NewsMakers
New study confirms forever chemicals are absorbed through human skin
New research, published in Environment International proves for the first time that a wide range of PFAS (perfluoroalkyl substances) – chemicals which do not break down in nature – can permeate the skin barrier and reach the body’s bloodstream.
A study of 17 commonly used synthetic ‘forever chemicals’ has shown that these toxic substances can readily be absorbed through human skin.
New research, published in Environment International proves for the first time that a wide range of PFAS (perfluoroalkyl substances) – chemicals which do not break down in nature – can permeate the skin barrier and reach the body’s bloodstream.
PFAS are used widely in industries and consumer products from school uniforms to personal care products because of their water and stain repellent properties. While some substances have been banned by government regulation, others are still widely used and their toxic effects have not yet been fully investigated.
PFAS are already known to enter the body through other routes, for example being breathed in or ingested via food or drinking water, and they are known to cause adverse health effects such as a lowered immune response to vaccination, impaired liver function and decreased birth weight.
It has commonly been thought that PFAS are unable to breach the skin barrier, although recent studies have shown links between the use of personal care products and PFAS concentrations in human blood and breast milk. The new study is the most comprehensive assessment yet undertaken of the absorption of PFAS into human skin and confirms that most of them can enter the body via this route.
Lead author of the study, Dr Oddný Ragnarsdóttir carried out the research while studying for her PhD at the University of Birmingham. She explained: “The ability of these chemicals to be absorbed through skin has previously been dismissed because the molecules are ionised. The electrical charge that gives them the ability to repel water and stains was thought to also make them incapable of crossing the skin membrane.
“Our research shows that this theory does not always hold true and that, in fact, uptake through the skin could be a significant source of exposure to these harmful chemicals.”
The researchers investigated 17 different PFAS. The compounds selected were among those most widely used, and most widely studied for their toxic effects and other ways through which humans might be exposed to them. Most significantly, they correspond to chemicals regulated by the EU’s Drinking Water Directive.
In their experiments the team used 3D human skin equivalent models – multilayered laboratory grown tissues that mimic the properties of normal human skin, meaning the study could be carried out without using any animals. They applied samples of each chemical to measure what proportions were absorbed, unabsorbed, or retained within the models.
Of the 17 PFAS tested, the team found 15 substances showed substantial dermal absorption – at least 5% of the exposure dose. At the exposure doses examined, absorption into the bloodstream of the most regulated PFAS (perfluoro octanoic acid (PFOA)) was 13.5% with a further 38% of the applied dose retained within the skin for potential longer-term uptake into the circulation.
The amount absorbed seemed to correlate with the length of the carbon chain within the molecule. Substances with longer carbon chains showed lower levels of absorption, while compounds with shorter chains that were introduced to replace longer carbon chain PFAS like PFOA, were more easily absorbed. Absorption of perfluoro pentanoic acid for example was four times that of PFOA at 59%.
Study co-author, Dr Mohamed Abdallah, said “our study provides first insight into significance of the dermal route as pathway of exposure to a wide range of forever chemicals. Given the large number of existing PFAS, it is important that future studies aim to assess the risk of broad ranges of these toxic chemicals, rather than focusing on one chemical at a time.”
Study co-author, Professor Stuart Harrad, of the University of Birmingham’s School of Geography, Earth and Environmental Sciences, added: “This study helps us to understand how important exposure to these chemicals via the skin might be and also which chemical structures might be most easily absorbed. This is important because we see a shift in industry towards chemicals with shorter chain lengths because these are believed to be less toxic – however the trade-off might be that we absorb more of them, so we need to know more about the risks involved.”
NewsMakers
Common drug class may increase risk of heart disease
The risk of cardiovascular disease increased in line with how much anticholinergic medication the participants used each year. Those with the highest exposure had a 71 per cent higher risk of a cardiovascular event than people who did not use anticholinergic medication at all.
People who use drugs with anticholinergic effects, including certain antidepressants, drugs for urinary incontinence and common antihistamines, are at higher risk of developing cardiovascular disease.
This is shown in a study from Karolinska Institutet published in BMC Medicine.
