A reduction in sense of smell precedes certain neurological conditions, and pollution has been shown to increase the risk of these diseases. A new study attempts to link these findings together.Olfaction, pollution, and Alzheimer’s â€” how are they connected?
Over the years, researchers have begun to see links between pollution and neurological diseases, such as Parkinson’s and Alzheimer’s
Although evidence is mounting, scientists have not yet figured out how airborne particles might impact the brain.
Recently, researchers from Penn State University, PA, investigated possible links between pollution, our sense of smell, and neurological disease.
They published their findings earlier this week in the journal eLife.
To investigate, the researchers were particularly interested in the flow of cerebrospinal fluid (CSF).
CSF is a fluid that surrounds the central nervous system (CNS), which comprises the brain and spinal cord. Classically, it was thought to act as a buffer that protects the CNS, but, over time, scientists have discovered more roles.
Prof. Patrick Drew, one of the authors of the study, explains, “More and more it is realized that it does not just cushion the brain, but may also transfer stuff out of the brain and spinal column area.”
The role of CFS in disease
Researchers are growing increasingly interested in the CSF’s role in waste clearance, and how it flows around the CNS. To date, researchers are not clear about what manages the production and outflow of CFS.
Neurological conditions, such as Parkinson’s and Alzheimer’s, are characterized by a buildup of faulty or misshapen proteins; perhaps CSF clearance could play a part.
The scientists wanted to understand how pollution in the air that we breathe influences the CSF and, therefore, refuse collection within the brain; but how would airborne compounds reach the CSF?
Another author of the study, graduate student Jordan N. Norwood, explains his first clue: “I was trying to label cerebrospinal fluid with a dye for another experiment. We started seeing this dyed cerebrospinal fluid drain out through the nose.”
Although surprising, Norwood was not the first person to have speculated that CSF might exit the brain through the nose. When he looked through old research papers, there were a few references to this possibility.
The scientists also noted that researchers have already shown that a reduced sense of smell is sometimes an early sign of neurological conditions. For instance, a study published in Neurology concluded that poor performance in an odor identification test might, one day, be a useful way to predict Alzheimer’s before the classic symptoms appear.
Destroying sensory nerves
To investigate further, the researchers destroyed the olfactory sensory nerves in mice with zinc sulfate. Interestingly, these nerves are the only part of the mammalian CNS that comes into direct contact with the external environment.
As expected, destroying these sensory nerves removed the mice’s ability to smell. Also, it “greatly reduced” the flow of CSF from the nose. The researchers then investigated whether this had any impact on the mice.
According to Prof. Drew, “Animals and people are constantly making CSF, so if it doesn’t go out, pressure will go up, but we found that the pressure did not increase after the flow from the nose stopped.”
The authors believe that the system must be compensating in other ways; perhaps another pathway is picking up the slack. For instance, the glymphatic system, which is the brain’s version of the lymphatic system, might be playing a part.
Alternatively, the body might produce less CSF to avoid increasing pressure within the CNS.
Taking all these findings into consideration, the researchers hypothesize that over time, pollution damages the olfactory sensory neurons. This produces a change in the flow or production of CSF. Because CSF is vital for clearing metabolic trash from the CNS, this plays a part in the development of neurological diseases. The authors write:
“[R]educed CSF turnover may be a contributing factor to the buildup of toxic metabolites and proteins that cause neurodegenerative disorders.”
The authors did not set out to prove that this is the exact route by which pollution impacts the brain, but the theory is intriguing. The researchers plan to test their hunch further.
“Next we would like to collaborate with a lab in the Materials Research Institute that is working with soot or jet fuel particles to see if we get the same effect,” explains Norwood.
Although these are early days, it will be fascinating to see how this narrative unfolds.
