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Published on Leave a comment on The Longer Overweight, the Greater A Woman’s Cancer Risk

Yikes! A good reason to lose weight now rather than years from now, and the importance of not ignoring a weight gain (you know, over the years as the pounds slowly creep up). The researchers found that for every 10 years of being overweight as an adult, there was an associated 7% increase in the risk for all obesity-related cancers. The degree of overweight (dose-response) during adulthood was important in the risk of developing cancer, especially for endometrial cancer. This study just looked at postmenopausal women, so it is unknown if it applies to men. From Medscape:

Longer Duration of Overweight Increases Cancer Risk in Women

A longer duration of being overweight during adulthood significantly increased the incidence of all cancers that are associated with obesity, a new study in postmenopausal women has concluded. The large population-based study was published August 16 in PLoS Medicine.

Dr Arnold and colleagues found that for every 10 years of being overweight as an adult, there was an associated 7% increase in the risk for all obesity-related cancers. The risk was highest for endometrial cancer (17%) and kidney cancer (16%). For breast cancer, the increased risk was 5%, but no significant associations were found for rectal, liver, gallbladder, pancreatic, ovarian, and thyroid cancer.

When the authors took into account the degree of excess weight over time, the risks were further increased, and there were "clear dose-response relationships," they note. Again, the risk was highest for endometrial cancer. For each additional decade spent with a body mass index (BMI) that was 10 units above normal weight, there was a 37% increase in the risk for endometrial cancer.

Study Details: The researchers used data from the huge American Women's Health Initiative (WHI) trial of postmenopausal women (aged 50 to 79 years at time of study enrollment). For this analysis, the team focused on a cohort of 73,913 postmenopausal women. During a mean follow-up of 12.6 years, 6301 obesity-related cancers were diagnosed. About 40% (n = 29,770) of women in the cohort were never overweight during their adult life....Women who were ever overweight were on average overweight for about 30 years, while those who were ever obese had been so for an average of 20 years. The authors found that the risk of being diagnosed with an obesity-related cancer rose for every 10 years of being overweight.

Published on Leave a comment on Overdiagnosed and Overtreated For Thyroid Cancer

The problem of overdiagnosis and overtreatment has been discussed in a number of posts on this site. And back in April 15, 2016 I posted that a type of noninvasive thyroid cancer had just been reclassified as a noncancer. Now a study in the prestigious New England Journal of Medicine finds that looking at 12 countries (including the USA): "Overall, we estimate that more than 470,000 women and 90,000 men may have been overdiagnosed with thyroid cancer over two decades in these 12 countries..."

The researchers further state that the "vast majority" of these patients received a diagnosis of small, low-risk papillary carcinomas, and they underwent surgery and other treatments, but these interventions have not shown "benefits in terms of improved survival". In fact, studies show that watchful waiting is just as effective. From Medscape:

Thyroid Cancer Overdiagnosis in Half a Million Patients

A large fraction of thyroid cancer cases represent overdiagnoses, and at least half a million patients, most of them women, may have received unnecessary surgery and other cancer treatments, say researchers from the the International Agency for Research on Cancer (IARC), in Lyons, France.

Their warning about an epidemic of thyroid cancer overdiagnosis comes from an analysis of cancer registry data from 12 countries published August 17 in the New England Journal of Medicine . Salvatore Vaccarella, PhD, and colleagues at the IARC estimate that more than 470,000 women and 90,000 men may have been overdiagnosed withthyroid cancer in 12 "high-income" countries (Australia, Denmark, England, Finland, France, Italy, Japan, Norway, Republic of Korea, Scotland, Sweden, and the United States) from 1987 to 2007.

Most of these thyroid cancers were small, low-risk papillary carcinomas, they note. The "vast majority" of these patients underwent total thyroidectomy, and a "high proportion" also received neck lymph-node dissection and radiotherapy, but these interventions do not have "proven benefits in terms of improved survival," the researchers point out...."However, if we take the most recent available period, 2003 - 2007, as typical of current practice, we estimate that overdiagnosis in women accounts for 90% of thyroid-cancer cases in South Korea; 70 to 80% in the United States, Italy, France, and Australia; and 50% in Japan, the Nordic countries, and England and Scotland."

The overdiagnosis is blamed on increasing medical surveillance and the introduction of new diagnostic techniques, such as neck ultrasonography (since the 1980s) and, more recently, CTscanning and MRI. This new technology has led to the detection of a large number of indolent, nonlethal diseases that exist in abundance in the thyroid gland of healthy people of any age, the researchers comment, adding that most of these tumors are very unlikely to cause symptoms or death....."It is fair to say that the large number of thyroid cancers being diagnosed represent an epidemic of diagnosis, or an epidemic of medical testing, rather than an epidemic of true disease."

