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An article comparing the U.S. versus the European Union's approach to chemicals in products (including in cosmetics, personal care products, and foods), which explains why a number of chemicals are banned in Europe, but allowed in the U.S. From Ensia:

BANNED IN EUROPE, SAFE IN THE U.S.

Atrazine, which the U.S. Environmental Protection Agency says is estimated to be the most heavily used herbicide in the U.S., was banned in Europe in 2003 due to concerns about its ubiquity as a water pollutant. 

The U.S. Food and Drug Administration places no restrictions on the use of formaldehyde or formaldehyde-releasing ingredients in cosmetics or personal care products. Yet formaldehyde-releasing agents are banned from these products in Japan and Sweden while their levels — and that of formaldehyde — are limited elsewhere in Europe. In the U.S., Minnesota has banned in-state sales of children’s personal care products that contain the chemical.

Use of lead-based interior paints was banned in France, Belgium and Austria in 1909. Much of Europe followed suit before 1940. It took the U.S. until 1978 to make this move, even though health experts had, for decades, recognized the potentially acute — even deadly — and irreversible hazards of lead exposure.

These are but a few examples of chemical products allowed to be used in the U.S. in ways other countries have decided present unacceptable risks of harm to the environment or human health. How did this happen? Are American products less safe than others? Are Americans more at risk of exposure to hazardous chemicals than, say, Europeans?

Not surprisingly, the answers are complex and the bottom line, far from clear-cut. One thing that is evident, however, is that “the policy approach in the U.S. and Europe is dramatically different."

A key element of the European Union’s chemicals management and environmental protection policies — and one that clearly distinguishes the EU’s approach from that of the U.S. federal government — is what’s called the precautionary principleThis principle, in the words of the European Commission, “aims at ensuring a higher level of environmental protection through preventative” decision-making. In other words, it says that when there is substantial, credible evidence of danger to human or environmental health, protective action should be taken despite continuing scientific uncertainty.

In contrast, the U.S. federal government’s approach to chemicals management sets a very high bar for the proof of harm that must be demonstrated before regulatory action is taken.

This is true of the U.S. Toxic Substances Control Act, the federal law that regulates chemicals used commercially in the U.S. The European law regulating chemicals in commerce, known as REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals), requires manufacturers to submit a full set of toxicity data to the European Chemical Agency before a chemical can be approved for use. U.S. federal law requires such information to be submitted for new chemicals, but leaves a huge gap in terms of what’s known about the environmental and health effects for chemicals already in use. Chemicals used in cosmetics or as food additives or pesticides are covered by other U.S. laws — but these laws, too, have high burdens for proof of harm and, like TSCA, do not incorporate a precautionary approach.

While FDA approval is required for food additives, the agency relies on studies performed by the companies seeking approval of chemicals they manufacture or want to use in making determinations about food additive safety. Natural Resources Defense Council senior scientist Maricel Maffini and NRDC senior attorney Tom Neltner “No other developed country that we know of has a similar system in which companies can decide the safety of chemicals put directly into food,” says Maffini.  The two point to a number of food additives allowed in the U.S. that other countries have deemed unsafe

Reliance on voluntary measures is a hallmark of the U.S. approach to chemical regulation. In many cases, when it comes to eliminating toxic chemicals from U.S. consumer products, manufacturers’ and retailers’ own policies — often driven by consumer demand or by regulations outside the U.S. or at the state and local level — are moving faster than U.S. federal policy. 

Cosmetics regulations are more robust in the EU than here,” says Environmental Defense Fund health program director Sarah Vogel. U.S. regulators largely rely on industry information, she says. Industry performs copious testing, but current law does not require that cosmetic ingredients be free of certain adverse health effects before they go on the market. (FDA regulations, for example, do not specifically prohibit the use of carcinogens, mutagens or endocrine-disrupting chemicals.) 

For the FDA to restrict a product or chemical ingredient from cosmetics or personal care products involves a typically long and drawn-out process. What it does more often is to issue advisories.

At the same time, built into the U.S. chemical regulatory system is a large deference to industry. Central to current U.S. policy are cost-benefit analyses with very high bars for proof of harm rather than a proof of safety for entry onto the market. Voluntary measures have moved many unsafe chemical products off store shelves and out of use, but our requirements for proof of harm and the American historical political aversion to precaution mean we often wait far longer than other countries to act.

