How light tells you when to sleep, focus and poo
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This is the next article in our ‘Light and health’ series, where we look at how light affects our physical and mental health in sometimes surprising ways. Read other articles in the series.
Exposure to light is crucial for our physical and mental health, as this and future articles in the series will show.
But the timing of that light exposure is also crucial. This tells our body to wake up in the morning, when to poo and the time of day to best focus or be alert. When we’re exposed to light also controls our body temperature, blood pressure and even chemical reactions in our body.
But how does our body know when it’s time to do all this? And what’s light got to do with it?
What is the body clock, actually?
One of the key roles of light is to re-set our body clock, also known as the circadian clock. This works like an internal oscillator, similar to an actual clock, ticking away as you read this article.
But rather than ticking you can hear, the body clock is a network of genes and proteins that regulate each other. This network sends signals to organs via hormones and the nervous system. These complex loops of interactions and communications have a rhythm of about 24 hours.
In fact, we don’t have one clock, we have trillions of body clocks throughout the body. The central clock is in the hypothalamus region of the brain, and each cell in every organ has its own. These clocks work in concert to help us adapt to the daily cycle of light and dark, aligning our body’s functions with the time of day.
However, our body clock is not precise and works to a rhythm of about 24 hours (24 hours 30 minutes on average). So every morning, the central clock needs to be reset, signalling the start of a new day. This is why light is so important.
The central clock is directly connected to light-sensing cells in our retinas (the back of the eye). This daily re-setting of the body clock with morning light is essential for ensuring our body works well, in sync with our environment.
In parallel, when we eat food also plays a role in re-setting the body clock, but this time the clock in organs other than the brain, such as the liver, kidneys or the gut.
So it’s easy to see how our daily routines are closely linked with our body clocks. And in turn, our body clocks shape how our body works at set times of the day.
What time of day?
Let’s take a closer look at sleep
The naturally occurring brain hormone melatonin is linked to our central clock and makes us feel sleepy at certain times of day. When it’s light, our body stops making melatonin (its production is inhibited) and we are alert. Closer to bedtime, the hormone is made, then secreted, making us feel drowsy.
Our sleep is also partly controlled by our genes, which are part of our central clock. These genes influence our chronotype – whether we are a “lark” (early riser), “night owl” (late sleeper) or a “dove” (somewhere in between).
But exposure to light at night when we are supposed to be sleeping can have harmful effects. Even dim light from light pollution can impair our heart rate and how we metabolise sugar (glucose), may lead to psychiatric disorders such as depression, anxiety and bipolar disorder, and increases the overall risk of premature death.
The main reason for these harmful effects is that light “at the wrong time” disturbs the body clock, and these effects are more pronounced for “night owls”.
This “misaligned” exposure to light is also connected to the detrimental health effects we often see in people who work night shifts, such as an increased risk of cancer, diabetes and heart disease.
How about the gut?
Digestion also follows a circadian rhythm. Muscles in the colon that help move waste are more active during the day and slow down at night.
The most significant increase in colon movement starts at 6.30am. This is one of the reasons why most people feel the urge to poo in the early morning rather than at night.
The gut’s day-night rhythm is a direct result of the action of the gut’s own clock and the central clock (which synchronises the gut with the rest of the body). It’s also influenced by when we eat.
How about focusing?
Our body clock also helps control our attention and alertness levels by changing how our brain functions at certain times of day. Attention and alertness levels improve in the afternoon and evening but dip during the night and early morning.
Those fluctuations impact performance and can lead to decreased productivity and an increased risk of errors and accidents during the less-alert hours.
So it’s important to perform certain tasks that require our attention at certain times of day. That includes driving. In fact, disruption of the circadian clock at the start of daylight savings – when our body hasn’t had a chance to adapt to the clocks changing – increases the risk of a car accident, particularly in the morning.
What else does our body clock control?
Our body clock influences many other aspects of our biology, including:
- physical performance by controlling the activity of our muscles
- blood pressure by controlling the system of hormones involved in regulating our blood volume and blood vessels
- body temperature by controlling our metabolism and our level of physical activity
- how our body handles drugs and toxins by controlling enzymes involved in how the liver and kidneys eliminate these substances from the body.
Morning light is important
But what does this all mean for us? Exposure to light, especially in the morning, is crucial for synchronising our circadian clock and bodily functions.
As well as setting us up for a good night’s sleep, increased morning light exposure benefits our mental health and reduces the risk of obesity. So boosting our exposure to morning light – for example, by going for a walk, or having breakfast outside – can directly benefit our mental and metabolic health.
However, there are other aspects about which we have less control, including the genes that control our body clock.
