Publisher Health

Two new studies published by researchers at the University of Illinois Chicago provide evidence that public policies to reduce consumption of added sugars through taxes on sugar-sweetened beverages are effective and sustainable.
Sugar-sweetened beverages like soda, juice, and energy and sports drinks, are the largest contributor of added sugars in American diets. Overconsumption of added sugars significantly contributes to obesity and is associated with comorbidities like diabetes, which can increase cancer risks and result in more severe COVID-19 illness. Currently, more than 50% of adults and 65% of children consume more added sugars than recommended.
Sugar-sweetened beverage taxes, often called soda taxes, aim to provide financial incentives to consumers choosing healthier beverages while also funding public health programs.
The research team has been studying the implementation of sugar-sweetened beverage taxes throughout the U.S. and the new studies analyzed data from Seattle, where the tax was implemented in 2018. The Seattle data was compared with data from Portland, Oregon, a city of similar size and demographics but without a sugar-sweetened beverage tax.
“While we and others have published a number of studies on the short-term effects of SSB taxes where they have been implemented in the U.S., these taxes are still relatively new, and we need scientific data on longer-term impacts to understand if the policies have the potential to generate sustained public health benefits,” said study lead author Lisa Powell, distinguished professor and director of health policy and administration in the UIC School of Public Health.
The studies are the first to comprehensively evaluate the tax’s long-term impact across all store types and across all beverages and sweets sold.

There are few places farther from your medicine cabinet than the tissues of an ascidian, or “sea squirt,” on the icy Antarctic sea floor — but this is precisely where scientists are looking to find a new treatment for melanoma, one of the most dangerous types of skin cancer.
In a new paper that was published today in mSphere, a research team from DRI, Los Alamos National Laboratory (LANL), and the University of South Florida (USF) made strides toward their goal, successfully tracing a naturally-produced melanoma-fighting compound called “palmerolide A” to its source: a microbe that resides within Synoicum adareanum, a species of ascidian common to the waters of Antarctica’s Anvers Island archipelago.
“We have long suspected that palmerolide A was produced by one of the many types of bacteria that live within this ascidian host species, S. adareanum,” explained lead author Alison Murray, Ph.D., research professor of biology at DRI. “Now, we have actually been able to identify the specific microbe that produces this compound, which is a huge step forward toward developing a naturally-derived treatment for melanoma.”
The bacterium that the team identified is a member of a new and previously unstudied genus, Candidatus Synoicihabitans palmerolidicus. This advance in knowledge builds on what Murray and her colleagues have learned across more than a decade of research on palmerolide A and its association with the microbiome (collective suite of microbes and their genomes) of the host ascidian, S. adareanum.
In 2008, Murray worked with Bill Baker, Ph.D., professor of chemistry at USF and Christian Riesenfeld, Ph.D., postdoctoral researcher at DRI to publish a study on the microbial diversity of a single S. adareanum organism. In 2020, the team expanded to include additional researchers from LANL, USF, and the Université de Nantes, and published new work identifying the “core microbiome” of S. adareanum — a common suite of 21 bacterial species that were present across 63 different samples of S. adareanum collected from around the Anvers Island archipelago.
In the team’s latest research, they looked more closely at the core microbiome members identified in their 2020 paper to determine which of the 21 types of bacteria were responsible for the production of palmerolide A. They conducted several rounds of environmental genome sequencing, followed by automated and manual assembly, gene mining, and phylogenomic analyses, which resulted in the identification of the biosynthetic gene cluster and palmerolide A-producing organism.
“This is the first time that we’ve matched an Antarctic natural product to the genetic machinery that is responsible for its biosynthesis,” Murray said. “As an anti-cancer therapeutic, we can’t just go to Antarctica and harvest these sea squirts en masse, but now that we understand the underlying genetic machinery, it opens the door for us to find a biotechnological solution to produce this compound.”