These results also mean that most patients are receiving treatment that does not benefit them and that subjects them to risks of injury to the voice, permanent hypoparathyroidism, as well as the attendant risks of radioactive iodine treatment, he pointed out.  

The researchers caution against systematic screening for thyroid cancer and overtreatment of nodules <1 cm. "Watchful-waiting approaches should be considered a research priority and a preferable option for patients with low-risk papillary thyroid cancers," they say. Studies from Japan suggest that immediate surgery and watchful waiting are equally effective in preventing mortality, Dr Vaccarella said. One study showed that of 1235 patients with papillary microcarcinomas, only 3.5% experienced clinical progression of disease during a 75-month follow-up, and there were no deaths.

At Memorial Sloan Kettering Cancer Center, active surveillance has been offered to patients with low-risk, small, intrathyroidal cancers for several years, Dr Morris said. "Our results have mirrored the Japanese results, and fewer than 5% of patients end up showing any signs of tumor growth under close observation," he said.

Published on Leave a comment on Farm Animal Exposure and Asthma In Children

Earlier posts discussed research that showed that farm and animal (pets such as dogs) exposures in the first year of life is protective against allergies and asthma (lowers the risk of developing them). New research examined this further by looking at Amish and Hutterite groups - looking at not just "farm life", but whether children had much exposure to farm animals. The Amish have close exposure to farm animals (traditional farming methods), but the Hutterites don't (communal highly industrialized farming). Both groups studied had similar lifestyles (drank raw milk, breastfeeding, little exposure to smoking), but both groups did not have indoor pets ("taboos against indoor pets"). Thus farming methods were important for exposures to animals and their microbes.

The researchers said: "The importance of environmental exposures in the development of asthma is most exquisitely illustrated by epidemiologic studies conducted in Central Europe that show significant protection from asthma and allergic disease in children raised on traditional dairy farms. In particular, children’s contact with farm animals and the associated high microbial exposures4,5have been related to the reduced risk." Traditional farming exposed the children to an environment rich in microbes, and these children had very low rates of asthma and "distinct immune profiles that suggest profound effects on innate immunity." Once again, note the importance of microbes in the development of the immune system. From Science Daily:

Growing up on an Amish farm protects children against asthma by reprogramming immune cells

By probing the differences between two farming communities -- the Amish of Indiana and the Hutterites of South Dakota -- an interdisciplinary team of researchers found that specific aspects of the Amish environment are associated with changes to immune cells that appear to protect children from developing asthma. In the Aug. 4, 2016, issue of The New England Journal of Medicine, the researchers showed that substances in the house dust from Amish, but not Hutterite, homes were able to engage and shape the innate immune system (the body's front-line response to most microbes) in young Amish children in ways that may suppress pathologic responses leading to allergic asthma.

The Amish and Hutterite farming communities in the United States, founded by immigrants from Central Europe in the 18th and 19th centuries, respectively, provide textbook opportunities for such comparative studies. The Amish and the Hutterites have similar genetic ancestry. They share similar lifestyles and customs, such as no television and a Germanic farming diet. They have large families, get childhood vaccinations, breastfeed their children, drink raw milk and don't allow indoor pets.

The communities, however, are distinct in two important ways. Although both groups depend on agriculture, their farming practices differ. The Amish have retained traditional methods. They live on single-family dairy farms and rely on horses for fieldwork and transportation. In contrast, the Hutterites live on large communal farms. They use modern, industrialized farm machinery. This distances young Hutterite children from the constant daily exposure to farm animals. The other striking difference is what Ober calls a "whopping disparity in asthma." About 5 percent of Amish schoolchildren aged 6 to 14 have asthma. This is about half of the U.S. average (10.3%) for children aged 5 to 14, and one-fourth of the prevalence (21.3%) among Hutterite children.

To understand this disparity, the researchers studied 30 Amish children 7 to 14 years old, and 30 age-matched Hutterite children. They scrutinized the children's genetic profiles, which confirmed the remarkable similarities between Amish and Hutterite children. They compared the types of immune cells in the children's blood, collected airborne dust from Amish and Hutterite homes and measured the microbial load in homes in both communities.