Frederic Gachon, Associate Professor, Physiology of Circadian Rhythms, Institute for Molecular Bioscience, The University of Queensland and Benjamin Weger, NHMRC Emerging Leadership Fellow Institute for Molecular Bioscience, The University of Queensland
This article is republished from The Conversation under a Creative Commons license. Read the original article.
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Toxic Gas That Sterilizes Medical Devices Prompts Safety Rule Update
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Over the past two years, Madeline Beal has heard frustration and even bewilderment during public meetings about ethylene oxide, a cancer-causing gas that is used to sterilize half of the medical devices in the U.S.
Beal, senior risk communication adviser for the Environmental Protection Agency, has fielded questions about why the agency took so long to alert people who live near facilities that emit the chemical about unusually high amounts of the carcinogenic gas in their neighborhoods. Residents asked why the EPA couldn’t close those facilities, and they wanted to know how many people had developed cancer from their exposure.
“If you’re upset by the information you’re hearing tonight, if you’re angry, if it scares you to think about risk to your family, those are totally reasonable responses,” Beal told an audience in Laredo, Texas, in September 2022. “We think the risk levels near this facility are too high.”
There are about 90 sterilizing plants in the U.S. that use ethylene oxide, and for decades companies used the chemical to sterilize medical products without drawing much attention. Many medical device-makers send their products to the plants to be sterilized before they are shipped, typically to medical distribution companies.
But people living around these facilities have been jolted in recent years by a succession of warnings about cancer risk from the federal government and media reports, an awareness that has also spawned protests and lawsuits alleging medical harm.
The EPA is expected to meet a March 1 court-ordered deadline to finalize tighter safety rules around how the toxic gas is used. The proposed changes come in the wake of a 2016 agency report that found that long-term exposure to ethylene oxide is more dangerous than was previously thought.
But the anticipated final rules — the agency’s first regulatory update on ethylene oxide emissions in more than a decade — are expected to face pushback. Medical device-makers worry stricter regulation will increase costs and may put patients at higher risk of infection from devices, ranging from surgical kits to catheters, due to deficient sterilization. The new rules are also not likely to satisfy the concerns of environmentalists or members of the public, who already have expressed frustration about how long it took the federal government to sound the alarm.
“We have been breathing this air for 40 years,” said Connie Waller, 70, who lives with her husband, David, 75, within two miles of such a sterilizing plant in Covington, Georgia, east of Atlanta. “The only way to stop these chemicals is to hit them in their pocketbook, to get their attention.”
The EPA says data shows that long-term exposure to ethylene oxide can increase the risk of breast cancer and cancers of the white blood cells, such as non-Hodgkin lymphoma, myeloma, and lymphocytic leukemia. It can irritate the eyes, nose, throat, and lungs, and has been linked to damage to the brain and nervous and reproductive systems. Children are potentially more vulnerable, as are workers routinely exposed to the chemical, EPA officials say. The agency calculates the risk based on how much of the gas is in the air or near the sterilizing facility, the distance a person is from the plant, and how long the person is exposed.
Waller said she was diagnosed with breast cancer in 2004 and that her husband was found to have non-Hodgkin lymphoma eight years later.
A 2022 study of communities living near a sterilization facility in Laredo found the rates of acute lymphocytic leukemia and breast cancer were greater than expected based on statewide rates, a difference that was statistically significant.
Beal, the EPA risk adviser, who regularly meets with community members, acknowledges the public’s concerns. “We don’t think it’s OK for you to be at increased risk from something that you have no control over, that’s near your house,” she said. “We are working as fast as we can to get that risk reduced with the powers that we have available to us.”
In the meantime, local and state governments and industry groups have scrambled to defuse public outcry.
Hundreds of personal injury cases have been filed in communities near sterilizing plants. In 2020, New Mexico’s then-attorney general filed a lawsuit against a plant in Santa Teresa, and that case is ongoing. In a case that settled last year in suburban Atlanta, a company agreed to pay $35 million to 79 people who alleged ethylene oxide used at the plant caused cancer and other injuries.
In Cook County, Illinois, a jury in 2022 awarded $363 million to a woman who alleged exposure to ethylene oxide gas led to her breast cancer diagnosis. But, in another Illinois case, a jury ruled that the sterilizing company was not liable for a woman’s blood cancer claim.
Greg Crist, chief advocacy officer for the Advanced Medical Technology Association, a medical device trade group that says ethylene oxide is an effective and reliable sterilant, attributes the spate of lawsuits to the litigious nature of trial attorneys.
“If they smell blood in the water, they’ll go after it,” Crist said.
