Why do I poo in the morning? A gut expert explains

10almonds is reader-supported. We may, at no cost to you, receive a portion of sales if you purchase a product through a link in this article.

No, you’re not imagining it. People really are more likely to poo in the morning, shortly after breakfast. Researchers have actually studied this.

But why mornings? What if you tend to poo later in the day? And is it worth training yourself to be a morning pooper?

To understand what makes us poo when we do, we need to consider a range of factors including our body clock, gut muscles and what we have for breakfast.

Here’s what the science says.

H_Ko/Shutterstock

So morning poos are real?

In a UK study from the early 1990s, researchers asked nearly 2,000 men and women in Bristol about their bowel habits.

The most common time to poo was in the early morning. The peak time was 7-8am for men and about an hour later for women. The researchers speculated that the earlier time for men was because they woke up earlier for work.

About a decade later, a Chinese study found a similar pattern. Some 77% of the almost 2,500 participants said they did a poo in the morning.

But why the morning?

There are a few reasons. The first involves our circadian rhythm – our 24-hour internal clock that helps regulate bodily processes, such as digestion.

For healthy people, our internal clock means the muscular contractions in our colon follow a distinct rhythm.

There’s minimal activity in the night. The deeper and more restful our sleep, the fewer of these muscle contractions we have. It’s one reason why we don’t tend to poo in our sleep.

Diagram of digestive system including colon and rectum
Your lower gut is a muscular tube that contracts more strongly at certain times of day. Vectomart/Shutterstock

But there’s increasing activity during the day. Contractions in our colon are most active in the morning after waking up and after any meal.

One particular type of colon contraction partly controlled by our internal clock are known as “mass movements”. These are powerful contractions that push poo down to the rectum to prepare for the poo to be expelled from the body, but don’t always result in a bowel movement. In healthy people, these contractions occur a few times a day. They are more frequent in the morning than in the evening, and after meals.

Breakfast is also a trigger for us to poo. When we eat and drink our stomach stretches, which triggers the “gastrocolic reflex”. This reflex stimulates the colon to forcefully contract and can lead you to push existing poo in the colon out of the body. We know the gastrocolic reflex is strongest in the morning. So that explains why breakfast can be such a powerful trigger for a bowel motion.

Then there’s our morning coffee. This is a very powerful stimulant of contractions in the sigmoid colon (the last part of the colon before the rectum) and of the rectum itself. This leads to a bowel motion.

How important are morning poos?

Large international surveys show the vast majority of people will poo between three times a day and three times a week.

This still leaves a lot of people who don’t have regular bowel habits, are regular but poo at different frequencies, or who don’t always poo in the morning.

So if you’re healthy, it’s much more important that your bowel habits are comfortable and regular for you. Bowel motions do not have to occur once a day in the morning.

Morning poos are also not a good thing for everyone. Some people with irritable bowel syndrome feel the urgent need to poo in the morning – often several times after getting up, during and after breakfast. This can be quite distressing. It appears this early-morning rush to poo is due to overstimulation of colon contractions in the morning.

Can you train yourself to be regular?

Yes, for example, to help treat constipation using the gastrocolic reflex. Children and elderly people with constipation can use the toilet immediately after eating breakfast to relieve symptoms. And for adults with constipation, drinking coffee regularly can help stimulate the gut, particularly in the morning.

A disturbed circadian rhythm can also lead to irregular bowel motions and people more likely to poo in the evenings. So better sleep habits can not only help people get a better night’s sleep, it can help them get into a more regular bowel routine.

Man preparing Italian style coffee at home, adding coffee to pot
A regular morning coffee can help relieve constipation. Caterina Trimarchi/Shutterstock

Regular physical activity and avoiding sitting down a lot are also important in stimulating bowel movements, particularly in people with constipation.

We know stress can contribute to irregular bowel habits. So minimising stress and focusing on relaxation can help bowel habits become more regular.

Fibre from fruits and vegetables also helps make bowel motions more regular.

Finally, ensuring adequate hydration helps minimise the chance of developing constipation, and helps make bowel motions more regular.

Monitoring your bowel habits

Most of us consider pooing in the morning to be regular. But there’s a wide variation in normal so don’t be concerned if your poos don’t follow this pattern. It’s more important your poos are comfortable and regular for you.

If there’s a major change in the regularity of your bowel habits that’s concerning you, see your GP. The reason might be as simple as a change in diet or starting a new medication.

