What's in your weed? Study suggests current labeling system doesn't tell you much

Analysis of 90,000 cannabis samples shows labels like indica and sativa fail to adequately reflect products' chemical make-up

Peer-Reviewed Publication

UNIVERSITY OF COLORADO AT BOULDER

 

IMAGE: BRIAN KEEGAN, A CANNABIS RESEARCHER AT THE UNIVERSITY OF COLORADO BOULDER, WATERS HEMP PLANTS GROWN FOR RESEARCH PURPOSES. view more 

CREDIT: NICHOLAS GODA/CU BOULDER

Labels like indica, sativa and hybrid—commonly used to distinguish one category of cannabis from another—tell consumers little about what’s in their product and could be confusing or misleading, suggests a new study of nearly 90,000 samples across six states.

Published May 19 in the journal PLOS One, the research constitutes the largest analysis to date of the chemical composition of marijuana products. It finds that commercial labels “do not consistently align with the observed chemical diversity” of the product. The authors are now calling for a weed labeling system akin to the Food and Drug Administration’s “nutrition facts panel” for food.

“Our findings suggest that the prevailing labeling system is not an effective or safe way to provide information about these products,” said co-author Brian Keegan, an assistant professor of Information Science at CU Boulder. “This is a real challenge for an industry that is trying to professionalize itself.”

2022 marks the 10th anniversary of the legalization of recreational marijuana in Colorado and Washington, the first two U.S. states to permit adult use. Over that time, the industry has grown into a multi-billion dollar one, in which sativa strains are generally associated with an energetic high while indica strains are associated with a relaxing effect. 

Yet no standardized labeling system exists.

What's in a name

Commercial strain names like Girl Scout Cookies, Gorilla Glue and Blue Dream abound, giving consumers the impression that if you buy it in one place, you’ll get the same product, or at least the same effect, if you buy it elsewhere.

While marketers generally must disclose dosage of the psychoactive compound THC (tetrahydrocannabinol) and CBD (cannabidiol) on the label, they are not obliged to include information about other compounds, including terpenes, which can influence not only the smell but also—via a hypothesized synergistic effect called the entourage effect—the way a product makes you feel. 

They are also free to name their product what they want.

“A farmer can't just pick up an apple and decide to call it a Red Delicious. A beer manufacturer can’t just arbitrarily label their product a Double IPA. There are standards. But that is not the case for the cannabis industry,” said co-author Nick Jikomes, director of science and innovation for the e-commerce cannabis marketplace Leafly.com.

To get a sense of how similar same-named products around the country truly are, Keegan teamed up with Jikomes and two other cannabis scientists to apply cutting-edge data science tools to a massive database of chemical analyses Leafly has compiled from cannabis testing centers.

After sorting about 90,000 samples from six states according to their cannabinoid and terpene make-up, the researchers found, not surprisingly, that the vast majority of the cannabinoids in recreational cannabis are the psychoactive THC.

And when they looked more closely at the samples, including terpene content, they found products do tend to fall into three distinct categories: Those high in the terpenes caryophyllene and limonene; those high in myrcene and pinene; and those high in terpinolene and myrcene.

But those categories do not neatly correspond to the indica, sativa and hybrid labeling scheme.

“In other words,” the authors wrote, “it is likely that a sample with the label indica will have an indistinguishable terpene composition as samples labelled sativa or hybrid.”

Inconsistency within strains

How biochemically similar are products with the same commercial names?

That depends on the strain, the study found.

Some strains, such as one called White Tahoe Cookies, were surprisingly consistent from product to product, while others, such as one called Durbin Poison, were “consistently inconsistent,” said Jikomes.

“There was actually more consistency among strains than I had expected,” he said. “That tells me that the cultivators, at least in some cases, may not be getting enough credit.” 

The study also found that the existing recreational cannabis available in the United States is quite homogenous, with plenty of room to innovate new breeds with different chemical profiles. That could be useful for both recreational and medicinal use, said Keegan.