The first gee-whiz moment came from the blood studies. These revealed startling differences between the innate immune response from the Amish and Hutterites. "The Amish had more and younger neutrophils, blood cells crucial to fight infections, and fewer eosinophils, blood cells that promote allergic inflammation," said study co-author, immunologist Anne Sperling, PhD, associate professor of medicine at the University of Chicago. Gene expression profiles in blood cells also revealed enhanced activation of key innate immunity genes in Amish children.

The second eureka moment came from experiments using mice. When study co-author, immunologist Donata Vercelli, MD, professor of cellular and molecular medicine and associate director of the Asthma and Airway Disease Research Center at the University of Arizona, exposed mice to house-dust extracts, she found the airways of mice that received Amish dust were protected from asthma-like responses to allergens. In contrast, mice exposed to Hutterite house dust were not protected.

What was different? Dust collected from Amish homes was "much richer in microbial products," the authors note, than dust from Hutterite homes. "Neither the Amish nor the Hutterites have dirty homes," Ober explained. "Both are tidy. The Amish barns, however, are much closer to their homes. Their children run in and out of them, often barefoot, all day long. There's no obvious dirt in the Amish homes, no lapse of cleanliness. It's just in the air, and in the dust."

To better understand how asthma protection was achieved, the researchers used mice that lack MyD88 and Trif, genes crucial for innate immune responses. In these mice, the protective effect of the Amish dust was completely lost. "The results of the mouse experiments conclusively prove that products from the Amish environment are sufficient to confer protection from asthma, and highlight the novel, central role that innate immunity plays in directing this process," Vercelli said.

Published on Leave a comment on Similar Fertility Decline In Both Dogs and Men

Take note: what is happening to dogs is also happening to men. Specifically, for many decades - year by year - there has been a decrease in male dog fertility. And yes, this is also happening with human male fertility - a decline in male semen quality (including sperm), along with an increase in the incidence of testicular cancer, the birth defect hypospadias, and undescended testes. This cluster of problems is called testicular dysgenesis syndrome (TGS), and it has an negative impact on male fertility.

Dr Richard Lea, who led the research said: "This is the first time that such a decline in male fertility has been reported in the dog and we believe this is due to environmental contaminants..." and "While further research is needed to conclusively demonstrate a link, the dog may indeed be a sentinel for humans -- it shares the same environment, exhibits the same range of diseases, many with the same frequency, and responds in a similar way to therapies."

What chemicals were detected that affect male fertilty? Why, the same chemicals that appear again and again in studies and are linked to a number of health problems: endocrine disruptors. Yes, they are all around us - in our food, our homes, our everyday products, our environment. From Science Daily:

Study demonstrates rapid decline in male dog fertility, with potential link to environmental contaminants

A study led by researchers at The University of Nottingham has discovered that the fertility of dogs may have suffered a sharp decline over the past three decades. The research, published in the academic journal Scientific Reports, found that sperm quality in a population of stud dogs studied over  a 26-year period had fallen significantly.The work has highlighted a potential link to environmental contaminants, after they were able to demonstrate that chemicals found in the sperm and testes of adult dogs -- and in some commercially available pet foods -- had a detrimental effect on sperm function at the concentrations detected.

 The study centered on samples taken from stud dogs at an assistance dogs breeding center over the course of 26 years. Professor Gary England.... said: "The strength of the study is that all samples were processed and analysed by the same laboratory using the same protocols during that time and consequently the data generated is robust." The work centred on five specific breeds of dogs -- Labrador retriever, golden retriever, curly coat retriever, border collie and German shepherd -- with between 42 and 97 dogs studied every year. Semen was collected from the dogs and analysed to assess the percentage of sperm that showed a normal forward progressive pattern of motility and that appeared normal under a microscope (morphology).

Over the 26 years of the study, they found a striking decrease in the percentage of normal motile sperm. Between 1988 and 1998, sperm motility declined by 2.5 per cent per year and following a short period when stud dogs of compromised fertility were retired from the study, sperm motility from 2002 to 2014 continued to decline at a rate of 1.2% per year. In addition, the team discovered that the male pups generated from the stud dogs with declining semen quality, had an increased incidence of cryptorchidism, a condition in which the testes of pups fail to correctly descend into the scrotum.

Sperm collected from the same breeding population of dogs, and testes recovered from dogs undergoing routine castration, were found to contain environmental contaminants at concentrations able to disrupt sperm motility and viability when tested. The same chemicals that disrupted sperm quality, were also discovered in a range of commercially available dog foods -- including brands specifically marketed for puppies. Dr Lea added: "We looked at other factors which may also play a part, for example, some genetic conditions do have an impact on fertility. However, we discounted that because 26 years is simply too rapid a decline to be associated with a genetic problem."