But sometimes this can signify an important change in the health of your gut. So your GP may need to arrange further investigations, which could include blood tests or imaging.

Vincent Ho, Associate Professor and clinical academic gastroenterologist, Western Sydney University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Don’t Forget…

Did you arrive here from our newsletter? Don’t forget to return to the email to continue learning!

Recommended

  • How gender-affirming care improves trans mental health
  • ‘Free birthing’ and planned home births might sound similar but the risks are very different
    Free births, without medical assistance, are on the rise. Lack of options and past trauma drive women to choose this risky path.

Learn to Age Gracefully

Join the 98k+ American women taking control of their health & aging with our 100% free (and fun!) daily emails:

  • Small Changes For A Healthier Life

    10almonds is reader-supported. We may, at no cost to you, receive a portion of sales if you purchase a product through a link in this article.

    It’s Q&A Day at 10almonds!

    Have a question or a request? You can always hit “reply” to any of our emails, or use the feedback widget at the bottom!

    In cases where we’ve already covered something, we might link to what we wrote before, but will always be happy to revisit any of our topics again in the future too—there’s always more to say!

    As ever: if the question/request can be answered briefly, we’ll do it here in our Q&A Thursday edition. If not, we’ll make a main feature of it shortly afterwards!

    So, no question/request too big or small

    I am interested in what I can substitute for ham in bean soup?

    Well, that depends on what the ham was like! You can certainly buy ready-made vegan lardons (i.e. small bacon/ham bits, often in tiny cubes or similar) in any reasonably-sized supermarket. Being processed, they’re not amazing for the health, but are still an improvement on pork.

    Alternatively, you can make your own seitan! Again, seitan is really not a health food, but again, it’s still relatively less bad than pork (unless you are allergic to gluten, in which case, definitely skip this one).

    Alternatively alternatively, in a soup that already contains beans (so the protein element is already covered), you could just skip the ham as an added ingredient, and instead bring the extra flavor by means of a little salt, a little yeast extract (if you don’t like yeast extract, don’t worry, it won’t taste like it if you just use a teaspoon in a big pot, or half a teaspoon in a smaller pot), and a little smoked paprika. If you want to go healthier, you can swap out the salt for MSG, which enhances flavor in a similar fashion while containing less sodium.

    Wondering about the health aspects of MSG? Check out our main feature on this, from last month:

    What’s the deal with MSG?

    I thoroughly enjoy your daily delivery. I’d love to see one for teens too!

    That’s great to hear! The average age of our subscribers is generally rather older, but it’s good to know there’s an interest in topics for younger people. We’ll bear that in mind, and see what we can do to cater to that without alienating our older readers!

    That said: it’s never too soon to be learning about stuff that affects us when we’re older—there are lifestyle factors at 20 that affect Alzheimer’s risk at 60, for example (e.g. drinking—excessive drinking at 20* is correlated to higher Alzheimer’s risk at 60).

    *This one may be less of an issue for our US readers, since the US doesn’t have nearly as much of a culture of drinking under 21 as some places. Compare for example with general European practices of drinking moderately from the mid-teens, or the (happily, diminishing—but historically notable) British practice of drinking heavily from the mid-teens.

    How much turmeric should I take each day?

    Dr. Michael Greger’s research (of “Dr. Greger’s Daily Dozen” and “How Not To Die” fame) recommends getting at least ¼ tsp turmeric per day

    Remember to take it with black pepper though, for a 2000% absorption bonus!

    A great way to get it, if you don’t want to take capsules and don’t want to eat spicy food every day, is to throw a teaspoon of turmeric in when making a pot of (we recommend wholegrain!) rice. Turmeric is very water-soluble, so it’ll be transferred into the rice easily during cooking. It’ll make the rice a nice golden yellow color, and/but won’t noticeably change the taste.

    Again remember to throw in some black pepper, and if you really want to boost the nutritional content,some chia seeds are a great addition too (they’ll get cooked with the rice and so it won’t be like eating seeds later, but the nutrients will be there in the rice dish).

    You can do the same with par-boiled potatoes or other root vegetables, but because cooking those has water to be thrown away at the end (unlike rice), you’ll lose some turmeric in the water.