“Knowing the producer of palmerolide A enables cultivation, which will finally provide sufficient quantity of the compound for needed studies of its pharmacological properties,” added Baker.
Many additional questions remain, such as how S. adareanum and its palmerolide-producing symbiont are distributed across the landscape in Antarctic Oceans, or what role palmerolide A plays in the ecology of this species of ascidian. Likewise, a detailed investigation into how the genes code for the enzymes that make palmerolide A is the subject of a new report soon to be published.
To survive in the harsh and unusual environment of the Antarctic sea floor, ascidians and other invertebrates such as sponges and corals have developed symbiotic relationships with diverse microbes that play a role in the production of features such as photoprotective pigments, bioluminescence, and chemical defense agents. The compounds produced by these microbes may have medicinal and biotechnological applications useful to humans in science, health and industry. Palmerolide A is one of many examples yet to be discovered.
“Throughout the course of disentangling the many genomic fragments of the various species in the microbiome, we discovered that this novel microbe’s genome appears to harbor multiple copies of the genes responsible for palmerolide production,” said Patrick Chain, Ph.D., senior scientist and Laboratory Fellow with LANL. “However the role of each copy, and regulation, for example, are unknown. This suggests palmerolide is likely quite important to the bacterium or the host, though we have yet to understand it’s biological or ecological role within this Antarctic setting.”
“This is a beautiful example of how nature is the best chemist out there,” Murray added. “The fact that microbes can make these bioactive and sometimes toxic compounds that can help the hosts to facilitate their survival is exemplary of the evolutionary intricacies found between hosts and their microbial partners and the chemical handshakes that are going on under our feet on all corners of the planet.”

An important player in the healthy development of female embryos turns out also to play a key role in regulating the behavior of chromosome loops and gene expression in both sexes, according to a new study by researchers at Massachusetts General Hospital (MGH). These findings, reported in the journal Cell, could help create new targets for drug development.
Chromosomes are long, string-like structures made up of DNA, RNA and proteins. A chromosome must fold into a loop in order to fit into the nucleus of a cell. These loops bring together distant genetic material. “Genes and control elements — sequences that regulate genes — have to communicate with one another for the cell to work properly,” says the senior author of the paper, Jeannie Lee, MD, PhD, of the Department of Molecular Biology at MGH. “Chromosome looping is kind of like bringing people together in a conference room so they can talk to one another.”
These interactions within a chromosome loop regulate gene expression, that is, whether a gene is turned “on” and thus producing proteins or turned “off.” Chromosome loops are in constant flux, growing and contracting as they change their composition of genes in response to environmental stimuli and the body’s developmental needs. Returning to the conference room metaphor, a protein called CTCF acts as a door, explains Lee, and it was already known that a chromosome loop may have multiple sets of double doors — some open, some closed. “But what wasn’t known is how these doors open and close,” explains Lee. “Who are the gatekeepers?”
The answer proved to be a surprise. Lee and her team discovered that a form of RNA known as Jpx is a gatekeeper that regulates the behavior of CTCF in chromosome looping. Jpx RNA was no stranger to Lee and her fellow investigators. Eight years ago, they showed that this noncoding form of RNA is a key player in the phenomenon known as X chromosome inactivation, which is essential for normal development in all female mammals, including humans. Jpx RNA helps count X chromosomes in female cells very early in development; if two are detected, one X chromosome is inactivated, or silenced.
However, Lee’s group, which included postdoctoral fellow Hyun Jung Oh, PhD, first author of the study, found that Jpx RNA also determines what combination of double doors are open at any given time by “evicting” CTCF from the chromatin (a substance within a chromosome). “Jpx regulates whether multiple doors are open or just one, as well as which panels of double doors are open, left or right,” says Lee. “By regulating that process, Jpx determines how big the chromatin loop is and, therefore, which genes around the loop are expressed.”