Over the past 70 years, studies have suggested a significant decline in human semen quality and a cluster of issues called 'testicular dysgenesis syndrome' that impact on male fertility which also include increased incidence of testicular cancer, the birth defect hypospadias and undescended testes.

However, declining human semen quality remains a controversial issue -- many have criticised the variability of the data of the studies on the basis of changes in laboratory methods, training of laboratory personnel and improved quality control over the years. Dr Lea added: "The Nottingham study presents a unique set of reliable data from a controlled population which is free from these factors. This raises the tantalising prospect that the decline in canine semen quality has an environmental cause and begs the question whether a similar effect could also be observed in human male fertility."

Excerpts from the original study in Scientific Reports: Environmental chemicals impact dog semen quality in vitro and may be associated with a temporal decline in sperm motility and increased cryptorchidism

A significant decline in human semen quality over the last 70 years has been widely reported1,2. The first meta-analysis reporting this phenomenon included 61 studies selected over a 50 year period (1938–1991)1 and such a trend was confirmed by re-analysis with an additional 47 studies included2.....Nevertheless, reports of declining sperm counts linked with epidemiological data on increased incidences of testicular cancer and genital tract abnormalities, is indicative of an adverse environmental effect on male reproduction6,7,8. Since these reproductive problems, termed by some as “testicular dysgenesis syndrome” (TDS), cluster in geographical areas9 they are thought to have a common aetiology and have been associated with endocrine perturbations in early life10. Exposure of developing males to environmental chemicals, particularly those with endocrine disrupting activity, is thought to be the initiator11. Although periods of development particularly sensitive to exposure encompass both pre-natal and pre-pubertal periods, environmental chemicals also perturb adult testis function e.g. gene expression and meiosis12. 

As ‘man’s best friend’ and closest animal companion, the dog shares the same environment, exhibits the same range of diseases, many with the same frequency, and responds in a similar way to therapeutic treatments. There is evidence that over the last 40 years, the incidence rate of canine testicular cancer has increased in parallel with changes seen in humans17,18. In addition, histological signs which characterise human TDS have recently been described in the dog19. These include seminiferous tubule abnormalities and testicular germ cell neoplasia in situ (GCNIS) cells which are known precursors of seminomas in the human20. Since human TDS includes a reduction in sperm count21 and an increased incidence of cryptorchidism, we hypothesised that the dog may exhibit similar manifestations of TDS and that this may be associated with exposure to endocrine disrupting chemicals.  

The dog is probably man’s closest companion and by sharing the same habitat, is likely to be exposed to similar environmental conditions including environmental chemicals. This was especially true in the current study since the dogs lived in homes with their handlers. Twelve chemicals detected in adult dog testes (DEHP, 7 PCB congeners, 4 PBDE congeners) were also detected in the 15 commercially available dog foods analysed. 

Published on Leave a comment on Strong Evidence That Alcohol Causes Seven Cancers

A medical article in the journal Addiction states that there is strong evidence that alcohol causes 7 cancers, that there is evidence that it probably causes more, the effects are dose related, and if one also smokes the risks are greatly increased. The 7 cancers are: oropharynx (mouth and pharynx), larynx, esophagus, liver, colon, rectum, and female breast.

An earlier post reported on conflicting results from some studies (e.g. that low to moderate alcohol consumption is beneficial), as well as the finding that effects are dose-related (the more alcohol a person drinks, the higher the risk of cancer). NOTE: One standard drink contains 14 grams of alcohol, and is equivalent to one ordinary beer, a glass of wine (5 oz), or a nip of spirits (1.5 oz or 44 ml). The article excerpts below state that the strongest effects are from consuming 50 grams or more of alcohol per day (compared to those who don't drink at all).

From Medscape: No Confusion: Alcohol Causes Seven Cancers

There is "strong evidence" that alcohol causes seven cancers, and other evidence indicates that it "probably" causes more, according to a new literature review published online July 21 in Addiction. Epidemiologic evidence supports a causal association of alcohol consumption and cancers of the oropharynx, larynx, esophagus, liver, colon, rectum, and female breast, says Jennie Connor, MB, ChB, MPH, from the Department of Preventive and Social Medicine, University of Otago, in Dunegin, New Zealand.

In short, alcohol causes cancer. This is not news, says Dr Connor. The International Agency for Research on Cancer (IARC) and other agencies have long identified alcohol consumption as being causally associated with these seven cancers. So why did Dr Connor, who is an epidemiologist and physician, write a new review? Because she wants to "clarify the strength of the evidence" in an "accessible way." 