“The founding fathers of cannabis research call it a pharmaceutical cornucopia because it produces so many different chemicals that interact with our bodies in different ways,” Keegan said. “We are only scratching the surface.”

As consumers increasingly use cannabis for specific purposes, including health purposes, precision in labeling will become even more critical, Keegan said.

He envisions a day when products are categorized based on a more comprehensive understanding of their chemical make-up and labeled with details on not only their THC and CBD, but on their terpenes, flavonoids and other compounds.

“It’s like if your cereal box only showed calories and fat and nothing else,” said Keegan. “We as consumers need to be pushing for more information. If we do that, the industry will respond.”

Daniela Vergara, then a research associate in the Department of Ecology and Evolutionary Biology, and data scientist Christiana Smith contributed to this study.

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JOURNAL

PLoS ONE

DOI

10.1371/journal.pone.0267498 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

The phytochemical diversity of commercial Cannabis in the United States

ARTICLE PUBLICATION DATE

19-May-2022

Are Republicans and Democrats driven by hatred of one another? Less than you think

Rather than being fueled by animosity for the other side — negative partisanship — a new study finds that Americans are at least as motivated by the passion they have for their own party

Peer-Reviewed Publication

UNIVERSITY OF PENNSYLVANIA

When it comes to attitudes and behaviors among members of American political parties, the conventional wisdom is that hate is stronger than love. 

Americans’ perception of negative partisanship — that Democrats or Republicans are primarily driven by their hatred for their political opponents — has ballooned in recent years, particularly in the aftermath of the 2016 presidential election. It has become a popular assumption that members of America’s political parties are united more by their hatred of the other side of the aisle than by their affinity to their own. 

A new study from the Annenberg School for Communication at the University of Pennsylvania suggests this is not the case. The research team, led by Amber Hye-Yon Lee (Ph.D. ’20) and Associate Professor Yphtach Lelkes, investigated what motivates Americans to affiliate with the Democratic and Republican parties. Published in Nature Human Behaviour, the paper finds that the perception of American partisanship as overwhelmingly negative is exaggerated. 

The researchers set out to answer two questions: First, to what extent is partisan hatred widespread? And second, is that hatred really more intense than their affinity to their own party members?

Using several different data sets – including a survey directly asking people how their hatred of another party impacts their affiliation decisions – the study found that people’s primary motivations for choosing a party are more strongly tied to love for their own party, rather than hatred of the other side. The study also measured the degree to which allegiances are motivated by hatred of the other party using an experiment designed to disentangle hurting the other side monetarily from helping one’s own side monetarily. 

Lelkes stresses that the implications of negative partisanship are problematic on many practical levels. 

“If there’s this gap in how much you like your side and dislike the other side, and it’s all motivated by emotions, you’re less likely to hold presidents accountable for things and more likely to vote for your side no matter what they do, even when it’s corrupt,” Lelkes says. “If it’s just driven by hatred, then it’s not about interest groups and coming together and fighting for your group. It’s much more toxic.” 

Lee hopes that the study can help everyday Americans better understand what motivates voters.

“Many people are led to believe that the other side is driven by hatred and is out to get them,” she says. “Hatred only breeds hatred, so by showing that there is really no clear evidence for hatred of the other party trumping everything, I am hoping we can clear up some of the misperceptions people have about how much they are hated by their political opponents, and by extension, discourage people from feeding their own hostility in response to exaggerated perceptions of hostility coming from the other side.”

Lelkes, who studies politician polarization and communication, agrees that the study’s findings merit more media attention. He notes that scholars tend to love the term “negative partisanship” and that news outlets may have a bias toward disproportionately covering expressions of extreme emotions, like hatred, that tend to garner more clicks.

The impact can be self-fulfilling: “When we talk about politics being overwhelmingly negative, it leads to that,” Lelkes says. “We are wildly off in how we think the other side feels about us. We’re trying to tone that down.”

“Negative partisanship is not more prevalent than positive partisanship,” published in Nature Human Behaviour, is viewable here. In addition to Lee and Lelke, other authors include Carlee B. Hawkins of Southern Illinois University Edwardsville’s Department of Psychology and Alexander G. Theodoridis, Associate Professor of Political Science at University of Massachusetts Amherst.