Anticholinergic drugs reduce the effect of the neurotransmitter acetylcholine and are commonly prescribed to middle-aged and older people. This large group of drugs includes antihistamines used for allergic conditions, anxiety or insomnia, drugs for urinary incontinence, and certain antidepressants, where tricyclic antidepressants have a strong anticholinergic effect, whereas SSRIs have a weaker effect. A high cumulative use of these drugs, referred to as anticholinergic burden (see fact box), has previously been linked to impaired cognitive ability.
May affect heart regulation
The new study suggests that the drugs may also affect the parasympathetic nervous system and thereby the regulation of the cardiovascular system. The results show that it may be important to monitor the total drug burden in everyday clinical practice.
The study included more than 500,000 people in Stockholm, Sweden, who were 45 years of age or older and had no prior cardiovascular disease, except for hypertension, at the start of the study. The researchers followed the participants for up to 14 years and analysed how the use of anticholinergic drugs was associated with the development of cardiovascular disease.
“Many of these drugs are used by older people and by people with multiple medical conditions. We wanted to investigate whether the total exposure had any significance for the risk of developing cardiovascular disease over time,” says Nanbo Zhu, postdoctoral researcher at the Department of Neurobiology, Care Sciences and Society, Karolinska Institutet.
71 per cent higher cardiac risk
The study showed that the risk of cardiovascular disease increased in line with how much anticholinergic medication the participants used each year. Those with the highest exposure had a 71 per cent higher risk of a cardiovascular event than people who did not use anticholinergic medication at all. The association was seen for all types of cardiovascular disease but was particularly clear for heart failure and various forms of arrhythmia.
“Our results indicate that the cumulative drug burden can affect heart regulation, not only in the short term but also over the long term. This does not mean that the drugs should always be avoided, but that exposure should be monitored carefully,” says Hong Xu, assistant professor at the Department of Neurobiology, Care Sciences and Society.
The researchers point out that the study is observational, meaning it cannot establish a causal relationship. Other factors, such as underlying diseases, may also influence the associations.
The work was carried out within the Stockholm CREAtinine Measurements project in collaboration between several research groups at Karolinska Institutet and Region Stockholm. The study was funded by the Swedish Research Council, the Center for Innovative Medicine Foundation, and other foundations. Some researchers report assignments for the pharmaceutical industry, which are disclosed in the scientific publication.
NewsMakers
Mindfulness practices found to significantly reduce depression symptoms, especially for those with early-life adversity
Mindfulness interventions help by regulating our emotions better when different challenges come up. For someone who has experienced childhood neglect or abuse, mindfulness training can help us make sense of that and respond skillfully to this moment in time.
A new study reveals that mindfulness practices may significantly reduce depression symptoms, particularly in people who have experienced early-life adversity, such as childhood abuse and neglect.
Led by Eric Loucks, professor of medicine, epidemiology, and of behavioral and social sciences and director of the Mindfulness Center at Brown, the study enrolled 201 participants, 101 of whom were randomized into the Mindfulness-Based Blood Pressure Reduction Program, while 100 were randomized into an enhanced usual care control, which included home blood-pressure monitors, physician access and health-education materials. Researchers also had a measure of participants’ early-life adversity, particularly their exposure to abuse or neglect.
Loucks and his team followed participants for six months to assess changes in blood pressure, health behaviors and mental health, finding that those in the mindfulness program showed significant improvements in their depression symptoms. Additionally, participants who experienced childhood neglect showed greater improvements in depression symptoms than those who had not. A similar, though less pronounced, trend was observed among people with a history of childhood abuse.
“In this program, that was primarily designed to lower blood pressure while addressing whole-person health, we also saw that mental well-being, particularly around depression symptoms, improved in participants that went through the program,” Loucks said. “The findings suggest that cultivating mindful self-regulation skills–such such as self-awareness, attention control and emotion regulation–may help interrupt maladaptive patterns shaped by past experiences.”
Over the last 15 years, Loucks has been studying social determinants of health such as early-life adversity and its impacts on cardiovascular health, body mass index and blood pressure. “I came to a point where I wanted to not just document it, but do something about it, and I wondered if mindfulness training might help,” he said. “I’d gone through a lot of mindfulness training myself outside of work and started to get trained up in mindfulness programs that are specific to health contexts.”
Loucks began to study the Mindfulness-Based Stress Reduction program, running it through two clinical trials that were funded by the NIH and finding that it reduced blood pressure in both trials. He also wanted to look at the intervention from a whole-person perspective.
“If we look at everyday folks out in the world, those that had exposure to early life adversity, like abuse and neglect, tend to have worse mental health and also worse cardiovascular health,” Loucks said. “Mindfulness interventions help by regulating our emotions better when different challenges come up. For someone who has experienced childhood neglect or abuse, mindfulness training can help us make sense of that and respond skillfully to this moment in time.”
Loucks discussed this work during a keynote address at the U.S. DOHaD Society this year. “It felt like a coming-home moment to see that this intervention, originally developed to address psychosocial factors that influence health, had even stronger effects among people with early-life adversity, particularly on depression,” he said. “It’s been about a 15-year arc of research that culminated in these findings.”
NewsMakers
High-fiber diet linked to reduced risk of heart disease in night shift workers
A moderate intake of about 19 grams of fibre per day was linked to a lower risk for those who worked night shifts regularly. For those who worked night shifts sporadically, about 15 grams was enough. The current recommendation for adults is about 25 grams of dietary fibre per day.
People who work at night have a higher risk of coronary artery disease, a type of heart disease. A new study suggests that a higher fibre intake in the diet may help reduce this risk. The study included over 220,000 adults in the UK and is published in the European Journal of Epidemiology.
The human body is built to sleep at night. This means that working during the night goes against this natural pattern, and can place additional strain on the body, including the heart. Previous research has linked night work to an increased risk of coronary artery disease. Since night work is often unavoidable, the researchers wanted to investigate whether certain dietary habits might have a protective effect.
More fibre associated with lower risk
The researchers used data from 220,000 adults in the UK Biobank (2006–2010) and divided the participants into three groups:
- Day workers
- Shift workers who worked night shifts sporadically
- Regular night shift workers
The participants had completed a detailed questionnaire about their dietary habits. During a follow-up after about 12 years, it was found that night shift workers who consumed little fibre in their diet had a higher risk of coronary artery disease than those who consumed more fibre.
“A moderate intake of about 19 grams of fibre per day was linked to a lower risk for those who worked night shifts regularly. For those who worked night shifts sporadically, about 15 grams was enough. The current recommendation for adults is about 25 grams of dietary fibre per day,” says Diana Nôga, lead author and researcher at Uppsala University.
The researchers stress that the figures from the study are not official dietary recommendations. But they do show a pattern in this UK study: a higher dietary fibre intake was linked to a lower risk of heart disease among night shift workers.
“The link between fibre and a lower risk of heart disease is not just because those who eat more fibre generally have a healthier lifestyle. We know this because we adjusted for various lifestyle factors in the analysis. One possible explanation, supported by previous research, is that fibre in the diet can improve intestinal flora and also reduce lipids, which can be particularly good for the heart in people who work at night,” says Christian Benedict, senior author of the study and Professor of Pharmacology at Uppsala University.
Dietary fibre can support heart health
According to the researchers, an increased intake of fibre-rich foods such as whole grains, vegetables, fruit, legumes and lentils may be a simple way to improve heart health for night shift workers. However, this requires that you do not have any medical obstacles to doing this, such as chronic gastrointestinal diseases.
“Dietary changes should be seen as a complement to, not a substitute for, other heart health-promoting habits such as not smoking, remaining physically active, and getting enough sleep,” says Diana Nôga.
-
NewsMakers3 weeks agoCreativity feels great — until tomorrow
-
NewsMakers3 weeks agoHigh-fiber diet linked to reduced risk of heart disease in night shift workers
-
NewsMakers3 weeks agoSleeping in on weekends may help boost teens’ mental health
-
Wellness3 weeks agoExercise to treat depression yields similar results to therapy
-
Destinations3 weeks agoChecking the charm of Baguio City’s Café by the Ruins
-
NewsMakers3 weeks agoTwo types of underconfidence linked to anxiety and gender
-
Wellness3 weeks agoAerobic exercise may be most effective for relieving depression/anxiety symptoms
-
NewsMakers2 weeks agoMindfulness practices found to significantly reduce depression symptoms, especially for those with early-life adversity