    Request: more people need to be aware of suicidal tendencies and what they can do to ward them off

    That’s certainly a very important topic! We’ll cover that properly in one of our Psychology Sunday editions. In the meantime, we’ll mention a previous special that we did, that was mostly about handling depression (in oneself or a loved one), and obviously there’s a degree of crossover:

    The Mental Health First-Aid That You’ll Hopefully Never Need

    Share This Post

  • Plant vs Animal Protein

    10almonds is reader-supported. We may, at no cost to you, receive a portion of sales if you purchase a product through a link in this article.

    Plant vs Animal Protein: Head to Head

    Some people will obviously have strong ideological opinions here—for vegetarians and vegans, it’s no question, and for meat-eaters, it’s easy to be reactive to that and double-down on the bacon. But, we’re a health science newsletter, so we’ll be sticking to the science.

    Which is better, healthwise?

    First, it depends on how you go about it. Consider these options:

    • A piece of salmon
    • A steak
    • A hot dog
    • A hot dog, but plant-based
    • Textured soy protein (no additives)
    • Edamame (young soy) beans

    Three animal-based protein sources, three plant-based. We could render the competition simple (but very unfair) by pitting the hotdog against the edamame beans, or the plant-based hot dog against the piece of salmon. So let’s kick this off by saying:

    • There are good and bad animal-based protein sources
    • There are good and bad plant-based protein sources

    Whatever you choose, keep that in mind while you do. Less processed is better in either case. And if you do go for red meat, less is better, period.

    Picking the healthiest from each, how do the nutritional profiles look?

    They look good in both cases! One factor of importance is that in either case, our bodies will reduce the proteins we consume to their constituent amino acids, and then rebuild them into the specific proteins we actually need. Our bodies will do that regardless of the source, because we are neither a salmon nor a soybean, for example.

    We need 20 specific amino acids, for our bodies to make the proteins we will use in our bodies. Of these, 9 are considered “essential”, meaning we cannot synthesize them and must get them from our diet,

    Animal protein sources contain all 9 of those (just like we do). Plant based sources often don’t, individually, but by eating soy for example (which does contain them all) and/or getting multiple sources of protein from different plants, the 9 can be covered quite easily with little thought, just by having a varied diet.

    Meats are #1!

    • They’re number 1 for nutritional density
    • They’re number 1 for health risks, too

    So while plant-based diet adherents may need to consume more varied things to get all the nutrients necessary, meat-eaters won’t have that problem.

    Meat-eaters will instead have a different problem, of more diet-related health risks, e.g.

    • Cardiovascular disease
    • Metabolic disorders
    • Cancers

    So again, if eating (especially processed and/or red) meat, moderation is good. The Mediterranean Diet that we so often recommend, by default contains small amounts of lean animal protein.

    Which is better for building muscle?

    Assuming a broadly healthy balanced diet, and getting sufficient protein from your chosen source, they’re pretty equal:

    (both studies showed that both dietary approaches yielded results that showed no difference in muscle synthesis between the two)

    The bottom line is…

    Healthwise, what’s more important than whether you get your protein from animals or plants is that you eat foods that aren’t processed, and are varied.

    And if you want to do a suped-up Mediterranean Diet with less red meat, you might want to try:

    A Pesco-Mediterranean Diet With Intermittent Fasting: JACC Review Topic of the Week

    ^This is from a review in the Journal of the American College of Cardiology, and in few words, they recommend it very highly

    Share This Post

  • Driving under the influence of marijuana: An explainer and research roundup

    10almonds is reader-supported. We may, at no cost to you, receive a portion of sales if you purchase a product through a link in this article.

    Update 1: On May 16, 2024, the U.S. Department of Justice sent a proposed rule to the Federal Register to downgrade marijuana from a Schedule I to a Schedule III drug. This is the first step in a lengthy approval process that starts with a 60-day comment period.

    Update 2: Two recent research studies were added to the “Studies on marijuana and driving” section of this piece on July 18, 2024.

    As marijuana use continues to rise and state-level marijuana legalization sweeps the U.S., researchers and policymakers are grappling with a growing public safety concern: marijuana-impaired driving.

    As of April 2023, 38 U.S. states had legalized medical marijuana and 23 had legalized its recreational use, according to the National Conference of State Legislatures. Recreational or medical marijuana measures are on the ballot in seven states this year.

    The issue of marijuana-impaired driving has not been an easy one to tackle because, unlike alcohol, which has well-established thresholds of impairment, the metrics for marijuana’s effects on driving remain rather elusive.