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JOURNAL

Nature Human Behaviour

DOI

10.1038/s41562-022-01348-0 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Negative partisanship is not more prevalent than positive partisanship.

Human-made iron inputs to the Southern Ocean ten times higher than previously estimated

Peer-Reviewed Publication

NAGOYA UNIVERSITY

 

IMAGE: IRON IS RELEASED BY BURNING BIOMASS AS WELL AS FOSSIL FUEL COMBUSTION INTO THE ATMOSPHERE AND THEN TRANSPORTED TO OCEANS. view more 

CREDIT: REIKO MATSUSHITA

Although it is important to control emissions of CO2 to mitigate global warming, atmospheric levels of the gas are also related to how quickly it is removed from the air by the means of land and ocean storage. The micronutrient iron is crucial for oceanic carbon storage because it can support the production of chemical energy in marine ecosystems by photosynthesis (known as iron fertilization). This process converts CO2 into O2 and organic compounds.  

It is generally thought that iron inputs from the atmosphere to the ocean primarily come from natural sources. However, a study reported in npj Climate and Atmospheric Science, led by Associate Professor Hitoshi Matsui and Mingxu Liu of the Graduate School of Environmental Studies, Nagoya University, in collaboration with Cornell and Colorado Universities, found that the contribution of human-made iron in the Southern Ocean is probably much larger than previously thought. It may, in fact, be up to ten times higher. This may have implications for future environmental management.  

The human-made contribution to iron is mostly produced by fossil fuel combustion, in which iron is released into the atmosphere and then transported to remote oceans. To better understand how human activities affect iron concentration levels, the scientists combined data obtained by aircraft measurement with an advanced global atmospheric model.   

They found that human-made iron is a major contributor to the iron supply from the atmosphere to the ocean in the Southern Ocean region, with a percentage contribution as high as 60%. In contrast, previous studies estimated that only 10% of iron was from human-made iron and thus strongly underestimated the contribution of human-made sources.  

The model also found that the supply of iron from the atmosphere to the ocean in this region is projected to decline significantly, which may have unexpected consequences for the future climate. With less iron in the atmosphere, the amount of photosynthesis of phytoplankton may fall, causing a decrease in the oceanic uptake of atmospheric CO2. Increased levels of CO2 have been associated with global warming.  

“Iron is a crucial micronutrient to sustain ocean phytoplankton growth and primary production in the Southern Ocean where it modulates atmospheric CO2 levels,” Dr. Matsui said. “A potential decline in iron availability, with the tightening controls on global fossil fuel emissions in the coming decades, may limit carbon storage in marine ecosystems and actually exacerbate global warming.” 

Meeting the target of achieving global carbon neutrality by cutting fossil fuel consumption in the coming decades would substantially reduce human-made emissions. Coupled with the warming of the atmosphere, it could have an impact on the climate. Future models must fully consider the role of human-made sources in iron fertilization in the Southern Ocean.  

Funding for this study was provided by Ministry of Education, Culture, Sports, Science, and Technology and the Japan Society for the Promotion of Science (MEXT/JSPS) KAKENHI (JP17H04709, JP19H04253, JP19H05699, JP19KK0265, JP20H00196, and JP20H00638), MEXT Arctic Challenge for Sustainability phase II project (ArCS-II; JPMXD1420318865), Environment Research and Technology Development (JPMEERF20202003) of the Environmental Restoration and Conservation Agency of Japan, Foundation of Kinoshita Memorial Enterprise (Basic Science Fund) and Nagoya University Research Fund 

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JOURNAL

npj Climate and Atmospheric Science

DOI

10.1038/s41612-022-00250-w 

METHOD OF RESEARCH

Computational simulation/modeling

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

The underappreciated role of anthropogenic sources in atmospheric soluble iron flux to the Southern Ocean

ARTICLE PUBLICATION DATE

Multiple habitats need protecting to save UK bumblebees, finds 10-year citizen science study

Peer-Reviewed Publication

BRITISH ECOLOGICAL SOCIETY

 

IMAGE: WHITE-TAILED BUMBLEBEE (BOMBUS_LUCORUM) ON CHRYSANTHEMUM SEGETUM. view more 

CREDIT: PIETER HARINGSMA

A study using 10 years of citizen science data from the Bumblebee Conservation Trust’s BeeWalk scheme has found that a variety of targeted conservation approaches are needed to protect UK bumblebee species. The findings are published the British Ecological Society’s Journal of Applied Ecology.