The newly published review "reinforces the need for the public to be made aware of the causal link between alcohol and cancer," said Colin Shevills, from the Alcohol Health Alliance UK, in a press statement....The lack of clarity about alcohol causing cancer, Dr Connor believes, is related to alcohol industry propaganda as well as the fact that the "epidemiological basis for causal inference is an iterative process that is never completed fully."

Dr Connor writes that the strength of the association of alcohol as a cause of cancer varies by bodily site. The evidence is "particularly strong" for cancer of the mouth, pharynx, and esophagus (relative risk, ~4-7 for ≥50 g/day of alcohol compared with no drinking) but is less so for colorectal cancer and liver and breast cancer (relative risk, ~1.5 for ≥50 g/day). "For cancers of the mouth, pharynx, larynx and oesophagus there is a well-recognized interaction of alcohol with smoking, resulting a multiplicative effect on risk," adds Dr Connor.

Other cancers are also likely caused by alcohol. Dr Connor writes that there is "accumulating research" supporting a causal contribution of alcohol to cancer of the pancreas, prostate, and skin (melanoma). One British expert had an opinion about alcohol's carcinogenicity. In a statement about the new review, Prof Dorothy Bennett, director of the Molecular and Clinical Sciences Research Institute at St. George's, University of London, said: "Alcohol enters cells very easily, and is then converted into acetaldehyde, which can damage DNA and is a known carcinogen."

In the new review, Dr Connor describes various hallmarks of causality that have been found in epidemiologic studies of alcohol and these seven cancers, such as a dose-response relationship and the fact that the risk for some of these cancers (esophageal, head and neck, and liver) attenuates when drinking ceases. Current estimates suggest that alcohol-attributable cancers at the seven cancer sites make up 5.8% of all cancer deaths worldwide, she states. The alcohol industry has a lot at stake, she says, which in turn leads to "misinformation" that "undermines research findings and contradicts evidence-based public health messages."

But there is no safe level of drinking with respect to cancer, says Dr Connor, citing research about low to moderate levels of alcohol, which has been covered by Medscape Medical News. This was also the conclusion of the 2014 World Cancer Report, issued by the World Health Organization's IARC.

Published on Leave a comment on Does Saline Nasal Irrigation Treat Sinusitis Symptoms?

A recent study compared saline nasal irrigation vs steam inhalation vs doing both saline irrigation and steam inhalation vs doing neither (the control group) for chronic or recurring sinusitis symptoms. In the study, people with a history of chronic or recurring sinusitis symptoms were randomly assigned to one of the 4 groups, and then studied 3 months and 6 months later. The results were: a modest (slight improvement) in the saline irrigation group in symptom and quality-of-life scores, but no improvement for the steam inhalation group. However, the researchers noted that the control group also had slight improvements at 3 and 6 months. Most of the improvement in the saline irrigation group was in the group that also did steam inhalation - thus perhaps some benefit to combining both.

In addition, patients in the nasal irrigation group reported fewer headaches, fewer of them used over-the-counter medications, and said they were less likely to consult with a physician about their nasal problems in the future when compared with patients in the steam inhalation group.

Most people with chronic or recurring sinusitis will probably agree with the findings. Yes, effects are modest with saline irrigation, but it definitely does improve nasal stuffiness (experiences of family members and readers). But it does NOT treat the sinusitis. The sinus microbial community continues to stay out of whack (dysbiosis). Which explains the researchers' finding that saline irrigation and steam inhalation did not result in differences in antibiotic use or physician visits after 6 months.

From Science Daily: Nasal irrigation may prevent chronic sinus ailments

Advising patient with chronic sinus congestion to use nasal irrigation -- a popular nonpharmacologic treatment -- improved their symptoms, but steam inhalation did not, according to a randomized controlled trial published in CMAJ(Canadian Medical Association Journal). More than 25 million people in the United States and about 2.5 million Canadians suffer from chronic rhinosinusitis, or sinus infection, and experience compromised quality of life. To alleviate symptoms, steam inhalation and nasal irrigation are widely suggested as an alternative to common treatment with antibiotics, which are often not effective and contribute to antibiotic resistance.

Researchers from the United Kingdom conducted a randomized controlled trial on the effectiveness of advice from primary care physicians to use nasal irrigation and/or steam inhalation for chronic sinusitis. The study involved 871 patients from 72 primary care practices in England who were randomly assigned to 1 of 4 advice strategies: usual care, daily nasal and saline irrigation supported by a demonstration video, daily steam inhalation, or combined treatment with both interventions.