    “We don’t have that kind of deep knowledge right now and it’s not because of lack of trying,” says Dr. Guohua Li, professor of epidemiology and the founding director of the Center for Injury Science and Prevention at Columbia University.

    “Marijuana is very different from alcohol in important ways,” says Li, who has published several studies on marijuana and driving. “And one of them is that the effect of marijuana on cognitive functions and behaviors is much more unpredictable than alcohol. In general, alcohol is a depressant drug. But marijuana could act on the central nervous system as a depressant, a stimulant, and a hallucinogenic substance.”

    Efforts to create a breathalyzer to measure the level of THC, the main psychoactive compound found in the marijuana plant, have largely failed, because “the THC molecule is much bigger than ethanol and its behavior after ingestion is very different from alcohol,” Li says.

    Currently, the two most common methods used to measure THC concentration to identify impaired drivers are blood and saliva tests, although there’s ongoing debate about their reliability.

    Marijuana, a term interchangeably used with cannabis, is the most commonly used federally illegal drug in the U.S.: 48.2 million people, or about 18% of Americans reported using it at least once in 2019, according to the latest available data from the Centers for Disease Control and Prevention. Worldwide, 2.5% of the population consumes marijuana, according to the World Health Organization.

    Marijuana is legal in several countries, including Canada, where it was legalized in 2018. Despite state laws legalizing cannabis, it remains illegal at the federal level in the U.S.

    As states grapple with the contentious issue of marijuana legalization, the debate is not just about public health, potential tax revenues and economic interests. At the heart of the discussion is also the U.S. criminal justice system.

    Marijuana is shown to have medicinal qualities and, compared with substances like alcohol, tobacco, and opioids, it has relatively milder health risks. However, it’s not risk-free, a large body of research has shown.

    Marijuana consumption can lead to immediate effects such as impaired muscle coordination and paranoia, as well as longer-term effects on mental health and cognitive functions — and addiction. As its use becomes more widespread, researchers are trying to better understand the potential hazards of marijuana, particularly for younger users whose brains are in critical stages of development.

    Marijuana and driving

    The use of marijuana among drivers, passengers and pedestrians has increased steadily over the past two decades, Li says.

    Compared with the year 2000, the proportion of U.S. drivers on the road who are under the influence of marijuana has increased by several folds, between five to 10 times, based on toxicology testing of people who died in car crashes, Li says.

    A 2022 report from the National Transportation Safety Board finds alcohol and cannabis are the two most commonly detected drugs among drivers arrested for impaired driving and fatally injured drivers. Most drivers who tested positive for cannabis also tested positive for another potentially impairing drug.

    “Although cannabis and many other drugs have been shown to impair driving performance and are associated with increased crash risk, there is evidence that, relative to alcohol, awareness about the potential dangers of driving after using other drugs is lower,” according to the report.

    Indeed, many U.S. adults perceive daily marijuana use or exposure to its smoke safer than tobacco, even though research finds otherwise.

    Several studies have demonstrated marijuana’s impact on driving.

    Marijuana use can reduce the drivers’ ability to pay attention, particularly when they are performing multiple tasks, research finds. It also slows reaction time and can impair coordination.

    “The combination is that you potentially have people who are noticing hazards later, braking slower and potentially not even noticing hazards because of their inability to focus on competing things on the road,” says Dr. Daniel Myran, an assistant professor at the Department of Family Medicine and health services researcher at the University of Ottawa.

    In a study published in September in JAMA Network Open, Myran and colleagues find that from 2010 to 2021 the rate of cannabis-involved traffic injuries that led to emergency department visits in Ontario, Canada, increased by 475%, from 0.18 per 1,000 traffic injury emergency department visits in 2010 to 1.01 visits in 2021.

    To be sure, cannabis-involved traffic injuries made up a small fraction of all traffic injury-related visits to hospital emergency departments. Out of 947,604 traffic injury emergency department visits, 426 had documented cannabis involvement.

    Myran cautions the increase shouldn’t be solely attributed to marijuana legalization. It captures changing societal attitudes toward marijuana and acceptance of cannabis use over time in the lead-up to legalization. In addition, it may reflect an increasing awareness among health care providers about cannabis-impaired driving, and they may be more likely to ask about cannabis use and document it in medical charts, he says.