Researchers at the Bumblebee Conservation Trust, Karlsruhe Institute of Technology and the University of Edinburgh, have used 10 years of bumblebee abundance data, collected by citizen scientists, to provide the most detailed overview currently possible of bumblebee habitat requirements across the UK.

The researchers found a wide range of differences between bumblebee species in the types of habitat they are associated with. This suggests that a one-size-fits-all approach to bumblebee conservation will not effectively protect all species and that conservation efforts need to be carefully tailored to particular species.

The study identified types of habitat that could be targeted for bumblebee conservation. Arable areas were found to be important for rare species like the large garden bumblebee (Bombus ruderatus), the largest species in the UK. Whereas large areas of semi-natural land, like moorland, were important for several species such as the moss and the brown-banded carder bees (Bombus muscorum and Bombus humilis), and the bilberry bumblebee (Bombus monticola).

Dr Penelope Whitehorn, at the Karlsruhe Institute of Technology, who led the study, said: “Our results suggest that reversing the loss of semi-natural areas such as wetlands may be the single most generally effective action for bumblebee conservation, while improving habitats in urban and arable areas could benefit particular rare species. As one of the most nature-depleted countries in the world it’s really important that we better protect our native species and habitats in the UK.”

Effective conservation requires in-depth knowledge of different species’ requirements which in turn depends on detailed habitat survey data. In this study these data were provided by a long-running citizen science project, which the researchers see as essential in both collecting the data and engaging the public in conservation.

Dr Whitehorn said: “Our study highlights the value of citizen science for understanding bumblebees and their habitats. Citizen science also gives everyone a chance to contribute to protecting these species.”

The study also identified differences in habitat association within bumblebee species. The queens and males of several species were particularly associated with areas of scrub, bracken and herbs, suggesting that these habitats are good for nesting. In contrast, workers were more commonly associated with hedges and lanes, suggesting these are good for providing food.

A third of the UK’s 24 species of bumblebee are listed as species of conservation concern because they’re being found in fewer places. “Bumblebees are mostly threatened by loss and degradation of nesting and feeding habitat” said Richard Comont, Science Manager at the Bumblebee Conservation Trust.

“Bumblebees need areas with lots of flowers available from March right through to September/October. Bees lose this vital resource when habitats are lost entirely because they’re either built on or changed into other environments or degraded through things like pesticide use.”

In the study the researchers used 10 years of data from the Bumblebee Conservation Trust’s BeeWalk scheme, a citizen science project involving over 500 volunteers across the UK who carry out monthly monitoring walks, identifying and counting bumblebees.

The researchers combined data from the BeeWalk scheme with land cover data, climate date and detailed observer-collected habitat data. These combined data sources allowed the researchers to look at associations between 14 UK bumblebee species and types of habitat.

As with many studies that rely on volunteers to collect data, the researchers did detect biases. Volunteers often selected survey sites to monitor bumblebees that were close to where they live, creating a bias towards urban areas. However, the researchers say the scale and distribution of volunteer efforts still covered a wide range of UK landscapes, allowing for statistically robust findings.

On the next steps in this area of research, Dr Whitehorn said: “We’d like to find out why different species are associated with different habitats, so we can create and preserve the right conditions for them in the future. We also need to better understand how shifting climate and land uses might affect bumblebees and their habitats.”

-ENDS-

CAPTION

Great yellow bumblebee (Bombus distinguendus) on Centaurea nigra.