Patients who were instructed to use nasal irrigation showed improvement at 3 and 6 months, as measured by the Rhinosinusitis Disability Index. Steam inhalation did not appear to alleviate symptoms of sinusitis.

"We found potentially important changes in other outcomes; in particular, fewer participants in the nasal irrigation group than in the no-irrigation group had headaches, used over-the-counter medications and intended to consult a doctor in future episodes," write the authors. "Although there was no significant difference in either physician visits or antibiotic use, as might be expected over only a 6-month follow-up period, our findings concerning consultations are important in the longer term, given antibiotic use increases the risk of antimicrobial resistance."

The Abstract (summary) of the study, which is from the Canadian Medical Association Journal (CMAJ): Effectiveness of steam inhalation and nasal irrigation for chronic or recurrent sinus symptoms in primary care: a pragmatic randomized controlled trial

ABSTRACT  Background: Systematic reviews support nasal saline irrigation for chronic or recurrent sinus symptoms, but trials have been small and few in primary care settings. Steam inhalation has also been proposed, but supporting evidence is lacking. We investigated whether brief pragmatic interventions to encourage use of nasal irrigation or steam inhalation would be effective in relieving sinus symptoms.

Methods: We conducted a pragmatic randomized controlled trial involving adults (age 18–65 yr) from 72 primary care practices in the United Kingdom who had a history of chronic or recurrent sinusitis and reported a “moderate to severe” impact of sinus symptoms on their quality of life. Participants were recruited between Feb. 11, 2009, and June 30, 2014, and randomly assigned to 1 of 4 advice strategies: usual care, daily nasal saline irrigation supported by a demonstration video, daily steam inhalation, or combined treatment with both interventions. The primary outcome measure was the Rhinosinusitis Disability Index (RSDI). Patients were followed up at 3 and 6 months. We imputed missing data using multiple imputation methods.

Results: Of the 961 patients who consented, 871 returned baseline questionnaires (210 usual care, 219 nasal irrigation, 232 steam inhalation and 210 combined treatment). A total of 671 (77.0%) of the 871 participants reported RSDI scores at 3 months. Patients’ RSDI scores improved more with nasal irrigation than without nasal irrigation by 3 months (crude change −7.42 v. −5.23; estimated adjusted mean difference between groups −2.51, 95% confidence interval −4.65 to −0.37). By 6 months, significantly more patients maintained a 10-point clinically important improvement in the RSDI score with nasal irrigation (44.1% v. 36.6%); fewer used over-the-counter medications (59.4% v. 68.0%) or intended to consult a doctor in future episodes. Steam inhalation reduced headache but had no significant effect on other outcomes. The proportion of participants who had adverse effects was the same in both intervention groups.

Interpretation: Advice to use steam inhalation for chronic or recurrent sinus symptoms in primary care was not effective. A similar strategy to use nasal irrigation was less effective than prior evidence suggested, but it provided some symptomatic benefit.

Published on Leave a comment on Twin Study Finds Being Overweight Not Linked To Early Death or Heart Attack

Another interesting study looking at whether being overweight is linked to premature death, heart attacks, and diabetes. This study looked at sets of twins, in which one is heavier than the other, and followed them long-term (average 12.4 years) and found that NO - being overweight or obese (as measured by Body Mass Index or BMI) is NOT associated with premature death or heart attack (myocardial infarction), but it is associated with higher rates of type 2 diabetes. These results are in contrast with what a large study recently found. From Science Daily:

Higher BMI not associated with increased risk of heart attack or early death, twin study shows

A study of 4,046 genetically identical twin pairs with different amounts of body fat shows that twin siblings with a higher Body Mass Index, as a measure of obesity, do not have an increased risk of heart attack or mortality. The study, conducted by researchers at Umeå University in Sweden, also shows that a higher BMI is associated with an increased risk of type 2 diabetes...."The results suggest that lifestyle changes that reduce levels of obesity do not have an effect on the risk of death and heart attack, which contradicts conventional understandings of obesity-related health risks," says Peter Nordström, researcher at the Department of Community Medicine and Rehabilitation at Umeå University.

In the cohort study, Peter Nordström and research colleagues at Umeå University compared health data from 4,046 monozygotic twin pairs. All twins in the study had different levels of body fat, as measured in BMI....During a follow-up period of on average 12.4 years, differences between the twins were compared when it comes to incidents of mortality, heart attack and type 2 diabetes. The results clearly showed that twin siblings with a higher BMI did not have an increased risk of mortality or heart attack compared to their thinner counterparts. However, twins with a higher BMI did have an increased risk of developing type 2 diabetes.