Vitamin D sufficiency may reduce complications of COVID-19
A recent small-scale study has concluded that hospitalized patients with COVID-19 are less likely to have life threatening complications if they have sufficient vitamin D levels.A new study demonstrates that people with sufficient levels of vitamin D are less likely to develop life threatening COVID-19 complications when hospitalized with the disease.The research, published in the…
A recent small-scale study has concluded that hospitalized patients with COVID-19 are less likely to have life threatening complications if they have sufficient vitamin D levels.A new study demonstrates that people with sufficient levels of vitamin D are less likely to develop life threatening COVID-19 complications when hospitalized with the disease.The research, published in the journal PLOS ONE, could be valuable for doctors attempting to reduce the mortality rates of COVID-19 in the absence of an effective vaccine.If further studies back up these findings, vitamin D supplements might offer a cost-effective way to limit the risk of severe COVID-19. It is important to note that this recent study has several limitations, which we address below.Stay informed with live updates on the current COVID-19 outbreak and visit our coronavirus hub for more advice on prevention and treatment.Since the sudden emergence of the virus SARS-CoV-2 and the disease that it causes, COVID-19, scientists have paid a great deal of attention to the development of a vaccine. Experts consider a vaccine to be crucial in reducing the effects of the virus, even if it is not yet clear to what extent an initial vaccine would moderate rates of transmission and infection.Alongside the endeavor to develop a vaccine, researchers are also focusing on developing effective COVID-19 treatments. Even if none can make a person immune to the virus, treatments may be able to reduce the disease’s severity.The Food and Drug Administration (FDA) have approved two drugs as treatments for COVID-19: remdesivir and dexamethasone.Another candidate is vitamin D. Research has suggested that it might, in theory, be effective, but corroborating this requires further efforts.Rather than analyzing the effects of vitamin D as COVID-19 treatment, the researchers behind the present study looked at the effects of a person’s vitamin D levels on the severity of the disease.To do so, they analyzed data from patients with confirmed COVID-19 who had been admitted to the Sina Hospital, in Tehran, Iran.Of the 611 people admitted with confirmed COVID-19 before May 1, 2020, there were records of the 25-hydroxyvitamin D levels, an indication of overall vitamin D levels, for 235 patients. Their mean age was 58.7 years, ranging from 20–90 years, and 37.4% were older than 65.The researchers classified the patients into two groups: those with vitamin D levels of at least 30 nanograms per milliliter (ng/ml) — an amount considered sufficient by the Endocrine Society — and those with lower values.They then analyzed the severity of the patients’ COVID-19 signs and symptoms using guidelines from the Centers for Disease Control and Prevention (CDC). Severe or critical disease might involve a range of issues, including shortness of breath, respiratory failure, or a significantly reduced blood oxygen level.After cross-checking the patients’ vitamin D levels with the severity of their COVID-19 symptoms and accounting for confounding factors, the researchers found that having a vitamin D level of above 30 ng/ml was significantly associated with having less severe COVID-19.Among the 235 patients with confirmed COVID-19, only 32.8% had sufficient levels of the vitamin.The researchers also found that the patients with sufficient vitamin D had higher blood lymphocyte counts and lower levels of C-reactive protein in their blood — both of which indicate a positive immune response.The researchers speculate that this may have reduced the likelihood of developing cytokine storm, which can cause acute respiratory distress syndrome in COVID-19 patients, sometimes resulting in death.The findings highlight, the researchers say, that vitamin D sufficiency may be important in the eventuality that people develop COVID-19 alongside another respiratory disease, such as influenza.According to the study’s corresponding author, Dr. Michael F. Holick, director of the General Clinical Research Unit at the medical campus of Boston University, in Massachusetts, “There is great concern that the combination of an influenza infection and a coronal viral infection could substantially increase hospitalizations and death due to complications from these viral infections.”For the researchers, their findings suggest that vitamin D supplementation would be valuable. As Dr. Holick notes: “Because vitamin D deficiency and insufficiency is so widespread in children and adults in the United States and worldwide, especially in the winter months, it is prudent for everyone to take a vitamin D supplement to reduce [the] risk of being infected and having complications from COVID-19.”It is worthing noting the present study’s limitations. First, the researchers only had access to a relatively small number of patients. Before drawing solid conclusions, scientists need to carry out much larger studies.Also, various issues can influence both vitamin D status and COVID-19 severity, such as socioeconomic factors and smoking status. The scientists accounted for neither of these in their analysis.Also, because the study was cross-sectional, the researchers could not prove that vitamin D insufficiency caused an increase in disease severity. To address these limitations, the researchers call for “large-scale studies and randomized clinical trials.”For live updates on the latest developments regarding the novel coronavirus and COVID-19, click here.