Most states have at least one sterilizing plant. According to the EPA, a handful, like California and North Carolina, have gone further than the agency and the federal Clean Air Act to regulate ethylene oxide emissions. After a media and political firestorm raised awareness about the metro Atlanta facilities, Georgia started requiring sterilizing plants that use the gas to report all leaks.
The proposed rules the EPA is set to finalize would set lower emissions limits for chemical plants and commercial sterilizers and increase some safety requirements for workers within these facilities. The agency is expected to set an 18-month deadline for commercial sterilizers to come into compliance with the emissions rules.
That would help at facilities that “cut corners,” with lax pollution controls that allow emissions of the gas into nearby communities, said Richard Peltier, a professor of environmental health sciences at the University of Massachusetts-Amherst. Stronger regulation also prevents the plants from remaining under the radar. “One of the dirty secrets is that a lot of it is self-regulated or self-policed,” Peltier added.
But the proposed rules did not include protections for workers at off-site warehouses that store sterilized products, which can continue to emit ethylene oxide. They also did not require air testing around the facilities, prompting debate about how effective they would be in protecting the health of nearby residents.
Industry officials also don’t expect an alternative that is as broadly effective as ethylene oxide to be developed anytime soon, though they support researching other methods. Current alternatives include steam, radiation, and hydrogen peroxide vapor.
Increasing the use of alternatives can reduce industry dependence on “the crutch of ethylene oxide,” said Darya Minovi, senior analyst with the Union of Concerned Scientists, an advocacy group.
But meeting the new guidelines will be disruptive to the industry, Crist said. He estimates companies will spend upward of $500 million to comply with the new EPA rules and could struggle to meet the agency’s 18-month timetable. Sterilization companies will also have difficulty adjusting to new rules on how workers handle the gas without a dip in efficiency, Crist said.
The Food and Drug Administration, which regulates drugs and medical devices, is also watching the regulatory moves closely and worries the updated emissions rule could “present some unique challenges” if implemented as proposed, said Audra Harrison, an FDA spokesperson. “The FDA is concerned about the rule’s effects on the availability of medical devices,” she added.
Other groups, like the American Chemistry Council and the Texas Commission on Environmental Quality, the state’s environmental agency, assert that ethylene oxide use isn’t as dangerous as the EPA says. The EPA’s toxicity assessment has “severe flaws” and is “overly conservative,” the council said in an emailed statement. Texas, which has several sterilizing plants, has said ethylene oxide isn’t as high a cancer risk as the agency claims, an assessment that the EPA has rejected.
Tracey Woodruff, a researcher at the University of California-San Francisco who previously worked at the EPA, said it can be hard for the agency to keep up with regulating chemicals like ethylene oxide because of constrained resources, the technical complications of rulemaking, and industry lobbying.
But she’s hopeful the EPA can strike a balance between its desire to reduce exposure and the desire of the FDA not to disrupt medical device sterilization. And scrutiny can also help the device sterilization industry think outside the box.
“We continue to discover these chemicals that we’ve already been exposed to were toxic, and we have high exposures,” she said. “Regulation is an innovation forcer.”
KFF Health News is a national newsroom that produces in-depth journalism about health issues and is one of the core operating programs at KFF—an independent source of health policy research, polling, and journalism. Learn more about KFF.
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The Green Roasting Tin – by Rukmini Iyer
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You may be wondering: “do I really need a book to tell me to put some vegetables in a roasting tin and roast them?” and maybe not, but the book offers a lot more than that.
Indeed, the author notes “this book was slightly in danger of becoming the gratin and tart book, because I love both”, but don’t worry, most of the recipes are—as you might expect—very healthy.
As for formatting: the 75 recipes are divided first into vegan or vegetarian, and then into quick/medium/slow, in terms of how long they take.
However, even the “slow” recipes don’t actually take more effort, just, more time in the oven.
One of the greatest strengths of this book is that not only does it offer a wide selection of wholesome mains, but also, if you’re putting on a big spread, these can easily double up as high-class low-effort sides.
Bottom line: if you’d like to eat more vegetables in 2024 but want to make it delicious and with little effort, put this book on your Christmas list!
Click here to check out The Green Roasting Tin, and level-up yours!