    “When you look at the 475% increase in cannabis involvement in traffic injuries, rather than saying legalizing cannabis has caused the roads to be unsafe and is a public health disaster, it’s that cannabis use appears to be growing as a risk for road traffic injuries and that there seem to be more cannabis impaired drivers on the road,” Myran says. “Legalization may have accelerated this trend. Faced with this increase, we need to think about what are public health measures and different policy interventions to reduce harms from cannabis-impaired driving.”

    Setting a legal limit for marijuana-impaired driving

    Setting a legal limit for marijuana-impaired driving has not been easy. Countries like Canada and some U.S. states have agreed upon a certain level of THC in blood, usually between 1 to 5 nanograms per milliliter. Still, some studies have found those limits to be weak indicators of cannabis-impaired driving.

    When Canada legalized recreational marijuana in 2018, it also passed a law that made it illegal to drive with blood THC levels of more than 2 nanograms. The penalties are more severe for blood THC levels above 5 nanograms. The blood test is done at the police station for people who are pulled over and are deemed to be drug impaired.

    In the U.S., five states — Ohio, Illinois, Montana, Washington and Nevada — have “per se laws,” which set a specific amount of THC in the driver’s blood as evidence of impaired driving, according to the National Conference of State Legislatures. That limit ranges between 2 and 5 nanograms of THC per milliliter of blood.

    Colorado, meanwhile, has a “permissible inference law,” which states that it’s permissible to assume the driver was under the influence if their blood THC level is 5 nanograms per milliliter or higher, according to NCSL.

    Twelve states, most which have legalized some form of marijuana of use, have zero tolerance laws for any amount of certain drugs, including THC, in the body.

    The remaining states have “driving under the influence of drugs” laws. Among those states, Alabama and Michigan, have oral fluid roadside testing program to screen drivers for marijuana and other drugs, according to NCSL.

    In May this year, the U.S. Department of Transportation published a final rule that allows employers to use saliva testing for commercially licensed drivers, including truck drivers. The rule, which went into effect in June, sets the THC limit in saliva at 4 nanograms.

    Saliva tests can detect THC for 8 to 24 hours after use, but the tests are not perfect and can results in false positives, leading some scientists to argue against using them in randomly-selected drivers.

    In a 2021 report, the U.S. National Institute of Justice, the research and development arm of the Department of Justice, concluded that THC levels in bodily fluids, including blood and saliva “were not reliable indicators of marijuana intoxication.”

    Studies on marijuana and driving

    Over the past two decades, many studies have shown marijuana use can impair driving. However, discussions about what’s the best way to measure the level of THC in blood or saliva are ongoing. Below, we highlight and summarize several recent studies that address the issue. The studies are listed in order of publication date. We also include a list of related studies and resources to inform your audiences.

    State Driving Under the Influence of Drugs Laws
    Alexandra N. Origenes, Sarah A. White, Emma E. McGinty and Jon S. Vernick. Journal of Law, Medicine & Ethics, July 2024.

    Summary: As of January 2023, 33 states and D.C. had a driving under the influence of drugs law for at least one drug other than cannabis. Of those, 29 states and D.C. had a law specifically for driving under the influence of cannabis, in addition to a law for driving under the influence of other drugs. Four states had a driving under the influence of drug laws, excluding cannabis. Meanwhile, 17 states had no law for driving under the influence of drugs, including cannabis.  “The 17 states lacking a DUID law that names specific drugs should consider enacting such a law. These states already have expressed their concern — through legislation — with drug-impaired driving. However, failure to name specific drugs is likely to make the laws more difficult to enforce. These laws may force courts and/or law enforcement to rely on potentially subjective indicators of impairment,” the authors write.

    Associations between Adolescent Marijuana Use, Driving After Marijuana Use and Recreational Retail Sale in Colorado, USA
    Lucas M. Neuroth, et al. Substance Use & Misuse, October 2023.

    Summary: Researchers use data from four waves (2013, 2015, 2017 and 2019) of the Healthy Kids Colorado Survey, including 47,518 students 15 and older who indicated that they drove. They find 20.3% of students said that they had used marijuana in the past month and 10.5% said they had driven under the influence of marijuana. They find that the availability of recreational marijuana in stores was associated with an increased prevalence of using marijuana one to two times in the past month and driving under the influence of marijuana at least once. “Over the study period, one in ten high school age drivers engaged in [driving after marijuana use], which is concerning given the high risk of motor vehicle-related injury and death arising from impaired driving among adolescents,” the authors write.

