressure and arterial stiffness

Just one cup of blueberries per day could be the key to reducing blood pressure and arterial stiffness, both of which are associated with cardiovascular disease. .... Johnson said she is interested in looking at how functional foods -- foods that have a positive impact on health beyond basic nutrition -- can prevent and reverse negative health outcomes, particularly for postmenopausal women.

Over an eight-week period, 48 postmenopausal women with pre- and stage-1 hypertension were randomly assigned to receive either 22 grams of freeze-dried blueberry powder -- the equivalent to one cup of fresh blueberries -- or 22 grams of a placebo powder. Participants, meanwhile, continued their normal diet and exercise routines.

At the end of the eight weeks, participants receiving the blueberry powder on average had a 7 mmHg (5.1 percent) decrease in systolic blood pressure, which is the top number in the blood pressure reading that measures the pressure in the arteries when the heart beats. They also saw a 5 mmHg (6.3 percent) reduction in diastolic blood pressure, or the bottom number measuring the pressure in the arteries between heartbeats.

Additionally, participants in the blueberry-treated group had an average reduction of 97 cm/second (6.5 percent) in arterial stiffness.They also found that nitric oxide, a blood biomarker known to be involved in the widening of blood vessels, increased by 68.5 percent. That is important, Johnson said, because arterial stiffness and the narrowing of blood vessels are both a part of hypertension. This rise in nitric oxide helps explain the reductions in blood pressure.

Published on

And the scary part is that they only tested for 32 chemicals, but there are thousands of others they didn't test for that could be lurking in the water, including pesticides used on the lawns and grounds around outdoor swimming pools. From Science Daily:

Pharmaceuticals, personal care products could taint swimming pools

A new study suggests pharmaceuticals and chemicals from personal care products end up in swimming pools, possibly interacting with chlorine to produce disinfection byproducts with unknown properties and health effects.

Chlorination is used primarily to prevent pathogenic microorganisms from growing. Previous research has shown that many constituents of urine including urea, uric acid, and amino acids, interact with chlorine to produce potentially hazardous disinfection byproducts in swimming pools. However, chemicals from pharmaceuticals and personal care products, or PPCPs, also could be interacting with chlorine, producing potentially harmful byproducts. There are literally thousands of chemicals from pharmaceuticals and personal care products that could be getting into swimming pool water.

A research group led by Ching-Hua Huang, a professor in the School of Civil and Environmental Engineering at the Georgia Institute of Technology, has developed an analytical technique that identifies and quantifies 32 pharmaceuticals and personal care products in water... Water samples were taken from indoor swimming pools in Indiana and Georgia.

Of the 32 chemicals investigated, the researchers detected three: N,N-diethyl-m-toluamide, known as DEET, the active ingredient in insect repellants; caffeine; and tri(2-chloroethyl)-phosphate (TCEP), a flame retardant.

"The other 29 could have been present at concentrations below the detection level," Blatchley said. "And because there are literally thousands of pharmaceuticals, this is just a small subset of compounds that could be present in swimming pools. The main issue is that the release of chemicals into a place like a swimming pool is completely uncontrolled and unknown. I don't want to be an alarmist. We haven't discovered anything that would be cause for alarm right now, but the bottom line is we just don't know."

Some chemicals are volatile, which means they can escape into the air to be inhaled. Others can be ingested or absorbed through the skin."Swimmers are exposed to chemicals through three different routes: You can inhale, you can ingest and it can go through your skin. So the exposure you receive in a swimming pool setting is potentially much more extensive than the exposure you would receive by just one route alone," Blatchley said.

His previous research has shown that certain airborne contaminants are created when chlorine reacts with sweat and urine in indoor swimming pools. Pharmaceuticals may get into swimming pool water from personal care products applied to the skin such as insect repellant, makeup and sunscreen. Many pharmaceuticals that are ingested are not fully metabolized by the body and are excreted in sweat and urine.

"Urine, I think, is really the primary mode of introduction," Blatchley said. "When it comes to pharmaceuticals, these are chemicals designed to be biologically active at pretty low concentrations. Birth control pills, for example, contain hormones. If those chemicals and others are present, especially in a mixture in a water sample that humans are going to be exposed to, then what are the consequences of that? That is a largely unanswered question."...The previous research suggested that about 93 percent of uric acid introduced to pools comes from human urine.