Video gaming as a child related to improvements in memory
A new study exploring the link between video games and cognition finds that playing video games as a child can improve a person’s working memory years later on specific tasks.Video games can be a contentious topic, particularly among parents or caregivers who may be concerned about the effects of spending hours in front of the…
A new study exploring the link between video games and cognition finds that playing video games as a child can improve a person’s working memory years later on specific tasks.Video games can be a contentious topic, particularly among parents or caregivers who may be concerned about the effects of spending hours in front of the console.Yet, it seems that some video gaming could actually be beneficial. Recent studies have shown that playing video games could improve learning and may even protect against dementia in older adults.The authors of a recent review of the evidence on video games concluded that gaming could have benefits for both cognitive and emotional skills.In a new study, which features in the journal Frontiers in Human Neuroscience, researchers from the Universitat Oberta de Catalunya in Barcelona trained volunteers to play “Super Mario 64” — a game that researchers have previously shown to induce structural changes in parts of the brain associated with executive function and spatial memory.The new study found that people who played video games as children showed greater improvements in their working memory than those who did not, suggesting that video games can have long lasting benefits for cognition.This study combined video game playing with transcranial magnetic stimulation (TMS), a noninvasive form of brain stimulation that scientists have studied as a treatment for mood disorders. In 2008, the Food and Drug Administration (FDA) approved its use for the treatment of major depression when other approaches have failed.Studies have also shown TMS to boost cognitive performance under some conditions, with more than 60 studies reporting that the treatment led to significant improvements in cognition, including in working memory (holding and manipulating information over a short period).The researchers behind the new study wanted to find out whether combining video game training and TMS could enhance cognitive function more than either element alone.They asked 27 healthy volunteers, with an average age of 29 years, to take part in 10 video game training sessions, during each of which they played “Super Mario 64” for an hour and a half.At the end of each session, the researchers applied TMS to part of the prefrontal cortex, which is at the front of the brain and is important for complex cognitive functions, such as working memory and reasoning. The researchers assessed the cognitive function of the participants before the study started, at the end of the 10 sessions, and 15 days after this.They assessed a range of cognitive functions, including reaction time, working memory, attention span, visuospatial skills, and problem-solving.Although the results overall showed very limited changes in cognitive ability, which seemed to result only from the video game training and not the TMS, the researchers did find that participants with early experience of video gaming had improved working memory.“People who were avid gamers before adolescence, despite no longer playing, performed better with the working memory tasks, which require mentally holding and manipulating information to get a result,” explains lead author of the study Dr. Marc Palaus, Ph.D.People with prior experience of playing video games (but not the actual game in the study) also showed improvements in processing and were better able to focus on relevant stimuli during the tasks.“People who played regularly as children performed better from the outset in processing 3D objects, although these differences were mitigated after the period of training in video gaming, when both groups showed similar levels,” adds Dr. Palaus.The results suggest that video games may induce cognitive changes that last for years after people have stopped playing.Dr. Palaus says that video games that provide motivation — making the player want to keep on playing — and also get more difficult to stay challenging require intensive use of brain resources, which makes them ideal for boosting cognitive ability.“Video games are a perfect recipe for strengthening our cognitive skills, almost without our noticing.”– Dr. Marc Palaus, Ph.D. It is important to note that this study included a small number of participants who were all healthy, young, and highly educated, meaning that the findings might not be more widely applicable.Talking about the findings of their study, Dr. Palaus stressed that these improvements only have a limited effect on the performance of other activities not linked to video gaming, as is the case with most cognitive training.
