from the world's big
Yes. Stress does give you gray hairs. Here’s how.
It's not just an old superstition — it's your stressed-out brain.
- Your brain's fight-or-flight response system is behind the appearance of premature gray hairs.
- The sympathetic nervous system essentially burns out melanin-producing hair follicles.
- New research may lead to a greater understanding of the connection between stress and body changes.
It's not your imagination, it turns out. Stress can turn a person's hair gray. It's said that if you look at before and after pictures of any eight-year U.S. president the impact of the office on hair color is clear, though in fairness, it may be that candidates dye their hair and then at some point stop doing so. Nonetheless, scientists from Harvard have not only verified the conventional wisdom on our graying noggins, but have also figured out why stress is so brutal to our follicular pigmentation.
The new research from Harvard scientists is published in the journal Nature.
An unusual chance to see stress at work
"Everyone has an anecdote to share about how stress affects their body, particularly in their skin and hair — the only tissues we can see from the outside. We wanted to understand if this connection is true, and if so, how stress leads to changes in diverse tissues. Hair pigmentation is such an accessible and tractable system to start with — and besides, we were genuinely curious to see if stress indeed leads to hair graying."
It turns out that stress activates nerves associated with our basic fight-or-flight system, and these nerves permanently damage pigment-regenerating melanocyte stem cells in hair follicles, causing them to cease production of melanin that normal provides color to hair follicles.
Hsu's team studied the issue using mice, and was somewhat stunned at their findings. "When we started to study this, I expected that stress was bad for the body — but the detrimental impact of stress that we discovered was beyond what I imagined," recalls Hsu.
The scientists stressed the mice using a combination of three methods:
Who’s in charge here?
Image source: Helga Lei/Shutterstock
Hsu and her colleagues first suspected an immune system reaction was at the root of graying hairs only to discover that mice without immune systems still turned gray in response to stressors. The next suspect was cortisol produced by the adrenal glands — however, this proved not to be so. "Stress always elevates levels of the hormone cortisol in the body," says Jsu, "so we thought that cortisol might play a role. But surprisingly, when we removed the adrenal gland from the mice so that they couldn't produce cortisol-like hormones, their hair still turned gray under stress."
It’s the sympathetic nervous system
Image source: Judy Blomquist/Harvard University
Finally, the researchers investigate the possibility that the system responding to stressors was the mice's sympathetic nervous systems, the part of the nervous system that kicks into action with the fight-or-flight impulse. The sympathetic nervous system is a vast network of nerves that connects, among other places, to hair follicles in the skin. In response to stress, the system sends a rush of the chemical norepinephrine to the follicles' melanocyte stem cell, causing them to quickly burn through and deplete their stores of pigment.
Say Hsu, "After just a few days, all of the pigment-regenerating stem cells were lost. Once they're gone, you can't regenerate pigments anymore. The damage is permanent." Great for survival, not so good for hair color.
A big hint of a much greater insight
Sympathetic system nerves are magenta above. Melanocyte stem cells are yellow.
Image source: Hsu Laboratory, Harvard University
"Acute stress," says lead author of the study Bing Zhang, "particularly the fight-or-flight response, has been traditionally viewed to be beneficial for an animal's survival. But in this case, acute stress causes permanent depletion of stem cells."
The research, done in collaboration with other Harvard researchers, presents a new appreciation of the effect the sympathetic system can have on the body's cells during stress.
One of these collaborators, Harvard immunologist Isaac Chu, notes, "We know that peripheral neurons powerfully regulate organ function, blood vessels, and immunity, but less is known about how they regulate stem cells. With this study, we now know that neurons can control stem cells and their function, and can explain how they interact at the cellular and molecular levels to link stress with hair graying."
Given this finding regarding the direct impact of stress on follicular stem cells, the question of what it else it may affect becomes an obvious one. As Hsu sums it up, "By understanding precisely how stress affects stem cells that regenerate pigment, we've laid the groundwork for understanding how stress affects other tissues and organs in the body."
This importance of the study therefore goes way beyond graying heads. "Understanding how our tissues change under stress is the first critical step," says Hsu, "toward eventual treatment that can halt or revert the detrimental impact of stress. We still have a lot to learn in this area."
Sallie Krawcheck and Bob Kulhan will be talking money, jobs, and how the pandemic will disproportionally affect women's finances.
Got $55 million lying around? If so, you might be able to score a spot aboard the International Space Station starting 2024.
- NASA awarded a contract to startup Axiom Space to attach a "habitable commercial module" to the International Space Station.
- The project will also include a research and manufacturing module.
- The move is a major step in NASA's years-long push to privatize.