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Pneumonia: Prevention Is Better Than Cure
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Pneumonia: What We Can & Can’t Do About It
Pneumonia is a significant killer of persons over the age of 65, with the risk increasing with age after that, rising very sharply around the age of 85:
While pneumonia is treatable, especially in young healthy adults, the risks get more severe in the older age brackets, and it’s often the case that someone goes into hospital with one thing, then develops pneumonia, which the person was already not in good physical shape to fight, because of whatever hospitalized them in the first place:
American Lung Association | Pneumonia Treatment and Recovery
Other risk factors besides age
There are a lot of things that can increase our risk factor for pneumonia; they mainly fall into the following categories:
- Autoimmune diseases
- Other diseases of the immune system (e.g. HIV)
- Medication-mediated immunosuppression (e.g. after an organ transplant)
- Chronic lung diseases (e.g. asthma, COPD, Long Covid, emphysema, etc)
- Other serious health conditions ← we know this one’s broad, but it encompasses such things as diabetes, heart disease, and cancer
See also:
Why Chronic Obstructive Pulmonary Disease (COPD) Is More Likely Than You Think
Things we can do about it
When it comes to risks, we can’t do much about our age and some of the other above factors, but there are other things we can do to reduce our risk, including:
- Get vaccinated against pneumonia if you are over 65 and/or have one of the aforementioned risk factors. This is not perfect (it only reduces the risk for certain kinds of infection) and may not be advisable for everyone (like most vaccines, it can put the body through its paces a bit after taking it), so speak with your own doctor about this, of course.
- See also: Vaccine Mythbusting
- Avoid contagion. While pneumonia itself is not spread person-to-person, it is caused by bacteria or viruses (there are numerous kinds) that are opportunistic and often become a secondary infection when the immune system is already busy with the first one. So, if possible avoid being in confined spaces with many people, and do wash your hands regularly (as a lot of germs are transferred that way and can get into the respiratory tract because you touched your face or such).
- See also: The Truth About Handwashing
- If you have a cold, or flu, or other respiratory infection, take it seriously, rest well, drink fluids, get good immune-boosting nutrients. There’s no such thing as “just a cold”; not anymore.
- Look after your general health too—health doesn’t exist in a vacuum, and nor does disease. Every part of us affects every other part of us, so anything that can be in good order, you want to be in good order.
This last one, by the way? It’s an important reminder that while some diseases (such as some of the respiratory infections that can precede pneumonia) are seasonal, good health isn’t.
We need to take care of our health as best we can every day along the way, because we never know when something could change.
Want to do more?
Check out: Seven Things To Do For Good Lung Health!
Take care!
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Applesauce vs Cranberry Sauce – Which is Healthier?
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Our Verdict
When comparing applesauce to cranberry sauce, we picked the applesauce.
Why?
It mostly comes down to the fact that apples are sweeter than cranberries:
In terms of macros, they are both equal on fiber (both languishing at a paltry 1.1g/100g), and/but cranberry sauce has 4x the carbs, of which, more than 3x the sugar. Simply, cranberry sauce recipes invariably have a lot of added sugar, while applesauce recipes don’t need that. So this is a huge relative win for applesauce (we say “relative” because it’s still not great, but cranberry sauce is far worse).
In the category of vitamins, applesauce has more of vitamins B1, B2, B5, B6, B9, and C, while cranberry sauce has more of vitamins E, K, and choline. A more moderate win for applesauce this time.
When it comes to minerals, applesauce has more calcium, copper, magnesium, phosphorus, and potassium, while cranberry sauce has more iron, manganese, and selenium. Another moderate win for applesauce.
Since we’ve discussed relative amounts rather than actual quantities, it’s worth noting that neither sauce is a good source of vitamins or minerals, and neither are close to just eating the actual fruits. Just, cranberry sauce is the relatively more barren of the two.
While cranberries famously have some UTI-fighting properties, you cannot usefully gain this benefit from a sauce that (with its very high sugar content and minimal fiber) actively feeds the very C. albicans you are likely trying to kill.
All in all, a pitiful show of nutritional inadequacy from these two products today, but one is relatively less bad than the other, and that’s the applesauce.
Want to learn more?
You might like to read:
From Apples to Bees, and High-Fructose Cs: Which Sugars Are Healthier, And Which Are Just The Same?
Enjoy!
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Dr. Kim Foster’s Method For Balancing Hormones Naturally
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Not just sex hormones, but also hormones like cortisol (the stress hormone), and thyroid hormones (for metabolism regulation) too! The body is most of the time self-regulating when it comes to hormones, but there are things that we can do to help our body look after us correctly.
In short, if we give our body what it needs, it will (usually, barring serious illness!) give us what we need.