Published on

Air pollution is harmful on so many levels for all of us, (See recent Dec.post on harmful air pollution effects on pregnancy.) From Reuters Health:

Heart experts warn of air pollution dangers

Air pollution should be one of the avoidable heart risk factors - just like smoking and excess fat - that doctors warn patients to steer clear of, according to a new statement from 20 heart experts.

Citing pollution’s heavy toll on cardiovascular health, the panel urges people to take steps to protect themselves from breathing heavy traffic fumes or industrial air pollution whenever possible, and public officials to pass laws to reduce air pollution.Air pollution causes more than 3 million deaths worldwide each year and causes 3.1 percent of all cases of disability, Storey and his coauthors write in the European Heart Journal.

Air pollution is also ninth most important on a list of modifiable heart-disease risk factors - ranking above low physical activity, high-salt diet, high cholesterol and drug use, the authors point out.

Although gaseous air pollutants can be dangerous too, Storey said, airborne particles are the biggest contributor to cardiovascular disease because they cause inflammation of the lungs and enter the circulation, inflaming blood vessels, provoking clots and causing heart rhythm disturbances.

Particulate matter includes coarse particles from road dust, construction work and industrial emissions and fine particles from traffic, power plants and industrial and residential burning of oil, coal or wood for heating. The bulk of particulate air pollution is made up of these fine particles, known as PM2.5, that are less than 2.5 micrometers - about one fifth the size of visible dust. In 2013, the U.S. Environmental Protection Agency lowered the 24-hour exposure limit to an average of 12 micrograms.

European studies have found that PM2.5 levels are often markedly higher near heavy traffic zones compared to elsewhere in the same city, and that the levels can more than double during rush hours, according to the position statement.

Some of the authors’ advice for people to protect themselves is as simple as walking, cycling and using public transportation instead of driving cars, and exercising in parks or gardens, rather than near busy roads. And everyone should avoid being outside when pollution is highest, though this is especially important for infants, elderly and people with heart problems, the authors say.People who live in heavily polluted areas should also consider ventilation systems with filtration in their homes, since a large portion of outdoor pollution can penetrate buildings.

The use of fossil fuels for heating and energy should also be decreased, according to the statement.

Studies have shown even short-term exposure to high PM2.5 levels increases deaths from heart disease and respiratory disease, and that people living in places with high PM2.5 have an 11 percent greater risk of dying from heart attacks, strokes and heart failure than those who live in cleaner areas.

Published on

Once again air pollution is linked to health problems, this time exposure during pregnancy is linked to congenital malformations (what are commonly called birth defects). From Science Daily:

Smoke signals: New evidence links air pollution to congenital defects

The health effects of air pollution are a major concern for urban populations all over the world. A new study provides new evidence linking high exposure to air pollution to an increased risk of congenital malformations. Children, the elderly, and people with impaired respiratory systems (such as asthmatics) tend to be especially sensitive to the impact of exposure to ozone, nitrogen dioxide, sulphur dioxide, and particulate matter.

A recent study by Tel Aviv University researchers provides new evidence linking high exposure to air pollution to an increased risk of congenital malformations. The nationwide study is the first to assess the association between different modes of conception-assisted reproductive technology (ART) versus spontaneous conception (SC) -- and the risks of exposure to air pollution to each.

"Our results suggest that exposure to higher levels of air pollution during pregnancy is associated with various adverse pregnancy outcomes," said Prof. Lerner-Geva. "While our study mainly followed SC infants, we also had the opportunity to assess a small sample of pregnancies that were conceived through ART, and observed a higher impact of air pollution -- particularly with regard to ozone exposure. This is clearly a uniquely susceptible population that should be further explored."

For the study, funded by the Environmental Health Fund (EHF), the research team analyzed data on 216,730 born in Israel between 1997 and 2004. Air pollution data, including, levels of sulfur dioxide (SO2), particulate matter (PM10), nitrogen oxides (NOx), and ozone (O3) were obtained from air monitoring stations for the study period. Using a geographic information system, exposure to air pollution during both the first trimester and the entire pregnancy was assessed for each woman according to her place of residence.

The researchers found that exposure to PM10 and NOX pollutants throughout full-term pregnancies were associated with an increased risk of congenital malformations, with specific defects evident in the circulatory system (from PM10 and NOX exposure) and genital organs (from NOX exposure). They also discovered that exposure to SO2 and O3 in ART pregnancies were associated, although not significantly, with a higher risk of congenital defects.