  

CAPTION

BeeWalk survey in Penally, Wales.

CREDIT

Clare Flynn

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JOURNAL

Journal of Applied Ecology

DOI

10.1111/1365-2664.14191 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

The effects of climate and land use on British bumblebees: Findings from a decade of citizen-science observations

ARTICLE PUBLICATION DATE

23-May-2022

Organic farming or flower strips – which 

is better for bees?

Research team including Göttingen University assess the efficiency of agri-environmental measures from different perspectives

Peer-Reviewed Publication

UNIVERSITY OF GÖTTINGEN

 

IMAGE: FLOWER STRIPS NEXT TO A CONVENTIONAL WHEAT FIELD NEAR SEBEXEN IN THE DISTRICT OF NORTHEIM, GERMANY. view more 

CREDIT: CONSTANZA GEPPERT

How effective environmental measures in agriculture are for biodiversity and wild bee populations depends on various factors and your perspective. This is shown by agroecologists from the University of Göttingen, Germany and the Centre for Ecological Research in Vácrátót, Hungary. The research team found that when assessing the effectiveness of different measures, whether in the field (organic farming) or next to the field (flower strips in conventional farming), biodiversity benefits should be evaluated differently. Like-for-like comparisons of environmental measures could easily be misleading, according to the scientists. The research was published in the journal Basic and Applied Ecology.

 

The researchers studied ten agricultural landscapes near Göttingen, each containing three winter wheat fields: one organic field, one conventional field with flower strips, and one conventional field without flower strips. For two years, the abundance of wild bees was recorded at the edges of each of these thirty fields. The results showed that a simple comparison of the data sampled at specific sites could lead to the conclusion that conventional fields with strips of flowers might attract many more bees than organic fields but this is not the full story.

 

"When we looked more closely, this did not give us a complete picture because it did not take into account that flower strips only cover about five percent of conventional fields which has significantly fewer bees overall than the organic farmland," explains Professor Teja Tscharntke, Department of Agroecology at Göttingen University. Dr Péter Batáry, group leader at the Centre for Organic Research in Vácrátót, Hungary goes onto say: "In short, organic farming, which typically has more wild plants than conventional fields, is actually more successful than conventional fields with flower strips in promoting bees."

 

The missing piece of the jigsaw is the fact that fields of grain in organic farming yield only half the harvest of conventional farming. When the loss in wheat yield is taken into account, a ten-hectare area of organic farmland should be compared to five hectares of conventional farmland plus five hectares of flower strips, which would lead to 3.5 times more bees but the same yield. In this scenario, organic farming would not be the best way to support wild bees.

 

"These data and considerations show that different benchmarks and criteria should be taken into account when evaluating agri-environmental measures. It is only when we take into account the area along with the yield together with the type of farming that we can achieve a balanced understanding of the ecological and economic effectiveness of environmental measures," the authors say.

  

CAPTION

Students in an organic wheat field near Bodensee, a municipality in the district of Göttingen, Germany.

CREDIT

Sinja Zieger

 

 

 

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JOURNAL

Basic and Applied Ecology

DOI

10.1016/j.baae.2022.05.001 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Scale-dependent effectiveness of on-field vs. off-field agri-environmental measures for wild bees

ARTICLE PUBLICATION DATE

15-May-2022

A family of termites has been traversing the world’s oceans for millions of years

Peer-Reviewed Publication

OKINAWA INSTITUTE OF SCIENCE AND TECHNOLOGY (OIST) GRADUATE UNIVERSITY

 

IMAGE: DRYWOOD TERMITES WERE THE CENTER OF A RECENTLY PUBLISHED STUDY THAT INVOLVED THREE DECADES OF SAMPLE COLLECTION AND COLLABORATORS FROM ACROSS THE WORLD. BY SEQUENCING THE MITOCHONDRIAL GENOMES, THE RESEARCHERS DISCERNED THAT THIS FAMILY HAS MADE AT LEAST 40 OCEANIC VOYAGES IN THE LAST 50 MILLION YEARS. view more 