    Are Blood and Oral Fluid Δ9-tetrahydrocannabinol (THC) and Metabolite Concentrations Related to Impairment? A Meta-Regression Analysis
    Danielle McCartney, et al. Neuroscience & Biobehavioral Reviews, March 2022.

    Summary: Commonly used THC measurements may not be strong indicators of driving impairment. While there is a relationship between certain biomarkers like blood THC concentrations and impaired driving, this correlation is often weak. The study underscores the need for more nuanced and comprehensive research on this topic, especially as cannabis usage becomes more widespread and legally accepted.

    The Effects of Cannabis and Alcohol on Driving Performance and Driver Behaviour: A Systematic Review and Meta-Analysis
    Sarah M. Simmons, Jeff K. Caird, Frances Sterzer and Mark Asbridge. Addiction, January 2022.

    Summary: This meta-analysis of experimental driving studies, including driving simulations, confirms that cannabis impairs driving performance, contrary to some beliefs that it might enhance driving abilities. Cannabis affects lateral control and speed — typically increasing lane excursions while reducing speed. The combination of alcohol and marijuana appears worse than either alone, challenging the idea that they cancel each other out.

    Cannabis Legalization and Detection of Tetrahydrocannabinol in Injured Drivers
    Jeffrey R. Brubacher, et al. The New England Journal of Medicine, January 2022.

    Summary: Following the legalization of recreational marijuana in Canada, there was a notable increase in injured drivers testing positive for THC, especially among those 50 years of age or older. This rise in cannabis-related driving incidents occurred even with new traffic laws aiming to deter cannabis-impaired driving. This uptick began before legalization became official, possibly due to perceptions that cannabis use was soon-to-be legal or illegal but not enforced. The data suggests that while legalization has broad societal impacts, more comprehensive strategies are needed to deter driving under the influence of cannabis and raise public awareness about its risks.

    Cannabis and Driving
    Godfrey D. Pearlson, Michael C. Stevens and Deepak Cyril D’Souza. Frontiers in Psychiatry, September 2021.

    Summary: Cannabis-impaired driving is a growing public health concern, and studies show that such drivers are more likely to be involved in car crashes, according to this review paper. Drivers are less affected by cannabis than they are by alcohol or cocaine, but the problem is expected to escalate with increasing cannabis legalization and use. Unlike alcohol, THC’s properties make it challenging to determine direct impairment levels from testing results. Current roadside tests lack precision in detecting genuine cannabis-impaired drivers, leading to potential wrongful convictions. Moreover, there is a pressing need for research on the combined effects of alcohol and cannabis on driving, as well as the impact of emerging popular forms of cannabis, like concentrates and edibles. The authors recommend public awareness campaigns about the dangers of driving under the influence of cannabis, similar to those against drunk driving, to address misconceptions. Policymakers should prioritize science-based decisions and encourage further research in this domain.

    Demographic And Policy-Based Differences in Behaviors And Attitudes Towards Driving After Marijuana Use: An Analysis of the 2013–2017 Traffic Safety Culture Index
    Marco H. Benedetti, et al. BMC Research Notes, June 2021.

    Summary: The study, based on a U.S. survey, finds younger, low-income, low-education and male participants were more tolerant of driving after marijuana consumption. Notably, those in states that legalized medical marijuana reported driving after use more frequently, aligning with studies indicating a higher prevalence of THC detection in drivers from these states. Overall, while the majority perceive driving after marijuana use as dangerous, not all research agrees on its impairment effects. Existing studies highlight that marijuana impacts motor skills and executive functions, yet its direct correlation with crash risk remains debated, given the variations in individual tolerance and how long THC remains in the system.

    Driving Under the Influence of Cannabis: A Framework for Future Policy
    Robert M. Chow, et al.Anesthesia & Analgesia, June 2019.

    Summary: The study presents a conceptual framework focusing on four main domains: legalization, driving under the influence of cannabis, driver impairment, and motor vehicle accidents. With the growing legalization of cannabis, there’s an anticipated rise in cannabis-impaired driving cases. The authors group marijuana users into infrequent users who show significant impairment with increased THC blood levels, chronic users with minimal impairment despite high THC levels, and those with consistent psychomotor deficits. Current challenges lie in the lack of standardized regulation for drivers influenced by cannabis, primarily because of state-to-state variability and the absence of a federal statutory limit for blood THC levels. European nations, however, have established thresholds for blood THC levels, ranging from 0.5 to 50.0 micrograms per liter depending on whether blood or blood serum are tested. The authors suggest the combined use of alcohol and THC blood tests with a psychomotor evaluation by a trained professional to determine impairment levels. The paper stresses the importance of creating a structured policy framework, given the rising acceptance and use of marijuana in society.