Image: Axiom Space<p>But first, space-tourist-hopefuls would have to pass through physical and medical exams, and 15 weeks of expert training. After that, the trip sounds pretty comfy:</p><p>"There will be wifi," Suffredini <a href="https://www.nytimes.com/2018/06/09/style/axiom-space-travel.html" target="_blank">told the New York Times</a> last year. "Everybody will be online. They can make phone calls, sleep, look out the window. [...] The few folks that have gone to orbit as tourists, it wasn't really a luxurious experience, it was kind of like camping. [...] Pretty soon we're going to be flying a butler with every crew."</p>
A render of the ISS tourist experience.
Image: Axiom Space<p>In a blog post, NASA wrote:</p><p>"Developing commercial destinations in low-Earth orbit is one of <a href="https://www.nasa.gov/press-release/nasa-opens-international-space-station-to-new-commercial-opportunities-private" target="_blank">five elements</a> of NASA's plan to open the International Space Station to new commercial and marketing opportunities. The other elements of the five-point plan include efforts to make station and crew resources available for commercial use through a new commercial use and pricing policy; enable private astronaut missions to the station; seek out and pursue opportunities to stimulate long-term, sustainable demand for these services; and quantify NASA's long-term demand for activities in low-Earth orbit."</p>
NASA's push to privatize the ISS<p>When a Russian rocket launched the first module of the ISS into space in 1998, NASA expected the space station to operate for about 15 years. But the agency has extended the life of the ISS twice, with funding currently set to expire in 2024. NASA spends between $3 and $4 billion per year operating and shuttling astronauts to and from the station. That's a decent chunk of the agency's $22.6 annual budget. What's more, the "major structural elements" of the ISS are certified only through 2028.</p><p>Meanwhile, NASA has been eyeing other projects, namely: putting humans back on the moon in 2024 and establishing a lunar presence. So, to save and redirect money, the agency has been starting to hand over the aging space station to the private sector, which could use it for commercial research and space tourism.</p><p>But some have questioned the move to privatize the ISS, including NASA's own inspector general, Paul K. Martin.</p><p>"An obvious alternative to privatization is to extend current ISS operations," Martin wrote in a <a href="https://oig.nasa.gov/docs/CT-18-001.pdf" target="_blank">2018 report</a>. "An extension to 2028 or beyond would enable NASA to continue critical on-orbit research into human health risks and to demonstrate the technologies that will be required for future missions to the Moon or Mars."</p>
Image: Axiom Space<p>Martin noted that "research into 2 other human health risks and 17 additional technology gaps is not scheduled to be completed until sometime in 2024," meaning that any slip-ups in the process would mean such research might go uncompleted. He also wrote that it's "questionable" whether the private sector could turn a profit on the ISS without "significant" government funding. The Institute for Defense Analyses, a federally funded research and development center, <a href="https://docs.house.gov/meetings/SY/SY00/20180517/108302/HHRG-115-SY00-Wstate-LalB-20180517.pdf" target="_blank">also found</a> that it "is unlikely that a commercially owned and operated space station will be economically viable by 2025."</p><p>The implication is that, if the ISS is handed over to the private sector, taxpayers could end up indirectly supporting space tourism for the ultra-rich. Whether that's worth any of the research benefits that might come from the ISS post-2024 is anybody's guess.</p><p>As the ISS enters its final years, China <a href="http://www.xinhuanet.com/english/2019-10/17/c_138479514.htm" target="_blank">plans</a> to complete construction of a manned space station in 2022.</p>
The coronavirus pandemic has brought out the perception of selfishness among many.
- Selfish behavior has been analyzed by philosophers and psychologists for centuries.
- New research shows people may be wired for altruistic behavior and get more benefits from it.
- Crisis times tend to increase self-centered acts.
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Exploring Morality and Selfishness in Modern Times<div class="rm-shortcode" data-media_id="02eX1Cag" data-player_id="FvQKszTI" data-rm-shortcode-id="45cc6180db791f32683988fb52faff26"> <div id="botr_02eX1Cag_FvQKszTI_div" class="jwplayer-media" data-jwplayer-video-src="https://content.jwplatform.com/players/02eX1Cag-FvQKszTI.js"> <img src="https://cdn.jwplayer.com/thumbs/02eX1Cag-1920.jpg" class="jwplayer-media-preview" /> </div> <script src="https://content.jwplatform.com/players/02eX1Cag-FvQKszTI.js"></script> </div> Philosopher Peter Singer discusses the state of global ethics.
Parenting could be a distraction from what mattered most to him: his writing.
Ernest Hemingway was affectionately called “Papa," but what kind of dad was he?