Jpx is the first form of RNA to be identified as playing a vital role in regulating the behavior of CTCF, but there will be many others, predicts Lee. That’s exciting, she says, because there are probably 10 times more varieties of RNA than there are proteins. While Jpx regulates genes involved in early in the development of an embryo, other RNAs awaiting discovery may regulate the formation of chromosome loops that influence the risk for cancer, autoimmune disorders and other diseases, says Lee. Identifying these RNA could speed the development of effective new medications.
Story Source:
Materials provided by Massachusetts General Hospital. Note: Content may be edited for style and length.

Researchers from The Australian National University (ANU) have identified unique molecular signals in the body that could hold the key to developing a supplement capable of administering the health benefits of exercise to patients incapable of physical activity.
The molecular messages are sent to our brain and potentially our eyes immediately after we exercise.
The ANU team is conducting research to better understand what impact these molecular messages have on retinal health, but also the central nervous system and eye diseases such as age-related macular degeneration (AMD).
Associate Professor Riccardo Natoli, Head of Clear Vision Research at ANU, says the molecules could potentially be hijacked, recoded and “bottled up” in a pill and taken like a vitamin.
“The beneficial messages being sent to the central nervous system during exercise are packaged up in what are known as lipid particles. We are essentially prescribing the molecular message of exercise to those who physically aren’t able to,” he said.
“We think that as you age, the ability to communicate between the muscles and the retina starts to be lost. Similar to taking supplements, maybe we can provide genetic or molecular supplementation that enables that natural biological process to continue as we age.

A secondary analysis of the Fragile Families and Child Wellbeing Study (Fragile Families) found a bi-directional relationship where a mother’s mental health symptoms impacted the child’s mental health symptoms and vice versa, according to researchers with Cizik School of Nursing at The University of Texas Health Science Center at Houston (UTHealth Houston).
The analysis, published Dec. 1 in the print edition of the Journal of Affective Disorders, investigated mother and child mental health symptoms over a 10-year period to provide new insights into the development of depression and anxiety among families. The research points to parental stress, or the processes and subsequent reactions that result from attempting to manage the challenges and burdens of parenthood, as the factor that partially links maternal depression and child anxiety and depressive symptoms.
“By focusing on mother-child duos, we identified that maternal depression at an earlier time point predicted child anxiety and depressive symptoms at a later time point. Further, children who experienced anxiety and depressive symptoms at an earlier time point were more likely to have mothers who experienced depression at later time points,” said Daphne Hernandez, PhD, associate professor and Lee and Joseph Jamail Distinguished Professor in the School of Nursing and senior author on the study.
Experiences with maternal depression increase feelings of being overwhelmed with the parenting role, contributing to hostility and lack of warmth in the family environment, according to the researchers. The lack of warmth could affect a child’s mental health negatively.
The Fragile Families study began at Princeton University and Columbia University between 1998 and 2000 to study the outcomes of familial relationships of unmarried parents on their offspring. The large population-based sample has allowed researchers across the U.S. to provide insights into various family and relationship dynamics.
The researchers’ findings have the opportunity to guide suggestions for mental health treatments for families where both mothers and children are experiencing symptoms of anxiety and depression.
“A dual intervention, where both mother and child are receiving treatment together, in addition to their separate treatment plans, may be a successful approach for families where mothers and children exhibit symptoms of anxiety and depression,” Hernandez said. “Most importantly, implementing strategies to lower parental stress is vital.”
Story Source:
Materials provided by University of Texas Health Science Center at Houston. Original written by Jaelyn Lyles. Note: Content may be edited for style and length.

The oldest unequivocal evidence of upright walking in the human lineage are footprints discovered at Laetoli, Tanzania in 1978, by paleontologist Mary Leakey and her team. The bipedal trackways date to 3.7 million years ago. Another set of mysterious footprints was partially excavated at nearby Site A in 1976 but dismissed as possibly being made by a bear. A recent re-excavation of the Site A footprints at Laetoli and a detailed comparative analysis reveal that the footprints were made by an early human — a bipedal hominin, according to a new study reported in Nature.