Lax gun laws in neighboring states may increase firearm deaths
A US study suggests strong gun control regulations reduce a state’s firearm deaths, but having neighbors with more lenient laws undermines their effect.Share on PinterestNew research suggests that one state’s lax gun laws could undo the effects of its neighbor’s stricter firearm regulations.In 2017, 39,773 people died from gun-related injuries in the United States, according…
A US study suggests strong gun control regulations reduce a state’s firearm deaths, but having neighbors with more lenient laws undermines their effect.Share on PinterestNew research suggests that one state’s lax gun laws could undo the effects of its neighbor’s stricter firearm regulations.In 2017, 39,773 people died from gun-related injuries in the United States, according to the National Center for Injury Prevention and Control.Overall, research indicates that stronger state laws governing the sale and ownership of firearms reduce firearm-related deaths. However, some states have relatively high rates of gun deaths despite strict regulations. To investigate why this might be the case, scientists at the University of Alabama at Birmingham, and the Boston University School of Public Health at Boston, MA, looked into the effects of firearm laws in neighboring states.They used the Web-based Injury Statistics Query and Reporting System to obtain figures for firearm-related deaths in the 48 adjacent U.S. states from 2000 to 2017. There were 578,022 firearm deaths in total, including homicides and suicides, but excluding deaths due to shootings by police or other law enforcement agents. The scientists also searched the State Firearm Laws Database for laws in each state regarding:background checksgun dealer regulationsbuyer regulationsgun-trafficking lawsThe team used the number of these laws as a proxy for gun control strength in each state.If you would like to check your registration status or register to vote, we have added some useful links at the bottom of this article.Overall, stronger state gun laws were associated with reduced firearm deaths, but having a neighboring state with more permissive laws undermined this protective effect.Larger policy differences across state borders were associated with increased gun-related deaths, suicides, and homicides, though the results were statistically stronger for suicide than homicide.The authors conclude:“This study adds to the growing literature emphasizing the role played by neighboring states’ firearm regulations in addition to own-state firearm regulations in firearm deaths. Failing to account for neighboring states with weaker laws, in some instances, can make a state’s own regulations appear less effective in reducing firearm deaths.”The scientists calculate that, on average, failure to account for weaker firearm laws in neighboring states make it appear as though a state’s laws were about 20% less effective at reducing deaths than they really were.They report their findings in the American Journal of Preventive Medicine.The researchers write that higher prices and strong marketing regulations can lead consumers to purchase firearms in adjacent, relatively unregulated markets. They say these are a frequent source of the guns used in crimes.They believe their work supports the case for more cooperative legislation between neighboring states and at the federal level.“I think the main message of this study is that to solve a nationwide problem we need to think of a nationwide or at least a regional-level (i.e. multistate) approach, like we may also need for the COVID-19 pandemic,” says Dr. Ye Liu, who is a doctoral student in the Department of Health Care Organization and Policy at the University of Alabama and the first author of the study. “An ‘each state on its own’ approach is ultimately inadequate to address one of the biggest public health challenges in this country,” Dr. Liu adds.The authors acknowledge the number of gun-control laws may not perfectly reflect the strictness of a state’s regulations. In addition, they note states may vary in how diligently they enforce these laws.They call for further studies that might use alternative measures of regulatory strength, focus on specific categories of law, or explore the effects of regulations in more distant states. To check your voter registration status, click here to visit VoteAmerica, a nonprofit, nonpartisan organization dedicated to increasing voter turnout. They can also help you register to vote, vote by mail, request an absentee ballot, or find your polling place.