CREDIT: ALEŠ BUČEK

Highlights

• A new study has mapped out the natural history of drywood termites—the second largest family of termites.
• Drywood termites form small colonies primarily in wood and are generally thought of as primitive termites but very little is actually known about the family.
• By sequencing the mitochondrial genomes of 120 species found across the world, the researchers discerned that this family has made at least 40 oceanic voyages in the last 50 million years.
• The study also confirmed that some species have, in recent centuries, hitched a ride with humans to reach far-flung islands.      
• Furthermore, it cast doubt on the common assumption that drywood termites have a primitive lifestyle as, among the oldest lineages in the family, there are species that do not exhibit this lifestyle.

Press release

Termites are a type of cockroach that split from other cockroaches around 150 million years ago and evolved to live socially in colonies. Today, there are many different kinds of termites. Some form large colonies with millions of individuals, which tend to live in connected tunnels in the soil. Others, including most species known as drywood termites, form much smaller colonies of less than 5000 individuals, and live primarily in wood.

Researchers from the Evolutionary Genomics Unit at the Okinawa Institute of Science and Technology Graduate University (OIST), alongside a network of collaborators from across the world, have mapped out the natural history of drywood termites—the second largest family of termites—and revealed a number of oceanic voyages that accelerated the evolution of their diversity. The research, published in Molecular Biology and Evolution, shines light on where termites originated and how and when they spread across the globe. It also confirms that some species have, in recent centuries, hitched a ride with humans to reach far-flung islands.

“Drywood termites, or Kalotermitidae, are often thought of as primitive because they split from other termites quite early, around 100 million years ago, and because they appear to form smaller colonies,” said Dr. Aleš Buček, OIST Postdoctoral Researcher and lead author of the study. “But very little is actually known about this family.”

Dr. Buček went on to explain how, before this study, there was very little molecular data on the family and the little understanding of the relationships between the different species that was known was based on their appearance. Previous research had focused on one genus within the family that contains common pest species, often found within houses.

To gain overarching knowledge, the researchers collected hundreds of drywood termite samples from around the world over a timespan of three decades. From this collection, they selected about 120 species, some of which were represented by multiple samples collected in different locations. This represented over a quarter of Kalotermitidae diversity. Most of these samples were brought to OIST where the DNA was isolated and sequenced.

By comparing the genetic sequences from the different species, the researchers constructed an extensive family tree of the drywood termites.

They found that drywood termites have made more oceanic voyages than any other family of termites. They’ve crossed oceans at least 40 times in the past 50 million years, travelling as far as South America to Africa, which, over a timescale of millions of years, resulted in the diversification of new drywood termite species in the newly colonized places.

“They’re very good at getting across oceans,” said Dr. Buček. “Their homes are made of wood so can act as tiny ships.”

The researchers found that most of the genera originated in southern America and dispersed from there. It takes a scale of millions of years for one species to split into several after a move. The research also confirmed that, more recently, dispersals have largely been mediated by humans.

Furthermore, this study has cast doubt on the common assumption that drywood termites have a primitive lifestyle. Among the oldest lineages in the family, there are termite species that do not have a primitive lifestyle. In fact, they can form large colonies across multiple pieces of wood that are connected by tunnels underground.

“This study only goes to highlight how little we know about termites, the diversity of their lifestyles, and the scale of their social lives,” stated Prof. Tom Bourguignon, Principal Investigator of OIST’s Evolutionary Genomics Unit and senior author of the study. “As more information is gathered about their behavior and ecology, we’ll be able to use this family tree to find out more about the evolution of sociality in insects and how termites have been so successful.”

CAPTION

The researchers collected samples of drywood termites from around the world. The numbers listed on this map are the number of samples collected from each area.

CREDIT

OIST

CAPTION

By comparing the mitochondrial genomes of 120 species of drywood termites, the researchers constructed a comprehensive family tree, revealing insights on how termites diversified and spread across the world.