“Given the increasing evidence for locomotor and species diversity in the hominin fossil record over the past 30 years, these unusual prints deserved another look,” says lead author Ellison McNutt, an assistant professor of instruction at the Heritage College of Osteopathic Medicine at Ohio University. She started the work as a graduate student in Ecology, Evolution, Environment, and Society at Dartmouth College, where she focused on the biomechanics of walking in early humans and utilized comparative anatomy, including that of bears, to understand how the heel bone contacts the ground (a foot position called “plantigrady”).
McNutt was fascinated by the bipedal (upright walking) footprints at Laetoli Site A. Laetoli is famous for its impressive trackway of hominin footprints at Sites G and S, which are generally accepted as Australopithecus afarensis — the species of the famous partial skeleton “Lucy.” But because the footprints at Site A were so different, some researchers thought they were made by a young bear walking upright on its hind legs.
To determine the maker of the Site A footprints, in June 2019, an international research team led by co-author Charles Musiba, an associate professor of anthropology at University of Colorado Denver, went to Laetoli, where they re-excavated and fully cleaned the five, consecutive footprints. They identified evidence that the fossil footprints were made by a hominin — including a large impression for the heel and the big toe. The footprints were measured, photographed and 3D-scanned.
The researchers compared the Laetoli Site A tracks to the footprints of black bears (Ursus americanus), chimpanzees (Pan troglodytes), and humans (Homo sapiens).
They teamed up with co-authors Ben and Phoebe Kilham, who run the Kilham Bear Center, a rescue and rehabilitation center for black bears in Lyme, New Hampshire. They identified four semi-wild juvenile black bears at the Center, with feet similar in size to that of the Site A footprints. Each bear was lured with maple syrup or apple sauce, to stand up and walk on their two hind legs across a trackway filled with mud to capture their footprints.
Over 50 hours of video on wild black bears was also obtained. The bears walked on two feet less than 1% of the total observation time making it unlikely that a bear made the footprints at Laetoli, especially given that no footprints were found of this individual walking on four legs.
As bears walk, they take very wide steps, wobbling back and forth,” says senior author Jeremy DeSilva, an associate professor of anthropology at Dartmouth. “They are unable to walk with a gait similar to that of the Site A footprints, as their hip musculature and knee shape does not permit that kind of motion and balance.” Bear heels taper and their toes and feet are fan-like, while early human feet are squared off and have a prominent big toe, according to the researchers. Curiously, though, the Site A footprints record a hominin crossing one leg over the other as it walked — a gait called “cross-stepping.”
“Although humans don’t typically cross-step, this motion can occur when one is trying to reestablish their balance,” says McNutt. “The Site A footprints may have been the result of a hominin walking across an area that was an unlevel surface.”
Based on footprints collected from semi-wild chimpanzees at Ngamba Island Chimpanzee Sanctuary in Uganda and two captive juveniles at Stony Brook University, the team found that chimpanzees have relatively narrow heels compared to their forefoot, a trait shared in common with bears. But the Laetoli footprints, including those at Site A, have wide heels relative to their forefoot.
The Site A footprints also contained the impressions of a large hallux (big toe) and smaller second digit. The size difference between the two digits was similar to humans and chimpanzees, but not black bears. These details further demonstrate that the footprints were likely made by a hominin moving on two legs. But in comparing the Laetoli footprints at Site A and the inferred foot proportions, morphology and likely gait, the results reveal that the Site A footprints are distinct from those of Australopithecus afarensis at Sites G and S.
“Through this research, we now have conclusive evidence from the Site A footprints that there were different hominin species walking bipedally on this landscape but in different ways on different feet,” says DeSilva, who focuses on the origins and evolution of human walking. “We’ve had this evidence since the 1970s. It just took the rediscovery of these wonderful footprints and a more detailed analysis to get us here.”