The results showed that: - Among twin siblings with a higher BMI (mean value 25.1), there were 203 heart attacks (5 %) and 550 deaths (13.6 %) during the follow-up period. - Among twin siblings with a lower BMI (mean value 23.9), there were 209 heart attacks (5.2 %) and 633 deaths (15.6 %) during the same period. - Among the 65 twin pairs in the study who had a BMI difference of 7 or higher, and where the larger twin siblings had a BMI of 30 or higher, there were still no noticeably increased risk of mortality or heart attack associated with a higher BMI.

The study, described in the article Risks of Myocardinal Infarction, Death, and Diabetes in Identical Twin Pairs With Different Body Mass Index, is based on the Swedish Twin Registry, the largest of its kind in the world. The median age of the twins in the study was 57.5 and participants' ages ranged from 42-92. The cohort study was conducted between 1998 and 2003, with follow-ups regarding incident of mortality, heart attack and diabetes during a 10 year period until 2013. One study limitation was that weight and length (used to calculate BMI) was self-reported.

Published on Leave a comment on E-Cigarettes Emit Varying Amounts of Harmful Chemicals

Yup, e-cigarettes are NOT harmless, but emit harmful compounds. Researchers detected significant levels of 31 chemical compounds, including nicotine, nicotyrine, formaldehyde, acetaldehyde, glycidol, acrolein, acetol, and diacetyl. Included in the harmful emissions are carcinogens and respiratory irritants. From Science Daily:

All e-cigarettes emit harmful chemicals, but some emit more than others

While previous studies have found that electronic cigarettes emit toxic compounds, a new study from Lawrence Berkeley National Laboratory (Berkeley Lab) has pinpointed the source of these emissions and shown how factors such as the temperature, type, and age of the device play a role in emission levels, information that could be valuable to both manufacturers and regulators seeking to minimize the health impacts of these increasingly popular devices.

The study, which was published in Environmental Science & Technology, found that the thermal decomposition of propylene glycol and glycerin, two solvents found in most "e-liquids" (the substance that is vaporized by the e-cigarette), leads to emissions of toxic chemicals such as acrolein and formaldehyde.

"Advocates of e-cigarettes say emissions are much lower than from conventional cigarettes, so you're better off using e-cigarettes," said Berkeley Lab researcher and the study's corresponding author Hugo Destaillats. "I would say, that may be true for certain users--for example, long time smokers that cannot quit--but the problem is, it doesn't mean that they're healthy. Regular cigarettes are super unhealthy. E-cigarettes are just unhealthy."

One finding was that the first and last puffs produce widely varying emissions. Using a custom-built vaping apparatus emulating realistic vaping habits, researchers drew on the e-cigarette by taking puffs lasting 5 seconds every 30 seconds. They found that vapor temperature rose quickly in the first 5 to 10 minutes until reaching a steady state temperature at around the twentieth puff. Correspondingly, emissions levels between the first few puffs and the steady state increased by a factor of 10 or more in some cases, depending on the device, the battery voltage, and the emitted compound

Because there is an immense variety of e-cigarettes as well as e-liquids, the Berkeley Lab researchers decided to focus on an element that is common to all of them: the solvent in the e-liquid. Almost all e-liquids use a combination of propylene glycol and glycerin in varying proportions as a solvent....The researchers vaporized liquids consisting solely of the solvents to verify that they were the source of the emissions. In all, the researchers detected significant levels of 31 harmful chemical compounds, including two that had never been previously found in e-cigarette vapor--propylene oxide and glycidol, both of which are probable carcinogens.

Published on Leave a comment on New Antibiotic Or Future Probiotic?

 Some people have nasal bacteria - Staphylococcus lugdunensis, that kills other disease causing bacteria such as Staphylococcus aureus (including strains of MRSA) and Enterococcus. This is because S. lugdunensis produces a molecule (lugdunin) that acts as an antibiotic. It is thought that 10% of people naturally carry S. lugdunensis in their nasal passages. Will this lead to a new class of antibiotics or to probiotics of the future? Could it help in treating sinusitis? Stay tuned... From Science News:

The nose knows how to fight staph

The human nose harbors not only a deadly enemy — Staphylococcus aureus — but also its natural foe. Scientists have now isolated a compound from that foe that might combat MRSA, the methicillin-resistant strain of S. aureus....Investigating the intense interspecies competition in the nose — where microbes fight for space and access to scant sugars and amino acids — might offer a fertile alternative to searching for new drug candidates in soil microbes.