CREDIT

OIST

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JOURNAL

Molecular Biology and Evolution

DOI

10.1093/molbev/msac093 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Molecular Phylogeny Reveals the Past Transoceanic Voyages of Drywood Termites (Isoptera, Kalotermitidae)

ARTICLE PUBLICATION DATE

Living with dogs (but not cats) as a toddler might protect against Crohn’s disease

New study suggests that growing up with a large family can also lower risk of inflammatory bowel disease

Reports and Proceedings

AMERICAN GASTROENTEROLOGICAL ASSOCIATION

San Diego, CA (May 23, 2022)—Young children who grow up with a dog or in a large family may have some protection later in life from a common inflammatory bowel disease known as Crohn’s disease, according to a study to be presented at Digestive Disease Week® (DDW) 2022.

“Our study seems to add to others that have explored the ‘hygiene hypothesis’ which suggests that the lack of exposure to microbes early in life may lead to lack of immune regulation toward environmental microbes,” said Williams Turpin, PhD, the study’s senior author and a research associate with Mount Sinai Hospital and the University of Toronto.

Researchers used an environmental questionnaire to collect information from nearly 4,300 first-degree relatives of people with Crohn’s disease enrolled in the Crohn’s and Colitis Canada Genetic, Environmental, and Microbial (CCC-GEM) project. Using responses to the questionnaire and historical data collected at the time of recruitment, Dr. Turpin and his team analyzed several environmental factors, including family size, the presence of dogs or cats as household pets, the number of bathrooms in the house, living on a farm, drinking unpasteurized milk and drinking well water. The analysis also included age at the time of exposure.

The study found that exposure to dogs, particularly from ages 5 to 15, was linked with healthy gut permeability and balance between the microbes in the gut and the body’s immune response, all of which might help protect against Crohn’s disease. Similar effects were observed with exposure to dogs across all age groups.

“We did not see the same results with cats, though we are still trying to determine why,” Dr. Turpin said. “It could potentially be because dog owners get outside more often with their pets or live in areas with more green space, which has been shown previously to protect against Crohn’s.”

Another protective factor seemed to be living with three or more family members in the first year of life, which was associated with microbiome composition later in life. The gut microbiome is believed to play a role in a number of health conditions, such as inflammatory bowel disease, colorectal cancer, diabetes, and high blood pressure.

Dr. Turpin and his colleagues hope their findings may assist physicians in asking detailed questions of patients to determine who is at highest risk. However, he noted that the early life environmental factors were assessed by questionnaires, so caution is warranted in interpreting these results due to possible recall bias at recruitment. The reasons dog ownership and larger families appear to provide protection from Crohn’s remain unclear.

Crohn’s disease is a type of inflammatory bowel disease that affects around half a million people in the U.S. It most often develops in young adults, people who smoke, and those with a close family member who has IBD. Symptoms include diarrhea, abdominal pain and weight loss. Treatments currently aim to prevent symptom flare-ups through diet modification, medication, and surgery.

DDW Presentation Details

Dr. Turpin will present data from the study, “Environmental factors associated with risk of Crohn’s disease (CD) development in a prospective cohort of healthy first-degree relatives of CD patients,” abstract 793, on Monday, May 23, at 4:28 p.m. PDT. For more information about featured studies, as well as a schedule of availability for featured researchers, please visit www.ddw.org/press.

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Digestive Disease Week® (DDW) is the largest international gathering of physicians, researchers and academics in the fields of gastroenterology, hepatology, endoscopy and gastrointestinal surgery. Jointly sponsored by the American Association for the Study of Liver Diseases (AASLD), the American Gastroenterological Association (AGA) Institute, the American Society for Gastrointestinal Endoscopy (ASGE) and the Society for Surgery of the Alimentary Tract (SSAT), DDW takes place May 21 – 24 in San Diego, California and virtually. The meeting showcases more than 3,100 abstracts and hundreds of lectures on the latest advances in GI research, medicine and technology. More information can be found at www.ddw.org.

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ARTICLE TITLE

Environmental factors associated with risk of Crohn’s disease (CD) development in a prospective cohort of healthy first-degree relatives of CD patients