Dr. Foster recommends…
Foods:
- Healthy fats (especially avocados and nuts)
- Lean proteins (especially poultry, fish, and legumes)
- Fruits & vegetables (especially colorful ones)
- Probiotics (especially fermented foods like sauerkraut, kimchi, etc)
- Magnesium-rich foods (especially dark leafy greens, nuts, and yes, dark chocolate)
Teas:
- Camomile tea (especially beneficial against cortisol overproduction)
- Nettle tea (especially beneficial for estrogen production)
- Peppermint tea (especially beneficial for gut health, thus indirect hormone benefits)
Stress reduction:
- Breathing exercises (especially mindfulness exercises)
- Yoga (especially combining exercise with stretches)
- Spending time in nature (especially green spaces)
Dr. Foster explains more about all of these things, along with more illustrative examples, so if you can, do enjoy her video:
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Want to read more about this topic?
You might like our main feature: What Does “Balance Your Hormones” Even Mean?
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Semaglutide’s Surprisingly Unexamined Effects
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Semaglutide’s Surprisingly Big Research Gap
GLP-1 receptor agonists like Ozempic, Wegovy, and other semaglutide drugs. are fast becoming a health industry standard go-to tool in the weight loss toolbox. When it comes to recommending that patients lose weight, “Have you considered Ozempic?” is the common refrain.
Sometimes, this may be a mere case of kicking the can down the road with regard to some other treatment that it can be argued (sometimes even truthfully) would go better after some weight loss:
How weight bias in health care can harm patients with obesity: Research
…which we also covered in fewer words in the second-to-last item here:
But GLP-1 agonists work, right?
Yes, albeit there’s a litany of caveats, top of which are usually:
- there are often adverse gastrointestinal side effects
- if you stop taking them, weight regain generally ensues promptly
For more details on these and more, see:
…but now there’s another thing that’s come to light:
The dark side of semaglutide’s weight loss
In academia, “dark” is often used to describe “stuff we don’t have much (or in some cases, any) direct empirical evidence of, but for reasons of surrounding things, we know it’s there”.
Well-known examples include “dark matter” in physics and the Dark Ages in (European) history.
In the case of semaglutide and weight loss, a review by a team of researchers (Drs. Sandra Christenen, Katie Robinson, Sara Thomas, and Dominique Williams) has discovered how little research has been done into a certain aspect of GLP-1 agonist’s weight loss effects, namely…
Dietary changes!
There’s been a lot of popular talk about “people taking semaglutide eat less”, but it’s mostly anecdotal and/or presumed based on parts of the mechanism of action (increasing insulin production, reducing glucagon secretions, modulating dietary cravings).
Where studies have looked at dietary changes, it’s almost exclusively been a matter of looking at caloric intake (which has been found to be a 16–39% reduction), and observations-in-passing that patients reported reduction in cravings for fatty and sweet foods.
This reduction in caloric intake, by the way, is not significantly different to the reduction brought about by counselling alone (head-to-head studies have been done; these are also discussed in the research review).
However! It gets worse. Very few studies of good quality have been done, even fewer (two studies) actually had a registered dietitian nutritionist on the team, and only one of them used the “gold standard” of nutritional research, the 24-hour dietary recall test. Which, in case you’re curious, you can read about what that is here:
Dietary Assessment Methods: What Is A 24-Hour Recall?
Of the four studies that actually looked at the macros (unlike most studies), they found that on average, protein intake decreased by 17.1%. Which is a big deal!
It’s an especially big deal, because while protein’s obviously important for everyone, it’s especially important for anyone trying to lose weight, because muscle mass is a major factor in metabolic base rate—which in turn is much important for fat loss/maintenance than exercise, when it comes to how many calories we burn by simply existing.
A reasonable hypothesis, therefore, is that one of the numerous reasons people who quit GLP-1 agonists immediately put fat back on, is because they probably lost muscle mass in amongst their weight loss, meaning that their metabolic base rate will have decreased, meaning that they end up more disposed to put on fat than before.
And, that’s just a hypothesis and it’s a hypothesis based on very few studies, so it’s not something to necessarily take as any kind of definitive proof of anything, but it is to say—as the researchers of this review do loudly say—more research needs to be done into this, because this has been a major gap in research so far!
Any other bad news?
While we’re talking research gaps, guess how many studies looked into micronutrient intake changes in people taking GLP-1 agonists?
If you guessed zero, you guessed correctly.
You can find the paper itself here:
What’s the main take-away here?
On a broad, scoping level: we need more research!
On a “what this means for individuals who want to lose weight” level: maybe we should be more wary of this still relatively new (less than 10 years old) “wonder drug”. And for most of those 10 years it’s only been for diabetics, with weight loss use really being in just the past few years (2021 onwards).
In other words: not necessarily any need to panic, but caution is probably not a bad idea, and natural weight loss methods remain very reasonable options for most people.
See also: How To Lose Weight (Healthily!)
Take care!
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