Story Source:
Materials provided by Dartmouth College. Original written by Amy Olson. Note: Content may be edited for style and length.

Vaccines are finally available in many African countries, but some people there, as well as in South Asia, are wary of taking them.JOHANNESBURG — The detection of the Omicron variant in Africa signals the next stage of the battle against Covid-19: getting many more people inoculated in poorer nations where vaccines have been scarcest in order to deter new mutations from developing.But while world leaders sometimes talk about this as if it were largely a matter of delivering doses overseas, the experience of South Africa, at least, hints at a far more complex set of challenges.Like many poor countries, South Africa was made to wait months for vaccines as wealthier countries monopolized them. Many countries still do not have anywhere near enough doses to inoculate their populations.The problems have not ended as shots began arriving in greater numbers.Neglected and underfunded public health infrastructure has slowed their delivery, especially to rural areas, where storage and staffing problems are common.And now, there are growing signs in parts of Africa, as well as South Asia, that skepticism or outright hostility toward the Covid vaccines may run deeper than expected, even as the new and possibly more dangerous Omicron variant is spreading. In Africa, at least three countries have now reported Omicron cases: South Africa, Botswana and, on Wednesday, Nigeria.Deep distrust of governments and medical authorities, especially among rural and marginalized communities, may already be stalling out vaccination drives. The legacy of Western exploitation and medical abuses during and after colonialism is weighing heavily, too.Misinformation circulating on social media often fills the vacuum, some of it floating in from the United States and Europe, where vaccine refusal has also been an issue.“There’s no doubt that vaccine hesitancy is a factor in the rollout of vaccines,” said Dr. Matshidiso Moeti, the Africa director of the World Health Organization. News or rumors of potential side effects, she said, “gets picked out and talked about, and some people become afraid.”Just days before the Omicron variant was first detected, health officials in South Africa turned away shipments of doses from Pfizer-BioNTech and Johnson & Johnson, worried that their stockpile of 16 million shots might spoil amid insufficient demand.Graves of Muslims who died during the pandemic in Lenasia, South Africa,  earlier this year.Bram Janssen/Associated PressThough only 36 percent of South African adults are fully vaccinated, daily vaccinations have already been flatlining, according to government statistics.It is not just South Africa.Namibia, Zimbabwe, Mozambique and Malawi have also asked vaccine manufacturers and donors to hold off on sending more shots because they can’t use the supplies they have, according to several health officials involved in the effort to distribute vaccines to developing nations.Research has consistently found that factors like public distrust and uneven vaccine distribution can increase vaccine hesitancy in any country. But these issues have often been more prevalent in poorer countries during the pandemic, said Dr. Saad Omer, a Yale University epidemiologist, and they have had a deeper effect.Public messaging campaigns and carefully orchestrated vaccine deliveries can counteract the distrust — but they are in short supply.“Almost no investment in vaccine education or promotion has gone into low-income countries,” Dr. Omer said. “Why do we expect that all we will have to do is drop vaccines at an airport, do the photo op, and people will come running to the airport and grab the vaccine?”Only one in four health workers in Africa are vaccinated, World Health Organization officials have said. In several countries, fewer than half say they intend to get vaccinated.It is not a problem only for Africa.In India, health workers have met sometimes-violent resistance in rural communities. Vaccine hesitancy rates there approach 50 percent among those who have not completed high school. In some parts of the country, more than a third of doses spoil amid the low demand.Still, many are eager to be vaccinated. When doses first became widely available in South Africa earlier this year, a third of the country’s adults swiftly got inoculated, a pattern that is repeating elsewhere.A Covid vaccination in Johannesburg on Tuesday.Joao Silva/The New York TimesExperts stress that even partial uptake will slow the spread of new or existing variants. But that may not be enough to achieve the high vaccination rates needed if the world is to put the pandemic behind it.Distrust of government and medical authorities long predates Covid in South Africa. But a series of setbacks with the vaccine rollout, as well as widespread allegations of corruption amid last year’s lockdown, have heightened public unease.