    Additional research

    Cannabis-Involved Traffic Injury Emergency Department Visits After Cannabis Legalization and Commercialization
    Daniel T. Myran, et al. JAMA Network Open, September 2023.

    Driving Performance and Cannabis Users’ Perception of Safety: A Randomized Clinical Trial
    Thomas D. Marcotte, et al. JAMA Psychiatry, January 2022.

    Medicinal Cannabis and Driving: The Intersection of Health and Road Safety Policy
    Daniel Perkins, et al. International Journal of Drug Policy, November 2021.

    Prevalence of Marijuana Use Among Trauma Patients Before and After Legalization of Medical Marijuana: The Arizona Experience
    Michael Levine, et al. Substance Abuse, July 2021.

    Self-Reported Driving After Marijuana Use in Association With Medical And Recreational Marijuana Policies
    Marco H. Benedetti, et al. International Journal of Drug Policy, June 2021.

    Cannabis and Driving Ability
    Eric L. Sevigny. Current Opinion in Psychology, April 2021.

    The Failings of per se Limits to Detect Cannabis-Induced Driving Impairment: Results from a Simulated Driving Study
    Thomas R. Arkell, et al. Traffic Injury Prevention, February 2021.

    Risky Driving Behaviors of Drivers Who Use Alcohol and Cannabis
    Tara Kelley-Baker, et al. Transportation Research Record, January 2021.

    Direct and Indirect Effects of Marijuana Use on the Risk of Fatal 2-Vehicle Crash Initiation
    Stanford Chihuri and Guohua Li. Injury Epidemiology, September 2020

    Cannabis-Impaired Driving: Evidence and the Role of Toxicology Testing
    Edward C. Wood and Robert L. Dupont. Cannabis in Medicine, July 2020.

    Association of Recreational Cannabis Laws in Colorado and Washington State With Changes in Traffic Fatalities, 2005-2017
    Julian Santaella-Tenorio, et al. JAMA Internal Medicine, June 2020.

    Marijuana Decriminalization, Medical Marijuana Laws, and Fatal Traffic Crashes in US Cities, 2010–2017
    Amanda Cook, Gregory Leung and Rhet A. Smith. American Journal of Public Health, February 2020.

    Cannabis Use in Older Drivers in Colorado: The LongROAD Study
    Carolyn G. DiGuiseppi, et al. Accident Analysis & Prevention, November 2019.

    Crash Fatality Rates After Recreational Marijuana Legalization in Washington and Colorado
    Jayson D. Aydelotte, et al. American Journal of Public Health, August 2017.

    Marijuana-Impaired Driving: A Report to Congress
    National Highway Traffic Safety Administration, July 2017

    Interaction of Marijuana And Alcohol on Fatal Motor Vehicle Crash Risk: A Case–Control Study
    Stanford Chihuri, Guohua Li and Qixuan Chen. Injury Epidemiology, March 2017.

    US Traffic Fatalities, 1985–2014, and Their Relationship to Medical Marijuana Laws
    Julian Santaella-Tenorio, et al. American Journal of Public Health, February 2017.

    Delays in DUI Blood Testing: Impact on Cannabis DUI Assessments
    Ed Wood, Ashley Brooks-Russell and Phillip Drum. Traffic Injury Prevention, June 2015.

    Establishing Legal Limits for Driving Under the Influence of Marijuana
    Kristin Wong, Joanne E. Brady and Guohua Li. Injury Epidemiology, October 2014.

    Cannabis Effects on Driving Skills
    Rebecca L. Hartman and Marilyn A. Huestis. Clinical Chemistry, March 2014.

    Acute Cannabis Consumption And Motor Vehicle Collision Risk: Systematic Review of Observational Studies and Meta-Analysis
    Mark Asbridge, Jill A. Hayden and Jennifer L. Cartwright. The BMJ, February 2012.

    Resources for your audiences

    The following resources include explainers from federal agencies and national organizations. You’re free to use images and graphics from federal agencies.

    This article first appeared on The Journalist’s Resource and is republished here under a Creative Commons license.