Published on

Two studies finding various forms of air pollution having effects on the developing fetus - the first one (fine particulate air pollution) to autism, and the second (outgassing of new flooring) to later breathing problems.

From Medical Xpress: Fine particulate air pollution linked with increased autism risk

Women exposed to high levels of fine particulate matter specifically during pregnancy—particularly during the third trimester—may face up to twice the risk of having a child with autism than mothers living in areas with low particulate matter, according to a new study from Harvard School of Public Health (HSPH). The greater the exposure, the greater the risk, researchers found. It was the first U.S.-wide study exploring the link between airborne particulate matter and autism.

"Our data add additional important support to the hypothesis that maternal exposure to air pollution contributes to the risk of autism spectrum disorders," said Marc Weisskopf, associate professor of environmental and occupational epidemiology and senior author of the study.... Prior studies have suggested that, in addition to genetics, exposure to airborne environmental contaminants, particularly during pregnancy and early life, may affect risk of autism. This study focused specifically on the pregnancy period.

The study population included offspring of participants living in all 50 states in Nurses' Health Study II, a cohort of more than 116,000 female U.S. nurses begun in 1989. The researchers collected data on where participants lived during their pregnancies as well as data from the U.S. Environmental Protection Agency and other sources on levels of fine particulate matter air pollution (PM2.5)—particles 2.5 microns in diameter or smaller—in locations across the U.S. The researchers identified 245 children who were diagnosed with autism spectrum disorder (ASD) and a control group of 1,522 children without ASD during the time period studied.

Exposure to PM2.5 was significantly associated with autism during pregnancy, but not before or after, the study found. And during the pregnancy, the third trimester specifically was significantly associated with an increased risk. Little association was found between air pollution from larger-sized particles (PM10-2.5) and autism.

From Science Daily: New floor covering can lead to breathing problems in babies

New flooring in the living environment of pregnant women significantly increases the risk of infants to suffer from respiratory diseases in their first year of life. This is the result of a study that demonstrates that exposure to volatile organic compounds in the months before and after birth induces breathing problems in early childhood. The scientists therefore recommend that redecoration should be avoided during pregnancy or in the first year of children’s life.

The observed health risks are caused by increased concentrations of volatile organic compounds (in short: VOCs), such as styrene or ethylbenzene, which escape from new flooring and are then absorbed through the respiratory air. "We therefore do not recommend that laminate, carpet or floor coverings be laid in the homes of pregnant women. Although the concentrations of these volatile chemicals are lower if no adhesive is used when installing the flooring, even then the concentrations are still high enough to significantly increase the risk of infants suffering from respiratory complaints in their first few months," explains Dr. Ulrich Franck from the UFZ. 

Earlier studies from Leipzig had already shown that chemicals from home renovations lead to changes in the immune system of new-born children.... According to our results, exposure to these volatile chemical compounds seems to be more critical in pregnancy than in the first year of a child's life," concludes Dr. Irina Lehmann from the UFZ, who is in charge of the LINA study on lifestyle and environmental factors and their influence on the risk of allergies in newborn babies. An analysis of the data showed that renovations after the birth of a child had a much lower impact on respiratory problems than during pregnancy.

Published on

Interesting, but it is currently unknown why this occurs. From Science Daily:

People with blood groups A, B and AB at higher risk of type 2 diabetes than group O

A study of more than 80,000 women has uncovered different risks of developing type 2 diabetes associated with different blood groups, with the biggest difference a 35 percent increased risk of type 2 diabetes found in those with group B, Rhesus factor positive blood compared with the universal donor group O, Rhesus factor negative.

While previous studies have investigated the links between blood group and stroke (finding an increased risk for group AB versus group O), those on blood groups and their link with diabetes have been small and thus underpowered and unable to provide definitive results. In this new research, Fagherazzi and colleagues took data from 82,104 women from the large prospective E3N cohort in France followed between 1990 and 2008. The objective of this study was to evaluate the relationship of ABO blood type (A, B, AB and O), Rhesus factor (positive or negative) and a combination of the two (ABO×Rhesus) with type 2 diabetes (T2D).

The results showed that, compared with women with group O blood, women with group A were 10% more likely to develop T2D, and those with group B 21% more likely (both statistically significant). The AB group was 17% more likely to develop T2D, but this result was not statistically significant. When looking solely at R+ versus R- women, neither group was at increased risk of developing T2D compared with the other.

The authors then combined ABO group and Rhesus group and compared each possible combination with O negative (O-), which is known as the universal donor group because since it contains none of the A. B, or Rhesus antigens, blood from people in this group can be successfully donated to any other group (without rejection).Compared with O- women, the highest increased risk of developing T2D was found in B+ (35% increased risk), followed by AB+ (26%), A- (22%), A+ (17%). The results for O-, B-, and AB- groups were not statistically significant.

Published on

Avoid unnecessary ultrasounds because there is an effect on the fetus, even if it's just a temporary effect. Medical associations warn against getting ultrasounds during pregnancy without a real reason. From The Atlantic:

FDA Warning: Stay Away From 'Keepsake' Ultrasounds

The medically unnecessary scans peddled by businesses—often set up in malls and administered by people with no healthcare training—may pose a health risk to both fetus and mother.

Despite repeated warnings by the Food and Drug Administration over the years, commercial ultrasound businesses—often set up in shopping malls and run by untrained technicians—continue to offer their services to expectant parents. And consumers, despite the FDA’s pleas, continue to pay for them, shelling out hundreds of dollars for photos or videos of their developing fetus (and fueling a thriving Etsy niche, where ultrasound images can be turned into ultrasound cufflinks, pillows, cake toppers, and truly unsettling night lights.)

Earlier today, the agency issued the latest of a long line of alerts against non-medical ultrasounds and heartbeat monitors, reminding consumers that “both are prescription devices designed to be used by trained healthcare professionals … only when there is a medical need, based on a prescription,” and that “the FDA strongly discourages their use for creating fetal keepsake images and videos.”

Ultrasounds, which use sound waves to produce an image, are considered a safe and valuable diagnostic tool during pregnancy, when they can provide information on the fetus' age, sex, and overall health. But “ultrasound can heat tissues slightly, and in some cases, it can also produce very small bubbles in some tissues,” FDA biomedical engineer Shahram Vaezy said in the alert. Because the long-term effects of the heating are unknown, these gratuitous ultrasounds, which provide no medical information, may pose a small but unecessary risk to both mother and fetus—compounded by the fact that their duration, and the qualifications of the people administering them, aren't subject to regulation.... (Researchers have recently focused on ultrasound as a possible method of male contraception, noting that it dramatically lowers sperm count when applied to the testicles.)

Several medical groups have also come out against commercial ultrasounds over the years, including the American Medical Association, the American College of Obstetricians and Gynecologists, the American College of Radiology, the American Institute of Ultrasound in Medicine, and the American Pregnancy Association.

Published on

This was so ridiculous that I couldn't resist - Male idiot Theory! More examples are in the original study published in the BMJ or British Medical Journal (e,g., the man who shot himself in the head with a “spy pen” weapon to show his friend that it was real). Please note: every Christmas the BMJ publishes research whose premises are a bit off kilter. From Science Daily:

Study supports the theory that men are idiots

Sex differences in risk seeking behaviour, emergency hospital admissions, and mortality are well documented. Males are more likely to be admitted to an emergency department after accidental injuries, more likely to be admitted with a sporting injury, and more likely to be involved in a fatal road traffic collision.

However, little is known about sex differences in idiotic risk-taking behaviour. So researchers in north east England decided to test "male idiot theory" (MIT) that many of the differences in risk seeking behaviour may be explained by the observation that men are idiots and idiots do stupid things.

They reviewed data on idiotic behaviours demonstrated by winners of the Darwin Award over a 20 year period (1995 to 2014), noting the sex of the winner. To qualify, nominees must improve the gene pool by eliminating themselves from the human race using astonishingly stupid methods.

Worthy candidates include a man stealing a ride home by hitching a shopping trolley to the back of a train, only to be dragged two miles to his death before the train was able to stop; and the terrorist who posted a letter bomb with insufficient postage stamps and who, on its return, unthinkingly opened his own letter.

Of these 318 cases, 282 Darwin Awards were awarded to males, and just 36 awards given to females. Males thus made up 88.7% of Darwin Award winners, and this sex difference is highly statistically significant, say the authors. This finding is entirely consistent with male idiot theory (MIT) and supports the hypothesis that men are idiots and idiots do stupid things.

However, this study has limitations, add the authors. For example, women may be more likely to nominate men for a Darwin Award or the sex difference may reflect differences in alcohol use between men and women. Despite this, it is puzzling that males are willing to take such unnecessary risks -- simply as a rite of passage, in pursuit of male social esteem, or solely in exchange for "bragging rights," say the authors.