“There’s a lack of confidence in the public health system’s ability to provide vaccines,” said Chris Vick, the founder of Covid Comms, a South African nonprofit group.The group has been holding vaccine information sessions, but overcoming skepticism is not easy. After a session in the Pretoria township of Atteridgeville, one 20-year-old who attended said she had not been persuaded.“I think that Covid is not real,” said the young woman, Tidibatso Rakabe. “They are playing with us, politicians and everyone.” Many say they fear side effects.Earlier this year, reports of extremely rare blood clots led the United States to briefly pause delivery of the Johnson & Johnson vaccine, leading South Africa to delay its rollout to health care workers. Both countries decided to resume the shots after concluding that they were safe.The South African government held regular briefings, but these were on television and in English, when radio remains the most powerful medium and most South Africans do not speak English as their mother tongue.Residents in Johannesburg receiving Covid-19 tests in January.Joao Silva/The New York TimesOnline registration systems also left out millions who do not have regular access to the internet.Lockdown relief efforts were tainted by corruption scandals, in which the president’s spokeswoman was forced to step down. The health minister later also resigned after his office was found to have fraudulently awarded a $9 million communication contract.The racial divide is another major factor.White South Africans are significantly more likely than others to express skepticism of the vaccines, a recent study found. That is in part because of mistrust of the Black-led government, but also because American Covid conspiracists have found wide reach among white South Africans on social media, according to Mr. Vick of Covid Comms.A vaccine protest in Cape Town in October.Mike Hutchings/ReutersThough Black South Africans express greater openness to inoculation, they are vaccinated at lower rates, often citing difficulty getting to vaccination sites. Some also express hesitation about getting a second shot.The Coronavirus Pandemic: Key Things to KnowCard 1 of 5The Omicron variant.

A medication originally used for patients with diabetes is the first to help people with heart failure and could revolutionise treatment, according to new research from the University of East Anglia.
Early research had shown that Sodium-glucose co-transporter-2 (SGLT2) inhibitors could help around half of heart failure patients — those with a condition known as reduction ejection fraction.
But new findings published today show that the medication could be beneficial for all heart failure patients — including those with a second type of heart failure called preserved ejection fraction.
It is the first drug to provide a real benefit in terms of improving outcomes for these patients. And the research team say it will revolutionise treatment options.
Lead researcher Prof Vass Vassiliou, from UEA’s Norwich Medical School and an Honorary Consultant Cardiologist at the Norfolk and Norwich University Hospital, said: “Heart failure is a condition where the heart is not pumping as well as it should, and it affects about one million people in the UK.
“There are two types of heart failure. Heart Failure with a reduction in ejection fraction happens when the heart is unable to pump blood round the body due to a mechanical issue. And heart failure with preserved ejection fraction happens when, despite the heart pumping out blood well, it is not sufficient to provide oxygen to all the parts of the body.

Plastics, part of modern life, are useful but can pose a significant challenge to the environment and may also constitute a health concern. Indeed, exposure to plastic-associated chemicals, such as base chemical bisphenol A and phthalate plasticizers, can increase the risk of human cardiovascular disease. What underlying mechanisms cause this, however, remain elusive.
A team led by Changcheng Zhou, a biomedical scientist at the University of California, Riverside, now raises the hopes of solving the mystery. In a mouse study, the researchers found a phthalate — a chemical used to make plastics more durable — led to increased plasma cholesterol levels.
“We found dicyclohexyl phthalate, or DCHP, strongly binds to a receptor called pregnane X receptor, or PXR,” said Zhou, who is a professor in the UCR School of Medicine. “DCHP ‘turns on’ PXR in the gut, inducing the expression of key proteins required for cholesterol absorption and transport. Our experiments show that DCHP elicits high cholesterol by targeting intestinal PXR signaling.”