Since myopia increased 66% between the early 1970s to early 2000s in the United States, it is thought that there are environmental factors at play, namely higher levels of education, all our close-up activities with new technology (reading, computers, tablets, etc.) straining our eyes, and spending too much time indoors. From The Atlantic:

Nearsightedness and the Indoor Life

Over the past 15 years, the world has witnessed an explosion of cases of myopia, or nearsightedness. A quarter of the world's population, or 1.6 billion people, now suffer from some form of myopia, according to the Myopia Institute. If unchecked, those numbers are estimated to reach one-third of the world's population by 2020. 

The 2009 study is hardly the first to suggest that an increase in years of formal education and access to technology across society may account for higher myopia rates in recent years. Ophthalmologists and optometrists have cautioned that close-up activities like reading and using computers, tablets, and smartphones interfere with normal blinking and put a strain on the eyes. When abused, they can lead to double vision, myopia, and serious conditions such as retinal detachment and vision loss. The overuse of handheld electronics such as iPads and tablets by young children is especially worrisome, since their eyes are still developing and are more likely to be affected, according to researchers.

Kathryn Rose, a researcher of visual disorders at the University of Sydney's college of health sciences, recently concluded  that spending too much time indoors also has a huge impact on eyesight deterioration. Rose said in a CNN interview that she was not sure how time spent using digital media relates to myopia progress, but that outdoor light has been shown to have a positive effect on vision. Studies from the U.S., Singapore, and China confirm a link between the time spent outdoors and the prevention of myopia, Rose said. However, both the level of light and the duration of exposure to outdoor light must reach a certain threshold to have a preventive effect, according to one of her studies. Spending at least 10 to 14 hours outside per week may prevent the early onset of myopia, she concluded.

Dr. Maria Liu, head of the Myopia Control Clinic that opened last year, explained that prevention and treatment success depend on early detection. Nearsighted children under 10 could benefit the most from intervention. This age group is also the most susceptible to eye damage from prolonged use of visual media, according to the myopia specialist."The eyeballs are very adaptive while they are developing," Liu told me. "If we impose a lot of near work on the eyes as they are developing, the eyes will interpret nearsightedness as being the normal state."

She explained the rise in myopia prevalence is likely caused by a shift in lifestyle from spending time outdoors to an indoor-oriented existence. Electronic devices play a major role in this shift, especially with young children being introduced to technology at an earlier stage in their life, and using handheld devices that require a smaller working distance than that for a physical book or television.

The Myopia Control Clinic specialists use corrective lenses (novel contact lenses) to slow down myopia in children. If applied early enough, corrective lenses have proven effective in treating the disorder. In cases with very high myopia progression, however, scleral reinforcement surgery is used to reduce or stop further damage caused by high myopia, which often can be degenerative. Atropine is the only drug that so far has proven effective in slowing myopia progression. The drug is used as a second line of treatment after all optical treatments fail.

Although modern lifestyle makes it harder to fight the disorder, there is something parents can do to prevent its early onset."Whether it is because hormonal levels are different outdoors, or because the light intensity is stronger, or because we do less close-up work, it has been shown consistently that outdoor activity is very protective and tends to slow the rate of progression."

Taking frequent 10-minute breaks from near-work and looking in the distance is also recommended, including for young adults who spend a lot of time working on computers or laptops and may suffer from accommodating spasms that cause blurry distance vision and dry eyes. Some specialists recommend limiting time in front of computers, TVs, and handheld devices to 1.5 hours a day, especially for young children.

Good news for those who enjoy drinking a little wine. From Medical Xpress:

A little wine might help kidneys stay healthy

An occasional glass of wine might help keep your kidneys healthy, new research suggests. And for those who already have kidney disease, which puts one at higher risk for cardiovascular problems, moderate wine drinking might help the heart. the researchers added.

"Those [with healthy kidneys] who drank less than one glass of wine a day had a 37 percent lower risk of having chronic kidney disease than those who drank no wine," said study author Dr. Tapan Mehta, a renal fellow at the University of Colorado Anschutz Medical Center, in Aurora.

"Those with chronic kidney disease who drank less than one glass a day had a 29 percent lower risk of cardiovascular events [than those who drank no wine]," he added.

Mehta and his colleagues looked at data from the 2003 to 2006 National Health and Nutrition Examination that included nearly 6,000 people. Of those, about 1,000 had chronic kidney disease.

Having chronic kidney disease increases the risk of cardiovascular disease. About 26 million Americans have chronic kidney disease, often caused by diabetes and high blood pressure, according to the National Kidney Foundation. Previous research has found that moderate drinking is linked to heart benefits.

Exactly why wine might do that is not known for sure, Mehta said. Drinking moderate amounts is linked with lower levels of protein in the urine. In those who have kidney disease, higher protein levels in the urine are linked with an increased risk of progression of kidney disease. The polyphenols found in wine have anti-inflammatory and antioxidant properties, which may help explain the protective heart effects, he said.

This study came out last month, but I think it is something to be concerned about any time you are thinking about getting cosmetic "fillers". Definitely check out the photo. From Science Daily:

Cosmetic treatment can open door to bacteria

Many people have 'fillers' injected into their facial tissue to give them 'bee-stung lips' or to smooth out their wrinkles. Unfortunately, a lot of cosmetic treatment customers experience unpleasant side effects in the form of tender subcutaneous lumps that are difficult to treat and which -- in isolated cases -- have led to lesions that simply will not heal. Research recently published by the University of Copenhagen now supports that, despite the highest levels of hygiene, this unwanted side effect is caused by bacterial infection.

Injections of fillers were previously reserved exclusively for trauma treatment -- when rebuilding a face disfigured in a traffic accident, for example. However, the jelly-like substances are increasingly being used in beauty treatments with the intention of making lips swell up and to erase the effects of ageing from the skin. Side effects in the form of stubborn, tender lumps or even lesions are becoming an increasing problem:

"Previously, most experts believed that the side effects were caused by an auto-immune or allergic reaction to the gel injected. Research involving tissue from patients and mouse models has now shown that the disfiguring lesions are actually due to bacteria injected in connection with the cosmetic procedure. What is more, we have demonstrated that the fillers themselves act as incubators for infection, and all it takes is as few as ten bacteria to create an ugly lesion and a tough film of bacterial material -- known as biofilm -- which is impossible to treat with antibiotics," says Morten Alhede, a postdoc at the Department of International Health, Immunology and Microbiology, University of Copenhagen.

Treatment with fillers is very common. According to the American Society for Aesthetic Plastic Surgery (ASAPS), treatment with products based on hyaluronic acid -- such as Restylane -- constitutes the second-most popular non-surgical cosmetic procedure in the United States. The precise figures for Denmark are not known, but there can be no doubt that the numbers are rising rapidly -- and a rise in the number of treatments will inevitably make the side effects more evident.

"Because a lot of cosmetic practitioners refuse to accept that side effects from filler procedures are caused by bacteria, claiming that such problems are caused by allergic reactions, the usual procedure has been to treat with steroids. This is actually the worst possible treatment because steroid injections exacerbate the condition and give the bacteria free rein. Fortunately, many of the filler producers have now become aware of the risk of bacteria and recognise that the gel can act as a bacterial incubator," says Associate Professor Thomas Bjarnsholt from the Department of International Health, Immunology and Microbiology. He continues:

"The problem will become very serious when the treatment becomes so widespread that people are able to walk in off the street to have their wrinkles smoothed out. Experts recommend keeping facial skin free from make-up for a month before undergoing a treatment involving fillers. Good hygiene is always important. Even when you abide by all the rules and regulations, it is difficult to avoid bacteria completely as they are often buried far below the surface of the skin."

Researchers estimate that between 1:100 and 1:1000 -- depending on the type of filler - develops an unfortunate bacterial infection which, in the worst-case scenario, may leave the person in question with a permanently disfigured face.

The biofilm that can develop in the wake of a filler treatment is resistant to antibiotics. "The good news is that infections can be prevented by prophylactic antibiotic treatment, i.e. injecting antibiotics together with the filler itself during the cosmetic treatment process. Our new research emphasises how important it is for all practitioners to follow this procedure to prevent the unwanted complications," explains Morten Alhede.

Injection of fillers: Side effects in the form of stubborn, tender lumps or even lesions are becoming an increasing problem. Photo credit: University of Copenhagen

A totally off the wall study that I think will interest those who have wondered if we can control our dreams. This is especially appealing for everyone wanting pleasant dreams and wanting to avoid nightmares. From Science Daily:

Mass participation experiment reveals how to create the perfect dream

Today psychologist Professor Richard Wiseman from the University of Hertfordshire announces the results of a two-year study into dream control. The experiment shows that it is now possible for people to create their perfect dream, and so wake up feeling especially happy and refreshed.

In 2010, Professor Wiseman teamed-up with app developers YUZA to create 'Dream:ON' -- an iPhone app that monitors a person during sleep and plays a carefully crafted 'soundscape' when they dream. Each soundscape was carefully designed to evoke a pleasant scenario, such as a walk in the woods, or lying on a beach, and the team hoped that these sounds would influence people's dreams. At the end of the dream, the app sounded a gentle alarm and prompted the person to submit a description of their dream.

The app was downloaded over 500,000 times and the researchers collected millions of dream reports. After studying the data, Professor Wiseman discovered that the soundscapes did indeed influence people's dreams.

Richard Wiseman, professor in the Public Understanding of Psychology at the University of Hertfordshire, said: "If someone chose the nature landscape then they were more likely to have a dream about greenery and flowers. In contrast, if they selected the beach soundscape then they were more likely to dream about the sun beating down on their skin."

"In 2013, neuroscientists from the University of Basel discovered that people experience more disturbed sleeping patterns around the time of a full Moon," remarked Wiseman. "We have seen a similar pattern, with more bizarre dreams being associated with a full moon."

Finally, the team also found that certain soundscapes produced far more pleasant dreams.

The findings are described in Professor Wiseman's book on sleep and dreaming, Night School. The Dream:ON app and all of the soundscapes are currently available free of charge.

Last month (Feb. 12, 2014) I posted two studies that discussed the link between exercise and health, including eye health and macular degeneration. This following article builds on those studies to discuss the link between eye health and exercise, how exercise could protect our eyes from age-related vision loss, and even repair eye damage. From the NY Times:

Exercising for Healthier Eyes

There have been suggestions that exercise might reduce the risk of macular degeneration, which occurs when neurons in the central part of the retina deteriorate. The disease robs millions of older Americans of clear vision. A 2009 study of more than 40,000 middle-aged distance runners, for instance, found that thise covering the most miles had the least likelihood of developing the disease. But the study did not compare runners to non-runners, limiting its usefulness. It also did not try to explain how exercise might affect the incidence of an eye disease. 

So, more recently, researchers at Emory University in Atlanta and the Atlanta Veterans Administration Medical Center in Decatur, Ga., took up that question for a study published last month in the Journal of Neuroscience. Their interest was motivated in part by animal research at the V.A. medical center. That work had determined that exercise increases the levels of substances known as growth factors in the animals’ bloodstream and brains. These growth factors, especially one called brain-derived neurotrophic factor, or B.D.N.F., are known to contribute to the health and well-being of neurons and consequently, it is thought, to improvements in brain health and cognition after regular exercise.

But the brain is not the only body part to contain neurons, as the researchers behind the new study knew. The retina does as well, and the researchers wondered whether exercise might raise levels of B.D.N.F. there, too, potentially affecting retinal health and vision.

To test that possibility, the researchers gathered adult, healthy lab mice. Half of these were allowed to remain sedentary throughout the day, while the other animals began running on little treadmills at a gentle rodent pace for about an hour a day. After two weeks, half of the mice in each group were exposed to a searingly bright light for four hours. The other animals stayed in dimly lit cages. This light exposure is a widely used and accepted means of inducing retinal degeneration in animals. It doesn’t precisely mimic the slowly progressing disease in humans, obviously. But it causes a comparable if time-compressed loss of retinal neurons.

The mice then returned to their former routine — running or not exercising — for another two weeks, after which the scientists measured the number of neurons in each animal’s eyes. The unexercised mice exposed to the bright light were experiencing, by then, severe retinal degeneration. Almost 75 percent of the neurons in their retinas that detect light had died. The animals’ vision was failing.

But the mice that had exercised before being exposed to the light retained about twice as many functioning retinal neurons as the sedentary animals; in addition, those cells were more responsive to normal light than the surviving retinal neurons in the unexercised mice. Exercise, it seems, had armored the runners’ retinas.

Separately, the researchers had other mice run or sit around for two weeks, and then measured levels of B.D.N.F. in their eyes and bloodstreams. The runners had far more. Tellingly, when the scientists injected still other mice with a chemical that blocks the uptake of the growth factor before allowing them to run and exposing them to the bright light, their eyes deteriorated as badly as among sedentary rodents. When the mice could not process B.D.N.F., exercise did not safeguard their eyes.

Taken together, these experiments strongly suggest that “exercise protects vision, at least in mice, by increasing B.D.N.F. in the retina,” said Jeffrey Boatright, an associate professor of ophthalmology at Emory University School of Medicine and a co-author of the study.

She and her colleagues are trying to find ways to determine the impact of exercise on human eyes. But such experiments will take years to return results.

For now, she and Dr. Boatright said, people who are concerned about their vision, and especially those with a family history of retinal degeneration, might want to discuss an exercise program with their doctor. “As potential treatments go,” she said, “it’s cheap, easy and safe.”

First researchers talked about second-hand cigarette smoke, but now there is a concern with third-hand smoke. From Science Daily:

Major 'third-hand smoke' compound causes DNA damage and potentially cancer

Leftover cigarette smoke that clings to walls and furniture is a smelly nuisance, but now research suggests that it could pose a far more serious threat, especially to young children who put toys and other smoke-affected items into their mouths. Scientists reported today that one compound from this "third-hand smoke," which forms when second-hand smoke reacts with indoor air, damages DNA and clings to it in a way that could potentially cause cancer.

Bo Hang, Ph.D., who presented the research, said that although the idea of third-hand smoke made its debut in research circles just a few years ago in 2009, evidence already strongly suggests it could threaten human health.

"The best argument for instituting a ban on smoking indoors is actually third-hand smoke," said Hang, a scientist at Lawrence Berkeley National Laboratory (LBNL).

Researchers have found that many of the more than 4,000 compounds in second-hand smoke, which wafts through the air as a cigarette is smoked, can linger indoors long after a cigarette is stubbed out. Based on studies led by Hugo Destaillats, also at LBNL, these substances can go on to react with indoor pollutants such as ozone and nitrous acid, creating brand-new compounds, some of which may be carcinogenic.

One of those compounds goes by the acronym NNA. Hang's research has shown that NNA, a tobacco-specific nitrosamine, locks onto DNA to form a bulky adduct (a piece of DNA bound to a cancer-causing chemical), as well as other adducts, in lab test tubes. Other large compounds that attach to DNA tend to cause genetic mutations. NNA also breaks the DNA about as often as a related compound called NNK, which is a well-studied byproduct of nicotine and a known potent carcinogen. This kind of DNA damage can lead to uncontrolled cell growth and the formation of cancerous tumors.

The biggest potential health risk is for babies and toddlers, he noted. As they crawl and put their hands or toys in their mouths, they could touch, swallow or inhale compounds from third-hand smoke. Their small size and early developmental stage make them more vulnerable than adults to the effects of environmental hazards.

Although many public places prohibit smoking, Hang noted that people can still smoke in most rental apartments and private residences -- and smoking remains a huge public health issue. In 2011, nearly 44 million American adults reported smoking cigarettes, which ranks as the leading cause of preventable death in this country. And 34 million people smoke every day, according to data from the Centers for Disease Control & Prevention.

So far, the best way to get rid of third-hand smoke is by removing affected items, such as sofas and carpeting, as well as sealing and repainting walls, and sometimes even replacing contaminated wallboard, he explained. Replacing furniture can be pricey, but Hang said vacuuming and washing clothes, curtains and bedding can also help.

This is really an important finding. For a while now many scientists have thought there was an environmental exposure (such as pesticides) link to autism. From Science Daily:

Autism, intellectual disability incidence linked with environmental factors

An analysis of 100 million US medical records reveals that autism and intellectual disability (ID) rates are correlated at the county level with incidence of genital malformations in newborn males, an indicator of possible congenital exposure to harmful environmental factors such as pesticides.

Autism rates -- after adjustment for gender, ethnic, socioeconomic and geopolitical factors -- jump by 283 percent for every one percent increase in frequency of malformations in a county. Intellectual disability rates increase 94 percent. Slight increases in autism and ID rates are also seen in wealthier and more urban counties.

The study, published by scientists from the University of Chicago March 13 in PLOS Computational Biology, confirms the dramatic effect of diagnostic standards. Incidence rates for Autism and ID on a per-person basis decrease by roughly 99 percent in states with stronger regulations on diagnosis of these disorders.

"Autism appears to be strongly correlated with rate of congenital malformations of the genitals in males across the country," said study author Andrey Rzhetsky, PhD, professor of genetic medicine and human genetics at the University of Chicago. "This gives an indicator of environmental load and the effect is surprisingly strong."

Although autism and intellectual disability have genetic components, environmental causes are thought to play a role. To identify potential environmental links, Rzhetsky and his team analyzed an insurance claims dataset that covered nearly one third of the US population. They used congenital malformations of the reproductive system in males as an indicator of parental exposure to toxins.

Male fetuses are particularly sensitive to toxins such as environmental lead, sex hormone analogs, medications and other synthetic molecules. Parental exposure to these toxins is thought explain a large portion of congenital reproductive malformations, such as micropenis, hypospadias (urethra on underside of the penis), undescended testicles and others.

The researchers created a statistical baseline frequency of autism and ID across the country. They then looked at the actual rates of these disorders, county-by-county. Deviations from the baseline are interpreted as resulting from local causes. Factors such as age, ethnicity, socioeconomic groups and geopolitical statuses were analyzed and corrected for.

The team found that every one percent increase in malformations in a county was associated with a 283 percent increase in autism and 94 percent increase in ID in that same county. Almost all areas with higher rates of autism also had higher rates of ID, which the researchers believe corroborates the presence of environmental factors. In addition, they found that male children with autism are almost six times more likely to have congenital genital malformations. Female incidence was linked with increased malformation rates, but weakly so. A county-by-county map of autism and ID incidence above or below the predicted baseline for the entire US is included in the study.

Non-reproductive congenital malformations and viral infections in males were also associated with double digit increases in autism and ID rates. Additionally, income appeared to have a weak effect -- every additional $1,000 of income above county average was correlated with around a three percent increase in autism and ID rates. An increased percentage of urban population in a county also showed a weak increase in rates.

Head lice is a big, big concern for parents of young school age children. From Science Daily:

Ordinary conditioner removes head lice eggs as effectively as special products

Eggs from head lice, also called nits, are incredibly difficult to remove. Female lice lay eggs directly onto strands of hair, and they cement them in place with a glue-like substance, making them hard to get rid of. In fact, the eggs are glued down so strongly that they will stay in place even after hair has been treated with pediculicides -- substances used to kill lice.

Some shampoos and conditioners that contain chemicals or special oils are marketed as nit-removal products. However, new research just published in the Journal of Medical Entomology shows that ordinary hair conditioner is just as effective.

In an article called "Efficacy of Products to Remove Eggs of Pediculus humanus capitis (Phthiraptera: Pediculidae) From the Human Hair," scientists from Belgium gathered 605 hairs from six different children. Each hair had a single nit attached to it. Approximately 14% of the eggshells contained a dead egg, whereas the rest were empty.

They then tried to remove the eggs and tested the amount of force needed to do so. They found that nits on the hairs that were left completely untreated were the most difficult to remove. Eggs on hairs that had been soaked in deionized water were much easier to remove, as were the eggs on hairs that had been treated with ordinary hair conditioner and with products specifically marketed for the purpose of nit removal.

However, they found no significant differences between the ordinary conditioners and the special nit-removal products. In all cases, less force was required to remove the nits after the hair had been treated, but the effectiveness of the products was essentially the same.

The authors hypothesize that the deionized water was effective because it acts as a lubricant, so less friction is needed to remove the nits from the hairs. The same goes for the conditioners.

From Medscape:

Allergic Rhinitis Patients Live Longer

Their runny noses might drive them crazy, but people with allergic rhinitis are likely to outlive the rest of us, a new study suggests.

"We found that allergic rhinitis patients had a decreased risk of heart attack, a decreased risk of stroke and, most strikingly, a decreased risk of all-cause mortality," said lead investigator Angelina Crans Yoon, MD, from the Department of Allergy and Clinical Immunology at the Kaiser Permanente Los Angeles Medical Center.

"They were basically half as likely to die during the study period," she told Medscape Medical News. 

Researchers studying data from the National Health and Nutrition Examination Survey (NHANES) found that people who tested positive for allergies were less likely to suffer cardiovascular events.

To explore the issue further, Dr. Crans Yoon and her team looked at a database of Southern California patients.The cohort consisted of 109,229 patients with allergic rhinitis and 109,229 people without allergic rhinitis who were matched for age, sex, and ethnicity. It also consisted of 92,775 patients with asthma who were matched with a similar group without asthma.

Risk for acute myocardial infarction was 25% lower in patients with allergic rhinitis than in those without, risk for a cerebrovascular event was 19% lower, and risk for all-cause mortality was 49% lower. Risk for all cardiovascular events was similar in the allergic rhinitis and control groups.

In contrast, risk for all cardiovascular events was 36% higher in patients with asthma than in those without, whereas risk for cerebrovascular disease and all-cause mortality were similar.

This could be the result of a difference in phenotypes in asthma patients, said Dr. Crans Yoon. People whose asthma is caused by allergies could be at less risk for cardiovascular events than people whose asthma has other causes.

Why should allergic rhinitis decrease someone's risk for death? 

Another explanation could be that the immune systems of patients with allergic rhinitis are hyperalert, aggressively fighting off disease, as well as causing symptoms, when it is not necessary. More work is needed to evaluate that.