Despite being a relatively nutrient-poor environment, the human nose is home to more than 50 species of bacteria. One of these is S. aureus, a dominant cause of hospital-acquired infections such as MRSA, as well as infections of the blood and heart. But there’s a huge variability in the nasal microbe scene between individuals: while S. aureus is present in the nasal passages of roughly 30 percent of people, the other 70 percent don’t have any sign of it.

Trying to explain this difference led Peschel and colleagues to study “the ecology of the nose.” They suspected that other nasal inhabitants, well-tuned to compete in that harsh niche, might be blocking S. aureus from colonizing the nose in those who don’t carry it. From nasal secretion samples, the team isolated 90 strains of different Staphylococcus species. Of these, one bacterium, S. lugdunensis, killed S. aureus when the two were grown together in a dish. Introducing a variety of mutations into S. lugdunensis produced a strain that didn’t kill. The missing gene, the team showed, normally produced an antibiotic, which the researchers named lugdunin; it represents the first example of a new class of antibiotic.

Lugdunin was able to fend off MRSA as well as a strain of Enterococcus resistant to the antibiotic vancomycin. Neither bacteria developed resistance. The team also pitted S. lugdunensis against S. aureus in test tube and mouse studies, with S. lugdunensis besting S. aureus. Only 5.9 percent of 187 hospital patients had S. aureus in their noses if they also carried S. lugdunensis, the team found, while S. aureus was present in 34.7 percent of those without S. lugdunensis. Peschel and colleagues also reported the results July 28 in Nature.

Lugdunin cleared up a staph skin infection in mice, but it’s unclear how the compound works. Researchers could not rule out that it damages the cell membrane, which could limit its use in humans to a topical antibiotic. Peschel and coauthor Bernhard Krismer also suggest that the bacterium itself might be a good probiotic, applied nasally, to fend off staph infections in vulnerable hospital patients.  (The original study and accompanying Commentary)

 A compound secreted by the nose-dwelling bacterium Staphylococcus lugdunensis may fight antibiotic-resistant strains of bacteria such as MRSA (pink). CREDIT: NIAID, NIH/WIKIMEDIA COMMONS

Published on Leave a comment on Exercise Instead of Meniscus Repair Surgery?

A new study followed adults with meniscus tears (in the knee), who were randomly assigned to either exercise only or meniscus repair surgery (arthroscopic partial meniscectomy) only. They found that after 2 years there was no difference between those  who just received exercise therapy compared to those who just received meniscus repair surgery. About 19% of the exercise only group decided to get surgery at some point, but the rest stayed in the exercise only group.

The study in BMJ says that the exercise therapy program consisted of progressive neuromuscular and strength exercises over 12 weeks, which were performed between two and a maximum of three sessions each week (24-36 sessions). Once again, a study shows that surgery for a condition may not be necessary. From Science Daily:

Most surgical meniscus repairs are unnecessary

Three out of four people could avoid knee surgery with a new form of exercise therapy, with significant cost savings for society. Injury to the menisci, the cartilaginous discs within the knee joint, can be painful when running, and can cause the knee to give way or 'lock'. Such injuries are troublesome and sometimes painful, and can prevent you from exercising or attending work. A new study shows that exercise therapy is just as effective for treating meniscus injuries as surgery. .

A total of 140 patients with meniscus injuries in Norway and Denmark took part in the study. They drew lots for treatment with either exercise or surgery. Nina Jullum Kise says, "Two years later, both groups of patients had fewer symptoms and improved functioning. There was no difference between the two groups." However, those who had exercised had developed greater muscular strength. This is consistent with previous research, which showed that surgery yielded no additional benefits for patients who had had exercise therapy.... Jullum Kise believes that as many as three in four could be spared surgery with the right exercise therapy programme. 

In the study, the patients attended training sessions with a physiotherapist 2-3 times a week for 12 weeks. "The exercise therapy programme involves a warm up and various types of strength training. It is built up in stages that become more challenging as the patient improves and becomes stronger," explains Dr Jullum Kise. Each patient receives a personalized training programme, and learns to do the exercises under the supervision of a physiotherapist.

Menisci are crescent-shaped discs of cartilage on both sides of the knee joint. The meniscus is a shock absorber that distributes weight across the joint and at the same time stabilizes the joint when you walk or run. "We hope that the stronger muscles of the exercise therapy group may counteract osteoarthritis, a type of arthritis that often occurs in patients who have undergone surgery for a meniscus injury," says Dr Jullum Kise.