DCHP, a widely used phthalate plasticizer, has recently been proposed by the Environmental Protection Agency as a high-priority substance for risk evaluation. Not much is known yet about DCHP’s adverse effects in humans.
“To our knowledge, our study is the first to show the effects of DCHP exposure on high cholesterol and cardiovascular disease risk in mouse models,” Zhou said. “Our results provide insights and new understandings of the impact of plastic-associated chemicals on high cholesterol — or dyslipidemia — and cardiovascular disease risk.”
Zhou’s team also found that mice exposed to DCHP had in their intestines higher circulating “ceramides” — a class of waxy lipid molecules associated with increased cardiovascular disease risk in humans — in a way that was PXR-dependent.
“This, too, points to the potentially important role of PXR in contributing to the harmful effects of plastic-associated chemicals on cardiovascular health in humans,” Zhou said.
Zhou was joined in the research by Zhaojie Meng, Jinwei Liu, Rebecca Hernandez, and Miko Gonzales of UCR; and Yipeng Sui, Taesik Gwag, and Andrew J. Morris of the University of Kentucky. The study was published in Environmental Health Perspectives, a top journal in the environmental health field.
The work was supported in part by the National Institute of Environmental Health Sciences, or NIEHS. Hernandez was supported by a recently renewed NIEHS training grant to UCR. Gonzales, an undergraduate student, was a UCR honors Capstone scholar.
Story Source:
Materials provided by University of California – Riverside. Original written by Iqbal Pittalwala. Note: Content may be edited for style and length.

In the first study of its kind to explore caffeine’s effects on dynamic visual skills, researchers concluded that caffeine increases alertness and detection accuracy for moving targets. Caffeine also improved participants’ reaction times.
“A lot of what happens in our environment is moving — like trying to cross a busy intersection as a pedestrian or finding something on a shelf as you’re walking through the aisles of a grocery store,” said Dr. Kristine Dalton of Waterloo’s School of Optometry & Vision Science. “Testing visual acuity under dynamic conditions can provide more information about our functional performance in these scenarios than traditional static visual acuity measurements alone.”
Visual acuity, also known as clarity of vision or sharpness of vision, refers to a person’s ability to detect and recognize small details and can be measured under static (stationary) or dynamic (moving) conditions. While both static and dynamic visual acuity provide important information about how we interact with the world around us, dynamic visual acuity skills are especially important in the many daily activities in which we, or objects around us are moving.
“While we already know that caffeine increases the velocity of rapid-eye movements, we wanted to further investigate how exactly caffeine enhances visual processing and facilitates the detection of moving visual stimuli by testing dynamic visual acuity,” said co-author Beatríz Redondo of the University of Granada’s Department of Optics.
On two separate days, half of the study’s participants ingested a caffeine capsule (4mg/kg) while the other half ingested a placebo capsule. Using a computer-based test designed and validated at the University of Waterloo, each participant’s dynamic visual acuity skills were measured before and 60 minutes after caffeine ingestion.
Researchers found that participants who had ingested the caffeine capsules showed significantly greater accuracy and faster speed when identifying smaller moving stimuli, inferring caffeine positively influences participants’ stimulus processing and decision-making. Eye movement velocity and contrast sensitivity, which are implicated in dynamic visual acuity performance, were also sensitive to caffeine intake.
“Our findings show that caffeine consumption can actually be helpful for a person’s visual function by enhancing alertness and feelings of wakefulness,” Dalton said. “This is especially true for those critical, everyday tasks, like driving, riding a bike or playing sports, that require us to attend to detailed information in moving objects when making decisions.”
The study, Effects of caffeine ingestion on dynamic visual acuity, co-authored by Waterloo’s School of Optometry & Vision Science’s Dalton, and the University of Granada’s Redondo, Raimundo Jiménez, Rubén Molina and Jesús Vera, was recently published in the Psychopharmacology journal.
Story Source:
Materials provided by University of Waterloo. Note: Content may be edited for style and length.