    Share This Post

Related Posts

  • How gender-affirming care improves trans mental health
  • Laziness Does Not Exist – by Dr. Devon Price

    10almonds is reader-supported. We may, at no cost to you, receive a portion of sales if you purchase a product through a link in this article.

    Some cultures prize productivity as an ideal above most other things, and it’s certainly so in the US. Not only is this not great for mental health in general, but also—as Dr. Price explains—it’s based on a lie.

    Generally speaking, when a person appears lazy there is something stopping them/you from doing better, and it’s not some mystical unseen force of laziness, not a set character trait, not a moral failing. Rather, the root cause may be physical, psychological, socioeconomic, or something else entirely.

    Those causes can in some cases be overcome (for example, a little CBT can often set aside perfectionist anxiety that results in procrastination), and in some cases they can’t, at least on an individual level (disabilities often stubbornly remain disabling, and societal problems require societal solutions).

    This matters for our mental health in areas well beyond the labor marketplace, of course, and these ideas extend to personal projects and even personal relationships. Whatever it is, if it’s leaving you exhausted, then probably something needs to be changed (even if the something is just “expectations”).

    The book does offer practical solutions to all manner of such situations, improving what can be improved, making easier what can be made easier, and accepting what just needs to be accepted.

    The style of this book is casual yet insightful and deep, easy-reading yet with all the acumen of an accomplished social psychologist.

    Bottom line: if life leaves you exhausted, this book can be the antidote and cure

    Click here to check out Laziness Does Not Exist, and break free!

    Don’t Forget…

    Did you arrive here from our newsletter? Don’t forget to return to the email to continue learning!

    Learn to Age Gracefully

    Join the 98k+ American women taking control of their health & aging with our 100% free (and fun!) daily emails:

  • Aging with Grace – by Dr. David Snowdon

    10almonds is reader-supported. We may, at no cost to you, receive a portion of sales if you purchase a product through a link in this article.

    First, what this book is not: a book about Christianity. Don’t worry, we didn’t suddenly change the theme of 10almonds.

    Rather, what this book is: a book about a famous large (n=678) study into the biology of aging, that took a population sample of women who had many factors already controlled-for, e.g. they ate the same food, had the same schedule, did the same activities, etc—for many years on end. In other words, a convent of nuns.

    This allowed for a lot more to be learned about other factors that influence aging, such as:

    • Heredity / genetics in general
    • Speaking more than one language
    • Supplementing with vitamins or not
    • Key adverse events (e.g. stroke)
    • Key chronic conditions (e.g. depression)

    The book does also cover (as one might expect) the role that community and faith can play in healthy longevity, but since the subjects were 678 communally-dwelling people of faith (thus: no control group of faithless loners), this aspect is discussed only in anecdote, or in reference to other studies.

    The author of this book, by the way, was the lead researcher of the study, and he is a well-recognised expert in the field of Alzheimer’s in particular (and Alzheimer’s does feature quite a bit throughout).

    The writing style is largely narrative, and/but with a lot of clinical detail and specific data; this is by no means a wishy-washy book.

    Bottom line: if you’d like to know what nuns were doing in the 1980s to disproportionally live into three-figure ages, then this book will answer those questions.

    Click here to check out Aging with Grace, and indeed age with grace!

    Don’t Forget…

    Did you arrive here from our newsletter? Don’t forget to return to the email to continue learning!

    Learn to Age Gracefully

    Join the 98k+ American women taking control of their health & aging with our 100% free (and fun!) daily emails:

  • Simple, 10-Minute Hip Opening Routine

    10almonds is reader-supported. We may, at no cost to you, receive a portion of sales if you purchase a product through a link in this article.

    Hips Feeling Stiff?

    If so, Flow with Adee’s video (below) has just the solution with a quick 10-minute hip-opening routine. Designed for intermediates but open to all, we love Adee’s work and recommend that you reach out to her to tell her what you’d like to see next.

    Other Methods

    If you’re a book loverwe’ve reviewed a fantastic book on reducing hip pain. Alternatively, learn stretching from a ballerina with Jasmine McDonald’s ballet stretching routine.

    Otherwise, enjoy today’s video:

    How was the video? If you’ve discovered any great videos yourself that you’d like to share with fellow 10almonds readers, then please do email them to us!

    Don’t Forget…

    Did you arrive here from our newsletter? Don’t forget to return to the email to continue learning!

    Learn to Age Gracefully

    Join the 98k+ American women taking control of their health & aging with our 100% free (and fun!) daily emails: